How Does the Bird Flu Virus Attack the Human Body?

Bird flue virus is regarded as a major global threat to human health: H5N1 has severely affected the poultry industry in many countries and even if it has killed a little more than 200 human victims, the death rates are high. But fear comes especially from a possible mutation or hybridization with common human flu virus: it could provoke a global pandemic as we still do not have an efficient cure against the deadly virus.

A new research could solve the problem, coming with specific effects of H5N1 on organs and cells, anatomic distribution and pathogenesis. The team at Beijing University, Columbia University Mailman School of Public Health and SUNY Downstate combined molecular and protein labeling techniques, discovering that H5N1 is located in the gastrointestinal tract and immune and central nervous systems, besides the respiratory tract. In one case, the virus passed the placenta into the fetus.

Even if the investigation of the virus' structure has come with positive results, only scarce data was available about the mechanisms causing the disease. H5N1 infections appeared initially to install just to the lungs, but later studies pointed that H5N1 could spread beyond the lungs.

The lung is severely harmed, containing a disproportionate number of infected cells, included immune macrophages and T-cells. The new study points that lung damage is not the result of the virus replication alone; indirect effects, like soluble factors such as cytokine and chemokines, are important.

"This is the first major paper from the Beijing Infectious Disease Center, established in the aftermath of SARS by Beijing University, the Chinese Ministry of Science and Technology (the CDC of China), and the Mailman School of Public Health. The work helps us to understand H5N1's high fatality rate, as well as serving as model for global collaboration in the field of emerging infectious diseases," said senior author Dr. W. Ian Lipkin, director of the Center for Infection and Immunity at Columbia University Mailman School of Public Health and professor of Epidemiology, Neurology and Pathology at Columbia.