August 22, 2009 – Original Source: New Straits Times, Malaysia, by Evangeline Majawat
KUALA LUMPUR: The warming earth is making us sick.
Rising temperatures, frequent floods and prolonged droughts are ideal conditions for infectious diseases to spread.
“Global warming is fuelling epidemics in areas which are unprepared. We’re seeing the emergence of new diseases around the world. Old diseases are also coming back with a vengeance,” warned Malaysian Society of Parasitology and Tropical Medicine president Dr S. Vellayan.
He said it was believed that infectious diseases thrived in the tropics because of the constant warm and wet weather, but climate change was dramatically changing infection trends.
He said disease-carrying animals and insects were breeding rapidly and causing outbreaks in new areas because of suitable conditions.
“Vectors such as mosquitoes, ticks, snails and rats are expanding into new regions, bringing with them the threat of tropical diseases.”
The World Health Organisation reported in 2005 that “rainfall can influence the transport and dissemination of infectious agents while temperature affects their growth and survival”.
“Extreme cold during the winter would usually kill tropical disease pathogens. Not anymore,” Dr Vellayan said.
He said the obvious example was malaria. The same WHO report found that heavy rainfall and high humidity was a major influence to periodic malaria epidemics.
The report also noted that “the malaria epidemic risk increased around five-fold in the year after an El Nino event”.
Dr Vellayan said the destruction of forests was also another factor.
“Habitat destruction causes human-animal conflicts. This means we come into contact with animals that carry diseases.”
He said outbreaks of “simian malaria” in Sabah and Sarawak were rising as forests were cleared.
“Pathogens are jumping from species to species via direct contact, faeces, urine or body fluids. This was what happened with the nipah virus.”
But Dr Vellayan said it was too early to say how climate change would affect the influenza A (H1N1) virus.