Economic factors contributing to the outbreaks of indigenous major infectious diseases from domestic animals in China between 2000 and 2016: a multicountry study

Infectious diseases remain a leading cause of morbidity and mortality in China. After entering the 21st century, some major outbreaks of infectious diseases in human beings have occurred in China, but little evidence is available on the disease burden because of economic factors. We investigated the burden of infectious diseases on the basis of economic factors in China and made comparisons with data from the UK and the USA. We investigated all the independent infectious disease outbreaks in mainland China, the UK, and the USA between 2000 and 2016 (appendix) using the WHO Disease Outbreak News, and we extracted Annual Producer Price Indices (PPI) for livestock meat from the Food and Agriculture Organization Statistics Database. We investigated the economic circumstances under which each independent outbreak of indigenous infectious disease in human beings originating from domestic animals had occurred. Between 2000 and 2016, 13 independent infectious disease outbreaks in human beings were recorded in the Chinese Disease Outbreak News, and seven of them were indigenous (not imported). Among these seven outbreaks, four outbreaks were of domestic-animal origin (H5N1, H7N9, and H5N6 avian influenza, and human Streptococcus suis infections). Before these four outbreaks, the corresponding PPI for domestic poultry or pig meat had increased sharply (at least on average more than 10% rise in PPI per year) and reached an unprecedented high price. However, in the same period, among the 11 independent outbreaks in human beings in the UK that were recorded in Disease Outbreak News, only one (H7N2 avian influenza, in 2007) was of indigenous domestic-animal origin, whereas the corresponding PPI for poultry meat in the UK was steady before the outbreak, unlike in China. Furthermore, between 2000 and 2016, none of the 20 independent outbreaks in the USA recorded in Disease Outbreak News originated from domestic animals. By comparison with the UK and the USA, China has had more and worse indigenous outbreaks in human beings, the sources of which were domestic animals. China has a highly diverse animal production throughout the country, as characterised by the diversity of farm sizes, different ways of farm management, and discrepant capabilities of disease prevention and control, along with large backyard feeding operations in rural areas and city suburbs. A sharp increase in PPI for domestic animal meat reflects a steep increase in the production costs. So, before the fou