PrePrevalence valence study ostudy off Bovine tuberculosis in Bovine tuberculosis in Nekemte Municipality Abattoir, Western Nekemte Municipality Abattoir, Western

Ethiopia Ethiopia DVM thesis DVM thesis (Jimma University and ALIPB, AAU)(Jimma University and ALIPB, AAU)

BByy:-:-

Tegegn GudetaTegegn Gudeta, Jaleta, Jaleta

Jun, Jun, 2 2008008 Jimma, EthiopiaJimma, Ethiopia

1. 1. IntroductionIntroduction Bovine Tuberculosis Bovine Tuberculosis

contagious, contagious, chronic and chronic and debilitating disease of both debilitating disease of both humans and animalshumans and animals

Formation of granulomas in tissues and organsFormation of granulomas in tissues and organs and also and also tubercles, tubercles, abscess abscess and and cheesy exudates cheesy exudates will be will be observedobserved

Mycobacterium bovis Mycobacterium bovis Acid fast bacili Acid fast bacili MTBCMTBC wide range wide range of of vertebrate animals hostvertebrate animals host

DiagnosisDiagnosis History and clinical findingsHistory and clinical findings Tuberculin testTuberculin test Postmortem examination Postmortem examination Histology Histology Invitro lymphocyt assay Invitro lymphocyt assay Enzyme linked immunosobent assay (ELISA)Enzyme linked immunosobent assay (ELISA) Culture of the mycobacteriumCulture of the mycobacterium and Staining and Staining Nucliec acid recognition techniquesNucliec acid recognition techniques ( (Technical problems and Technical problems and costcost))

Postmortem examination of the lesions are very critical Postmortem examination of the lesions are very critical 60% Africa 60% Africa , , 47% Asian 47% Asian , , 38% south America and Caribbean countries 38% south America and Caribbean countries

reported from sporadic to enzootic occurrencereported from sporadic to enzootic occurrence of BTB of BTB(Cosivi (Cosivi et alet al., ., 1998)1998)

Common disease(animals and human) in developing countriesCommon disease(animals and human) in developing countries BTB is BTB is disease of intensifications disease of intensifications (dairy cattle)(dairy cattle) Significant public health importance Significant public health importance Man acquires BTB by aerosols and ingestion Man acquires BTB by aerosols and ingestion Poor concept of pasteurization of milk Poor concept of pasteurization of milk in developing countries in developing countries Increasing incidenceIncreasing incidence BTB with BTB with human immune virus (HIV) human immune virus (HIV) In Ethiopia studies shows that In Ethiopia studies shows that the prevalence rate ofthe prevalence rate of BTB ranges from 3.4% BTB ranges from 3.4%

in a small holder production system to 50% in intensive dairy in a small holder production system to 50% in intensive dairy productions productions by tuberclin tests by tuberclin tests (Kiros, 1998; Ameni and Roger, 1998; Ameni et (Kiros, 1998; Ameni and Roger, 1998; Ameni et al., 2003; Regassa, 2001, 2005).al., 2003; Regassa, 2001, 2005).

BTB PBTB Prevalence rates revalence rates of 5.2% (Ameni and Wudie, of 5.2% (Ameni and Wudie, 2003), 4.5% (Teklu et al., 2004) and 3.5% (Shitaye et 2003), 4.5% (Teklu et al., 2004) and 3.5% (Shitaye et al., 2006)al., 2006), 24.7%( Mammo, 2007) , 24.7%( Mammo, 2007) have been reported in have been reported in different abattoirs in the country.different abattoirs in the country.

Kidane et al. (2002) indicated that M. bovis was found to be a cause forKidane et al. (2002) indicated that M. bovis was found to be a cause for tuberculous lymphadenitis in 17.1% of 29 human tuberculosistuberculous lymphadenitis in 17.1% of 29 human tuberculosis

In Nekemte area, West Ethiopia the status of BTB in cattle is not studied so In Nekemte area, West Ethiopia the status of BTB in cattle is not studied so far,far,

The objectives of this study were: The objectives of this study were: To determine the prevalence of BTB in cattle

slaughtered in Nekemte Municipality abattoir. abattoir. To assess the efficiency of routine meat inspection to To assess the efficiency of routine meat inspection to

identify tuberculous lesion in slaughtered cattle.identify tuberculous lesion in slaughtered cattle. To look into trends of human tuberculosis in the study To look into trends of human tuberculosis in the study

area.area.

