Malaria Stats


Malaria is a parasitic infection spread by Anopheles mosquitoes. The Plasmodium parasite that causes malaria is neither a virus nor a bacterium – it is a single-celled parasite that multiplies in red blood cells of humans as well as in the mosquito intestine.
When the female mosquito feeds on an infected person, male and female forms of the parasite are ingested from human blood. Subsequently, the male and female forms of the parasite meet and mate in the mosquito gut, and the infective forms are passed into another human when the mosquito feeds again.
There are four species of thePlasmodium parasite that can cause malaria in humans: P. falciparum, P. vivax, P. ovale, and P. malariae. The first two types are the most common. Plasmodium falciparum is the most dangerous of these parasites because the infection can kill rapidly (within several days), whereas the other species cause illness but not death. Falciparum malaria is particularly frequent in sub-Saharan Africa and Oceania.

Method of transmission

You can only get malaria if you’re bitten by an infected mosquito, or if you receive infected blood from someone during a blood transfusion. Malaria can also be transmitted from mother to child during pregnancy.
The mosquitoes that carry Plasmodium parasite get it from biting a person or animal that’s already been infected. The parasite then goes through various changes that enable it to infect the next creature the mosquito bites. Once it’s in you, it multiplies in the liver and changes again, getting ready to infect the next mosquito that bites you. It then enters the bloodstream and invades red blood cells. Eventually, the infected red blood cells burst. This sends the parasites throughout the body and causes symptoms of malaria.

Malaria Symptoms and Complications

Symptoms usually appear about 12 to 14 days after infection. People with malaria have the following symptoms:

  • abdominal pain
  • diarrhea, nausea, and vomiting (these symptoms only appear sometimes)
  • headache
  • high fevers
  • low blood pressure causing dizziness if moving from a lying or sitting position to a standing position (also called orthostatic hypotension)
  • muscle aches
  • poor appetite

In people infected with P. falciparum, the following symptoms may also occur:

  • anemia caused by the destruction of infected red blood cells
  • extreme tiredness, delirium, unconsciousness, convulsions, and coma
  • kidney failure
  • pulmonary edema (a serious condition where fluid builds up in the lungs, which can lead to severe breathing problems)

P. vivax and P. ovale can lie inactive in the liver for up to a year before causing symptoms. They can then remain dormant in the liver again and cause later relapses. P. vivax is the most common type in North America.

Global Malaria situation
  • Half the world’s population is at risk for malaria, which is endemic (where a constant, measurable number of new cases and natural transmission occurs over time) in more than 100 countries. Children are at particular risk, accounting for most malaria deaths globally.
  • Although preventable and treatable, malaria causes significant morbidity and mortality, particularly in resource-poor regions. Sub-Saharan Africa is the hardest hit region in the world, and parts of Asia and Latin America also face significant malaria epidemics.
  • Widespread regional and international efforts to address malaria began in the 1940s and 1950s, and strategies have evolved over time. From the early 1950s until 1978, malaria was eliminated in parts of the Americas, Europe, and Asia. But such efforts did not reach or were unsuccessful in many of the hardest hit areas, particularly sub-Saharan Africa. More recent attention to these regions by the United States, other donor governments, multilateral institutions, and affected countries, has helped to increase access to prevention and treatment and reduce cases and deaths
  • Still, while access to interventions has increased, gaps remain and many challenges continue to complicate malaria control efforts in hard-hit areas, including poverty, poor sanitation, weak health systems, limited disease surveillance capabilities, drug and insecticide resistance, natural disasters, armed conflict, migration, and climate change.

Current Global Snapshot

The Anopheles mosquito, which transmits malaria parasites to humans, thrives in warm, tropical, and subtropical climates. While anyone living in or visiting an endemic country may be at risk, certain groups, particularly children and pregnant women, are more vulnerable. The World Health Organization (WHO) estimates that

