Climate change adding sting to mosquito bite, says WHO report

NEW DELHI: The warning is ominous — climate change and global warming will make vector-borne diseases like dengue and malaria - already causing havoc in the country more lethal.

A landmark report on climate change and health, published by the World Health Organization on Monday, said that in the last 100 years, the world has warmed by approximately 0.75 degree Celsius. Over the last 25 years, the rate of global warming has accelerated, at over 0.18 degree Celsius per decade.

Global health will suffer a loss of $2 billion-$4 billion per year by 2030 due to climate change.

Global warming, which has occurred since the 1970s, caused over 1.4 lakh excess deaths annually by 2004.

"Many of the major killers such as diarrhoeal diseases, malnutrition, malaria and dengue are highly climate-sensitive and are expected to worsen as the climate changes," said WHO.

It added, "Malaria is strongly influenced by climate. Transmitted by Anopheles mosquitoes, malaria kills almost one million people every year. The Aedes mosquito vector of dengue is also highly sensitive to climate conditions. Studies suggest that climate change could expose an additional 2 billion people to dengue transmission by the 2080s."

WHO said over the last century, the surface area on which malaria remains a risk has been reduced from half to a quarter of the earth's landmass, but due to demographic changes the number of people exposed to malaria has increased substantially over the same period.

Estimates of cases and deaths differ greatly: the number of cases stands between 200 million and 500 million, while the death estimate is around one million per year.

Dengue has become the most rapidly spreading mosquito-borne viral disease in the world.

It is estimated to cause over 50 million infections and around 15,000 deaths annually in around 100 countries.

"Infection could range from a mild flu-like fever to the potentially fatal severe dengue, which particularly affects individuals who are exposed to one of the four different strains of the virus as a secondary infection. Heavy rainfall can cause standing water, while drought can encourage people to store more water around the home, both providing breeding sites for Aedes mosquitoes. Warm temperatures increase the development rates of both the mosquito vector and the virus, fuelling more intense transmission," the report said.

Extreme high air temperatures contribute directly to deaths from cardiovascular and respiratory disease, particularly among senior citizens.

High temperatures also raise the levels of ozone and other pollutants in the air that exacerbate cardiovascular and respiratory disease. Urban air pollution causes about 1.2 million deaths every year.

Pollen and other aeroallergen levels are also higher in extreme heat.

These can trigger asthma, which affects around 300 million people. Ongoing temperature increases are expected to increase this burden.

WHO added that globally, the number of reported weather-related natural disasters has more than tripled since the 1960s.

Every year, these disasters result in over 60,000 deaths, mainly in developing countries, it says.

In 2011, 332 disasters from natural hazards were recorded in 101 countries, causing more than 30,770 deaths, and affecting over 244 million people.

Recorded damages amounted to more than $ 366.1 billion. "Over the past 30 years the proportion of the world's popu-lation living in flood-prone river basins has increased by 114% and those living on cyclone-exposed coastlines by 192%. Reports of extreme weather events and disasters have more than tripled since the 1960s," it added.

(sumber: economictimes.indiatimes.com)