The H7N9 version of the avian flu has been confirmed in Hong Kong and public health officials have gone into high gear to prevent an outbreak. Half a million people cross the border between southern China and Hong Kong every day, and Hong Kong officials do careful monitoring at the border to protect the country from dangerous diseases.
A 36-year-old woman was hospitalized November 27th after having had contact with poultry in Shenzhen, China. Other people with minor respiratory symptoms are being held for observation. No poultry will be imported into Hong Kong from three Shenzhen poultry farms, and officials have raised the pandemic danger level to “serious.”
The H7N9 avian influenza may or may not be more deadly than the infamous H5N1 virus, but the new face of the disease appears to be mutated to be more infectious to mammals. The World Health Organization has denied that humans can pass the disease to each other, but China has confirmed 139 human cases of H7N9 since April, transmitted by human contact with infected poultry. Forty-five of those have died. Health officials’ great fear is that a strain will erupt that can pass directly from human to human, exposing the world to a true pandemic.
The H5N1 version of the bird flu killed six people in 1997 and resulted in the slaughter of 1.5 million birds, and in 2003 SARS (Severe Acute Respiratory Syndrome) infected over 1700 people and killed 299. One strain of H2N2 killed millions of people across the world in the 1950s, and St. Jude Children’s Research Hospital has just reported evidence that this virus is still out and there and a potential danger to people under the age of 50.
The Journal of Virology has published the results of the St. Jude study on H2N2 viruses found in all manner of ducks and other wetlands fowl, as well as domestic poultry, between 1961 and 2008. The deadly H2N2 virus largely disappeared from the human population after the 1957–58 pandemic, but it is still widely found in the bird population across the world. People who were alive in the 1950s should have some immunity to the killer strain, but those born since have not been exposed to the virus and therefore are unlikely to have any specific resistance to it.
“This study suggests H2N2 has the characteristics necessary to re-emerge as a significant threat to human health in part because most individuals under the age of 50 lack immunity to the virus,” said corresponding author Robert Webster, Ph.D., a member of the St. Jude Department of Infectious Diseases. “This highlights the importance of continued surveillance of viruses circulating in animals and additional research to enhance our ability to identify viruses that are emerging health threats.”
Viruses cannot reproduce sexually, but they are able to change-up their genetic code by swapping genes with one another. This means that a flu virus that affects humans and a virus that affects birds can exchange genes with one another and produce a new monster that neither population is ready to handle. It takes time for individual humans and the population as a whole to develop an immunity to new infections, and lives can be lost in the meanwhile. The H2N2 virus is susceptible to antiviral drugs, but it is difficult to anticipate exactly how a virus might mutate in order to produce vaccines that can target any specific form.
Our bodies are amazing. We have built-in systems dedicated to attacking microscopic invaders that might do us harm, systems with the flexibility to develop enemy-specific weaponry. Each time new viruses invade, our B cells try various antibody attacks on them until one works. Our memory T-cells then able to remember those invaders and pull out the heavy artillery as soon as they show up again. The immune process takes time, though. New viruses can do damage before they’re licked.
In 2009 the H1N1 “swine flu” killed at least 18,500 people. At least, those were the lab-confirmed cases. The actual number of deaths are now estimated to be from 123,000 to 203,000 worldwide, according to a new article in PLOS Medicine. Even in our modern age of technology, pandemics can infect and kill multitudes. The brilliance of our immune systems prevent these pandemics from destroying even a majority of those infected, but the beasts of the earth still get to have their hour of glory.
- Hong Kong Confirms First Human H7N9 Bird-Flu Case
— The Wall Street Journal
- 1950s Pandemic Influenza Virus Remains A Health Threat, Particularly To Those Under 50
— Medical XPress
- Risk Assessment of H2N2 Influenza Viruses from the Avian Reservoir
— Journal of Virology
- Flu Pandemic In 2009 Killed 10 Times More Than Thought
— USA Today