Why do many diseases originate in Asia and Africa?

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

Although it has always been in human history, the disease now seems to be on the rise. In the past 20 years, the corona virus alone has caused three serious outbreaks worldwide. More noticeable is the shorter time between epidemics. According to Suresh V Kuchipudi, deputy director of the Laboratory of Animal Diagnostics at the University of Pennsylvania, a bacteriologist specializing in zoonotic viruses, most diseases have at least one thing in common. Asia or Africa for many reasons.

Cattle ranch in Zambia.(Photo: AFP).

Booming population and changing urban landscape

Population movement is one of the reasons why more and more diseases are coming from Asia or Africa. Rapid urbanization is taking place throughout 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 during the first decade of the 21st century.

Such large-scale migration causes forest land to be destroyed to make way for residential areas. Wildlife is forced to come close to cities and towns, clashing with pets and people. Wildlife often carries the virus in the body. For example, bats contain hundreds of viruses. As a result, viruses transmitted from one species to another can infect humans.

Urbanization becomes a vicious cycle . Increasing numbers of people, deforestation, expanding settlements and loss of natural habitats make predators extinct, including many species that eat rats. The number of exploding mice has the potential to cause an infectious disease outbreak. A large part of East Africa's population still lives in rural areas. Therefore, urbanization will continue in the coming decades.

Subsistence agriculture and animal markets

The tropics have high biodiversity, and also store large numbers of pathogens, increasing the likelihood of new pathogens. In both Asia and Africa, many households depend on subsistence agriculture and the source of meat is cattle and poultry. Disease control, feed management and animal housing are extremely limited. Cattle, poultry, and pigs can carry diseases and often come in close contact with one another, with wildlife and humans.

Not only farms, live animal markets are very popular on two continents with crowded environments and close distances between species. This also plays an important role in allowing pathogens to emerge and spread from one species to another.

Wildlife hunting and slaughtering are especially common in sub-Saharan Africa. These activities not only threaten mammals and change ecosystems, but also pave the way for key infection of zoonotic viruses. Similarly, Asia is a huge market for traditional medicine products. Tigers, bears, pangolins, and many other species are poached for body parts used in drug preparation, contributing to increased interaction between humans and animals.

Thousands of viruses continue to evolve . The risk of an emerging disease in Asia or Africa is only a matter of time. While it is difficult to accurately predict the sequence of events that lead to diseases, we can certainly reduce risks by developing measures to minimize human impact on the ecosystem, prevent deforestation and reduce contact between people and animals.