Molecular epidemiology of bovine tuberculosis in Cameroon

Molecular epidemiology of bovine tuberculosis in Cameroon

Franklyn Nkongho

• Background• Design• Results• Concluding remarks

Outline

Background

• WT funded project on the epidemiology of bTB in Cameroon– Describe the basic epidemiology– Estimate the performance of available

diagnostic tests– Estimate the prevalence of bTB– Identify the strains circulating– Explore co-infection with liver fluke,

paraTB, BVD– Estimate human zoonotic TB risk and

strains

Mycobacterium bovis

• Poorly reported in Africa• Potential zoonotic PH problem

– Infected raw milk or meat– Risk to herdsmen/slaughtermen

• High TB burden linked to HIV– Zoonotic component poorly understood

• Potential for cattle production loss• Control based on meat inspection

Design

• Three study components– Convenience sample of 4 abattoirs

(Bamenda, Ngaoundere, Garoua, Maroua)

– Population based cross sectional study in 2 areas

– Human DTC based study in NW Region

• Focus of talk is on the abattoir study

M

G

NB

Nig

eria

Chad C

AR

Sampling Design

Collection of blood sample for serological tests

Bamenda TB Lab

Automated MGIT BACTEC 960

SYSTEM

Sample Processing

GRINDING PASTE MADE

LJ GlycerolLJ Pyruvate

Hain MTBC/CM/AS kits

Spoligotyping/MIRU-VNTR (Genoscreen)

WGS (ArkGenomics)

Buea Lab

Results abattoirBamenda Ngaoundere Garoua Maroua

No. sampled 1129 935 160 122

No. with TB like lesions

45 106 38 18

Prev lesions 4.0% 11.3% 23.8% 14.8%

% lesions with M bovis

68.9% 67.9% 89.5% 88.8%

Prev M bovis 2.7% 7.7% 21.3% 13.1%

Prev bovigam

5.6% 6.8% - -

Results abattoir – proxy age

Abattoir lesions and M bovis

Lesion M bovis

pos neg

pos 150 51 201

neg 2 177 179

152 228 380

Bovigam M bovis

pos neg

pos 43 15 58

neg 55 200 255

98 215 313

NB. 380 animals had LN culture results

NB. 67 had no bovigam results (mainly Garoua + Maroua)

All observed

Random sample

Abattoir results – other Mycobacteria

Abattoir BAMENDA NGAOUNDERE GAROUA MAROUA

M tuberculosis 1 0 0 0

M gordonae 2 0 0 0

M phlei 9 1 0 0

M fortuitum 2 1 1 0

M mucogenicum 0 1 0 0

M scrofulaecum 1 0 1 0

M species 7 4 1 1

Only 2 animals recorded mixed infections of M bovis and M fortuitum and an untyped Mycobacterium species

Results where were zoonotic cases

3 human cases or ~2% of human TB is zoonotic in the NW Region

M. bovis sub species

Bam

enda

sa

mpl

es

M. tuberculosis

M. africanum

Bamenda

samples

Mycobacterium tuberculosis complex Species and Lineages

M. canetti

Spoligotyping

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SB0944

SB0953

Spoligotyping

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Spoligotyping

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SB0953

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Nigeria

Spoligotyping

SB1026

SB0944

SB0953

BoyoBui

MenchumMezam

MomoDonga Mantung

Molecular work ongoing

• Data analysis still on going• Majority of spoligotype and MIRU-VNTR data still

to come• WGS underway

Concluding remarks• Relatively high prevalence of bTB• Range of other Mycobacteria in cattle

– M tb and several NTMs

• 3 human M bovis cases (yet to be typed)– Represents potential significant human burden

• Complex epidemiological situation with transmission in both directions

• Currently 3 spoligotypes in NWR– More diversity by MIRU-VNTR – Appear to be widely dispersed

• Reinforce meat inspection and condemnation of infected carcasses

• Public sensitization particularly around milk consumption• BUT DATA ANALYSIS STILL ON GOING

Questions?

Partners• UoEdinburgh, UK

– Mark Bronsvoort (PI)– Rob Kelly (RA/PhD)– Ian Handel– Adrian Muwonge

• IRAD, Cameroon– Vincent Tanya (CoPI)

• UoBuea, Cameroon– Lucy Ndip (CoPI)– Franklyn Nkongho (PhD)

• Swiss TPH– Jakob Zinstaag (CoPI)

• LRVZ de Farcha, Chad– Richard Ngondolo

• GIZ/TBRL, Cameroon– Melissa Sander

• UoGlasgow, UK– Roman Biek

• UoLiverpool, UK– Kenton Morgan– Diana Williams

• MINEPIA, Cameroon– Walters Andu

• UoNgoundere, Cameroon- Dr Victor Ngwa

- Jean Marc Babningom