The Supporting Evidence Based Interventions (SEBI) project we investigated whether livestock abortion surveillance could be used to understand the causes and effects of livestock abortion in Tanzania. In addition, we investigated the economic impact that abortion in livestock has on livestock keepers in Tanzania. To do this, our researchers asked farmers to report abortion cases to livestock field officers. These officers alerted investigation teams to collect samples and conduct questionnaires which provided information on the frequency, livestock breeds, seasonal patterns and potential pathogens involved in abortion cases in cattle, sheep and goats.
Analysis revealed that successfully identifying the cause of abortion depends heavily on the timing and quality of the samples. The chances of diagnosis decreased with each day that passed between the abortion and the samples being collected. Vaginal swabs, which are easier to collect than those from the placenta or aborted foetus, were the most effective at detecting abortion-causing infectious agents.
The analysis also revealed that many of the livestock which had an abortion in the previous 12 months had experienced one or more abortions before. This suggests that an infectious agent may be the cause and that, through surveillance and accurate diagnosis, managing these animals by removing them from the herd might improve productivity. Abortions were also more common in non-local breeds of cattle and goats, suggesting that local breeds may have a degree of resistance to abortion.
The findings revealed a method of livestock surveillance that is feasible in areas with limited resources and could be used to increase understanding of the causes of livestock abortion. Such information could help to direct interventions that prevent abortion and improve livestock health, ultimately helping to improve food security while reducing the risk of infection for livestock-owners in lower- and middle-income countries.
Regarding the economic impact of livestock abortion, we estimated that the annual national gross loss due to livestock abortions was approximately $263 million, with a net loss of $131 million. This loss is equivalent to the value of about one quarter and one sixth of all juvenile stock value for the gross and net losses in Tanzania, respectively. This represents a substantive financial loss for low-income rural households, and, given that the livestock sector contributes approximately 7.1% to the Tanzania’s GDP (Ministry of Agriculture, 2020), it represents an important economic loss for livestock-dependent countries like Tanzania.
Lankester F, Kibona TJ, Allan KJ, Glanville W De, Buza JJ, Katzer F, et al. Livestock abortion surveillance in Tanzania reveals disease priorities and importance of timely collection of vaginal swab samples for attribution. Elife. 2024;13(RP95296):1–19. DOI: https:// doi. org/ 10. 7554/ eLife. 95296
Clara Akpan, Disease Surveillance: Monitoring livestock pregnancy loss; https://elifesciences.org/articles/98828
Gurmu EB, Bronsvoort B, Cook EAJ, Lankester F, Özkan Ş, Rosenstein PK, et al. Environmental and food security implications of livestock abortions and calf mortality : a case study in Kenya and Tanzania. Front Sustain Food Syst. 2024;(November):1–13. DOI: 10.3389/fsufs.2024.1390047
Semango G, Yoder J, Kibona T, Claxton JR, Buza J, Mmbaga BT, et al. Economic Burden of Livestock Abortions in Northern Tanzania. J Agric Appl Econ [Internet]. 2024 Feb 16;1–21. DOI: 10.1017/aae.2024.6
