Tuesday, December 1, 2009

World AIDS Day

"Malaria and HIV are two of the most devastating global health problems of our time. Together they cause more than 4 million deaths a year" (WHO). On this World AIDS Day, Infectious Bite looks at the relationship between malaria and HIV (the virus that causes AIDS), and discusses new research to treat co-infected (simultaneously infected with both diseases) individuals.

"Our current understanding of the human immune response to malaria and HIV leads us to expect that either infection might influence the clinical course of the other." Ordinarily, "infections are associated with at least a transient increase in HIV viral load" (measure of severity) and it is logical to assume that malaria accelerates "HIV disease progression." On the other side, "immune deficiency caused by HIV infection should, in theory, reduce the immune response to malaria parasitemia and therefore increase the frequency of clinical attacks of malaria" (Whitworth).

According to UNICEF, "HIV infection increases the incidence and severity of clinical malaria. In non-pregnant adults, HIV infection has been found to roughly double the risk of malaria parasitemia and clinical malaria...Although the effect of malaria on HIV has not been so well documented, some recent research is now adding to the growing body of evidence. Acute malaria infection increases viral load, and one study found that this increased viral load was reversed by effective malaria treatment. This malaria-associated increase in viral load could lead to increased transmission of HIV and more rapid disease progression, with substantial public health implications" (UNICEF).

Treatment of malaria is also complicated by HIV. "Artemisinin combination therapy has become the standard of care for uncomplicated malaria in most of Africa. However, there is limited data on the safety and tolerability of these drugs, especially in young children and patients co-infected with HIV" (Shereen). Recently, a "controlled trial was conducted" in Uganda consisting of "HIV-infected and uninfected children aged 4-22)." Participants were randomly designated to receive treatments of artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP). Both therapies were deemed "safe and well tolerated for the treatment of uncomplicated malaria in young HIV-infected and uninfected children" (Shereen).

In conclusion, co-infection of HIV and malaria fuels the spread of both diseases. HIV increases the severity of the episode and the patient susceptibility to malaria infection. Malaria increases the viral load of HIV, thereby elevating the risk of spreading HIV. "Co-infection might...have facilitated the geographic expansion of malaria in areas where HIV prevalence is high. Hence, transient and repeated increases in HIV viral load resulting from recurrent co-infection with malaria may be an important factor in promoting the spread of HIV in sub-Saharan Africa" (Abu). The connection between HIV and malaria also corresponds to the treatment of both diseases. Artemether-lumefantrine and dihydroartemisinin-piperaquine are safe for the treatment of malaria in HIV-infected children. It is also believed that the effective treatment of malaria within HIV-infected individuals may reverse the increased viral load of co-infected individuals.

Abu-Raddad, Laith J. Et. Al. "Dual Infection with HIV and Malaria Fuels the Spread of Both Diseases in Sub-Saharan Africa". Science 8 December 2006.

Shereen, Katrak Anne. Et al. Malaria Journal 2009, 8:272
UNICEF. "Malaria and HIV/AIDS." http://www.unicef.org/health/files/UNICEFTechnicalNote6MalariaandHIV.doc

Whitworth, James. HIV InSite Knowledge Base Chapter. May 2006. http://hivinsite.ucsf.edu/InSite?page=kb-05-04-04

WHO. http://apps.who.int/malaria/malariandhivaids.html

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