H5N1 Family Clusters and Limited Human-to-Human Transmission Found in China and Pakistan
By Michelle Cantu, April 11, 2008
On April 8, 2008, the Lancet
published results from investigations by Chinese health officials into the 2007 H5N1 influenza family cluster in Jiangsu Province, China. In this cluster, possible human-to-human transmission of the H5N1 virus occurred between two members of a family, who both tested positive for H5N1 virus. The index case, a 24 year old male, is thought to have contracted the virus at a live poultry market; however, the second case (the man’s 52 year old father) had no contact with infected poultry. His only exposure to the virus appears to be through contact with his ill son. According to the article, it cannot be ruled out that the father's exposure to the virus occurred through other means. However, genomic sequencing has shown that both cases were "identical except for one…nucleotide substitution," and that “all [virus] genes were entirely of avian origin.”1
During the investigation, 91 close contacts of one or both cases consented to serological testing and all were negative for H5N1 antibodies. The son died five days following hospitalization and on the same day that H5N1 was confirmed by RT-PCR. According to the Lancet
article, the father had provided unprotected bedside care for prolonged periods of time and did not wear personal protective equipment until after the confirmation of H5N1. The father received oseltamivir and later two plasma transfusions from a clinical trial patient that had been vaccinated for H5N1
- Wang H, Feng Z, Shu Y, et al. Probable limited person-to-person transmission of highly pathogenic avian influenza A (H5N1) virus in China. The Lancet. Published online April 8, 2008. http://www.thelancet.com/journals/la...04936/abstract . Accessed April 10, 2008.
- Father “caught bird flu from son’. BBC News. April 8, 2008. http://news.bbc.co.uk/2/hi/health/7335986.stm. Accessed April 10, 2008.
- World Health Organization. Avian influenza—situation in Pakistan—update 2. April 3, 2008. http://www.who.int/csr/don/2008_04_03/en/index.html. Accessed April 10, 2008.