CHAPTER ONE

INTRODUCTION

1.0 Introduction

This chapter provides the background of the study, the statement of the problem, the

objectives of the study, the research questions, the significance of the study, the scope

and limitation of the study.

1.1 Background of the Study

The advancement in medical research is aimed at enhancing diagnosis of various

diseases. Over the last several years focus has been on achieving sustainable diagnosis of

several genetically transmitted, non-atherosclerotic cardiovascular diseases. Diagnostics

are an integral and critical part of a health care system of any country as the results of

these tests inform a wide range of medical decision making. From the genetic tests that

inform personalized cancer treatment to the microbial culture that identifies the right

antibiotic to fight an infection, diagnostic tests. The identification of the sequence of the

human genome and of human genes has changed our understanding of health and

pathogenesis. It is now recognized that virtually all diseases may have a genetic

component. Thus, molecular genetics could become a powerful diagnostic and screening

tool. The complex interplay between genetic predisposition and environmental

influences, however, limits the predictive power of genetic testing.

As the traditional laboratory remains a mainstay for diagnostic testing while significant

testing is done outside the laboratory, in such point of care settings as hospitals,

physicians’ offices, and clinics, and for personnel in the field, such as emergency

responders and soldiers. Pregnancy tests and diabetes test strips are familiar examples of

diagnostics that are available directly to consumers. The main categories of diagnostics

are clinical chemistry, immunology, hematology, microbiology and molecular

diagnostics. The diagnostics industry continues to innovate in all of these important areas,

and molecular diagnostics has captured particular attention in recent years because of the

deep insights these types of tests bring to diagnosis and treatment.

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The emergence of nucleic acid amplification and detection is a shift from the past and has

resulted in a change from conventional laboratory methods that rely on phenotypic

expression of antigens or biochemical products, to molecular methods for the rapid

identification of a number of infectious agents. These new methods have become

increasingly incorporated into the clinical microbiology laboratory, particularly for the

detection and characterisation of virus infections and for the diagnosis of diseases due to

fastidious bacteria.

The advantages of rapid turn-around time and high sensitivity and specificity are

appealing but must be matched by rigorous validation and quality control. Such

diagnoses have mostly come to the clinical microbiology laboratory in the form of PCR

technology, initially involving single round or nested procedures with detection by gel

electrophoresis. However, with the introduction of automation for the various stages of

DNA or RNA extraction, amplification and product detection together with real-time

PCR, molecular laboratories will continue to become more efficient and cost-effective.

Micro-array technology such as the DNA chip will likely further increase the utility of

molecular detection in the clinical microbiology laboratory.

1.2 Statement of the Problem

Dissecting a patient’s fundamental constitutional makeup also raises psychological,

ethical and professional questions. Molecular diagnostics is a dynamic and transformative

area of diagnostics, leading to insights in research and treatment in many disease states

that are revolutionizing health care. Molecular diagnostics detect and measure the

presence of genetic material or proteins associated with a specific health condition or

disease, helping to uncover the underlying mechanisms of disease and enabling clinicians

to tailor care at an individual level facilitating the practice of “personalized medicine.

Molecular techniques using antibodies and molecular probes will be analysed in detail.

Methods employing differential hybridisation of nucleic acids will be discussed. A

variety of inherited gene defects and DNA sequence changes that ultimately result in

diseases such as cancer will be studied. The ethics of such molecular analysis will be

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discussed. Therefore, accurate diagnosis of infections is crucial to reduce morbidity and

mortality in tropical areas. Available literature on epidemiology and immunity depend on

accurate detection, diagnosis, and density estimation. Traditionally, light microscopy

(LM) examination of blood smears has been considered the gold standard for the

diagnosis of diseases. LM has clear advantages since it incurs low costs, allows species

identification and quantification and neither complex sample preparation nor advanced

technology is required. However, the role of LM as gold standard has been questioned

due to false negative results at low levels of parasitaemia, with a predicted limit of

detection of five to 20 parasites per microlitre of blood and frequent errors in species

identification in mixed infections. In this sense, microscopy seems to be an imperfect

reference standard.

Therefore, it is difficult to estimate its true sensitivity and specificity or to evaluate new

diagnostic methods. Several molecular methods based on the amplification of DNA have

been developed for the detection of malarial infections in humans. The semi-nested

multiplex malaria PCR (SnM-PCR) is a widely used method and it is considered a

molecular gold standard due to its good performance in the detection of mixed species

infection and the ability to differentiate disease causing species of bacteria and viruses.

In recent years, new molecular methods have been developed for the detection of various

species, mostly based on real time quantitative PCRs (qPCR). These new molecular

methods have been promoted as an automated, quantitative, and closed system that

reduces the risk of cross-contamination inherent in conventional PCR. Several real-time

PCR methods for malaria have been described and validated within a research setting

with high sensitivity and specificity values. However, some advantages should be

considered such as their ability to detect mixed Plasmodium infections but also some

limitations, such as their application in rural areas without adequate laboratory

conditions.

Alternative methods sensitive enough to detect low levels of parasitaemia in

asymptomatic infections are required to complement or replace parasitological

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examination with light microscopy. This would allow minimization of errors in diagnosis

(false positives, false negatives and species misidentification) that may lead to biased

estimates of protective efficacy against the parasite.

The incorporation of molecular tools for the characterization of parasite infections has

allowed increase sensitivity in the detection of human malarial parasites in blood. The

aim of the present study was to compare different malaria diagnostic methods and to

broaden the knowledge of malaria prevalence in a hospital in Moi Teaching and Referral

Hospital (MTRH) Eldoret Town, Kenya.

1.3 Objectives of the Study

The general objective of this study was to investigate the effects of Molecular Biology on

Diagnosis of Infectious Diseases in Laboratory Testing.

The specific objectives of the study were as follows:

i) To examine the usefulness of molecular biology on treatment of diseases

ii) To examine the effects of effects of molecular biology on screening of diseases

iii) To determine the influence of molecular lab test on risk assessment of diseases

iv) To examine the effects of molecular biology on staging and prognosis of diseases

1.4 Research Questions

The study sought to answer the following questions:

i) To what extent has molecular biology enhanced accuracy in treatment of detected

diseases?

ii) What are the effects of molecular biology on early identification of high-risk

diseases on patient?

iii) How has molecular biology influenced diagnostic tests to complement traditional

risk factors?

iv) What the effects of molecular biology on assessing severity and risk of recurrence

of diseases?

