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The diagnosis & management of Malaria: Learners Guide

Revised by: Md. Baha Uddin (ISMC-03):::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: 3131

Review & synopsis:When you are discharging the patient, summarize the events of the patients illness.

Indicate the distinguishing features of the illness & the patients responses to treatment. A formto enter this information could be attached to other record sheets.

Referral of patient with severe malaria:It is extremely difficult to frame rigid guidelines for referral because of non-uniformity in

availability of facilities in small hospitals & financial constrains of the patients. However,following are a few guidelines to help the treating doctors in taking a decision.

Indications for referral-1. Cerebral malaria not responding to treatment in 48 hours.2. Persisting oliguria even after correction of dehydration.3. Respiratory distress (not due to over-hydration).4. Severe malaria in pregnant women.5. Multi organ failure,6. Severe anemia requiring blood transfusion,7. Active bleeding.

The following measures should be taken while referring a patient toreferring hospital:

Maintain IV access & infusion IV fluids to correct dehydration. Provide life support system & guidance to the person accompanying the patient. Startappropriate anti-malarial drugs & other essential drugs required to suffice until the

patient admitted. Insert a urethral catheter in patient with reduced urine output, Provide a referral note.

A format for referral card is included on annex-4.

LEARNING UNIT -08:Exercise in the diagnosis & management of severe malaria:

You should read carefully the next section of this module the

session to which it relates.

Leaning ObjectivesBy the end of this unit you should be able to:

Assess the severity of the disease in adults.Assess the severity of the disease in children.Determine what malaria specific treatment to provide by which route& in which doses.Decide which investigations need to be carried out & when.Interpret correctly the results of special investigations.Provide appropriate management of the patient for variouscomplications of severe malaria.


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Doctors / participants will preferably see and prepare cases from nearby hospital by themselves.

Case Study:Patient A

PREVENTION &CONTROL OF MALARIACONTROL OF MALARIA:

Control means that a disease is reduced to a level when it is no longer a major publichealth problem & implies that control measures may have to be continued indefinitely.

Provision of early diagnosis, prompt treatment & disease prevention is the fundamental clementof malaria control & the basic right of the affected populati on.

PREVENTION OF MALARIA:1. Personal protection:

a. By using mosquito net at night, Insecticide treated bed net,b. By repellent creams & spray use,c. By use of long sleeves & trousers.

2. Anti-mosquito measures: these may be directed towards adult mosquitoes & their larvae:a. Destruction of adult mosquitoes can be carried out by spraying with insecticide,

such as DDT or Gammexane.b. Anti-larval measures consist of elimination of breeding places of the mosquitoes

& use larvicides (oil, paris green, DDT, dissolved in oil) culture of Gappi fish,telapya fish etc in small ponds.

3. (?) All visitors, unless eradication is complete, should take regular prophylactic drugs.4. By malaria vaccine but this needs further evaluation.

PARASITOLOGICAL DIAGNOSIS:Presence of P. falciparum, parasites in the blood can be detected by microscopy or byimmunological tests for parasite derived proteins.

The place: Bangladesh is a country whereP

. falciparummalaria is transmitted in forest & forest-fringe areas but not in mainly cities.

A women aged 25 years is brought to the OPD of DMCH in the capital. She is a local resident,the wife of a business executive & is in the seventh month of her first pregnancy.

The patient became ill 5 days ago, with chills, sweating & headaches. An antibiotic wasprescribed & her condition seemed to improve but yesterday she developed rigors & persistent

vomiting. A blood film at the local clinic revealed malaria parasites & oral quinine (600mgevery 8 hours) was prescribed. She took two doses.

Today she has been referred to your hospital because of restlessness & increasing mental

confusion. Examination reveals a semiconscious woman, who is unable to converse. She withdraws her hand from a painful stimulus but cannot localize a stimulus applied to thesternum or forehead. There is no neck rigidity, Jaundice, pallor or rash. Auxiliary temperatureis 390C, pulse 90 beats per minutes, BP 110/70 mmHg, the uterine fundus is palpable (26-28

weeks) & the foetal heart can be heard.


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LIGHT MICROSCOPY:Giemsa stained thick & thin blood smears should be examined in all malaria patients. A thicksmear should be examined in all suspected cases of malariabecause of its ability to detect parasites even

when parasite is low. A thin film is used for species & stage identification & to provideinformation regarding erythrocytes & leukocytes & platelets. High parasitaemia, growing stagesof parasites (trophozoites & schizonts) & pigment-laden neutrophils indicate poor prognosis. Incase of uncertainty in identification of the species in severe malaria patients, it should always be

considered as P. falciparum.

Advantage of light microscopy: It is cost effective, fairly sensitive & highly specific. Can estimateparasite density & differentiates between parasites species, provides information about platelets& leucocytes & can diagnose many other conditions. Parasite count, stage of malaria parasitedevelopment & proportion of neutrophil containing malaria pigment can be assessed by bloodfilm.

Disadvantages of light microscopy:False negative results may be seen in conditions of very lowparasitaemia, maturation of sequestered parasites in broods, partially treated with anti-malarial oron chemoprophylaxis. And may be due to technical factors (poorly prepared slides, poorlystained slides, poor quality microscope, examination of only thin films, inexperienced technician

etc). false positive results are seen due to stain particles, which may be confused for malariaparasites by an inexperienced microscopist.

