Turkish Bird-Flu Outbreak Puzzling Experts

An IHT article today contains some interesting developments on the avian-flu outbreak in Turkey -- 1) a sudden appearance of cases whose method of transmission is baffling health experts, and 2) people who test positive but not (yet) getting sick:

Two young brothers, aged 4 and 5, are being closely watched at the gleaming new Kecioren Hospital here [in Ankara], a police car at the entrance guarding a potential scientific treasure. Though both boys have tested positive for the H5N1 virus after contact with sick birds, neither has any symptoms of the frequently deadly disease.

Doctors are unsure if - for the first time - they are seeing human bird flu in its earliest stages, or if they are discovering that infection with the H5N1 virus does not necessarily lead to illness.

In any case, the unusual cluster of five cases detected in this capital city over the past four days is challenging some doctors' assumptions about bird flu and giving them new insights into how the virus spreads and causes disease.

These cases have raised the possibility that human bird flu is not as deadly as has been thought, and that there may be many mild cases that have gone unreported.