Why do many plagues originate in Asia and Africa?

Urbanization, poaching and animal markets all facilitate the transmission of the virus to humans.

Although always appearing in human history, today epidemics seem to be on the rise. Over the past 20 years, coronavirus alone has caused three severe outbreaks worldwide. Notably, the time between outbreaks is getting shorter and shorter. According to Suresh V Kuchipudi, deputy director of the Animal Diagnostic Laboratory at the University of Pennsylvania, a microbiologist specializing in the study of viruses transmitted from animals to humans, most epidemics have at least one thing in common: they originate in viruses. Asia or Africa for a variety of reasons.

Why do many plagues originate in Asia and Africa?
Cattle farm in Zambia. (Photo: AFP).

Population shifts are one of the reasons why more and more diseases are originating in Asia or Africa. Rapid urbanization is taking place across Asia and the Pacific region, where 60% of the world’s population is concentrated. According to the World Bank, nearly 200 million people moved to urban areas in East Asia in the first decade of the 21st century.

Migration on such a large scale causes forest land to be destroyed to make way for residential areas. Wild animals are forced to approach cities and towns, clashing with livestock and people. Wild animals often carry viruses in their bodies. For example, bats contain hundreds of viruses. As a result, viruses that pass from one species to another can infect humans.

Urbanization becomes a vicious circle . More people, deforestation, expansion of settlements and loss of natural habitats have led to the extinction of predators, including many rat-eating species. The exploding rat population brings with it the risk of an outbreak of infectious diseases. A large part of East Africa’s population still lives in rural areas. Therefore, urbanization will continue in the coming decades.

The tropics have a high ecological diversity, and also store large amounts of pathogens, increasing the likelihood of new pathogens appearing. In both Asia and Africa, many households depend on subsistence agriculture and their meat sources are livestock and poultry. Disease control, feed management and animal housing are extremely limited. Cattle, poultry and pigs can carry diseases and are in frequent close contact with each other, wildlife and people.

Not only farm, live animal market is very popular in two continents with crowded environment and close distance between species. This also plays an important role in allowing pathogens to emerge and spread from one species to another.

Hunting and butchering of wild animals for meat is particularly common in sub-Saharan Africa. These activities not only threaten mammal species and alter ecosystems, but also open up key routes of infection for zoonotic viruses. Similarly, Asia is a huge market for traditional medicine products. Tigers, bears, pangolins and many other species are poached for their body parts used in medicine, contributing to increased human-animal interactions.

Thousands of viruses continue to evolve . The risk of a new epidemic emerging in Asia or Africa is only a matter of time. While it is difficult to predict the exact sequence of events that lead to disease, we can certainly reduce the risk by developing measures to reduce human impact on ecosystems, prevent deforestation, and prevent deforestation. reduce human-animal contact.