A WHO (World Health Organization) team would soon be reaching Pakistan to investigate eight reported cases of bird flu in people living near the Afghan border in the country.
The team of experts would establish whether the disease is spreading, and whether the cases were caused by human-to-human transmission.
For this, it will track down, treat and test people who came into contact with the infected cases. Monitoring for cases in the area will be key to establishing whether the virus has become more virulent or shows signs of spreading.
According to a report in Nature News, though Pakistan has had repeated outbreaks of avian flu in poultry over the past two years, the latest cases possibly started in mid-November, when five family members fell ill in Abbottabad, north of Islamabad. Out of the five members, two have already died due to the disease.
In December, a man and his niece in the same town were found to have the H5N1 virus (that causes bird flu). They are thought to have worked on the same farm as the first family affected. Another man was found to have H5N1 in a nearby town some distance from there. Another case is suspected but not yet confirmed, which would bring the cluster to nine.
These cases are a cause of worry, the journal notes, because it involves the biggest batch of closely related cases since a cluster of eight infected people was reported in Indonesia in May 2006.
The latest outbreak has also coerced Pakistani health authorities to pore over hospital records from the past few months to see, retrospectively, whether there has been any upsurge in the incidence of respiratory illnesses, the report adds.
"Human-to-human transmission cannot be ruled out, as it has occurred on a limited basis on several occasions in the past," the journal quoted Gregory Hartl, a spokesman for WHO, as saying. "Tests of 40 people who have had contact with the patients have so far all turned up negative. Genetic sequencing will help to pin down the mode of transmission and whether any important genetic changes have occurred in the virus," he said.
The strategy for the WHO team calls for early diagnosis of cases, in the hope that blanket treatment with antivirals will stamp out an emerging pandemic before it spirals out of control. Computer models suggest that for this to have any chance of succeeding, WHO would have a window of three weeks for this diagnosis at most.
Cases of bird flu continue to occur worldwide, mostly in Indonesia, and this is the colder time of year when flu is expected to hit hardest in the northern hemisphere.