Why is malaria only in some countries?

Why is malaria only in some countries?

Malaria occurs mostly in poor, tropical and subtropical areas of the world. Africa is the most affected due to a combination of factors: A very efficient mosquito (Anopheles gambiae complex) is responsible for high transmission.

Why does malaria occur mainly in hot countries?

Lowlands are warm (good for malaria transmission), highlands are too cold for malaria parasites and vectors to develop. Higher humidity makes the vector live longer; malaria is transmitted by vectors that live 8–10 days so the parasites have time to develop.

Why does temperature increase in malaria?

Infection rates tend to increase as temperatures go up, since the Plasmodium parasite that causes the disease reproduces faster inside vector mosquitoes when it’s warmer, increasing the infection likelihood when the mosquito bites someone, Pascual explained.

Why is malaria not in the US?

Malaria transmission in the United States was eliminated in the early 1950s through the use of insecticides, drainage ditches and the incredible power of window screens. But the mosquito-borne disease has staged a comeback in American hospitals as travelers return from parts of the world where malaria runs rampant.

Does temperature affect malaria?

Temperature is particularly critical. For example, at temperatures below 20°C (68°F), Plasmodium falciparum (which causes severe malaria) cannot complete its growth cycle in the Anopheles mosquito, and thus cannot be transmitted.

Does climate change increase malaria?

An increase in temperature, rainfall, and humidity may cause a proliferation of the malaria-carrying mosquitoes at higher altitudes, resulting in an increase in malaria transmission in areas in which it was not reported earlier.

What countries have malaria problems?

Epidemics occur most often in areas with unstable malaria, such as Ethiopia, northern India, Madagascar, Sri Lanka, and southern Africa. Many other African countries situated in the Sahelian and Sub-Saharan areas are susceptible to epidemics (Djimdé and others 2004; Worrall, Rietveld, and Delacollette 2004).

Where does malaria transmission occur in the world?

In many malaria-endemic countries, malaria transmission does not occur in all parts of the country. Even within tropical and subtropical areas, transmission will not occur In some countries where transmission has been interrupted through successful control/elimination programs. Generally, in warmer regions closer to the equator

Who are the most at risk for malaria?

In many of the countries affected by malaria, it is a leading cause of illness and death. In areas with high transmission, the most vulnerable groups are young children, who have not developed immunity to malaria yet, and pregnant women, whose immunity has been decreased by pregnancy.

How does temperature affect the risk of malaria?

Temperature has been especially contentious. Some previous research indicated that warmer weather only plays a minor role in this mosquito-borne illness, with human factors being the major influence on disease risk ( ClimateWire, Feb. 4).

Are there any countries with no cases of malaria?

While the mosquito-borne parasite has been absent from most of the continent since 1975, it has lingered in countries along the border between Europe and Asia. In 1995, Turkey, Georgia, Tajikistan, and seven other nations in the area reported more than 90,000 cases of the disease. That number is now zero, WHO officials say.