Man has known malaria for centuries and AIDS has been around for nearly 6 decades. Malaria has already killed millions and continues to kill nearly 3 million every year. As of 1999, nearly 36 million people around the world are infected with HIV and 5 million have died of AIDS related illness. And in the coming millennium, both the diseases are expected to infect many more and to kill many many more around the world. But the bigger tragedy is that HIV infection is on a dramatic increase in those countries where malaria is already a uncontrollable problem.
Many interesting studies have been conducted on the relationship between these two potentially fatal diseases. Here below you will find a summary of these studies:
Effect of HIV infection on malaria:
With what we know of HIV infection, it is only natural that one expects a far poorer outcome for malaria in HIV infected patients. But on the contrary, the reports available indicate either no effect or even a protective effect against death from complications of falciparum malaria!
- Malaria does not occur as an opportunistic infection in patients with HIV infection.3
- Incidence of malaria is not more common in HIV infected patients.1,3
- The response to antimalarial treatment is identical in HIV infected and non-infected patients.3
- Although high levels of malarial parasitemia have been observed in African children with symptomatic HIV infection, these children have been found to be ‘protected’ against cerebral malaria and deaths due to cerebral malaria. This has been attributed to lower levels of Tumor Necrosis Factor in HIV infected children. TNF is reported to have a potentiating effect on the endothelial adherence and clogging of microcirculation by parasitized red cells1. In an animal study using mice, murine AIDS was found to confer protection against the severity of neurological manifestations of experimental cerebral malaria and this protection was higher with longer duration of immunodefeciency. Interleukin 10 from splenic cells was shown to play a crucial role in this protection.2
- However, there are also studies that have found no difference in the incidence, clinical features and response to treatment of malaria among the HIV positive and HIV negative groups.3,6
- Patients with HIV infection may have a false positive serological test for malaria. Therefore, serological tests for malaria may not be useful as surrogate tests for assessing the travel status of individuals.4
Effect of malaria on HIV infection:
It appears that malaria does more harm to HIV patients and HIV transmission than vice versa. Many studies from the African countries have thrown light on this aspect.
- It is common knowledge that in areas where malaria is common, the health workers are assigned the job of conducting active surveillance by screening the population for malaria by peripheral smear examination. It is feared that this practice of collecting peripheral smears on a mass scale can certainly heighten the risk of transmission of HIV infection through needle pricks.5
- Also in areas where malaria is common, children and pregnant women often suffer from malaria related anemia and may require transfusion of either whole blood or packed cells. This also increases the risk of transmission of HIV infection as it may not be possible to ascertain the serological status of the donor in areas where HIV is also rampant.6,7,8 Therefore it is important to develop definite guidelines for blood transfusion in areas where anemia (due to malnutrition, helminthiasis, malaria etc.) and HIV infection are prevalent.
- Malaria has potent immunosuppressive effects. It has been found that patients with HIV infection who contact malaria tend to deteriorate rapidly into AIDS Realted Complex or AIDS. Malarial infection supposedly accelerates the replication of HI virus.9
- Chloroquine, the most commonly used antimalarial has been found to have inhibitory effects on the antiviral activity of Interferons alpha and beta in animal studies. It has also been found that chloroquine enhances viral replication in mice. It may suggest a possible connection between AIDS and malaria infection, since the spread of AIDS has been rapid in parts of tropical Africa that have a high incidence of malaria and chloroquine has been frequently used in the chemotherapy of malaria.10
Malaria and Kaposi’s sarcoma:
In sub-Saharan Africa, Kaposi’s sarcoma is a frequent tumor (endemic Kaposi’s) and it has been blamed on environmental factors. Kaposi’s sarcoma also occurs in association with AIDS (AIDS associated Kaposi’s sarcoma). One study on the association of endemic Kaposi’s sarcoma and transmission of malaria based on the available data from 27 African countries found a significant geographical association between proportional rate of Kaposi’s sarcoma and malaria transmission.11 The following possibilities have been suggested to explain this association:
- The immunosuppressive effects of malaria might be an additional cofactor in the pathogenesis of endemic Kaposi’s sarcoma.
- Abnormalities of cell-adhesion, observed as blood-flow sludging, have been observed in malaria as well as AIDS associated Kaposi’s sarcoma. This factor might be contributory to the pathogenesis of both AIDS associated and endemic Kaposi’s sarcoma.
- Kaposi’s sarcoma may also be an arthropod borne illness in Africa.
Interactions of antimalarial and antiretroviral drugs:12,13,14 Research on interactions between antiretrovirals and antimalarials has been lacking. One study found no interaction between mefloquine and indinavir or nelfinavir. The results of a pharmacokinetic study of mefloquine and ritonavir suggest that mefloquine reduces ritonavir blood levels by at least 30%.
- Dayachi F, Kabongo L, Ngoie K. Decreased mortality from malaria in children with symptomatic HIV infection. Int Conf AIDS. 16-21 Jun 1991;2:164
- Eckwalanga M et al. Murine AIDS protects mice against experimental cerebral malaria: down regulation by interleukin 10 of a T- helper type 1 CD4+ cell-mediated pathology. Proc Natl Acad Sci USA. 1994 Aug 16;17:8097-101
- Muller O, Moser R. The clinical and parasitological presentation of Plasmodium falciparum malaria in Uganda is unaffected by HIV-1 infection. Trans R Soc Trop Med Hyg. 1990 May-Jun;3:336-8.
- Chrystie IL, Palmer SJ, Voller A, Banatvala JE. False positive malaria and leishmania serology associated with HIV positivity. Int Conf AIDS. 1993 Jun 6-11;2:763
- Risk of transmission of AIDS and other blood-related diseases during routine malaria activities. Bull World Health Organ. 1991;2:242-3
- Greenberg AE. Studies of the relationship between Plasmodium falciparum malaria and HIV infection in Africa. Int Conf AIDS. 1989 Jun 4-9:983
- Fleming AF. Tropical obstetrics and gynaecology. 1. Anaemia in pregnancy in tropical Africa. Trans R Soc Trop Med Hyg. 1989 Jul-Aug;4:441-8.
- Lackritz E, Campbell C, Hightower A, Ruebush T, Were J. Is the cure worse than the disease: anemia, malaria, blood transfusion and child mortality in western Kenya. Int Conf AIDS. 1990 Jun 20;236(1):273
- Weinke T, Schere W, Pohle HD. Malaria tropica in HIV infection (German). Klin Wochenschr. 1990 May17; 68(10):533-6
- Maheshwari RK et al. Effect of interferon in malaria infection. Immunol Lett. 1990 Aug;1-3:53-7
- Baumann S, Geier SA, Noehl MA, Goebel FD. On the epidemiologic association between endemic Kaposi’s sarcoma and malaria. Int Conf AIDS. 1994 Aug; 1:(170):7-12
- Schippers EF, Hugen PW, den Hartigh J, et al. No drug-drug interaction between nelfinavir or indinavir and mefloquine in HIV-1-infected patients. AIDS 2000;14:2794-5.
- Khaliq Y, Gallicano K, Tisdale C et al. Pharmacokinetic interaction between mefloquine and ritonavir in healthy volunteers. Br J Clin Pharmacol 2001;51:591-600
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