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1.5 Significance of the Study

A thorough understanding of the extent to which molecular biology has revised

traditional diagnostic criteria is essential. The role of genetic testing in assessing

prognosis and identifying high-risk subgroups or in defining basic disease mechanisms

and pathophysiology. Demonstrating the presence of the infecting organism, or a

surrogate marker of infection, is often crucial for effective clinical management and for

selecting other appropriate disease control activities such as contact tracing. A

diagnostic tests have multiple uses, including: patient management, especially when

clinical symptoms are not specific for a particular infection; screening for asymptomatic

infections; surveillance; epidemiological studies; evaluating the effectiveness of

interventions, including verification of elimination; and detecting infections with markers

of drug resistance.

The findings of this study will be useful in facilitating the setting of appropriate standards

for test evaluation; to provide best-practice guidelines for assessing the performance and

operational characteristics of diagnostic tests for infectious diseases; to help those

designing evaluations at all levels, from test manufacturers to end-users; and to facilitate

critical review of published and unpublished evaluations, with a view to selecting or

approving tests that have been appropriately evaluated and shown to meet defined

performance targets.

The target audience for this document includes institutions and research groups that are

planning trials of diagnostic tests; organizations that fund or conduct trials of diagnostic

tests; agencies responsible for the procurement of diagnostic tests; diagnostic test

manufacturers; and regulatory authorities. The results and findings of this study will

confirm major achievements in the laboratory diagnosis of diseases enabling medical

practitioners in the country to utilize the literature from this study. It will also be useful in

determining the effective methods of patient management, disease detection enabling

simplicity of medical treatment.

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1.6 Scope and Limitations of the Study

There are the scope and limits within which this study was carried out and its

generalization applicable. These areas are covered in the section that follows:

1.6.1 Scope of the Study

The study focused mainly on the infectious diseases that can be diagnosed in the lab from

patients visiting the MTRH in Eldoret town. This facility was the only one used as a case

study hence many other pubic and private hospitals were not investigated minimizing the

generalization of the findings making their applicability to within the under said scope.

1.6.2 Limitations of the Study

The study faced several limitation first several participants had to be convinced of their

importance and the ethical use of the information obtained from them in the study as

purely for academic purposes. There are many factors that influence the performance of

tests in different settings. They include differences in the characteristics of the population

or the infectious agent, including the infection prevalence and genetic variation of the

pathogen or host, as well as the test methodology. Therefore, wherever possible, test

evaluations had to be performed under the range of conditions in which they are likely to

be used in practice. In some situations, it forced the evaluations to be facilitated through

multi-centre trials. Secondly, many specimens testing required a lot of accuracy hence a

lot of time was needed to carry out the tests over a repeated period of time. Some devices

were also not easily available hence a compromise was made although the outcomes were

not compromised.

Lack of resources and expertise limited the performance of adequate evaluations of

diagnostic tests, and many new tests are marketed directly to end-users who lack the

ability to assess their performance. The onus is therefore on those who perform the

evaluations to ensure that the quality of the methods and the documentation used is such

that the findings add usefully to the pool of knowledge on which others can draw.

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CHAPTER TWO

LITERATURE REVIEW

2.0 Introduction

This chapter reviews the study on the related field, acknowledgement the contribution

made various scholars publication, medic journal, text and periodicals, its identifies the

gap and provide the way forward a critical review is done to identify gaps, thereafter a

summery is made on the study .

2.1 The Concept of Disease Diagnosis

In any health care system, the performance of practitioner can be based on their ability to

accurately detect and diagnose a medical problem. This enhances an accurate response to

medication and management of the problem as may early be detected. A diagnostic test

for an infectious agent can be used to demonstrate the presence or absence of infection, or

to detect evidence of a previous infection. Demonstrating the presence of the infecting

organism, or a surrogate marker of infection, is often crucial for effective clinical

management and for selecting other appropriate disease control activities such as contact

tracing.

The usefulness of diagnostic methods lies on their accuracy, simple and affordability for

the population for which they are intended. They must also provide a result in time to

institute effective control measures, particularly treatment. For some infections, early

diagnosis and treatment can have an important role in preventing the development of

long-term complications or in interrupting transmission of the infectious agent. In a

broader context, diagnostic tests can have multiple uses, including: patient management,

especially when clinical symptoms are not specific for a particular infection (as is often

the case); screening for asymptomatic infections; surveillance; epidemiological studies

(for example, rapid assessments of disease burden or outbreak investigations); evaluating

the effectiveness of interventions, including verification of elimination; and detecting

infections with markers of drug resistance.

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The other important measures of test performance are positive predictive value (PPV),

the probability that those testing positive by the test are truly infected, and negative

predictive value (NPV), the probability that those testing negative by the test are truly

uninfected. Both of these measures are often expressed as percentages. PPV and NPV

depend not only on the sensitivity and specificity of the test, but also on the prevalence of

infection in the population studied. The reproducibility of a test is an assessment of the

extent to which the same tester achieves the same results on repeated testing of the same

samples, or the extent to which different testers achieve the same results on the same

samples, and is measured by the percentage of times the same results are obtained when

the test is used repeatedly on the same specimens.

Reproducibility can therefore be measured between operators or with the same operator,

or using different lots of the same test reagent. The accuracy of a test is sometimes used

as an overall measure of its performance and is defined as the percentage of individuals

for whom both the test and the reference standard give the same result (that is, the

percentage of individuals whom both tests classify as infected or uninfected). Note that

the use of this measure of diagnostic accuracy is of limited value and is often difficult to

interpret, as it depends on sensitivity, specificity and the prevalence of infection.

Operational characteristics include the time taken to perform the test, its technical

simplicity or ease of use, user acceptability and the stability of the test under user

conditions. The ease of use will depend on the ease of acquiring and maintaining the

equipment required to perform the test, how difficult it is to train staff to use the test and

to interpret the results of the test correctly, and the stability of the test under the expected

conditions of use. All of these characteristics are important for determining the settings in

which a diagnostic test can be used and the level of staff training required.

Recent technological developments have led to the proliferation of new, rapid diagnostic

tests that hold promise for the improved management and control of infectious diseases.

Whether these tests are useful in a given setting and, if so, which test is most appropriate

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are questions that can be answered only through evaluations in the appropriate laboratory,

clinical or field settings.

2.2 Molecular Biology

Molecular methods have become increasingly incorporated into the clinical microbiology

laboratory, particularly for the detection and characterisation of virus infections and for

the diagnosis of diseases due to fastidious bacteria. The advantages of rapid turn-around

time and high sensitivity and specificity are appealing but must be matched by rigorous

validation and quality control.

Molecular biology tools are aimed at bringing a very sophisticated level of sensitivity and

specificity to diagnostics. These tools are expected to detect a bacterium, virus, yeast,

parasite or genetic marker through the presence of DNA or RNA genetic sequences in a

blood sample. Tests are performed directly on a clinical sample and make it possible to

obtain results in just a few hours.

 

These tests are used to detect pathogens (bacteria, viruses, yeasts), identify antibiotic

resistance mechanisms, and measure the quantity of a virus, such as HIV, in the blood.

