Malaria Linked to Cancer in Africa
Plasmodium falciparum Infection May Initiate Burkitt’s Lymphoma
Researchers in Sweden and Uganda have discovered a long-suspected connection between Epstein-Barr virus, falciparum malaria, and Burkitt's lymphoma.
Medical researchers have probably solved the mystery of why Burkitt’s lymphoma is primarily a disease of children in equatorial Africa. It looks as though it’s the result of the interplay of a virus (Epstein-Barr virus), a parasite (Plasmodium falciparum), and the human immune system. In a nutshell, catching falciparum malaria after having already had infectious mononucleosis can theoretically lead to Burkitt’s lymphoma.
What is Burkitt’s lymphoma?
Burkitt’s lymphoma is a malignancy of immune cells in which B-cells, a type of white blood cell intimately involved in immunity, proliferate and form tumors in the lymph nodes. It is most common in children and, in equatorial Africa where it accounts for about 74% of all childhood malignancies, it frequently presents as disfiguring enlargement of the jaw and cheeks. In the United States, Burkitt’s lymphoma accounts for about 30% of childhood lymphomas and usually starts as an abdominal disease.
There is a longstanding suspicion that there is a link between Epstein-Barr virus, Plasmodium falciparum malaria, and Burkitt’s lymphoma in African children—reactivation of the virus has been recognized in Burkitt’s lymphoma cases and high levels are also seen in falciparum malaria—but we are only now beginning to understand the complex process that leads from one disease to another.
What is Epstein-Barr virus?
Epstein-Barr virus causes infectious mononucleosis, often just referred to as infectious mono or kissing disease. More than 90% of us become infected with the virus in our lifetime—most infections are without symptoms or are mild and go unnoticed. In some cases, particularly in young adults, typical symptoms of sore throat, fever, swollen glands and fatigue last for weeks to months.
After infection, the immune system keeps the Epstein-Barr virus under control but never really gets rid of it—it lives on in B-cells, immune white blood cells, knitted into the DNA of the cell. Most children in equatorial Africa have immunity to the virus by their third birthday, and therefore harbor the virus from a very young age.
In most people, the presence of Epstein-Barr virus (EBV) in B cells causes no problems whatsoever. Occasionally the virus reactivates, beginning replication once again inside the white blood cells. This can occur in diseases of the immune system, such as AIDS, and is associated with certain cancers, notably B cell tumors, malignancy of the nose and throat, and Burkitt’s lymphoma. The virus is suspected of playing a role in the development of these malignancies.
The malaria connection
Scientists Arnaud Chêne, Daria Donati and others have now shown that latent Epstein-Barr virus is reactivated by Plasmodium falciparum malaria. When the parasite is growing inside red blood cells, the infected cells display a microbial protein, dubbed CIDR1α, on the cell surface. Research has proven that CIDR1α stimulates latent Epstein-Barr virus to begin replicating once again, at least in the laboratory. The researchers believe that when immune B-cells infected with latent Epstein Barr virus interact with the protein in an acute case of malaria, the virus is reactivated and immediately multiplies to high levels in the body, significantly increasing the risk of Burkitt’s lymphoma.
Other articles that might interest you:
Dengue: Fever and Hemorrhagic Fever
A Parasite in the Blood Supply
Sources:
Chêne, Arnaud, Daria Donati, André Ortlieb Guerreiro-Cacais et al. “A Molecular Link Between Malaria and Epstein-Barr Virus Reactivation.” PLoS Pathogens
The Merck Manuals Online Medical Library
