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The New Avian Influenza
Posted on Apr 15, 2013 by Ailee Slater (G+)
The most recent reports from China confirm that over 60 people have been diagnosed with bird flu, and 13 have died. So far, there are no cases of the disease being passed from one human to another - all of those people infected contracted the disease directly from infected poultry.
The absence of human-to-human transmission means that this particular strain of bird flu, H7N9, has less chance of spreading - a person unknowingly infected with the illness will not be able to simply board a bus or plane and spread the virus to other parts of the world.
Both China's health ministry and the World Health Organization are currently investigating poultry markets within China, in hopes of discovering where the infection originated. According to the United Nations' Food and Agriculture Organization, H7N9 is difficult to identify in live birds as the virus causes only mild symptoms in poultry.
In humans, on the other hand, H7N9 is hard to miss. The virus is accompanied by a sudden high fever, headache, loss of appetite and an upset stomach. Bird flu tends to affect humans more strongly than mammalian flu, and so a patient with bird flu can quickly deteriorate. If complications such as pneumonia or organ failure occur, the results may be fatal. Indeed, the Spanish Flu of 1918, an illness that killed around 50 million people, began as a strain of bird flu.
Following the outbreak of Spanish Influenza at the beginning of the 20th century, there were no widespread reports of avian flu until nearly a century later. In 2003 and continuing through 2009, outbreaks of a bird flu virus H5N1 were seen in China and other parts of Asia such as Thailand and Vietnam.
In an effort to protect their poultry from H5N1, farmers in China initiated the practice of vaccinating poultry against this strain of the flu virus. However, according to a statement by Dr. Alex Thiermann of the World Organization for Animal Health, these vaccination practices may have made it more difficult for farmers in China to notice the spreading of the most recent bird flu virus. Because the H5N1 vaccine produces antibodies in chickens, tests will not as easily detect the presence of the H7N9 virus.
However, large scale poultry vaccination may be part of the reason why flu from the H5N1 virus has become less and less of a threat. China has in fact received much praise for its follow-up handling of the H5N1 virus, as well as for its quick response to the recent cases of H7N9. Most importantly, health officials in China have publicized the influenza outbreak, a step toward honesty and transparency that global health officials say can help prevent this strain of bird flu from becoming a pandemic.
To stop the spread of H7N9, authorities in China have shut down live poultry markets in major cities; killed thousands of chickens in a series of culls; and, increased surveillance for disease among populations of livestock. All of this is good news for healthcare, but has already taken a toll on China economically - Reuters reported this week that China has lost more than $1.6 billion U.S. dollars (10 billion yuan) due to a drop in the price of chicken and fewer consumers purchasing poultry and eggs.
Like the poultry industry, hospitals in China have also taken steps to contain bird flu outbreaks in case a strain is found which can be transmitted from one human to another. Hospitals have also told doctors to be on alert for patients exhibiting bird flu symptoms, and to treat them as necessary - speed is of the utmost importance, as the virus can lead from the flu to pneumonia in less than a week.
In neighboring Hong Kong, public health officials are also making preparedness arrangements, prompted by fears that the city could see a human-to-human transmissible avian flu. Hong Kong's Hospital Authority director Dr Cheung Wai-lun said in a press conference last week that hospitals are well prepared for a H7N9 outbreak, with contingency plans outlining how to act in such a situation. Although poultry in Hong Kong has tested negative for the disease, and the importation of chicken from China has been limited, there are still fears that infected migratory birds could bring the virus south. Following the SARS pandemic of 2003, hospitals in Hong Kong increased beds and built more resources designed to keep infectious patients in isolation; should bird flu become a problem in the future, these hospital facilities ought to aid treatment and containment.
Taiwan is likewise taking precautions against the possibility of an avian flu pandemic. The nation's National Health Research Institute has said that if necessary, it will be possible to produce a vaccine to protect humans against H7N9. The health department of Taiwan has already contacted China and the United States with requests for access to the H7N9 viral strain, and is hopeful that should an emergency situation arise, a vaccine can be produced for mass production in about six months.
Indeed, other nations are also asking their national health researchers to investigate a vaccine against H7N9. In the United States, biomedical researchers with the Health and Human Services Department are working with the genetic sequence of the virus to create a vaccine. This genetic sequencing technique is different from traditional flu vaccine production; normally, a virus is combined with another flu strain, incubated in chicken eggs and then purified. Genetic sequencing, however, is much quicker.
Health officials in the United States have also called attention to the importance of flu vaccinations as a general practice, and are developing plans for encouraging the public to get vaccinated should H7N9 become a threat.
In China, the vaccine supplier Sinovac Biotech Ltd. has begun preparations for an immunization against H7N9. Yin Weidong, Sinovac's Chief Executive Officer, has said that the company will begin creating a vaccine upon receiving orders from the Chinese government to do so.