Fifteen Confirmed H5N1 Cases in Indonesia
Recombinomics Commentary
May 17, 2007
WHO can now confirm 15 additional cases, including 13 deaths of human infection with H5N1 avian influenza that occurred in Indonesia from the end of January 2007 up to the present…
Seven of these cases had exposure to sick or dead poultry; the source of infection is unknown for eight cases.
The above comments from the latest WHO update on Indonesia describe the cases that were confirmed during negotiations between WHO and Indonesia regarding vaccine development based on Indonesian sequences.
Although the number of confirmed cases in the past several months is not a surprise, the number of cases that have no known source of infection create continuing concern. Matching human cases with infected poultry has been a problem in Indonesia, dating back to the first confirmed cases in July, 2005. The cluster involved three fatal infections of a family of a government employee who had no known connection to poultry. Testing of birds and swine in the region failed to identify a likely source, and similar problems have been associated with multiple confirmed H5N1 cases in Indonesia.
Similarly, initial sequences from H5N1 poultry also failed to match the sequences from patients. Although more matches have been found in recent poultry isolates, the H5N1 evolution in poultry appears to lag behind the evolution in patients, suggesting an alternate reservoir.
Sequences from alternate sources have not been made public. Media reports describe H5N1 positive cats, as well as swine. Moreover, there have been reports of expanded testing of wild birds. However, these results have not been made public. To date there has only been one cat sequence disclosed, and it did match the human sequences. Early isolates from swine did not match, although recent isolates have not been made public. Detection of H5N1 in wild birds has also not been described.
Media reports also raise questions on the sequencing of the 15 recently described patients. Some reports indicate only 3 samples have been sent for sequencing outside of Indonesia. The samples are at the WHO reference lab in Tokyo. Previously, human samples were sent to WHO reference labs in Hong Kong and Atlanta for confirmation and sequencing. A WHO reference lab in Australia has also been involved in sequencing poultry isolates.
However, in spite of the involvement of multiple WHO reference labs, the situation in Indonesia remains murky.
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