They thus allow choices to be made about a specific treatment, monitor its effectiveness,

and determine how human cells react to a disease or infection. Identifying patients who

will be responsive to a given treatment, and those for whom such therapy may cause

significant side effects, represents a recent application for molecular biology.

Molecular detection has mostly come to the clinical microbiology laboratory in the form

of PCR technology, initially involving single round or nested procedures with detection

by gel electrophoresis. However, with the introduction of automation for the various

stages of DNA or RNA extraction, amplification and product detection together with

real-time PCR, molecular laboratories will continue to become more efficient and cost-

effective. Microarray technology such as the DNA chip will likely further increase the

utility of molecular detection in the clinical microbiology laboratory.

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Molecular biology usage includes the discipline of virology where it has been applied to

resistance testing, genotyping and viral load quantification in addition to routine viral

detection. In the area of bacteriology molecular methods have been applied to resistance

testing, the detection of infection due to fastidious bacteria, the more rapid detection of

serious bacterial infections compared to conventional methods and the detection of

bacterial infection after antibiotics have been administered. Advances into the areas of

parasitology and mycology have also been made such as more rapid diagnosis of fungal

infection in neutropenic patients. Other applications include detection of biosecurity

agents; applications to epidemiology and infection control together with the potential

pitfalls with molecular methods.

2.3 Techniques used in Detection and Diagnosis of Diseases

There are many techniques used in modern diagnostics to detect and quantify specific

DNA or DNA sequences, as well as proteins. The fundamental of these techniques

include the polymerase chain reaction, which is used to amplify specific sequences of

DNA or RNA. Subsequent reports will elaborate on additional genetic test methods, such

as in situ hybridization or whole genome sequencing, and such protein detection tests as

mass spectrometry.

One of the essential methods underlying many molecular diagnostics is amplification, the

process of making copies of a specific DNA or RNA sequence found in a sample until

there are so many copies that they can be detected and measured.

There are a number of different amplification technologies, but polymerase chain reaction

(PCR) testing is the most widely used and is considered a work horse in molecular

diagnostics. PCR is a powerful tool for locating short segments of a gene where known

critical mutations or variances can lead to altered cell functions associated with disease or

altered function. PCR tests for the presence of a portion of DNA that has a known base

sequence, employing the same enzymatic process used by natural DNA replication to

rapidly amplify, or copy, that sequence until there are thousands or millions of copies.

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Because PCR relies on amplification, it is highly sensitive, meaning it can detect specific

DNA segments that may be present at very low levels in the sample.

The past studies developed ways to detect the presence of PCR-amplified DNA by how

far it traveled in a gel in relation to other, different-sized, pieces of DNA when all the

pieces were pulled by an electric current. Gel electrophoresis can still be used, but now

the use of fluorescent dyes, that bind to the target DNA segment as it is amplified, enable

automated instruments to monitor the resulting fluorescence without using gels. In this

manner, technologies such as quantitative real-time PCR not only can detect the presence

of the target DNA segment, but also quantify the amount of target DNA that was

originally present in the sample. This can be used, for example, to determine the

prevalence of an infectious agent in the body.

2.4 Empirical Review

Diagnosis of several other communicable diseases has come to rely heavily on molecular

diagnostic tests. An important case is the use of molecular kits for the detection of MDR

TB. Keeping in mind the steady rise in cases with drug resistant TB, and limitations of

drug susceptibility testing, rapid molecular tests appear promising. An increasing number

of laboratories are adopting the techniques, especially in developing countries with a

heavy burden of the disease. It has been reported that mutations outside the region of a

specific gene may not be detected by some assays designed to detect drug resistance.

These strains could still be resistant, with the risk of the patient being subjected to

ineffective treatment with the drug. Another scenario is the highly mutable Human

Immunodeficiency Virus (HIV).

Similar to the case of many other infectious diseases, nucleic acid amplification methods

provide an alternative approach in the detection of microorganisms and thus offer new

possibilities for a more rapid and accurate diagnosis of tuberculosis. As mentioned

before, rather than to increase the number of microorganisms by culture, amplification

methods, like PCR, directly increase the amount of nucleic acid target in vitro.

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Rapid mutations in a drug-resistant strain can impact the potential for detection 3.

Another major drawback is that the mere presence of resistance genes may not correlate

with expressed resistance and vice versa. The absence of the gene does not rule out

resistance, which could be by another mechanism. Similarly, resistance genes may be

present but unexpressed due to mutational or regulatory silencing. As much as it is

necessary to use rapid molecular tests, it is also important to be vigilant towards

emergence of mutants which might escape the detection limit. Awareness and vigilance

are required to avoid this pitfall in addition to looking out for new and emerging mutants.

The clinical benefit of genetic testing for HNPCC has been demonstrated, but it is not

part of standard management. The identification of mutations in families fulfilling

clinical criteria makes genetic testing an important option in the management of HNPCC.

Morbidity and mortality can be reduced in individuals at the risk for HNPCC by using

early and intensive screening. In patients who are carriers of mutations associated with

HNPCC, prophylactic colectomy is the most effective method of reducing the risk of

colorectal cancer. A decision analysis model shows that the benefits of intervention range

from 13.5 years of gains in life expectancy for endoscopic surveillance to 15.6 years for

prophylactic colectomy compared with no intervention

Alternative methods sensitive enough to detect low levels of parasitaemia in

asymptomatic infections are required to complement or replace parasitological

examination with light microscopy. This would allow minimization of errors in diagnosis

(false positives, false negatives and species misidentification) that may lead to biased

estimates of protective efficacy against the parasite. The incorporation of molecular tools

for the characterization of parasite infections has allowed increase sensitivity in the

detection of human malarial parasites in blood.

Traditionally, light microscopy (LM) examination of blood smears has been considered

the gold standard for the diagnosis of malaria. LM has clear advantages since it incurs

low costs, allows species identification and quantification and neither complex sample

preparation nor advanced technology is required. However, the role of LM as gold

12

standard has been questioned due to false negative results at low levels of parasitaemia,

with a predicted limit of detection of five to 20 parasites per microlitre of blood and

frequent errors in species identification in mixed infections.

A total of 471 samples, selected as defined above, were included in the cross-sectional

malaria study. Based on PCR results, weighted parasite prevalence was estimated at 7%

(95% CI: 4.7–9.3). The prevalence of P. falciparum was 2.1% (95% CI: 0.81–3.4) while

that of P. vivax was 5% (95% CI: 2.9–6.7). Plasmodium vivax was the dominant species

detected and the difference was statistically significant (χ2 = 5.121 p<0.05). Malaria

prevalence in children was lower than in adults and the difference was statistically

significant (χ 2 = 5.93 p<0.05) (Table 2). Among tested adult individuals, infection

frequently occurred before 30 years of age and only in three adults were parasitized at an

age over 30 years old. The highest prevalence of the parasite (10.9%) was observed in

age groups under 15 years old with a mean age of five years.