2.Materials and Methods 2.Materials and Methods

2.1 Study Area 2.1 Study Area Nekemte M. abattoir (October,2007 Nekemte M. abattoir (October,2007

to march, to march, 2008)2008)

NekemteNekemte Located at 336 km west of ALocated at 336 km west of Addis Ababaddis Ababa Receive average annual rain fall of Receive average annual rain fall of

1675mm1675mm Average annual temperature of 22.7 Average annual temperature of 22.7 oocc 90,000 human population90,000 human population 28 legally registered butcheries 28 legally registered butcheries

Nekemte

2.2 Study Populations2.2 Study Populations Local Horro Local Horro cattle breedcattle breed 25 cattle slaughtered daily five times a week 25 cattle slaughtered daily five times a week 3300 slaughter cattle (both male and female )3300 slaughter cattle (both male and female )

Slaughter animals are brought from Slaughter animals are brought from Sire, Diga, Sasiga , Arjo, Bedelle, ChewakkaSire, Diga, Sasiga , Arjo, Bedelle, Chewakka Guttin, A/Guddattu, Nekemte Guttin, A/Guddattu, Nekemte

Horro Bull

3.3 Study design 3.3 Study design Cross sectionalCross sectional and Retrospective study and Retrospective study

3.4 Sampling method and sample size 3.4 Sampling method and sample size Simple random sampling technique Simple random sampling technique 15 animal carcasses 15 animal carcasses werewere examined daily examined daily five five

times a week times a week 940 animals 940 animals werewere examined for the BTB using examined for the BTB using

abattoir meat inspection abattoir meat inspection during the study periodduring the study period The tissue specimen for culture were collected The tissue specimen for culture were collected

into sterile universal bottle in normal saline into sterile universal bottle in normal saline and kept in deep freezer (-20oC) at Nekemte and kept in deep freezer (-20oC) at Nekemte Veterinary ClinicVeterinary Clinic

Tissue samples were transported to the Aklilu Tissue samples were transported to the Aklilu Lemma Institute of Pathobiology of Addis Lemma Institute of Pathobiology of Addis Ababa University (ALIPB, AAU) TB laboratory in a Ababa University (ALIPB, AAU) TB laboratory in a ice bag every 2 weeks for mycobacterial culture.ice bag every 2 weeks for mycobacterial culture.

3.5 Study Methodology3.5 Study Methodology Routine Routine postmortem meat inspections postmortem meat inspections Detailed Detailed PostmortemPostmortem examination examination Bacteriology Bacteriology

Culture of the Mycobacterium(Culture of the Mycobacterium(Pyruvate and Glycerol enriched L-J Pyruvate and Glycerol enriched L-J media)media)

Zeil Nelson staining for bacilli detectionZeil Nelson staining for bacilli detection

Retrospective human TB dataRetrospective human TB data collected from collected from Nekemte H.Nekemte H.

3.6 Data collection 3.6 Data collection SexSex Body condition score Body condition score Age category Age category Frequency of anatomical sites wFrequency of anatomical sites whhere lesions found were ere lesions found were

recorded.recorded. The results of detailed laboratory examination and The results of detailed laboratory examination and

bacteriology were recorded bacteriology were recorded Human TB data record from Nekemte HospitalHuman TB data record from Nekemte Hospital

Data analysisData analysis

Chi-square test statistic (X2) Chi-square test statistic (X2) SensitivitySensitivity Specificity Specificity Test of agreement (Kappa Value)Test of agreement (Kappa Value)

Result and Discussion Result and Discussion 1.1. Postmortem results( Table 1 & 2 and Pic)Postmortem results( Table 1 & 2 and Pic)

Prevalence=5.1 %Prevalence=5.1 %(48/940)(48/940)based on based on detailed meat inspection detailed meat inspection , this is similar , this is similar with the results of with the results of Ameni and Wudie, Ameni and Wudie, 20032003 from Wuchale Jiddafrom Wuchale JiddaP =0.53%P =0.53%(5/940(5/940 based on routine meat based on routine meat inspection inspection

Estimated ratio of lesions RM/Estimated ratio of lesions RM/DDM=1:10.4.M=1:10.4.(Mammo, 2007)(Mammo, 2007)

Estimated probability of Estimated probability of mismissing lesions with sing lesions with BTB, using the routine meat inspection 89.6%BTB, using the routine meat inspection 89.6%

Poor Poor agreement (0.agreement (0.118).8).

Low sensetivity of RMI (10.4%)Low sensetivity of RMI (10.4%)

Statistically significant difference (P<0.05) was Statistically significant difference (P<0.05) was recorded in srecorded in seexx, Mammo, 2007 found similar , Mammo, 2007 found similar results in Adama abattoirresults in Adama abattoir

BTB abattoir lesions(BTB abattoir lesions(mmacroscopic findings acroscopic findings )) AA cumscribed yellowish lesions cumscribed yellowish lesions Grannlomatous tubercle lesions Grannlomatous tubercle lesions In two of 48 postmortem positive in lungs, In two of 48 postmortem positive in lungs,

abdominal thoraabdominal thoracicic cavities and mesenteryc cavities and mesentery milliary tuberculosis was foundmilliary tuberculosis was found

