Newszine

Wild Weather Around the World

Weather and disease

There’s been much coverage in the news lately about swine flu and its apparently imminent pandemic status.

An interesting Reuters article explains how weather can affect the spread of the influenza virus. According to the article, weather factors such as temperature and humidity can have significant affects on typical flu viruses and scientists are now trying to determine the effects of weather on the H1N1 “swine” strain.

A typical flu virus will spike in incidences during the winter months of temperate regions because the cold, dry conditions help the virus survive outside the body longer. Conversely, influenza incidences are less common in the hot, humid tropics although poor health data in Africa and Latin America make it difficult to determine.

This current strain of influenza originated from the Central American country of Mexico, where there have already been 149 deaths. It will be interesting to see what researchers discover about the swine flu in terms of the effect of weather or climate conditions on the development and spread of this illness.

The flu is not the only disease that is affected by weather. A recent article from the Times Herald-Record (Middleton, NY) warns about the summer threat of Lyme disease, an illness spread by ticks. According to the article, warmer winters mean ticks can survive longer and spread farther. Weather patterns are certainly responsible for warmer than average winters.

Additionally, a 2007 AP article explains how doctors are paying attention to weather forecasts to predict disease outbreaks. The article said that weather patterns are often key in discovering when an epidemic is imminent because the conditions necessary for germs and their carriers to survive can be determined. For example, diseases spread by insects like malaria, yellow fever and encephalitis are highly dependent on the conditions needed for the insects’ survival, such as warm temperatures and plenty of water to breed. The article also cited waterborne diseases such as cholera and typhoid as particularly susceptible to weather changes.

However, as swine flu is not transmitted by insects but rather by human-to-human contact (it’s not even possible to get the virus from handling or eating pork), the weather needed for insect survival is not as important as appropriate weather conditions for virus transmission. Only time will tell how much of an effect the weather will have on the spread of the swine influenza virus.