Testing for autoantibodies provides a cornerstone of diagnosis of these diseases,

especially PBC. Molecular biological methods have made possible the identification of

some of the intracellular protein antigens and the predominant epitopes recognized by

some of the disease-specific autoantibodies. This work has led to development of assays

that can be used in the clinical laboratory. Assays utilizing recombinant proteins should

make tissue-based immunofluorescence assays obsolete in cases where the auto antigen is

known. In PBC, cDNAs for several of the major mitochondrial and nuclear auto antigens

have been cloned and sequenced, and recombinant proteins have been used to detect

autoantibodies.

Screening of bacteriophage lcDNA expression libraries with autoantibodies from affected

patients identified the E2 subunits of the pyruvate dehydrogenase complex, the branched-

chain 2-oxoacid dehydrogenase complex, and the 2-oxoglutarate dehydrogenase complex

as the major mitochondrial auto antigens in PBC. ELISAs utilizing expressed

recombinant proteins or designer polypeptides have been devised that are sensitive and

specific for detection of antibodies against these proteins. Determination of the

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immunodominant epitopes on these three proteins has allowed construction of a

“designer hybrid” clone that contains the major epitope of each. An immunoassay

utilizing a designer polypeptide expressed from this clone is highly sensitive and specific

for the diagnosis of PBC.

In addition to antibodies against mitochondrial oxoacid dehydrogenase E2 subunits, some

individuals with PBC also have other specific autoantibodies. The cDNA cloning of

gp210 made possible the identification of its immunodominant epitope, which was

mapped to a stretch of 15 amino acids. Two ELISAs have been developed for detection

of autoantibodies against the predominant autoepitope of gp210.

Apart from the high-sensitive detection of bacterial pathogens, amplified DNA segments

can be used for a variety of purposes. The number and position of repetitive DNA

elements present in the genome of M. tuberculosis, for example, are representing strain-

specific markers and the information has been used in epidemiologic studies of

tuberculosis.

2.5 Critical Review of Literature and Knowledge Gap

The basis for effective treatment and cure of a patient is the rapid diagnosis of the disease

and its causative agent, which is founded on the analysis of the clinical symptoms

coupled with laboratory tests. As we approach the 21st century, clinicians are becoming

increasingly able to diagnose and treat diseases at the molecular level. The rapid

development of new methods and techniques in the area of molecular biology has gained

new insights into the genetic and structural features of a considerable number of human

pathogens. These results obtained by intensive basic research are currently leading to

improved diagnostic procedures.

The alarming trend of coinfection of TB with HIV, has been associated with the

worsening of the urban and social conditions, and changes in immigration patterns.

Widespread emergence of multidrug-resistant tuberculosis (MDR-TB), especially in

institutional settings, has made it difficult to control the spread of TB (20). The

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emergence of multidrug-resistant strains has reduced the efficacy of treatment almost to

the level of the pre-antibiotic era (21). Recent MDR-TB outbreaks have been

characterized by mortality rates of 50 -80% and a duration of only 4-16 weeks from the

time of diagnosis to the time of death. Resistance to rifampin, for example, involves

alterations of the RNA polymerase.

Improvements in antibiotic and antiviral therapy for specific microorganims will require

development of increasingly more accurate method of diagnosis. Nucleic acid-based

technology has the potential to become one of the most powerful tools in clinical

microbiology since it essentially circumvents the necessity for the microorganism to be

isolated in pure culture prior to its definitive identification.

In the face of the current problems in laboratory diagnosis of infectious diseases, it is

apparent that the continued use of older and slower methods of detection is unacceptable.

Especially in the case of severe infections, the diagnostic capabilities of molecular

biology-based techniques will have major positive impact on health care costs, as well as

on the associated morbidity and mortality. If, for example, generation of a report that a

given patient is infected with an antibiotic-resistant pathogen, can help the physician to

better tailor therapy to that person's needs.

These advances in molecular biology have enhanced our understanding of the primary

defects and basic mechanisms responsible for the pathogenesis of these conditions and

their phenotypic expression, and in the process, new perspectives on cardiac diagnosis

have been formulated. In the course of this scientific evolution, a certain measure of

uncertainty has also arisen regarding the implications of genetic analysis for clinical

diagnostic criteria.

Despite the rapid development of new molecular techniques, the implementation of

genetic testing for many disorders in standard clinical management has not been justified.

With their high costs, their variable analytical and clinical validity and their limited

availability, genetic tests for many types of hereditary cancers are far from satisfactory.

15

Legal, social and ethical issues also affect the integration of genetic testing into the health

care system. New subgroups of genetically affected individuals without conventional

clinical diagnostic findings have been identified solely by virtue of access to molecular

laboratory techniques, creating a number of medical and ethical concerns regarding the

possible clinical implications.

Indeed, the extent to which such individuals should receive sequential evaluations and/or

therapy or be subjected to employment or insurance discrimination, psychological harm,

loss of privacy, or unnecessary withdrawal from competitive athletics is uncertain but

remains a legitimate source of concern. It is therefore particularly timely and appropriate

to analyze these issues in detail, specifically the extent to which molecular biology has

revised traditional diagnostic criteria. The role of genetic testing in assessing prognosis

and identifying high-risk subgroups or in defining basic disease mechanisms and

pathophysiology is, however, largely beyond the scope of this scientific statement.

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CHAPTER THREE

RESEARCH METHODOLOGY

3.0 Introduction

This chapter outlines the research design and methodology adopted for the purpose of

this study. It gives a detailed description of how the study was conducted. The chapter is

divided into sections as follows: The geographical locale of study area, research design,

target population, sampling size, sampling procedure and design, data collection and data

analysis and interpretation.

3.1 Research Design

The research design employed in this study was the evaluation trial that depended on its

purpose and the population for which the test is intended. In general, a diagnostic test

should be evaluated using methods and equipment that are appropriate for that purpose.

The staff performing the evaluation should be appropriately trained so that they are

proficient in performing the test being evaluated and the comparator tests.

3.2 The Study Area

The study was carried out in Moi Teaching and referral Hospital in Eldoret town from

among the patients who visited the clinics in the second week of February.

3.3 Target Population

Target population in statistics is the specific population about which information is

desired (leedy and Ormond, 2005). Kothari (2004) defines a population as a set of people,

elements, events, group of things that are being investigated. The target population in

which the diagnostic test was done included all patients attending clinic in week two of

February. This totaled to about 2000 participants expected to visit the clinic in that week.

