Lingering bird flu infections in recovering patients could be missed by laboratory tests, leaving the patients vulnerable and a potential source of infection in the community, a microbiologist warned yesterday.
The warning came from the deputy director of Chinese University's Stanley Ho Centre for Emerging Infectious Diseases, Professor Paul Chan Kay-sheung, who said the tests could miss the H5 virus as the viral load - a measure of the severity of a viral infection - dropped.
He said Hong Kong should not lower its vigilance against the H5 virus even after an 11-year-old boy and his 48-year-old mother suspected of having bird flu both tested negative for the virus.
'The [viral] load of H5 in humans is usually not as heavy as human flu, making it more difficult to detect, especially for patients who show only mild symptoms or have their symptoms subsiding,' he said.
'Therefore, the health authorities should continue their investigation to ensure the pair did not contract avian flu.'
He said that testing their antibodies after two weeks would be a more accurate method.