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Malaria

photo: disease

Malaria is a life-threatening, parasitic disease transmitted from person-to-person by the bite of a female Anopheles mosquito.

  • More than 2 billion people (about 40% of the world's population in 100 countries) are at risk.
  • There are more than 300 million cases of acute malaria each year.
  • About 2.7 million people die each year from malaria, mostly children in sub-Saharan Africa.
  • High-risk groups include pregnant women and non-immune travelers.
  • Countries in tropical Africa are most affected, accounting for more than 90% of the cases.

Infectious Agent

Malaria is caused by Plasmodium, a tiny, single-celled parasite that lives in the red blood cell. Parasites are animals which live on or in other animals at the latter's expense.

Four species of the parasite cause malaria in humans; Plasmodium falciparum, P. vivax, P. ovale, P. malariae.

P. falciparum causes the most severe disease. Infections with P. vivax are rarely fatal, but infections with this parasite will relapse.

Transmission

Malaria is transmitted through the bite of an infected Anopheles mosquito.

Of the 400 species of Anopheles throughout the world, only about 60 are vectors of malaria.Avector isa carrier which transmits the infective agent from one host to the next.

Only female mosquitoes drink blood (to provide protein for their eggs).

The Disease

When an infected mosquito bites a human to drink blood, parasites are injected into the blood stream.

The classic clinical course of malaria consists of bouts of fever and chills that coincide with the parasites bursting from the red cells.

Infected red cells can also clump together blocking blood flow and damaging internal organs, especially the brain (cerebral malaria).

Variation in some human genes, e.g. those responsible for sickle cell, reduce susceptibility to malaria.

Treatment

Malaria is generally curable with prompt treatment using appropriate drugs.

The parasite has developed some resistance to many currently used antimalarial drugs, especially chloroquine.

There is no vaccine against malaria.

Our Research

We use monkey models of human malaria for our research studies. Monkeys are given the malaria parasite, studied, and then cured of the disease.

We have developed a model of malaria in pregnancy using the rhesus macaque.

We are working on host gene expression in response to malaria (using microarray) to determine which genes are up or down regulated during a malaria infection and during relapses.

We have developed a series of compounds to treat drug resistant malaria. The compounds were first evaluated against cultured parasites (in vitro), then tested in monkey models. Our lead compound, patented by Tulane, has just finished Phase I safety trial in Charity Hospital and is now being tested in malaria patients in Mali. The monkey model was critical to our success in that the monkey metabolizes drugs in a similar fashion to humans, and it's been our experience that compounds which work well in the monkey model also work well in human patients.

The TNPRC is a division of Tulane University (985) 871-6201 tnprc@tulane.edu