(Hong Kong, 7 December 2004) A series of rapid diagnostic kits for detecting infection of H5N1 influenza virus has been successfully developed recently, through joint efforts between Shantou University Medical College/University of Hong Kong Joint Influenza Research Center and the Medical Molecular Virology Research Center, Xiamen University. The Joint Influenza Research Center was established in 2001 by Shantou University and The University of Hong Kong with the support of the Li Ka-shing Foundation.
Prior to the development of the rapid diagnostic kits, it would take scientists three to five days and sometimes more than one week to confirm H5N1 infection by virus isolation or other techniques. As influenza virus could be transmitted rapidly from individuals to individuals within animal or human populations, it is critical to control the disease at the very beginning of an outbreak. The rapid diagnostic kits make the early diagnosis possible and efficient. The three universities have worked together since April 2004 with the goal of developing these kits before another major H5N1 influenza outbreak in the coming winter.
The new diagnostic kits use Enzyme-linked immunosorbent assay, Colloidal gold immunochromatographic assay and Indirect immunoflorescent assay to detect the viral antigens and/or their antibodies. Different types of specimens, such as nasal pharyngeal aspirate, throat swab, virus isolate and serum, could be used for detection or confirmation of the infection. Within one to two hours the suspected human or animal case could be confirmed. These techniques are convenient, rapid, and are easy for non-specialists to use. The kits could be used directly in the outbreak site.
Given the fact that H5N1 human infection cases continue to occur in Thailand and Vietnam, it is very likely there will be another outbreak in Southeast Asia this winter.
To prepare for this, Shantou University Medical College/The University of Hong Kong Joint Influenza Research Center, together with the Medical Molecular Virology Research Center, Xiamen University, have recently organised a training workshop for technical staff from 21 provincial centers for disease prevention and control. The new diagnostic kits and detection approaches were demonstrated in the workshop, and were made available to regional authorities for immediate use.
H5N1 avian influenza virus first broke out in humans in Hong Kong in 1997, infecting a total of 18 and subsequently claiming a death toll of six. Since 2001, novel reassortant H5N1 influenza virus has caused outbreaks almost every year in Hong Kong. Studies carried out in Hong Kong and the Mainland suggest that H5N1 influenza virus is endemic in poultry in this region. Since 2003/2004, H5N1 influenza virus has caused outbreaks in most countries in Southeast Asia. So far, more than 40 people have been infected in Thailand and Vietnam, with a mortality rate of over 70 per cent. The World Health Organisation has issued a pre-warning that if there should be a new human pandemic, the most probable pandemic influenza strain would be this H5N1 virus.
Given that three of four influenza pandemics during last century were originally generated in Southern China, the Joint Influenza Research Center was established in 2001 by Shantou University and The University of Hong Kong to make significant contributions to the knowledge of influenza and has become an important base for influenza research. The Medical Molecular Virology Research Center of the Xiamen University has extensive success in developing HIV, HTLV and hepatitis diagnostic reagents. The joint effort to develop H5N1 rapid diagnostic kits is a successful example of quickly translating research into a practical application. The diagnostic kits will play a key role in influenza surveillance and disease control in the near future.