Annex-01:

P. falciparum & P. vivax are commonly detected in our country. There issome occasional reporting of P. malariae but P. ovale is not reported yet.

Stage P. falciparum P. vivax P. ovale P. malariaeStage of asexualparasites in the

peripheral blood

Usually only rings, latetrophozoites &

schizonts in heavyinfections orcomplications

All stages All stages All stages

Ring forms Small five ring at firstcytoplasm become thick1-2 chromatin dots.Opaque forms. Multipleinfection of RBC iscommon.

Small & largering. Singlechromatin dots

Small & largering. Singlechromatin dots

Small or largechromatin

Trophozoites Uncommon inperipheral blood. Solidirregularly rounded

chromatin, indistinctpigment concentrate.

Large, amoeboidof yellow brownpigment

Large,amoeboid ofyellow brown

pigment

Narrow bandform

Schizont Rare 8-36 merozoites.Heavy pigmented;occupy 2-3rd of normalcell.

Common, roundoccupy most ofRBC, 12-24merozoites.

Round occupy3/4th of RBC,6-12merozoites

Round 6-10merozoites fillsRBC

Gametocytes Crescentic or beanshaped

Round, occupymost of theenlarged RBC

Round, occupymost of theenlarged RBC

Round, fillsRBC

Erythrocyte Scanty to 15% or more Usually scanty Usually scanty Low,


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infection route rarely >2% rarely >2%Changes in RBC Not enlarged,

Maurers dots.Not enlarged,Schuffners dots

Enlarged, pale.Oval fimbriate

Enlarged, palein blood film.

Annex-01:

Parasite count-Both parasites & WBC are counted & the number of parasites per unit volume calculated

from total leucocytes count in a thick film. A minimum of 200 leucocytes should be counted. If atotal leucocytes will give the number of parasites per cubic millimeter of blood. This is known asparasite count. For designation of a relative parasite count, a simple code from 1-4 crosses isoften used by laboratory technicians. A rough estimate of parasite density may be made byenumerating the number of asexual parasite (rings, trophozoites, and schzionts) against 100WBC in the thick film & multiplying by 80. The answer thus obtained is an approximate total permicrolitre of blood. The average leucocytes count per microscopic field is usually about 10 & asimple multiplication by 800 of the average number of parasites per field gives an approximatetotal per microlitre of blood. Where parasitaemia is high, a simpler method consists of countingthe parasites in thousand RBCs on the thin film & determining the percentage of infected cells.Serial blood examinations should be carried out at daily interval to observe the speed of the

disappearance of parasites after the initiation of treatment. In P. falciparum infection,parasitaemia may fluctuate widely in the first day of treatment & may rise alarmingly despiteadministration of adequate anti-malarial drugs. The relationship between peripheral circulatoryring from infectd RBCs & the number of sequestered infected cells is a functionof the stage ofdevelopment & the parasite multiplication rate. Serial blood films are required as long as thediagnosis is in doubt.

Annex-02:

Rapid Diagnostic test:

Principle:

The test is based on the detection of P. falciparum antigen, histidine rich protein-2 (HRP-2)released from parasitized erythrocytes & is specific to the falciparum species.

Procedure:Approximately 5microlitre of blood is collected from a finger prick with the applicator pipette,supplied with the test kit. The collected blood is released in the square chamber, marked as A,in the kit. Then 6 drops of clearing buffer are added into the device well, marked as B. Thenpositive results appear within 15mins. In another format, dipstick is placed in a clean test tube

with 4 drops of cleaning buffer.

Interpretation:1. The test ispositive if 2 pink vertical lines appear in the boxes marked as C (Control) &

T (Test).2. The test is negative if1 pink line appears in the box C, but no pink line on box T.3. The test is invalid, if no line appears in any of the boxes.

Advantages:1. Para-check Pf test is fast & simple.2. One test can be completed in less than 15 minutes.3. Many can be done simultaneously. 4. The equipment is minimal, simple & durable.5. Requires little space & no electricity.


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6. Both the specificity & sensitivity of the Para-check Pf are generally around 90%.7. Requires no expertise, simple training can do.

Disadvantages: A potential problem with the para-check Pf is that circulating antigen may be selected afterelimination of viable parasites from the blood stream.

N.B. - As false positive may occur, increase of asymptomatic parasitaemia or within 28 days ofP. falciparuminfection, despite full cure, clinical correlation is vital.

Annex-03:ABC of coma management:

A.Airway:Maintain the airway by keeping airway clean, i.e. free from saliva, vomitus etc.

- Unconscious patient should be nursed on side, preferably left lateral position, on a flatsurface a pillow. This reduces incidence of aspiration of gastric contents.

- Keep changing the side every 2 hours.- Insert a nasogastric tube & aspirate stomach contents.- Airway should be used to prevent the tongue from falling back & to keep the airway

clean.

B. Breathing:If breathing is smooth, no support is necessary. If tachypnoea, labored respiration, acidoticbreathing is present or develops in the course of the management, patient may need ventilatorsupport. Hence it should be referred to centers with facilities for intensive care.

C. Circulation:Check for dehydration by examining the pulse rate, blood pressure, skin elasticity, jugular venouspressure.

- If dehydration is present, infuse intravenous fluids.- Frequently check the rate of infusion.- Suspected infection must be treated with antibiotics. Keep an accurate record of fluid

intake & output. Strict intake & output chart should be maintained. Normal u rine outputis approximately1ml/min.

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