  • There are currently 104 malaria-endemic countries and approximately half the world’s population is at risk for infection, worldwide.
  • There were an estimated 219 million cases of malaria and 660,000 deaths, mostly among children under the age of five, in 2010.
  • Malaria is a leading cause of death for children, who represent 86% of all malaria deaths. Children are at risk because they lack developed immune systems to protect against the disease.
  • Tens of millions of pregnant women living in endemic regions become pregnant each year Pregnancy reduces immunity to malaria, increasing the risk of infection, severe illness, and death for the woman; other adverse outcomes include spontaneous abortion, stillbirth, low birth weight, and neonatal death.
  • Other high-risk groups include travelers, refugees, displaced persons, and migrant workers entering endemic areas.
  • Scale-up of malaria control programs has helped to greatly reduce malaria cases and deaths. Since 2000, eight African countries have experienced at least a 75% reduction in newly reported malaria cases; 37 countries outside of Africa have experienced at least a 75% reduction in newly reported malaria cases.
  • Africa With 44 countries with ongoing malaria transmission, Africa accounts for the majority of estimated malaria cases (81%) and deaths (90%), but only about 12% of the world’s population. Recent data, however, indicate that effective programs have helped reduce newly reported cases by at least 75% in eight countries (Algeria, Botswana, Cape Verde, Namibia, Rwanda, Sao Tome and Principe, South Africa, and Swaziland).
  • South-East Asia There are 10 countries with ongoing malaria transmission in South-East Asia which accounts for 32 million (13% of estimated cases worldwide), the second highest number after Africa. India, Indonesia, and Myanmar comprise most of the region’s reported cases (94%). Bhutan, the Democratic Republic of Korea, Nepal, Sri Lanka, and Thailand have made notable achievements in programmatic activities targeting malaria which have led to at least a 75% reduction in reported cases in each country between 2000 and 2011.
  • Eastern Mediterranean There are 9 countries with ongoing malaria transmission in the Eastern Mediterranean. Together, Afghanistan, South Sudan, Sudan, and Yemen made up 98% of the region’s reported cases in 2011.
  • Western Pacific Representing less than 1% of estimated global cases, there were 10 malaria-endemic countries in the region. Cambodia, Papua New Guinea, and Solomon Islands represented 75% of the region’s reported cases in 2011.
  • Americas There are 21 countries with ongoing malaria transmission in the region, which includes the Caribbean and North, Central, and South America. Over the past decade, Brazil and Colombia have consistently accounted for over half of the region’s reported cases.
  • Europe With five countries with ongoing malaria transmission in Europe, in 2011, the region accounted for less than 0.01% of the estimated cases and none of the deaths worldwide.
Malaria Prevention and Treatment

The international community generally applies four strategies for combating malaria:

Treatment Anti-malarial treatments include chloroquine, primaquine, and artesmisinin-based combination therapy (ACT). ACT is the preferred treatment in areas with particularly deadly forms of malaria or with drug resistance to earlier generations of anti-malarials. Multi-drug resistant malaria is found worldwide, and there is evidence that ACT resistance is occurring in Asia.

Intermittent Preventive Treatment in Pregnancy (IPTp) In areas with high concentrations of malaria, physicians give pregnant women an anti-malarial drug to prevent them from transmitting the disease to their infants.

Insecticide-Treated Bed Nets (ITNs) Insecticides used to treat bed nets kill and repel mosquitoes. ITNs are used as personal protection against mosquito bites, but evidence suggests that high community coverage of ITNs can lower the number of mosquitoes in a general area and reduce the life span of mosquitoes that remain. ITNs retain effective levels of insecticide for up to six months. Newly developed long-lasting insecticide-treated nets (LLINs) last for at least three years.

Indoor Residual Spraying (IRS) IRS involves covering household walls with an insecticide to kill any mosquito that comes into contact with the surfaces for several months. To be effective, IRS must be applied to a high percentage (80%) of household surfaces. Resistance to insecticides is a growing concern.
While there is presently no malaria vaccine, research is ongoing. There are currently over a dozen vaccine candidates in clinical development.

Environmental management for vector control Environmental management for vector control aims to induce changes in ecosystems to help reduce their receptivity to the propagation of disease vectors. Disease vectors are organisms that play a key role in the transmission of certain diseases. Environmental management for vector control is not intended to replace other control strategies .Rather, it provides a basis on which other methods such as chemical controls can build in a complementary fashion, while reducing the environmental costs and resistance risks incurred by excessive use of insecticides. It also adds resilience to the results of control programs, important at times of economic instability or social unrest. Clear decision-making criteria and procedures in an Integrated Vector Management (IVM) framework will ensure the most cost-effective combination of measures for each local situation. Environmental management for vector control is a particularly powerful approach in the context of development projects, especially infrastructure projects such as dams, irrigation schemes, roads and railroads, airports, flood control projects and urban development’s. These usually offer important opportunities to minimize adverse effects for the health of local and resettled populations and, indeed, to promote their health status in an efficient and sustainable manner.

U.S. Response to the Global Threat of Malaria:Basic Facts

scroll up