H5N1 influenza, also known as avian influenza, is considered a major global threat to human health, with high fatality rates.
While little had been known about the specific effects of H5N1 on organs and cells targeted by the virus, researchers at Beijing University, Columbia University Mailman School of Public Health, and SUNY Downstate report in the September 29, 2007 issue of the Lancet detailed studies of human H5N1 victims that shed light on the anatomic distribution of the virus and its pathogenesis. Using a combination of molecular and protein labeling techniques, the authors found that H5N1 is present in the gastrointestinal tract and immune and central nervous systems, as well as the respiratory tract. In one patient, virus was transmitted across the placenta to the fetus.
The newly obtained data are important in the clinical, pathological, and epidemiological investigations of human H5N1 infection, and have widespread implications for public-health and healthcare providers. Although there has been considerable progress in studying the virus itself, and in developing surveillance networks, diagnostic tests, drugs and vaccines, only limited information has been obtained concerning the mechanisms by which H5N1 causes disease.