This population had the reliable information for a replacement to an existing test, use of a

triage instrument to identify those in need of further investigation, and used as an

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additional test in a diagnostic strategy. It is of little value to evaluate tests that are

unlikely to be affordable or accessible to the target population, or which yield results that

are unlikely to influence patient care or public health practice.

3.4 Sample Size and Sampling Technique

The study group consisted of all subjects who satisfy the criteria for inclusion and are not

disqualified by one or more of the exclusion criteria. In this case, a consecutive series of

subjects were included. This also included the sub-selection, for example, only those who

test negative by the reference test. However, this can lead to biased estimates if the

sample is not truly random. Where possible, all tests under evaluation should were

compared with a reference (gold) standard. The choice of an appropriate reference

standard is crucial for the legitimacy of the comparison. A serological assay was not

compared with an assay that detects a microorganism directly, as clinically defined

reference standards are not appropriate when clinical presentation is not sensitive or

specific. The results from the assays were combined to produce a composite reference

standard.

The key question to be addressed before embarking on a study, and the question that is

often hardest to answer, is what level of performance is required of the test. The levels

that might be acceptable in one setting might be inappropriate in another. The indications

for performing the test can vary. The level and availability of healthcare resources and

disease prevalence all have a bearing on setting the acceptable performance of a test.

Increasing the sample size reduces the uncertainty regarding the estimates of sensitivity

and specificity (the extent of this uncertainty is summarized by the confidence interval).

The narrower the confidence interval, the greater the precision of the estimate. A 95%

confidence interval is often used that is, we can be 95% certain that the interval contains

the true values of sensitivity (or specificity).

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The formula for calculating the 95% confidence interval is given by equation 1

where p = sensitivity (or specificity) measured as a proportion (not a percentage) and n =

number of samples from infected people (or, for specificity, from uninfected people).

In the study 97 samples are positive by the gold standard test and 90 of these are positive

by the test under evaluation, then the sensitivity of the test is estimated by p = 90/97 =

0.928 and the confidence interval, using the formula above, is given in equation 2.

This means that the study was 95% sure that the interval 87.7% to 97.9% contains the

true sensitivity of the test under evaluation. In considering sample size, it is important to

consider the desired precision with which the sensitivity of the test was measured. In this

order, a rough estimate of what was expected to be the sensitivity is made. Since the

study expected the sensitivity of the test under evaluation is approximately p(0.8 (80%))

and aimed to measure the sensitivity to within ± x (where x is expressed as a proportion

rather than a percentage; 0.10 rather than 10%) and choose n so that the confidence

interval is ± x (for example ± 10%). This is shown in equations 3–5.

which translates to:

Thus, if p = 0.80 and x = 0.10, then

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Therefore, to measure the sensitivity to within ± 10% the study required at least 62

samples that are positive by the gold standard test. A sensitivity of a new test is 80% and

a confidence interval of ± 6%, the study required to recruit or have archived specimens

from, 170 infected study subjects by the reference standard test. Again with the

prevalence of infection in the study population as 10%, then there were 10 infected

subjects per 100 patients seen at the clinic. So, to have 170 infected subjects, the study

recruited 1,700 patients (100/10 × 170).

3.5 Data Collection Procedure

Two common circumstances in which diagnostic tests are deployed are: Screening people

presenting to a clinic who have symptoms that might be caused by the infection to

identify those who are truly infected (for example, persons presenting with a fever that

might be caused by malaria) and Distinguishing infected people from non-infected people

in a population, irrespective of whether or not they have any symptoms that might be

characteristic of the infection.

In the first situation, tests with high sensitivity was required so that a high proportion of

all truly infected patients are identified for treatment and in the second case, if the

infection is rare, high specificity was required or else a high proportion of those who test

positive could be false positives (that is, the test will have a poor PPV). In either

circumstance it is necessary to identify a group of truly infected and truly uninfected

individuals to assess sensitivity and specificity, respectively.

A common design for an evaluation study is to enroll consecutive subjects who are

clinically suspected of having the target condition. The suspicion of infection can be

based on presenting symptoms or on a referral by another healthcare professional. These

participants then undergo the test under evaluation as well as the reference standard test.

In studies in which only a small proportion of those tested are likely to be infected, all

subjects can be subjected to the reference standard test first. All positives and only a

random sample of test negatives can then be subjected to the test under evaluation. This

can lead to more efficient use of resources if the target condition is rare.

20

Tests were evaluated using stored specimens collected from those with known infection

status. Such studies are rapid and can be of great value but there is a risk that they can

lead to inflated estimates of diagnostic accuracy (when the stored samples have been

collected from the 'sickest of the sick' and the 'healthiest of the well'). The estimate of

specificity could be biased, for example, the negative samples relate only to a group with

one alternative condition, rather than a group including the full range of conditions that

presented symptoms that are similar to the infection under study hence the study

considered minimizing biasness in the results.

The setting where patients were recruited and where the evaluation was conducted

defined. This might was done in a clinic or laboratory, a remote health post or a hospital

in this case all tests were done at MTRH. Tests were performed differently in a primary

care setting compared with a secondary or tertiary care setting. The spectrum of endemic

infections and the range of other conditions observed varied from setting to setting, due

to referral mechanism. Other factors that affected test performance and differ between

sites included climate, host genetics and the local strains of pathogens. Because the test

characteristics varied in different settings, hence it was valuable to conduct multi-centre

studies. 

3.6 Data Collection Instruments

The data was collected using a lab schedule that included a list of specimen taken form

the participants. This was supported by a simple questionnaire to help obtain some

demographic information from the participant.

3.7 Pilot Study

Before subjecting the respondents to the questionnaires, a pre-test was conducted. The

pre-test conducted reviewed the designed questionnaires for reliability. The respondents

were conveniently selected since statistical conditions are not necessary in the pilot study

(Cooper and Schindler, 2003).The purpose of the pilot was to refine the questionnaires to

improve reliability. The participants of the pre-test were from the Turbo health centre.

21

The sample size of the pre-test was 30. Out of the 30 participants, 50 percent were male

and 50 percent were female.

3.7.1 Reliability of the Research Instruments

Mugenda and Mugenda (2006), defines reliability as a measure of the degree to which a

research instrument yields consistent results or data after repeated trials. A re-test method

assessing reliability of data involves administering the same instrument twice to the same

subjects. According to Kumar (2006), the ratio between the test and the re-test scores is

an indication of the reliability of the instrument.

Pearson’s product moment correlation was used to find the coefficient of correlation.

Chronbach’s Alpha tests of multiple questionnaires following each profile were

calculated to test the reliability of responses for each individual. The level of .700 or

greater is suggested as an indication of the internal consistency (Nunnally, 1978).

