Why region should be concerned about 320,000 unknown viruses in mammals

There are more than 320,000 viruses in mammals alone that are yet to be discovered by scientists.

The finding by a group of scientists from Europe and America should be a major concern for East African countries, which are rich in wildlife diversity, and also have a large population of pastoralists who depend on livestock for their livelihood.

The researchers noted that the majority of these viruses originate in wildlife, and are the main cause of zoonoses (diseases transmitted from animals to human beings), and are responsible for the deaths of thousands of people in the world every year.

“These diseases are largely viral, for example, severe acute respiratory syndrome (SARS) and Nipah virus, and represent a significant global health threat,” the study published in the latest mBio Journal, says. The journal publishes the best research on microbiology and allied fields.

The region has already endured some of the worst outbreaks of viral diseases like swine flu and Ebola.

SPORADIC OUTBREAKS

Uganda, for example, has continued to report multiple outbreaks of Ebola, with the latest one occurring last year, killing at least 10 people.

Kenya, on the other hand, reported its first case of swine flu) in 2009, after a British medical student on tour of the country tested positive to the new virus strain.

The disease affected more than 18 people before it was brought under control.

A recent study by the International Livestock Research Institute (ILRI) on zoonoses hotspots put Tanzania on top of the list of countries in East Africa with the highest number of deaths caused by diseases transmissible between animals and humans.

The study also cited Ethiopia and DR Congo as countries having a high endemic zoonoses prevalence.

“Endemic zoonoses are present in many places and are responsible for the majority of human cases of illness (we estimate 99.9 per cent) and deaths (we estimate 96 per cent), as well as the greatest reduction in livestock production,” says the study titled Mapping of Poverty and Likely Zoonoses Hotspots.

Endemic zoonoses, ILRI said, may occur as outbreaks in remote regions or when triggered by events such as climate changes, flooding, waning immunity or concomitant hunger or disease.

INCREASING DISEASE BURDEN

The study also mentioned Kenya, Uganda and Sudan as countries whose zoonoses disease burden is on the increase. ILRI estimated that around 60 per cent of all human diseases and around 75 per cent of emerging infectious diseases are zoonotic.

“From cyst-causing tapeworms to avian flu, zoonoses present a major threat to human and animal health,” Delia Grace, the lead study author who is also a veterinary epidemiologist and food safety expert with ILRI said.

The scientists from America and Europe on the other hand believe that research on the 320,000 unknown viruses will help the world stay a step ahead of zoonotic diseases.

The scientists estimate it will cost approximately $6.3 billion (or $1.4 billion for 85 per cent of the total diversity) to discover such viruses, which, they argued, if annualised over a 10-year study time frame would represent a small fraction of the cost of many pandemic zoonoses.

“The projected $1.4 billion cost of discovering 85 per cent of the estimated mammalian viral diversity is far less than the economic impact of even a single pandemic like SARS, which has been estimated at $16 billion,” the scientists said.

The article first appeared in The East African