Unexpected Consequences

What lessons should the general public take from the pandemic and veterinary public health? Dr. Kelly: Public health measures, such as social distancing, wearing masks, and hand washing, are remarkably effective in reducing transmission of the SARS-CoV-2 virus. The design, production and manufacture of COVID-19 vaccines is nothing short of miraculous. The scientists that developed those vaccines should be given Nobel Prizes in medicine. • By: Ethan Brightbill Photo: Bronson Teichert

The theme of this year’s Utah One Health Symposium has been “Unexpected Consequences” which had me thinking about some of the unusual consequences of diseases, zoonotic and other, including historical diseases and very recent ones. We are all living in the midst of the COVID-19 pandemic and we have all heard about some of the unexpected positive and negative consequences of widespread quarantine. A much older example of unexpected consequences is a disease of cattle called rinderpest that has actually been eradicated and is not even a zoonotic disease. However, it had profound public health implications in Africa. Rinderpest, a viral disease of cattle and wild ungulates, such as wildebeest, was introduced to Africa by cattle from India in 1889. The cattle were completely naïve immunologically having never been exposed to the virus, and this disease (also called cattle plague) killed approximately 90% of the cattle in central Africa as well as countless buffalo and wildebeest. The Maasai people of Tanzania relied on their cattle for meat and milk. Cattle were their livelihood. With most of the cattle dead, there was mass starvation and two-thirds of the Maasai in Tanzania died. There are historical reports of hyenas dragging off weakened villagers. Because of greatly reduced cattle and wild ungulate populations, the growth of vegetation increased leading to greater numbers of tsetse flies. Tsetse flies are vectors for a disease of humans called sleeping sickness (trypanosomiasis). The foot and mouth disease outbreak in the UK in 2001 is another example of an animal disease having farreaching consequences for human health even though it is not a zoonotic disease. Foot and mouth disease is a highly contagious viral disease of cattle, sheep, goats, pigs, and other cloven-hooved animals. Countries that diagnose it are required to notify the World Organization for Animal Health (OIE) within 24 hours of the first diagnosed case. In 2001, there was a large outbreak in Britain. The cause was likely the feeding pigs improperly treated waste food and the disease rapidly spread to sheep and cattle. The OIE was notified as is required and within 24 hours the EU banned imports from the UK. Shortly thereafter, the United States and Canada banned meat imports from the EU. In this outbreak, vaccinations were not used. Instead, animal movement was restricted and there were mass depopulations of exposed farm animals and those within a 3 km radius of affected farms. Huge numbers of carcasses were incinerated. So, as well as the expected economic and trade consequences of the disease, there were unexpected and tragic mental health consequences. The mass euthanasia and burning of carcasses had a huge toll on people’s emotional health. An increased number of farmers dying by suicide was blamed on the FMD outbreak. As Mort et al. *stated in their paper on the psychological effects of the 2001 epidemic, “the disease epidemic was a human tragedy, not just an animal one.” • By: Dr. Jane Kelly, DVM, MS, MPH, DACVPM, DACVM

*Find the paper at: tinyurl.com/MortFootandMouth