Prospective cohort study reveals unexpected aetiologies of livestock abortion in northern Tanzania

Livestock abortion is an important cause of productivity losses worldwide and many infectious causes of abortion are zoonotic pathogens that impact on human health. Little is known about the relative importance of infectious causes of livestock abortion in Africa, including in subsistence farming communities that are critically dependent on livestock for food, income, and wellbeing. We conducted a prospective cohort study of livestock abortion, supported by cross-sectional serosurveillance, to determine aetiologies of livestock abortions in livestock in Tanzania. This approach generated several important findings including detection of a Rift Valley fever virus outbreak in cattle; high prevalence of C. burnetii infection in livestock; and the first report of Neospora caninum, Toxoplasma gondii, and pestiviruses associated with livestock abortion in Tanzania. Our approach provides a model for abortion surveillance in resource-limited settings. Our findings add substantially to current knowledge in sub-Saharan Africa, providing important evidence from which to prioritise disease interventions.

Automated summary

Livestock abortion is a significant factor contributing to productivity losses globally, and many of the infectious causes of abortion are zoonotic pathogens that affect human health. This study conducted in Tanzania investigated the causes of livestock abortion and identified several important findings, including the outbreak of Rift Valley fever virus in cattle and the presence of various infections associated with livestock abortion. These findings not only provide a model for abortion surveillance in resource-limited settings, but also contribute to the current knowledge in sub-Saharan Africa and help prioritize disease interventions.