Since HIV was identified as the viral cause of AIDS in the 1980s, an estimated 20 million AIDS-related deaths have occurred and 60 million people have been infected, according to UNAIDS. The largest burden of disease is in Sub-Saharan Africa, which accounts for 71 percent of all HIV/AIDS cases. Unlike HIV/AIDS, malaria is not a "new" disease. Malaria has caused illness and death globally for thousands of years in countries of the northern and southern hemispheres. But today, like HIV/AIDS, the heaviest disease burden for malaria falls on developing countries; in particular, according to Roll Back Malaria, more than 90 percent of malaria-related deaths occur in Sub-Saharan Africa.
Epidemiology
Human immunodeficiency virus 1 (HIV) is the infectious agent that leads to acquired immune deficiency syndrome (AIDS). According to UNAIDS, in 2008 there were approximately two million AIDS-related deaths, and 2.7 new HIV infections were acquired; 33.4 million people are estimated to be living with HIV/AIDS. According to Roll Back Malaria, malaria infections cause an estimated one million deaths each year and around 85 percent percent of all malaria-related deaths occur among children under five years of age in Sub-Saharan Africa. In 2008, there were also an estimated 247 million new malaria infections, causing significant morbidity.
Disease Interactions
The heaviest burdens of HIV are in the Southern African region, while the heaviest malaria burdens are in Eastern and Western African countries. However, there are some regions where the diseases do overlap, and evidence from Abu-Raddad et al, in 2006 suggests that interactions between HIV and malaria infections can increase both AIDS cases and malaria incidence.
Pregnant Women
According to some studies, for pregnant women there is clear evidence of negative effects of co-infection with HIV and malaria. In 2004 ter Kuile et al. described that pregnant women with HIV have more malaria parasites in the placenta, overall higher malaria parasite burdens, more clinical malaria, more anemia and greater risks of problematic birth outcomes than those without HIV. In 2004, Mwapasa et al. showed that for pregnant women infected with malaria, HIV levels were increased in the placenta compared to those who didn't have malaria. Both HIV and malaria can be transmitted from mother to infant at birth, but it remains unclear whether rates of mother to child transmission change when both infections are present.
Disease Transmission
While both HIV/AIDS and malaria create heavy disease burdens in Sub-Saharan Africa, the diseases are very different in their infectious organisms, modes of transmission, symptoms and treatments, among other factors. Both organisms are, however, found in the blood of their human hosts. Unlike malaria, which is transmitted to humans by infected mosquitoes, HIV is transmitted directly from person to person via exchange of blood or bodily fluids. The most common method of HIV transmission is via sexual intercourse.
Preventing Infection
Just as HIV/AIDS and malaria have very different transmission routes, they also have very different preventative measures. To reduce the risk of malaria, intermittent preventative treatments (IPT) are recommended by the World Health Organization for pregnant women and infants; prophylactic drugs are recommended for travelers to malaria endemic regions. For HIV, there are no recommended preventative medications. However, risk of disease can be significantly reduced by other personal protection measures for both malaria and HIV. For HIV, proper use of condoms during intercourse can prevent infection. For malaria, insecticide treated bed-nets (ITN) can reduce the risk of disease.
While there is some hope that vaccines will become available to combat these diseases, as of 2010 there are no licensed vaccines available to prevent either malaria or HIV.
