20.04.2012

BMC Infectious Diseases

A study of blood samples from 306 poultry workers in a Chinese province that has had H5N1 avian influenza outbreaks and two human cases found that 8 workers (2.6%) had serologic evidence of H5N1 infection.

This study was designed to better understand the real infection rate of H5N1. It investigated the potential for the zoonotic spread to humans and evaluates the risk

factors associated with subclinical infection among poultry workers in Jiangsu, China.

Since 2003 to 06 Jan 2012, the number of laboratory confirmed human cases of infection with avian influenza in China was 41 and 27 were fatal. However, the official estimate of the H5N1 case-fatality rate has been described by some as an over estimation since there may be numerous undetected asymptomatic/mild cases of H5N1 infection. This study was conducted to better understand the real infection rate and evaluate the potential risk factors for the zoonotic spread of H5N1 viruses to humans.
They found the rate of seropositive samples varied from 0 to 5.4% among three counties, but did not specify individual titers or history of exposure to H5N1 viruses. They also reported that, of the two strains used in testing, no samples were positive for a 2010 H5N1 strain; all positive samples were for a 2005 H1N1 strain. The authors conclude that avian-to-human transmission of influenza H5N1 virus remains low in China.