Study reveals dynamic state of bTB epidemiology in Cameroon

Dr Adrian Muwonge and Professor Mark Bronsvoort from The Roslin Institute and colleagues from the UK, Cameroon, Nigeria and Chad conducted the largest molecular epidemiological study of bovine tuberculosis (bTB) in a sub-Saharan African country to understand the incidence and diversity of the disease throughout Cameroon. Their findings are published in Scientific Reports.

They collected 499 samples from 380 cattle with and without bTB-like lesions at abattoirs in four different cities across Cameroon. Mycobacterium bovis evolves slowly by losing genetic material, producing a highly clonal population. By exploiting this aspect, the scientists were able to use methodology previously developed for human tuberculosis epidemiology to infer how and to what extent the pathogen was transmitted.

They discovered that bTB is rather dynamic in Cameroon, but region specific. The disease is characterised by limited evidence of transmission but high prevalence of unique genotype in the Adamawa region which is a product of constant additions from the Great Sahel transhumance movement. On the other hand, the North West region is characterised by high transmission and a local endemic expansion.

The researchers say that their study demonstrates the utility of granular molecular and spatial data in understanding the epidemiology of bTB in resource-limited settings. “This information is now more than ever critical for developing bovine tuberculosis control strategies such as disease free zoning and targeted animal movement restrictions in Africa as an alternative to the cost intensive “test and slaughter” with compensation that is currently practiced in high income settings. The reporting of 21 novel spoligotypes in this study indicates the overall dynamic state of bTB epidemiology in Cameroon and the need for a surveillance/control system,” they conclude.

Article: Molecular epidemiology of Mycobacterium bovis in Cameroon by N. F. Egbe, A. Muwonge, L. Ndip, R. F. Kelly, M. Sander, V. Tanya, V. Ngu Ngwa, I. G. Handel, A. Novak, R. Ngandalo, S. Mazeri, K. L. Morgan, A. Asuquo and B. M. de C. Bronsvoort, published in Scientific Reports (2017) 7, article number: 4652, doi: 10.1038/s41598-017-04230-6

[SOURCE: The Roslin Institute]