Officials close to Cambodia’s investigation into the avian influenza epidemic have questioned the accuracy of the government’s outbreak reports, even as Agriculture Ministry officials claim that the absence of reported cases signals that no new outbreaks of the disease have occurred.
“The ring [of countries] around Cambodia is infected,” Sean Tobin, an epidemiologist with the World Health Organization, said on Tuesday. “That’s why it would surprise me if it has burnt itself out.”
Authorities have delayed releasing test results while waiting to confirm specific strains of influenza, Tobin said.
Withholding information on suspected cases can delay control of the disease, giving the virus time to possibly mutate and spread, he said.
An estimated 40 million birds in neighboring Vietnam have died of the disease or from culls to stop its spread. More than 36 million birds have died in Thailand.
Government teams stationed in each province are assigned to conduct daily, random inspections of local farms and kill birds at farms where the flu is suspected, said Dr Suon Sothoeun, deputy director of the Department of Animal Health and Production.
Although he receives daily updates from the teams, no new kills have been reported in the last two weeks, Suon Sothoeun said Friday.
That, he said, was a sign that the epidemic is dying in Cambodia—not that the teams were not working.
“It does not mean that if there are no cases we’re doing nothing, no,” he said. “There is a report, but there are no new cases, no sick animals.”
On Friday, the most recent figures available stated that the total number of birds in Cambodia that have reportedly died as a result of avian influenza, fowl cholera or Newcastle disease since mid-January was 26,294, Suon Sothoeun said. The number of birds that the teams had killed to halt the spread of the disease was 4,898.
The teams are only killing birds at farms where other birds have died, Suon Sothoeun said, and “do not touch” birds at neighboring farms that appear healthy.
The department has obtained several hundred of thousand dollars worth of protective equipment and disinfectant for this purpose, Suon Sothoeun said, purchased through a trust fund managed by the UN Food and Agriculture Organization.
An official close to the investigation who declined to be named said there was suspicion that provincial-level inspection teams were not conducting investigations.
In addition, the official said, the Agriculture Ministry had been tight-fisted with its findings in the investigation, limiting understanding of where and when outbreaks had taken place.
Blood samples that arrive at the Pasteur Institute in Phnom Penh, where suspected cases are tested, are marked only with an identification number, and no other information on where or when the sample was obtained, said Dr Jean Louis Sarthou, a biologist and epidemiologist at Pasteur.
For confidentiality reasons, Sarthou said he could not provide any more information on the number of samples sent to the institute or the results.
Tobin confirmed that there have often been long delays in the government’s release of test results.
“It’s important for the human health side to know what places are being tested,” he said. “Initially, it wasn’t happening much at all.”