[Ip-health] Dual Infection with HIV and Malaria Fuels the Spread of Both Diseases in Sub-Saharan Africa

[Ira Glazer]

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http://www.medicalnewstoday.com/healthnews.php?newsid=58583

Scientists working in Kenya have found that the interaction between
malaria and HIV infection may be causing both to spread more quickly in
sub-Saharan Africa. The researchers are from the Fred Hutchinson Cancer
Research Center and the University of Washington.

The study is published in the Dec. 8, 2006 issue of /Science/.

After conducting tests in Kisumu, a town on the shores of Lake Victoria
where there is a high incidence of malaria, researchers noticed that a
co-infection effect may be occuring between malaria and HIV infection.

Once malaria gets into the blood of a person with HIV, it increases the
level of the HIV virus by up to ten times during a malaria fever
episode. This significantly increases the risk of them infecting a
sexual partner with HIV. And once a person has HIV, they are more
susceptible to malaria, and so it continues.

This could explain why HIV is spreading more quickly than through sexual
transmission alone in that region.

The researchers used a mathematical model developed with HIV and malaria
infection data from Malawi to estimate that in a population of 200,000,
since 1980, 8,500 excess HIV infections and nearly 1 million excess
malarial episodes (when the fever breaks out from time to time in an
infected person) may be due to this "partnership" between the two diseases.

They suggest it is possible that similar effects may exist between HIV
and other common diseases such as genital herpes and tuberculosis, which
are widespread in the region.

abstract below:

Laith J. Abu-Raddad, Padmaja Patnaik, and James G. Kublin
/Science/ 8 December 2006: Vol. 314. no. 5805, pp. 1603 - 1606
DOI: 10.1126/science.1132338

Mounting evidence has revealed pathological interactions between^ HIV
and malaria in dually infected patients, but the public^ health
implications of the interplay have remained unclear.^ A transient almost
one-log elevation in HIV viral load occurs^ during febrile malaria
episodes; in addition, susceptibility^ to malaria is enhanced in
HIV-infected patients. A mathematical^ model applied to a setting in
Kenya with an adult population^ of roughly 200,000 estimated that, since
1980, the disease interaction^ may have been responsible for 8,500
excess HIV infections and^ 980,000 excess malaria episodes. Co-infection
might also 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.