In What Countries is Malaria Found?

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QUESTION

What countries can malaria be found in?

ANSWER

Malaria is found on every continent of the world except Antartica—however, regular transmission every year mainly only occurs in Central and South America, Africa, parts of the Middle East, Asia and parts of Oceania/the Pacific Islands.

The world’s highest areas of malaria prevalence and transmission occur in sub-Saharan Africa, followed by India, south-east Asia (especially the Indo-Pacific islands, such as Papua New Guinea) and parts of Central America and northern South America.

Based on the latest available data, the top five countries reporting the most annual malaria deaths were Kenya, the Democratic Republic of Congo, Cote d’Ivoire and Burkina Faso. However, the top five countries with the highest number of malaria cases per 100,000 members of the population were Guinea, Botswana, Burundi, Zambia and Malawi.

The Solomon Islands have the highest number of malaria cases per 100,000 outside of Africa, followed by Yemen. Note that these statistics are highly dependent on quality of diagnosis, treatment and reporting!

Malaria in Africa

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QUESTION

Why do Africans catch malaria more than others?

ANSWER

There are a number of reasons why malaria is more widespread in Africa than in many other parts of the world. However, it is worth mentioning that other parts of the world, such as India and south-east Asia, also have very high prevalence of malaria, especially in rural areas.

The high transmission of malaria is Africa is predominantly due to two factors: climate and control measures, or rather, the lack of them.

Malaria is spread by mosquitoes of the genus Anopheles, and so in order to persist, an area must have a suitable temperature for the development of both the mosquito as well as the malaria parasite. This limits malaria transmission to the sub-tropics and tropics, primarily. The area must also have sufficient rainfall and areas of standing water, since the malaria mosquitoes lay their eggs in stagnant water, which the larvae live in until they pupate into adults. This means that malaria transmission cannot occur in desert regions.

Unfortunately, a large portion of Africa, and particularly West, Central and East Africa, are climatically very well suited to the development of mosquitoes and thus the transmission of malaria.

In addition, many countries in Africa are not as developed as other tropical countries. This means that health resources have not been as focused on control efforts in Africa—for example, Malaysia very successfully reduced malaria transmission by a huge amount through a combination of vector control (namely spraying households with insecticides and filling up stagnant water pools so larvae couldn’t develop), distribution of bednets (which reduces mosquito biting rate) and better diagnoses and treatment facilities.

All of these efforts are beginning to be developed and rolled out in Africa as well, so hopefully in the near future we will also see a dramatic reduction in malaria transmission in Africa.

Malaria Deaths in the Tropics

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QUESTION

What’s the difference of malaria deaths between the subtropical and tropical regions and all the other regions?

ANSWER

I am assuming you are asking about the distribution of deaths caused by malaria between the tropics/sub-tropics and the rest of the world.

95% percent of all fatal malaria cases occur in sub-Saharan Africa, which lies entirely in the sub-tropics and tropics. Additionally, most of the deaths occur in Central, West and Eastern Africa (North Africa and South Africa have more advanced malaria prevention and control initiatives to the rest of the continent, and transmission is also less severe), and the other 5% of malaria deaths are mostly found in India and south-east Asia, so you could say that virtually all deaths due to malaria occur in tropical regions alone.

Indeed, there is almost no malaria in non-tropical or sub-tropical regions; the few cases each year in North America and Europe are usually due to imported cases from people who have traveled to tropical or sub-tropical regions.

Does malaria kill?

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QUESTION

Is malaria a killer disease?

ANSWER

Yes. Malaria causes somewhere between 700,000 to 1 million deaths worldwide, mostly in children under five, and mostly in sub-Saharan Africa. As such, it is actually one of the leading causes of death in young children in developing countries.

Given this high mortality, many initiatives working to control malaria are dedicated to reducing the number of deaths as a key way of lowering the overall burden of this disease; groups such as Malaria No More and the Roll Back Malaria Partnership have committed to bringing the number of deaths from malaria to zero or near zero by 2015.

Malaria Mosquitoes Reveal Pathogen Defense Strategies

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In analyzing malaria mosquitoes in sub-Saharan Africa, a Cornell-led team of researchers finds evidence of two very different evolutionary paths in the immune systems of neighboring mosquito groups.

Genes in animal immune systems may evolve in one of two main ways in the constant fight against pathogens: They may evolve diverse forms of genes (alleles) to fight a wide variety of pathogens, or when only a few pathogens dominate, they may evolve one or a few alleles that specialize against common infections. The Cornell researchers have found evidence of both these adaptive strategies occurring in the same immune-defense genes in different subpopulations of the human malaria vector mosquito, Anopheles gambiae.

via PhysOrg.com.