The Eurasian Tree Sparrow, perhaps Cambodia’s most common and widespread wild terrestrial bird, is “highly susceptible” to avian influenza and capable of spreading it on to domesticated birds, according to a new study. The research also raised concerns that the birds could spread the virus to humans during interactions with the birds in Buddhist ceremonies.
“[T]he presence of significant quantities of H5N1 virus on sparrows’ feathers, including infectious particles, would suggest that Merit Release Birds represent a risk for human contamination in countries where avian influenza virus is circulating and where this religious ritual is practiced,” says the study, published earlier this month in the scientific journal PloS ONE and written by researchers from Institut Pasteur, the Ministry of Agriculture, Forestry and Fisheries, and the University of Hong Kong.
Some Buddhists believe that kissing the sparrows before releasing them can bring positive karma or “merit,” according to the study.
While much has been studied concerning the spread of H5N1 among poultry and between the domesticated birds and humans, little research has been conducted on their feral counterparts.
Philippe Buchy, head of the Virology Unit at the Institut Pasteur and one of the study’s authors, said yesterday that the research demonstrated the potential dangers of handling the sparrows. “It’s an at-risk behavior to do this,” he said. “We can have infected birds in our hands and nothing happens, but some people will be very susceptible. We don’t know how many particles it will take to infect.”
Since bird flu was first detected in Cambodia in 2004, there have been 28 poultry outbreaks; 16 people have died. Pointing to an increasing number of cases where domestic birds were handled, Dr. Buchy said it was worth considering the role of sparrows as potential infectors.
“People in Siem Reap [where there was an outbreak] had their poultry in bio-safety cages—no contact with anything. The Battambang outbreak was in a commercial farm—there was bio-safety covers but holes in the nets, and a lot of these small birds were flying around there.”