3.7.2 Validity of the Instruments

Smith (1991) defines validity as the degree to which the researcher has measured what he

/she has set out to measure. Mugenda and Mugenda (2006), defines validity as the

accuracy and meaningfulness of inferences, which are based on the research results. The

instruments were rated in terms of how effective its samples are in significant aspects of

the purpose of the study. Validity involves content, face, and construct. Validity was

determined using expert help from my supervisor and other experienced members.

The content validity of the instruments was determined in two ways. First, the researcher

discussed the items in the instruments with the supervisor. Advice given helped the

researcher to determine the validity of the research instruments. The advice included

suggestions, clarifications and other inputs in order. These suggestions were used to make

necessary changes. Secondly content validity of the instruments was determined through

piloting, where the responses of the subjects were checked, against the research

objectives. This gave a reason as to why content was used. For a research instrument to

22

be considered valid, the content selected and included in the questionnaires must be

relevant to the variable being investigated argues (Neuman 2000).

3.8 Data Analysis

This study adopted both qualitative and quantitative analysis in order to achieve the aims

and objectives of the study. Descriptive methods were employed. The data was organized

in tabular form and represented in frequency distribution tables and percentage

distribution of the respondents. The data collected, from the students, college

administrators and the lecturers was treated separately, then the information analyzed and

compared. This study analysed the research questions in relations to the objectives

described in the previous chapter, the variables in relation to the dependent variable.

Statistical Package for Social Sciences (SPSS) version 16 was used to assist in obtaining

the output for the techniques of analysis such as the Cronbach’s for the analysis.

Qualitative techniques (frequency tables and charts) were used for the presentation of

quantifiable data that was presented textually using descriptive statistics and inferential

statistics (regression models). This was used as a strategy for analysis between study

variables. Mean scores, standard deviations were used in analyzing items that adopt a

Likert format.

23

CHAPTER FOUR

RESULT ANALYSIS AND INTERPRETATION

4.0 Introduction

This chapter is presented under the following headings: descriptive statistics of effects of

molecular biology on diagnosis of infectious diseases, and multiple linear regression

analyses with the necessary assumptions.

4.1 Demographic Characteristics

The demographic information of this study included gender, age, level of education,

position held, and duration in the post. The participants were asked to the most

appropriate and accurate feature of demographic characteristics.

4.1.1 Gender of Respondents

Table 4.1: Gender Distribution of Respondents

Frequency Percent Valid Percent

Gender

Valid Male 42 35.9 35.9

Female 75 64.1 64.1

Total 117 100.0 100.0

The result in table 4.1 indicates that female accounted for 64.1% (75) while male were

38.9% (42). This means that male were the majority participants in this study. This can be

attributed to the fact that the hospital is a case for women as mostly many women visit

hospitals than men, however, in some cases today gender parity has not been

experienced, and gender factor was in influencing exploratory variables in this study.

4.1.2 Age Bracket of Respondents

Knowing the age bracket of the participants was important as there may be some

influence age may pose on the clinical testing and the diagnosis of the problem within the

selected sampled population.

24

Table 4.2: Age Distribution of Respondents

Age Bracket Frequency Percent Valid Percent

Valid 20-25 15 12.8 12.8

25-30 52 44.4 44.4

30-40 18 15.4 15.4

40-50 12 10.3 10.3

50-60 10 08.5 08.5

60 Above 10 08.5 08.5

Total 117 100.0 100.0

The research sought to find out the age bracket of the respondents. From the results in

table 4.2 and figure 4.2 above, 20-25 represented 12.8% (15), 25-30 44% (52), 30-40

15.4% (18), 40-50 10.3% (12), 50-60 08.5% (10) and lastly 60 above years accounted for

08.5% (10). This indicated that majority of participants were aged between age bracket

25-30 years old. This is true since the larger percentage of participants were youthful

female individuals.

4.1.3 Level of Education of Respondents

Table 4.3: Highest Education Achieved

Level of Education Frequency Percent Valid Percent

Valid Certificate 27 23.1 23.1

Diploma/Higher Diploma 38 32.5 32.5

Degree 24 20.5 20.5

Masters Degree 18 15.4 15.4

Others 10 08.5 08.5

Total 117 100.0 100.0

The study sought to find out the highest level of education of the respondents. From the

results in table 4.3 and figure 4.3 above, those with certificate qualification accounted for

23.1% (27), diploma or higher diploma 32.5% (38), degree 20.5% (24), masters 15.4%

(18) while others accounted for 08.5% (10). This showed that many participants in this

25

study had diploma or higher diploma level of education, followed by the certificate and

then degree, at the same time masters also accounted for a significant proportion of the

respondents.

4.2 Descriptive Statistics Results of Diagnosis of Infectious Diseases

Table 4.4: Descriptive Statistics

N Mean Std. Dev

Diagnosis is Accurate in its test results 117 3.0769 1.40905

The Diagnosis is simple to use 117 3.4957 1.36220

The Diagnosis Provide a result in time

to institute effective control measures 117 3.0684 1.42470

Early diagnosis and treatment 117 3.6325 1.24982

Diagnosis has positive predictive value 117 3.8889 1.04037

Diagnosis enhances responses to medication

and management 117 3.9060 1.38329

The results in table 4.4, the descriptive statistics of variables indicated that the mean

scores of Diagnosis enhances responses to medication and management is moderately

stable at highest score of mean 3.9060 and standard deviation of 1.38329 with the least

mean score of 3.0684 and standard deviation of 1.40905. This is an indication that

generally the testing and diagnosis of infectious diseases provide avenues for responses to

medication and management.

4.3 Statistics and Frequency Distributions for the Traditional Diagnosis System

This section presents all the items used to measure the Traditional Diagnosis System

(TDS) of Diagnosis of infectious diseases in MTH measured on a Likert scale of 5

ranging from 5=Strongly Agree, 4=Agree, 3=Neutral, 2=Disagree, 1=Strongly Disagree.

Molecular biology tools bring a very sophisticated level of sensitivity and specificity to

diagnostics. These tools can detect a bacterium, virus, yeast, parasite or genetic marker

through the presence of DNA or RNA genetic sequences in a blood sample. Tests are

performed directly on a clinical sample and make it possible to obtain results in just a few

26

hours. These tests are used to detect pathogens (bacteria, viruses, yeasts), identify

antibiotic resistance mechanisms, and measure the quantity of a virus, such as HIV, in the

blood. They thus allow choices to be made about a specific treatment, monitor its

effectiveness, and determine how human cells react to a disease or infection. Identifying

patients who will be responsive to a given treatment, and those for whom such therapy

may cause significant side effects, represents a recent application for molecular biology.

4.3.1 Opinion on Knowledge of Use of Diagnosis Testing

To find out if the if diagnosis is Extracting, Amplification and Detection of diseases,

participants were asked to state yes or no.

