Monkeys in Asia found to have viruses from humans

Washington: Monkeys found in Asia harbour diverse viruses which are known to cause infectious gastroenteritis or diarrhoea in humans, a new study of nearly 900 nonhuman primates in Bangladesh and Cambodia has found. The research is the first to show evidence of human astroviruses in animals, and among the earliest to demonstrate that astroviruses can move between mammalian species, researchers said.

"If you are a bat, you have bat astrovirus, but if you are a monkey, you could have everything," said Lisa Jones-Engel, from the University of Washington National Primate Research Primate Centre and a co-author of the study. Astroviruses from a number of species, including human, bovine, bird, cow and dog, were detected in monkeys. This "challenges the paradigm that AstV (astrovirus) infection is species-specific," the researchers said. It is still unknown whether these viruses are two-way and can be transmitted to humans. They did find evidence that, in monkeys, two species of astrovirus recombined.

Knowing that nonhuman primates can harbour diverse astroviruses - including novel, recombinant viruses that may be pathogenic and more efficiently transmitted - highlights the importance of continued monitoring, the researchers said. This is particularly true in countries such as Bangladesh and Cambodia, where macaques and humans live side-by-side. Astroviruses are most commonly associated with diarrhoea. They can also cause clinical diseases such as nephritis, hepatitis and encephalitis.

Astroviruses also can be asymptomatic - that is the

patient is a carrier for the disease or infection but experiences no symptom - depending on the species, the researchers said. Currently, the only treatment is oral rehydration. In the study of 879 samples of primate feces, 68 (7.7 per cent) were positive for astroviruses. The majority of the positive samples (72 per cent) were 79-100 per cent similar to astroviruses associated with human infections; 23.5 per cent of the samples were similar to mammalian astroviruses isolated from diverse animal hosts including dogs, pigs and sheep.

Slightly more than 4 per cent of the positive samples were associated with avian astroviruses. The team, including researchers from St Jude Children's Research Hospital, also collected blood samples, which confirmed that more than 25 per cent of the monkeys had been infected with human astroviruses. Whether the monkeys were getting sick from these viruses is unknown, researchers said. The study was published in the journal PLOS Pathogens.