Distribution of tDistribution of tuberculous uberculous lesions found in 124 lesions found in 124 different organs and tissues different organs and tissues

48.4% lungs and associated 48.4% lungs and associated LNLN 22.5% retropharyngeal 22.5% retropharyngeal LNLN 13.7% mesenteric 13.7% mesenteric LNLN 8.06% in liver 8.06% in liver 7.25% in hepatic L7.25% in hepatic LNN

Variables No Examined

Positive

Negative

% Positive

95% CI X2 P-value

Total 940 48 892 5.1 0.0369-0.061

4.48 0.11

Sex Male Female

86278

3711

82567

4.2914.1

0.029-0.560.062-0.220

14.2 0.000

Age <5 6-10 >11

57624259

62715

51597243

10.54.335.8

0.15-0.970.21-1.490.13-1.05

4.74 0.094

BCS Poor edium Good

34701205

03216

34669189

04.67.8

0.50-1.800.5-3.090.467-2.99

5.33 0.069

Table 3: Summary of tuberculous lesions by sex, age and body condition score

Routine Meat

Inspection

Detailed Meat Inspection Total

Positive Negative

Positive 5 0 5

Negative 43 892 935

Total 48 892 940

Table 2: Comparison of routine meat inspection and detailed meat inspection for examination of tissues for the detection of carcasses with tuberculous lesions.Sens =10.42%, Kappa=0.18RMI/DMI=1:10.4

0

5

10

15

20

25

30

Frequency of Lesions

Mediast BronchRetrophMesen Hepatic lung Liver

Tissues/ Organs

Figure 1. Frequency of occurrence of tuberculous lesions in different tissuesand/or organs of cattle slaughtered in Nekemte abattoir during the study period

2 Culture result (table 3)2 Culture result (table 3) 40 Specimens submitted to A40 Specimens submitted to ALLIPB, TB IPB, TB LLaboratoryaboratory CColony growth was observed in olony growth was observed in 8 samples8 samples 6 speci6 specimemen from carn from carccassasseses with visible TB lesion with visible TB lesion 2 specimens from carca2 specimens from carcassessses with no visible TB lesion with no visible TB lesion 66 onon pypyruruvate enriched vate enriched LJ LJ media media 2 on glycerol enriched 2 on glycerol enriched LJ LJ media media All eight samples All eight samples subject a subject acid fast stain cid fast stain and bacilli and bacilli

were observedwere observed 33. . Retrospective data resultRetrospective data result(Pic 2)(Pic 2)

34,747 Tb cases 34,747 Tb cases 20,776(59.8%) pulmonary TB20,776(59.8%) pulmonary TB 13,971(40.2%) Extrap13,971(40.2%) Extrapuulimony TBlimony TB similar results are similar results are

reported in Wuchale Jida 16.5 by Amenu, 2002, 38.5 in reported in Wuchale Jida 16.5 by Amenu, 2002, 38.5 in Addis Ababa by Kiro, 1998, 27.5 in Adama by Mammo, Addis Ababa by Kiro, 1998, 27.5 in Adama by Mammo, 2007, 2007,

Demissie et al , 1997, reported 44% TB patient were Demissie et al , 1997, reported 44% TB patient were HIV +HIV +

Detailed

Laboratory

Examination

Bacteriology Total

Positive Negative

Positive 6 28 34

Negative 2 4 6

Total 8 32 40

Table 2: Evaluation of Detailed laboratory examination for the detection of tuberculous carcass based on bacteriology resultSens=75%, Spec=11.76%, Kappa=0.98%

Figure 2. Trend and forms of human TB recorded at Nekemte Hospital between 2000 and 2007

01000200030004000500060007000

1 2 3 4 5 6 7 8

Year

Fre

qu

en

cy o

f T

B

cas

es

Year

PTB

EPTB

Total

ConclusionsConclusions Moderate prevalence of BTB was obtained Moderate prevalence of BTB was obtained

in this studyin this studyVery low sensitivity of routine meat Very low sensitivity of routine meat

inspection to detect tuberculous lesions inspection to detect tuberculous lesions in postmortem positive carcasses in postmortem positive carcasses

Most tuberculous lesions are detected in Most tuberculous lesions are detected in lung and associated lymph nodes, lung and associated lymph nodes,

Extra pulmonary form of human TB is in Extra pulmonary form of human TB is in increasing trend increasing trend

RRecommendationecommendations:s: Attempt should be made to improve the Attempt should be made to improve the

sensitivity of routine meat inspection sensitivity of routine meat inspection BTB should be considered as a national BTB should be considered as a national

issue issue Detailed studies should be conducted to Detailed studies should be conducted to

know the status of the disease through out know the status of the disease through out the country the country

Public health awareness should be raisedPublic health awareness should be raised Strict collaboration of medical and Strict collaboration of medical and

veterinary personnel's is criticalveterinary personnel's is critical