Table 4.5: Frequency Distribution of Opinion on Use of Diagnosis

Opinion Frequency Percent Valid Percent

Valid Yes 78 66.7 66.7

No 39 33.3 33.3

Total 117 100.0 100.0

The result indicates that 66.7% (78) of participants answered yes to the question and

33.3% (39) declined. It was an indication that more than half of the sampled population

agreed that the diagnosis enhance Extracting, Amplification and Detection of diseases.

4.4 Diagnosis Methods of Molecular Biology

The study explored the form of methods that are applied in the molecular diagnosis

testing. The results were ass shown in table 4.6 below.

The results indicated that the most method used is in the area of virology as there are

many methods applied in the virus diagnoses. This included Herpes simplex virus,

cytomegalovirus, Epstein-Barr virus, varicella zoster virus, human herpes virus type 6, 7,

8 respiratory viruses (such as influenza virus, respiratory syncytial virus, parainfluenza

virus, adenovirus, rhinovirus), SARS-CoV, avian influenza virus, HIV, hepatitis B,

hepatitis C, human papilloma virus, enterovirus and orf virus, mulloscum contagiosum.

27

Table 4.6: Molecular Biology Diagnosis Methods for Infectious DiseasesArea Method Freq (%)

Virology

Herpes simplex virus, cytomegalovirus, Epstein-Barr

virus,

10 8.6

varicella zoster virus, human herpes virus type 6, 7, 8 10 8.6

respiratory viruses (such as influenza virus, respiratory

syncytial virus,

8 6.8

parainfluenza virus, adenovirus, rhinovirus) 12 10.3

SARS-CoV, avian influenza virus 6 4.7

HIV, hepatitis B, hepatitis C 12 10.3

human papilloma virus, enterovirus 5 4.3

orf virus, mulloscum contagiosum 5 4.3

rotavirus, norovirus, enteric adenoviruses 6 5.1

Bacteriology

C. trachomatis, N. gonorrhoeae, B. pertussis, M.

tuberculosis, nontuberculous

11 9.4

mycobacteria, T. whipplei, B. henselae, genital

mycoplasmata, C. burnettii M. pneumoniae, C.

pneumoniae, Legionella spp., N. meningitidis, S.

pneumoniae

12 10.3

Parasitology Plasmodium spp., T. gondii 10 8.6

Mycology P. jiroveci, Aspergillus spp. 10 8.6

Total 117.0 100.0

HIV, hepatitis B, hepatitis C and para-influenza virus, adenovirus, rhinovirus) both

accounted for 10.3%(12) each as the highest reported methods of virus diagnosis and was

followed by Herpes simplex virus, cytomegalovirus, Epstein-Barr virus and varicella

zoster virus, human herpes virus type 6, 7, 8 at 8.6%(10). The least method reported in

virus diagnosis was human papilloma virus, enterovirus and orf virus, mulloscum

contagiosum both at 4.3%(5).

28

4.5 Importance of Molecular Biology Lab Diagnosis

The study also sought to establish the benefits of using molecular biology lab testing in

diagnosing infectious disease. The results were as shown in table 4.7 below.

Table 4.7: Benefits of Molecular Biology Lab Testing

Benefit Freq (%)

Faster results and accurate 45 38.5

Screening and Identify selected serotypes associated with disease 25 21.4

Eliminates bacterial overgrowth as a problem 17 14.5

Quantitates bacteria more readily 18 15.4

Confirm bacterial invasion 12 10.2

Total 117.0 100.0

The result in table 4.7 indicate that the benefits of molecular biology form of diagnosis

included Faster results and accurate, identify selected serotypes associated with disease,

eliminates bacterial overgrowth as a problem, quantitates bacteria more readily and

confirm bacterial invasion. The most reported was 38.5%(45) representing faster results

and accuracy, which was followed by identify selected serotypes associated with disease

at 21.4%(25). The least reported was 10.2%(12) representing confirm bacterial invasion.

This means that importance of molecular biology diagnosis of infectious diseases is

placed on its accuracy, screening and identifying selected serotypes associated with

disease.

4.6 Effects of Molecular Biology Diagnosis

To help achieve the objectives of this study, four questions were asked and the study

sought for their solutions. The results in table 4.9 were obtained.

It was indicated that indicated the enhanced accuracy in treatment of detected diseases,

early identification of high-risk diseases on patient, diagnostic tests to complement

traditional risk factors and assessing severity and risk of recurrence of diseases were key

29

to the influence of this diagnosis formula and their influence were in that order

respectively.

Table 4.8: Molecular Biology Effects on Infectious Disease Diagnosis

Effects on Lab Diagnosis of Infectious Diseases Freq (%)

Enhanced accuracy in treatment of detected diseases 48 41.0

Early identification of high-risk diseases on patient 35 29.9

Diagnostic tests to complement traditional risk factors 19 16.2

Assessing severity and risk of recurrence of diseases 18 15.4

Total 117.0 100.0

Majority indicated that enhanced accuracy in treatment of detected diseases was most

common, and the least was in assessing severity and risk of recurrence of diseases.

In summary the result of the test performed indicated varying results but confirmed the

similarities of the studies done in other parts of the world.

30

CHAPTER FIVE

DISCUSSIONS OF FINDINGS, CONCLUSIONS AND RECOMMENDATIONS

5.0 Introduction

This chapter presents the discussions of findings, conclusions and recommendations as

well as some suggested areas of consideration for future studies.

5.1 Discussions of findings

The findings were that majority of the participants were female at 64.1%, this is a

common phenomenon in the patients visiting hospitals and clinics in particular the

government health centres, it is however, not clear whether this general perception

attributed to the problem of study is influenced by this female dominancy.

The majority of the participants were aged between 25-30 44% (52), followed by 30-40

15.4%. These were the average age of the participants. A prime age for introduction of

change that can result in experienced medical challenges, yet it is not clear if there is a

formed opinion of this age that has influenced the study about the outcomes reported in

chapter four above. Those with diploma education were the majority at 32.5% followed

by the degree holder at 20.5%.

The study found out that Diagnosis enhanced responses to medication and management is

so important in the use of molecular biology test. This means that it was difficult to have

the stability of accurate result with the traditional methods used before. This is an

indication that generally the testing and diagnosis of infectious diseases provide avenues

for responses to medication and management. Priority is placed in diagnosis accuracy ass

this would facilitate the proper treatment and management of infectious diseases.

Tests are performed directly on a clinical sample and make it possible to obtain results in

just a few hours. These tests are used to detect pathogens (bacteria, viruses, yeasts),

identify antibiotic resistance mechanisms, and measure the quantity of a virus, such as

HIV, in the blood. They thus allow choices to be made about a specific treatment,

monitor its effectiveness, and determine how human cells react to a disease or infection.

31

Identifying patients who will be responsive to a given treatment, and those for whom

such therapy may cause significant side effects, represents a recent application for

molecular biology.

