Molecular epidemiology of bovine tuberculosis in Cameroon Franklyn
Molecular epidemiology of bovine tuberculosis in Cameroon Franklyn Nkongho
Outline • • Background Design Results Concluding remarks
Background • WT funded project on the epidemiology of b. TB in Cameroon – Describe the basic epidemiology – Estimate the performance of available diagnostic tests – Estimate the prevalence of b. TB – Identify the strains circulating – Explore co-infection with liver fluke, para. TB, 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 ge Ni N CAR B M G Chad ria • 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
Sampling Design
Collection of blood sample for serological tests
Bamenda TB Lab
Sample Processing GRINDING PASTE MADE Hain MTBC/CM/AS kits Spoligotyping/MIRU-VNTR (Genoscreen) Automated MGIT BACTEC 960 SYSTEM LJ Pyruvate LJ Glycerol WGS (Ark. Genomics)
Buea Lab
Results abattoir Bamenda 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 6. 8% - - 5. 6%
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 All observed Random sample NB. 380 animals had LN culture results Bovigam M bovis pos neg pos 43 15 58 neg 55 200 255 98 215 313 NB. 67 had no bovigam results (mainly Garoua + Maroua)
Abattoir results – other Mycobacteria Abattoir BAMENDA NGAOUNDERE GAROUA 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 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
Mycobacterium tuberculosis complex Species and Lineages Ba sa men mp d les a M. tuberculosis M. africanum M. bovis sub species Ba me am nda ple s M. canetti
Spoligotyping SB 1026 SB 0944 SB 0953
Spoligotyping SB 0944 SB 0953 SB 1026
Spoligotyping ia r e g i N SB 0953 SB 1026 SB 0953 SB 0953 SB 0953 SB 0944 SB 0953 SB 0953
Spoligotyping SB 1026 SB 0953 SB 0944 Boyo Bui Menchum Mezam Momo Donga 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 b. TB • 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 • Uo. Edinburgh, UK – – Mark Bronsvoort (PI) Rob Kelly (RA/Ph. D) Ian Handel Adrian Muwonge • IRAD, Cameroon – Vincent Tanya (Co. PI) • Uo. Buea, Cameroon • GIZ/TBRL, Cameroon – Melissa Sander • Uo. Glasgow, UK – Roman Biek • Uo. Liverpool, UK – Kenton Morgan – Diana Williams • MINEPIA, Cameroon – Walters Andu – Lucy Ndip (Co. PI) • Uo. Ngoundere, Cameroon – Franklyn Nkongho (Ph. D) • Swiss TPH – Jakob Zinstaag (Co. PI) • LRVZ de Farcha, Chad – Richard Ngondolo - Dr Victor Ngwa - Jean Marc Babningom
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