Climate and behavioral change

In recent years, "malaria has been spreading into highland areas of East Africa, Indonesia, Afghanistan, and elsewhere" it was previously unknown. High elevations, low temperature, and temperate rainy seasons prevented malaria from entering these regions before. Now, the deadly disease is contracted locally in these previously malaria-safe environments. Malaria "is on the rise in some parts of the world" partly due to climate change. Other "factors such as migration and land-use changes are likely also at play."

"We assessed...conclusions from both sides and found that evidence for a role of climate in the dynamics is robust," write study authors Luis Fernando Chaves from Emory University and Constantianus Koenraadt of Wageningen University in the Netherlands. "However, we also argue that over-emphasizing a role for climate is misleading for setting a research agenda, even one which attempts to understand climate change impacts on emerging malaria patterns."

"Malaria, a parasitic disease spread to humans by mosquitoes, is common in warm climates of Africa, South America and South Asia." Development and survival of the mosquito and parasite depend on warm temperatures; therefore, "the disease has been spreading to the highlands, and many studies link the spread to global warming. But that conclusion is far from unanimous. Other studies have found no evidence of warming in highland regions, thus ruling out climate change as a driver for highland malaria."

Most studies, which conclude that climate change plays a significant role in highland malaria, tend to be statistically strong. Clearly, climate change does impact the range of malaria endemic regions; however, it may not be the only contributing factor. "What is needed, the researchers say, is a research approach that combines climate with other possible factors."

"Even if trends in temperature are very small, organisms can amplify such small changes and that could cause an increase parasite transmission," a researcher said. "More biological data will improve our overall understanding of malaria and will allow scientists to propose more general and accurate models on the impacts of climate change on malaria transmission."

Some factors contributing to the spread of malaria may be migration and agriculture. People "migrating from lowlands may be introducing the malaria parasite into highland regions. Changes in farming practices may also play a role. Irrigation associated with more intensive farming may be creating more places for mosquitoes to breed."

"The spread of malaria in highlands is of great concern to those who work to contain the disease. But understanding the many factors that influence the spread of highland malaria could help with efforts to control the disease worldwide."

Source:
University of Chicago Press Journals (2010, March 4). Climate change one factor in malaria spread. ScienceDaily. Retrieved March 4, 2010, from http://www.sciencedaily.com­ /releases/2010/03/100303162906.htm

Malaria in the UK

"Prepare for outbreaks of malaria," government agencies warn hospitals in the UK (Prince). Malaria is often considered a minor problem for the UK in modern times, but outbreaks are not unheard of and may become increasingly likely as global warming expands mosquito breeding grounds.

Hospitals must prepare for epidemics as they have been the site of malaria transmission in the past. In 1999 "two patients...contracted malaria while being treated at a hospital in Nottingham." The disease was transmitted from an infected patient in the hospital to the two other patients via a mosquito. That was "the second time there has been an outbreak of the tropical disease in a British hospital" (Malaria).

In 2008 reports of 1370 cases and 6 deaths from malaria were published in the UK (HPA). "A high likelihood of a major heat wave" may lead "to as many as 10,000 deaths, hitting the UK by 2012" warns the government (Prince). In coming years "the UK is to be hit by regular malaria outbreaks, fatal heat waves and contaminated drinking water within five years because of global warming, the Government has warned the NHS [National Health Service]" (Prince).

Malaria has been endemic in the UK before. "Malaria has been seen in these islands in the past" (Prince). "The marshlands of coastal southern and eastern England had unusually high levels of mortality from the sixteenth to the nineteenth century. The unhealthiness of the environment aroused frequent comment during this period and it was attributed to an endemic disease known as "marsh fever" or "ague"." This "marsh fever" is considered to be "malaria transmitted by anopheline mosquitoes. Malaria, once endemic in the coastal marshes of England, had a striking impact on local patterns of disease and death" (Dobson).

Malaria is present in the UK and outbreaks are not impossible. Heat waves from global warming may cause flooding and encourage mosquito breeding, but mosquito havens exist now. "The Thames Estuary has been identified as the likeliest place for a new outbreak of malaria, following an investigation by insect experts" (Thames). An outbreak of malaria may be possible even without the feared heat wave if such mosquito habitats are not addressed effectively.

"A spokesman for the Health Protection Agency said: Our work is based on what is likely to happen if we do nothing to prevent" the development of mosquito breeding grounds, "and it could well be that we see an increase in diseases such as malaria" (Prince).

The idea of a modern malaria epidemic in the UK is horrifying but preventable. "Better management and control of man-made sites where malarial mosquitoes may easily reproduce - such as water wells and bore holes - may help reduce malaria breeding close to human settlements" (Vector). Furthermore, home and land owners should take responsibility to prevent standing and stagnant water on their property. Fountains can be installed into ponds and lakes to agitate the water so that mosquitoes cannot breed. Even small amounts of standing water can serve as a nursery for the mosquitoes that transmit deadly malaria.

Sources:
Dobson MJ. Malaria in England: a geographical and historical perspective. 1994 August.
"Malaria outbreak at UK hospital" BBC. 29 March 1999.
Prince, Rosa. "Malaria Warning as UK becomes warmer." Telegraph.co.uk. 12 Feb 2008.
"Thames marshes 'perfect breeding grounds for malaria'." Evening Standard, The. 1 Feb 2002.
"Vector Control Tools..." The Health and Environment Linkages Initiative. http://www.who.int/heli/risks/vectors/malariacontrol/en/index3.html