Avian, human flu coinfection reported in Indonesian teenager
- ------------------------------------------------------------
Date : Mon 17 Mar 2008
Source: CIDRAP News [edited]
<http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/news/mar1708coinfect.html>
An Indonesian teenager has been brought forward as a case of simultaneous infection with seasonal and avian strains of influenza
- -- a possibility that health planners have long warned could give rise to a pandemic flu strain. In a paper presented today [Mon 17 Mar 2008] at the International Conference on Emerging Infectious Diseases, Vivi Setiawaty of Indonesia's Center for Biomedical and Pharmaceutical Research and Development described the case of a 16-year-old girl who was tested for flu in Jakarta in April 2007 under a flu-surveillance system established in 2005 by the Indonesian Ministry of Health. The girl, who had been experiencing flu symptoms for several days, was only mildly ill, with a 100.5 DEGF fever, sore throat, cough, headache, and body aches, but no difficulty breathing and no signs of pneumonia. (Case reports of H5N1 patients in countries such as Thailand have described more dramatic clinical
presentations.)
Throat and nasal-swab samples that were taken on the 6th day of her symptoms tested positive by reverse-transcriptase polymerase chain reaction (RT-PCR) for both avian influenza H5N1 and the seasonal flu strain H3N2 at the Indonesian National Institute of Health Research and Development. Serology test results were less clear. Antibody titers from serum samples taken the 6th day provided a weak indication of H5N1 infection (titer of 1:10) but were negative for H3N2; convalescent sera, on the other hand, gave a strong indication of H3N2 infection (titer of 1:640) but were negative for H5N1.
The test results were confirmed by the Eijkman Institute for Molecular Biology in Jakarta, an arm of the Indonesian Ministry of Research and Technology, according to the paper. The girl's case fell within the period when the Indonesian government was not sharing flu isolates with the international laboratory system maintained by the World Health Organization, and there was no indication whether her isolates were evaluated outside the country.
"This is the 1st case-report of a human with both influenza A/H5N1 and H3N2 co-infection," the paper states. "Such infections are of great concern due to the possibility of genetic reassortment leading to the emergence of a H5N1 strain that is more easily transmitted human to human, and emphasizes the importance of advanced laboratory-based surveillance in geographic regions where both human and avian influenza viruses are co-circulating."
[Byline: Maryn McKenna]
- --
Communicated by:
ProMED-mail
<promed@promedmail.org>
[The reassuring outcome of these observations is that co-infection of a human patient by seasonal and avian strains of influenza A virus is not sufficient to yield recombinants or genome reassortants that might evolve into a pandemic strain of influenza A virus. However the relevance of these data is doubtful. The RT-PCR assays indicated that the patient was co-infected by an H3N2 human influenza virus and H5N1 avian influenza virus. However, the patient displayed only mild signs and symptoms of infection, which together with the negative H5N1 convalescent serum titre suggest that the avian virus did not multiply extensively (or at all) in the human host. Few people have developed severe H5N1 virus infections despite the very large number of people exposed to infection, suggesting a significant genetic component in susceptibility. Until co-infection occurs in such a genetically susceptible individual, the level of risk associated with co-infection will remain undefined. - Mod.CP]
[The risk of unintentional cross-contamination in RT-PCR tests is high. It would be desirable to have confirmation of these results from an international reference lab. - Mod.JW] |
