Effect of HIV-1 and increasing immunosuppression on malaria parasitaemia and clinical episodes in adults in rural Uganda: a cohort study.
BACKGROUND
An association between HIV-1 and malaria is expected in theory, but has not been convincingly shown in practice. We studied the effects of HIV-1 infection and advancing immunosuppression on falciparum parasitaemia and clinical malaria.


METHODS
HIV-1-positive and HIV-1-negative adults selected from a population-based cohort in rural Uganda were invited to attend a clinic every 3 months (routine visits) and whenever they were sick (interim visits). At each visit, information was collected on recent fever, body temperature, and malaria parasites. Participants were assigned a clinical stage at each routine visit and had regular CD4-cell measurements.


RESULTS
484 participants made 7220 routine clinic visits between 1990 and 1998. Parasitaemia was more common at visits by HIV-1-positive individuals (328 of 2788 [11.8%] vs 231 of 3688 [6.3%], p<0.0001). At HIV-1-positive visits, lower CD4-cell counts were associated with higher parasite densities, compared with HIV-1-negative visits (p=0.0076). Clinical malaria was significantly more common at HIV-1-positive visits (55 of 2788 [2.0%] vs 26 of 3688 [0.7%], p=0.0003) and the odds of having clinical malaria increased with falling CD4-cell count (p=0.0002) and advancing clinical stage (p=0.0024). Participants made 3377 interim visits. The risk of clinical malaria was significantly higher at visits by HIV-1-positive individuals than HIV-1-negative individuals (4.0% vs 1.9%, p=0.009). The risk of clinical malaria tended to increase with falling CD4-cell counts (p=0.052).


CONCLUSIONS
HIV-1 infection is associated with an increased frequency of clinical malaria and parasitaemia. This association tends to become more pronounced with advancing immunosuppression, and could have important public-health implications for sub-Saharan Africa.
Whitworth
J
J
Medical Research Council Programme on AIDS, Uganda Virus Research Institute, Entebbe. mrc@starcom.co.ug
Morgan
D
D
Quigley
M
M
Smith
A
A
Mayanja
B
B
Eotu
H
H
Omoding
N
N
Okongo
M
M
Malamba
S
S
Ojwiya
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018791:CD4 Lymphocyte Count; D002648:Child; D015331:Cohort Studies; D005260:Female; D005334:Fever / Q000209:etiology; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology / Q000821:virology; D018023:HIV Seronegativity; D006679:HIV Seropositivity; D015497:HIV-1; D006801:Humans; D007165:Immunosuppression Therapy; D016778:Malaria, Falciparum / Q000097:blood* / Q000150:complications / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009819:Office Visits / Q000706:statistics & numerical data; D011247:Pregnancy; D012424:Rural Population; D012720:Severity of Illness Index; D014454:Uganda / Q000453:epidemiology