The conclusion made on the findings of the benefits was that molecular biology use has

been implemented and its benefits are being experienced in the laboratories of MTRH

and hopefully in other health facilities in the country. These benefits are able to correct

misdiagnosis of problems resulting in wrong medication and management care of

infectious diseases. It provides quick and accurate results from the lab to enhance

treatment of the patients. This will enable unnecessary deaths due to improper diagnosis

or delayed results from eventual occurrences.

There are four main areas of application of molecular biology in diagnosis of infectious

diseases. These include: Virology, Bacteriology, Parasitology and Mycology. The

virology problem has several methods used in its diagnosis. The remainder tow areas of

infectious microbes don’t portray wider usage in the diagnosis. It is important to note the

number of methods used in each area.

The findings indicted that the benefits of molecular biology was its accuracy and faster in

producing results. This means that importance of molecular biology diagnosis of

infectious diseases is placed on its accuracy, screening and identifying selected serotypes

associated with disease.

It was found out that the enhanced accuracy in treatment of detected diseases, early

identification of high-risk diseases on patient, diagnostic tests to complement traditional

risk factors and assessing severity and risk of recurrence of diseases were key to the

influence of this diagnosis formula and their influence were in that order respectively.

Majority indicated that enhanced accuracy in treatment of detected diseases was most

common, and the least was in assessing severity and risk of recurrence of diseases.

32

5.1.1 Achieving the Objectives of the Study

The objective one intended to examine the usefulness of molecular biology on treatment

of diseases. The findings indicated that the methodology is essential in screening for

detection of high level risk problems so that early detections can be made for proper

management and treatment to start at its earliest time possible. It is also useful in its

accuracy in the result from the lab test. This included both objectives one, three and four

the findings in the usefulness and screening provided the solutions to these objectives.

The study also examined the effects of molecular biology on screening of diseases. These

findings indicated that early detection, isolation of infected cases is some of the functions

of molecular biology. It implies that molecular biology can enhance detection, selection,

amplification of diseases hence influencing proper screening of infectious diseases to

produce accurate results. This is also made possible as the method will screen deeply into

the sample specimen to ensure nothing is left unnoticed for the result to be accurate, even

the lowest level of microbes in a specimen will be detected.

5.2 Conclusions

in the findings it was indicated that majority of the participants were female, conclusions

drawn form this findings is that gender disparity is common in the visits, diagnosis and

treatment and management of infectious diseases in the public health centres especially

MTRH.

The other conclusion drawn was that main individuals visiting these health centres are the

youth, a situation resulting from the current state of young generations leading with

challenges requiring hospitalisation. There was no highest level of education as majority

was in the diploma levels. It is therefore concluded that lack of highest level of education

may hinder proper diagnosis, treatment and management of infectious diseases. This is

true where majority of patients with lower education levels fail to observe dosage

requirements.

33

The findings has revealed that the level of acceptance of the variables explored is on

averagely about 80%, this is similar to a conclusion made on the past studies on use of

modern diagnosing methods such as molecular biology. The conclusion is that the same

trend of state of change is reported however, it important to note that the limitations of

this method is huge that the other traditional ones cannot be replaced hence it is intended

for integration into the conventional ones. The study would conclude that there is a

general state of perception in the laboratory tests of infectious diseases that would

encourage these findings. That means molecular biology lab testing at MTRH is

approved as on going with majority approval.

The study found out that Diagnosis enhanced responses to medication and management is

so important in the use of molecular biology test. This means that it was difficult to have

the stability of accurate result with the traditional methods used before. This is an

indication that generally the testing and diagnosis of infectious diseases provide avenues

for responses to medication and management. Priority is placed in diagnosis accuracy ass

this would facilitate the proper treatment and management of infectious diseases.

These tools can detect a bacterium, virus, yeast, parasite or genetic marker through the

presence of DNA or RNA genetic sequences in a blood sample. Tests are performed

directly on a clinical sample and make it possible to obtain results in just a few hours.

These tests are used to detect pathogens (bacteria, viruses, yeasts), identify antibiotic

resistance mechanisms, and measure the quantity of a virus, such as HIV, in the blood.

They thus allow choices to be made about a specific treatment, monitor its effectiveness,

and determine how human cells react to a disease or infection. Identifying patients who

will be responsive to a given treatment, and those for whom such therapy may cause

significant side effects, represents a recent application for molecular biology.

The findings from the result show that the diagnosis enhances Extracting, Amplification

and Detection of diseases. It implies that these three areas represent main benefit of

molecular biology use. There are cases where diseases have been diagnosed for the

wrong symptoms and treatment and management is given for wrong diagnosis hence

34

complicating the whole situation. This has resulted in many deaths therefore the concern

by introducing molecular biology is to enhance clear detection, extracting and

amplification of the diseases so that proper medicine can be provided and tools for

management be given properly.

There are four main areas of application of molecular biology in diagnosis of infectious

diseases. These include: Virology, Bacteriology, Parasitology and Mycology. The

virology problem has several methods used in its diagnosis. The remainder tow areas of

infectious microbes don’t portray wider usage in the diagnosis. It is important to note the

number of methods used in each area.

The findings indicted that the benefits of molecular biology was its accuracy and faster in

producing results. This means that importance of molecular biology diagnosis of

infectious diseases is placed on its accuracy, screening and identifying selected serotypes

associated with disease.

It was found out that the enhanced accuracy in treatment of detected diseases, early

identification of high-risk diseases on patient, diagnostic tests to complement traditional

risk factors and assessing severity and risk of recurrence of diseases were key to the

influence of this diagnosis formula and their influence were in that order respectively.

Majority indicated that enhanced accuracy in treatment of detected diseases was most

common, and the least was in assessing severity and risk of recurrence of diseases.

5.3 Recommendations

There are some areas reported as requiring support in terms of resources. These areas if

not addressed would make it hard for the process to be completely successful; therefore

the study makes the following recommendations:

The training of personnel to handle the molecular biology instruments to be provided at

all the times especially during the implementation period of this newly discovered

35

method of diagnosis. This will enable the urgency of access to important facilities thus

reducing time wastage.

The study also recommends that professionally qualified human resource be recruited

where there are such shortages.

There is also a need to ensure appropriate budget support so that priorities are achieved

today other than being suspended for future period due to financial shortages.

The last important recommendation is to ensure that this molecular biology method of

diagnosis is successfully implemented and that this level of performance be increased.

5.4 Suggestions for Further Studies

A study is needed to investigate on the factors influencing an informed opinion in change

introduction and implementation modern diagnosis methods in lab testing process.

A longitudinal survey study is also required to investigate on the reasons why the

implementation of modern methods does not immediately result into long term solutions

to medical problems faced in health centres in the country.

36

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