Introduction: Fighting the menace of zoonoses

This article is an excerpt from the research magazine “Tackling Global Issues vol.3 Fighting the menace of zoonosis.”  Click here to see the table of contents. For the Japanese translation, click here.

The world has witnessed outbreaks of zoonoses – any disease or infection naturally transmissible from vertebrate animals to humans – as our environment has drastically changed over the years. An explosive increase in the global population has required more farmland to produce food, while the expansion of economic activities has caused deforestation and desertification. Such radical environmental changes have disrupted the ecology and home range of natural reservoirs, eliminating some boundaries between wildlife and human society. Indeed, zoonoses present an existing and future menace to mankind.

Adobe Stock (c) Jo Panuwat D

Animals are natural hosts to bacterial, viral or parasitic agents that do not cause any harm to the reservoirs themselves, but transmit infections to other species of wild and domestic animals – and eventually to humans.

About 60 percent of infectious diseases and almost all emerging ones are zoonoses, according to Hiroshi Kida, one of the world’s top zoonosis experts and Head of Hokkaido University’s Research Center for Zoonosis Control (CZC). Zoonoses include pandemic and avian influenzas, Ebola hemorrhagic fever, acquired immunodeficiency syndrome (AIDS), bovine spongiform encephalopathy (BSE), Lassa fever and yellow fever. About 1 billion cases of illness and millions of deaths occur every year from zoonoses, according to an estimate by the World Health Organization (WHO). In one high-profile case, the 2014-16 Ebola pandemic in Guinea, Liberia and Sierra Leone resulted in about 28,000 people becoming infected and more than 11,000 deaths.

In the most recent outbreak, the novel coronavirus (SARS-CoV-2) , which was first reported from Wuhan, China, on December 31, 2019, and causes Coronavirus Disease 2019 (COVID-19), has infected more than 63 million people around the globe causing nearly 1.5 million deaths as of December 3, 2020, according to the WHO. Chinese officials say the virus first transmitted from animals to humans at a fresh fish market and human-to-human transmission was soon reported, suggesting it is a zoonosis.

“It is impossible to eradicate zoonoses,” Kida said. “Therefore, our mission is to control zoonotic diseases as much as possible through preemptive measures and effective treatments. That’s why it is crucial to identify the natural reservoirs as well as the transmission route of diseases.”

Spearheading comprehensive research on zoonoses

The researchers’ endeavors are in line with the “One Health” concept, which recognizes that human health and animal health are interdependent and bound to the health of our ecosystem. This concept, established in the 2000s, is now embraced by such international organizations as the WHO, the World Organization for Animal Health (OIE), the World Bank, UNICEF and the Food and Agriculture Organization (FAO).

Just as the concept was starting to become accepted, Hokkaido University established the CZC in 2005 as a unique research and educational institution. The center has adopted a unique interdisciplinary approach and brings together experts in wide-ranging fields such as microbiology, virology, immunology, pathology and information science to conduct comprehensive research. “Zoonoses cannot be studied solely with expertise in medicine or veterinary medicine,” Kida said. “It is a new academic area that does not fit in any conventional field.” Indeed, the center’s research topics include isolating and detecting new viruses; developing easy-to-use, rapid and accurate diagnosis kits; developing anti-viral drugs to treat zoonoses; and even playing a key role as the OIE Reference Laboratory for Avian Influenza. “Everything we do at the center must help us achieve the goal of controlling zoonoses under the concept of One Health,” Kida said.

“Everything we do at the center must help us achieve the goal of controlling zoonoses under the concept of One Health.”

Click here to see the table of contents.