Jan 11, 2006 (CIDRAP News) – A World Health Organization (WHO) official says two Turkish brothers who have tested positive for H5N1 avian influenza were not sick, potentially offering scientists a rare opportunity to learn more about how the virus affects humans, according to news reports.
The two boys had played with dead birds they found near their home in the town of Beypazari, prompting their anxious parents to have them tested for the virus, according to a Reuters report published today.
"This is a very interesting case. They have still shown no symptoms of the virus and yet have tested positive," Dr. Guenael Rodier, head of a WHO team in Turkey, told Reuters.
"We hope to study this case carefully," he added. "This is an opportunity to learn about the disease."
The two boys tested positive on Jan 8, according to Reuters. They are among 15 Turks who have tested positive in Turkish labs in little more than a week. Reports have not specified what kind of test was used in the boys' cases.
The WHO has officially recognized only four of the Turkish cases so far, following confirmation by reference laboratories outside Turkey. However, the agency has praised the quality of testing done by Turkey's national influenza lab and has said that the other cases are likely to be confirmed by further tests.
The two boys' cases could help answer one of the pressing questions about H5N1: whether, or how often, it infects people without causing serious illness.
Nearly all of the 147 human cases registered by the WHO since late 2003 have been severe, and 78 patients have died, a fatality rate of 53%. But some suspect that the confirmed cases may be heavily outnumbered by mild and asymptomatic cases that have gone undetected.
So far, no one has published any large-scale blood-testing, or serologic, surveys to assess how many people in bird flu–affected areas carry antibodies to H5N1. If many people do, it would suggest they had infections that went undiagnosed.
The two symptomless boys were being observed in Kecioren Hospital in Ankara, the Turkish capital, the International Herald Tribune reported yesterday. A Canadian Press (CP) report yesterday said doctors began treating the boys, aged 4 and 5, with oseltamivir (Tamiflu) as soon as they tested positive.
Two other brothers from the Ankara area tested positive for H5N1 though they had only mild symptoms, according to the Herald Tribune. They too were under observation in an Ankara hospital. They had touched gloves that had been used to dispose of a dead duck.
The atypical human cases are the not the only reason the Turkish situation offers a good opportunity to learn more about the H5N1 virus, according to news reports.
The CP report said some of the Turkish cases were detected early, permitting doctors to assess how oseltamivir treatment affects the disease when started early. In addition, Turkish authorities have shown a willingness to cooperate with international scientists, the story said.
"It is likely that the Turkish outbreaks will be more accessible to flu scientists than those cases in Vietnam and Thailand, where it's been very difficult to penetrate," virologist John Wood of Britain's National Institute for Biological Standards and Control was quoted as saying.
Rodier said Turkish scientists are already making plans for serologic studies, according to the CP report.
Turkish Health Minister Recep Akdag today described the condition of all 13 surviving H5N1 patients as good, according to the Reuters report.