Malaria in humans is caused by single cell parasites, the Plasmodium protozoa. The four subspecies are falciparum, vivax, malariae and ovale. The species that causes the greatest illness and death in Africa is P.falciparum. The disease is transmitted by the female Anopheles mosquito, of which the Anopheles gambiae complex (the most efficient) is responsible for the disease in Africa. About 60 species of the Anopheles mosquito are major transmitters of the disease.

Fever is the main symptom of malaria. The most severe manifestations are cerebral malaria (mainly in children and people without previous immunity), anemia (mainly in children and pregnant women), kidney and other organ dysfunction (e.g. respiratory syndrome).

Severe malaria usually occurs in children and pregnant women or people who travel into malarial areas and have no prior immunity.

Malaria: A Global Burden

Malaria infects almost 1 billion people a year, between 1 and 2.7 million die from the disease globally. In an estimated 350,000 cases of P. falciparum malaria, 70 percent oc in Africa and 18 percent in the South East Asia region. Of those who die from malaria, at least 75 percent are African children under the age of five. Every 30 seconds a child in Africa dies from malaria.

Malaria now threatens half of the world’s population, endemic to 106 nations. Although malaria has been eliminated in the United States, Canada and most all the Caribbean Islands there are reports of rising incidence of imported cases. Malaria has re-emerged in certain countries where it had been previously eliminated. P.vivax malaria re-emerged on the Korean peninsula after 20 years of malaria free status. In Central Asia and the Caucasus, malaria returned years after it had been eliminated.

THE AMERICAS

There are 21 malaria-endemic countries in central and South America. The highest incidence of malaria in the central region is Nicaragua, Honduras and Guatemala. In this region the P.vivax parasite is mainly found, which represents about 70 percent of all cases. In South America 80 percent of all cases reported are from countries in and around the Amazon rain forest.

EASTERN EUROPEAN REGION

There are 7 malaria-endemic countries in Eastern Europe. Independent states of the former Soviet Union had a major increase of malaria P. falciparum, during the 1990’s. This was mainly due to economic decline, migration and deteriorated health services.

EASTERN MEDITERRANEAN REGION

There are 13 malaria-endemic countries in the Eastern Mediterranean region, although 70 percent of the population lives in regions where malaria is controlled. Morocco and Oman are close to eliminating P. vivax as well as Egypt, Libya and Tunisia.

SOUTH EAST ASIA REGION

There are 10 malaria-endemic countries in South East Asia with India, Indonesia and Thailand reporting the highest number of cases. The highest number of all malaria cases in this region is India. Infection of the P. falciparum parasite has become more common in urban areas due to over population, unplanned urbanization and poor socio-economic conditions.

WESTERN PACIFIC REGION

There are 10 malaria-endemic countries in the Western Pacific region. A major resurgence of malaria occurred in this region due to economic deterioration, population movement, drug resistance and ecological factors. The highest rates of incidence are reported in Cambodia, Lao People’s Democratic Republic, Papua New Guinea, Solomon Islands and Vanuatu. Both P. Vivax and Falciparum malaria are found in this region.

AFRICA

There are 45 malaria-endemic countries in Africa. In Sudan, the entire population is at risk of infection. Almost 90 percent of all malaria related deaths are caused by the P. falciparum parasite. The malarial situation has exploded with the movement of large populations of indigent refugees, civil strife and disrupted health services. In Uganda 95 percent of the country suffers from perennial malaria transmission. Children suffer on an average of 6 malaria episodes a year, which accounts for about 25 percent of deaths in children under five. Zambia has the highest infection rate in children under five to over 100 percent. In Kenya 30 percent of all hospital out patient admissions and almost 20 percent of all in patient admissions are from malaria. A wetter and warmer climate is taking malaria into new regions of Africa that were historically malaria free. The populations in the highlands of Kenya, Tanzania and Rwanda are particularly vulnerable to malaria. The people in these regions often die quickly, because they have no immunity to the disease.
The economic loss in Africa due to malaria is estimated to be 12 billion, representing 1.3 percent annual loss in GDP growth in endemic countries.