Climate change makes you sick

As predicted, a rise in temperatures is causing a surge in cases of dengue fever. There are signs that climate change, combined with rapid urbanisation, could make 2007 the worst ever year for this low-profile serious health risk. Classic dengue — known as "bonebreak fever" — can cause severe flu-like symptoms, excruciating joint pain, high fever, nausea and rashes. More alarming is that a deadly hemorrhagic form of the disease, which adds internal and external bleeding to the symptoms — is becoming more common, especially in South America. South East Asian nations are battling a massive increase in the disease, and the cause is not in doubt: "The threat of dengue is increasing because of global warming; mosquitoes are becoming more active year by year and their geographical reach is expanding both north and south of the Equator," said Lo Wing-lok, an expert in infectious diseases. "Even Singapore, which is so affluent and modern, can't exercise adequate control," Hong Kong-based Lo added. The number of dengue cases in Singapore last month was nearly three times that in the same period a year ago. Indonesian experts warn that 2006's record 106,425 cases could easily be overtaken. Neighbouring Thailand had more than 11,000 cases of dengue fever and 14 deaths by this month, up 18% from the same period of 2006. In Malaysia, 48 people died from dengue during the first five months of the year, health officials said, up 71% percent from 2006.

South America is facing a similar epidemic after 16 years without the disease. The deadly hemorrhagic form of dengue fever is increasing dramatically in Mexico, and experts predict a surge throughout Latin America fuelled by climate change, migration and faltering mosquito eradication efforts. Overall, dengue cases have increased by more than 600% in Mexico since 2001. It accounts for one in four cases in Mexico, compared with one in 50 seven years ago, according to Mexico's public health department. There's no drug to treat hemorrhagic dengue, but proper treatment, including rest, fluids and pain relief, can reduce death rates to about 1%. But the region’s hospitals are ill-equipped to handle major outbreaks, and officials say the virus is likely to grow deadlier, in part because tourism and migration are circulating four different strains across the region. The rapid growth of cities has added to the crisis. They are accompanied by large areas of slums where the absence of proper sanitation is a factor in the outbreak of dengue fever. Earlier this year, the Intergovernmental Panel on Climate Change, made up of the world's leading climate scientists, predicted that climate change would cause an upsurge in dengue. The globalisation process means that the fever is transported around the world by tourists and business travellers. Meanwhile, world leaders, compromised by corporate interests, sit back as if the planet had time on its hands to tackle climate change. The outbreak of dengue fever shows that the very opposite is true.

Penny Cole, environment editor