18 June 2007
Indonesia reports 100th patient with H5N1 avian flu (80% mortality), asymptomatic infected chickens, and possible mutation facilitating poultry-to-human spread
On June 15th the World Health Organization (WHO) posted on their avian flu website that the Indonesian Ministry of Health reported the death on June 12th of a 26 year-old man with laboratory-confirmed H5N1 avian influenza virus infection. This young man was from Riau province. He is the 100th lab-confirmed patient with H5N1 virus infection in Indonesia, of whom 80 have died. Globally, there have been 311 lab-confirmed human infections and 191 deaths in 12 nations.
While this 26 year-old man did have documented exposure to ill and dead poultry the Jakarta Post newspaper (online at www.thejakartapost.com) carried an Associated Press article on June 17 titled “Bird flu-infected chickens in Indonesia showing no symptoms”. The article quoted the Agriculture Ministry director of animal health, Musni Suatmodjo: “Chickens are testing positive for the H5N1 virus, but they are staying health”.
Previously, most chickens with H5N1 avian flu virus infection became ill and often died rapidly, facilitating surveillance efforts to identify and cull infected flocks and identify persons exposed to these infected poultry.
While ducks have been noted in the past to be able to have asymptomatic H5N1 virus infection yet still shed the virus and be infectious, this has not been the case with the majority of chickens to date. Such a development could make animal health and human public health efforts to control the spread of H5N1 virus much more difficult.
In addition, on June 6th Reuters carried an article from Jakarta quoting the head of Indonesia’s commission on bird flu, Bayu Krisnamurthi, stating that preliminary data suggested that the H5N1 virus might be able to spread more easily from poultry to humans: “In the past it took exposure of high intensity and density to the virus to get infected. There are now suspicions, early indications that this has become easier”.
A microbiologist at the bird flu commission, Wayan Teguh Wibawan, was also quoted by Reuters explaining that: “Virus samples from poultry cases have increasingly shown a similarity in their amino acid structures to virus samples extracted from humans…This makes it easier for the virus to attach to human receptors”.
Such information that the H5N1 virus might be mutating in a functionally important manner that facilitates spread of the virus from poultry to humans is very important. Analyses of these latest H5N1 virus isolates have not yet been reported from any laboratories outside of Indonesia.
It should be noted that both Indonesian officials quoted by Reuters emphasized appropriately that these data are only preliminary. Hopefully, independent analyses will be performed and made public soon, given the potential importance of such findings for control efforts in both the animal and human public health domains.
Daniel R. Lucey, MD, MPH
Director, Center for Biological Counterterrorism & Emerging Infectious Diseases
EROne Institute, Washington Hospital Center Emergency Medicine Department
Adjunct Professor, Department of Microbiology and Immunology
Georgetown University Medical Center, Washington, DC
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