The effect of dual infection with HIV and malaria on pregnancy outcome in western Kenya.

OBJECTIVE: To determine the effect of dual infection with HIV and malaria on birth outcomes and maternal anaemia among women delivering at a large public hospital in Kisumu, western Kenya. SUBJECTS AND METHODS: Data on obstetric and neonatal characteristics, maternal and placental parasitaemia, and postpartum haemoglobin levels were collected from women enrolled in a cohort study of the interaction between malaria and HIV during pregnancy. RESULTS: Between 1996 and 1999, data were available from 2466 singleton deliveries. The maternal HIV seroprevalence was 24.3%, and at delivery 22.0% of the women had evidence of malaria. Low birthweight, preterm delivery (PTD), intrauterine growth retardation (IUGR) and maternal anaemia (haemoglobin < 8 g/dl) occurred in 4.6, 6.7, 9.8 and 13.8% of deliveries, respectively. Maternal HIV, in the absence of malaria, was associated with a 99 g (95% CI 52-145) reduction in mean birthweight among all gravidae. Malaria was associated with both IUGR and PTD, resulting in a reduction in mean birthweight of 145 g (95% CI 82-209) among HIV-seronegative and 206 g (95% CI 115-298) among HIV-seropositive primigravidae, but not among multigravidae. Both HIV and malaria were significant risk factors for postpartum maternal anaemia, and HIV-seropositive women with malaria were twice as likely to have anaemia than HIV-seronegative women with or without malaria. CONCLUSION: Women with dual infection are at particular risk of adverse birth outcomes. In areas with a moderate or high prevalence of HIV and malaria, all pregnant women should be the focus of malaria and anaemia control efforts to improve birth outcomes.

HIV increases the risk of malaria in women of all gravidities in Kisumu, Kenya.

OBJECTIVE: To study the importance of HIV infection for malaria in pregnancy in Kisumu, Kenya. SUBJECTS AND METHODS: Healthy women with an uncomplicated pregnancy of 32 weeks or more attending the prenatal clinic in the Provincial Hospital between June 1996 and March 1999 were tested for HIV and malaria after consent had been obtained. For participating women who delivered in the same hospital, a blood smear of the mother and the placenta were obtained. RESULTS: In the third trimester, 5093 women consented to testing: the prevalence of malaria and HIV was 20.1 and 24.9%, respectively. Among the 2502 screened women who delivered in the hospital, the prevalence of HIV, peripheral parasitaemia and placental malaria was 24.5, 15.2, and 19.0%, respectively. Compared with HIV-seronegative women, HIV-seropositive women were more likely to be parasitaemic, to have higher parasite densities, and to be febrile when parasitaemic. Placental infections in HIV-seropositive women were more likely to be chronic, as indicated by the presence of moderate to heavy pigment depositions. When adjusted by age, the typical gravidity-specific pattern of malaria in pregnancy disappeared in HIV-seropositive women; HIV-seropositive primigravidae had a similar risk of malaria as HIV-seropositive multigravidae. The excess malaria attributable to HIV in the third trimester increased from 34.6% among HIV-seropositive primigravidae, to 41.5% among HIV-seropositive secundigravidae, and 50.7% among HIV-seropositive gravidae with three or more pregnancies. CONCLUSION: HIV infection alters patterns of malaria in pregnant women; in areas with both infections, all pregnant women should use malaria prevention.

Genetic diversity of HIV-1 in western Kenya: subtype-specific differences in mother-to-child transmission.

BACKGROUND: Little is known about the impact of HIV-1 group M subtypes on mother-to-child transmission (MTCT) of HIV-1 in African settings where multiple HIV-1 group M subtypes are co-circulating. OBJECTIVE: To assess the role of subtype variation on MTCT. METHODS: HIV-1-infected women attending an antenatal clinic in western Kenya were enrolled for a prospective study (1996-2000) of MTCT. HIV-1 subtype analysis of p24gag and gp41env identified potential recombinants, and their role in MTCT was determined. RESULTS: Among 414 women for whom HIV-1 subtype and HIV transmission status were available, MTCT occurred in 80 (19.3%). MTCT rates were higher among women with subtype D compared with subtype A in either the gp41 region [31.6 versus 16.1%, relative risk (RR) 2.0, P=0.002] or p24 region (29.9 versus 18.0%, RR 1.7, P=0.02). Discordant subtype combinations were identified in 103 of the women (25.9%), and were associated with higher rates of MTCT (28.2 versus 17.0%, RR 1.7, P=0.01). In multivariate analysis, women with subtype combinations D/D, D/A, and A/D had an increased risk of MTCT (adjusted odds ratios 3.5, 2.5, 6.2; P=0.005, 0.05, and 0.0003, respectively) compared with A/A women after adjustment for maternal HIV viral load, placental malaria infection, episiotomy or perineal tear, and low birthweight. CONCLUSION: MTCT appears to be more common among mothers infected with subtype D compared with subtype A. Such differences in MTCT frequency may be caused by altered cellular tropism for placental cell types.

Malaria and human immunodeficiency virus infection as risk factors for anemia in infants in Kisumu, western Kenya.

The role of maternal and pediatric infection with human immunodeficiency virus type 1 (HIV-1) and malaria as risk factors for anemia was determined in a birth cohort of infants born to mothers participating in a study of the interaction between placental malaria and HIV infection, in Kisumu, Kenya. Between June 1996 and April 2000, 661 infants born to 467 HIV-seropositive and 194 HIV-seronegative mothers were monitored monthly from birth. At each visit a questionnaire was completed and a blood sample was collected for the determination of hemoglobin levels and detection of malaria and HIV. Anemia was common and increased from 13.6% at one month to 75% at six months and remained high throughout the second half of infancy. Placental malaria, infant malaria, and HIV infection of the infant were all associated with infant anemia in a multivariate model, adjusting for other co-variates found to be associated with infant anemia. The HIV-infected infants with malaria parasitemia had lower mean hemoglobin levels compared with HIV-uninfected infants, or HIV-infected infants without malaria, suggesting that HIV-infected infants are particularly vulnerable to the adverse consequences of malaria at this age. Early detection and prompt treatment of infant malaria and treatment of anemia as part of the study protocol failed to prevent most of the infants from becoming anemic. Although not proven effective in this study, micronutrient supplementation should be prospectively assessed in HIV-infected infants as a means of preventing anemia.

Risk factors for malaria in pregnancy in an urban and peri-urban population in western Kenya.

To assess risk factors for malaria in pregnancy in Kisumu, western Kenya, we studied healthy women with an uncomplicated pregnancy of > or = 32 weeks attending the antenatal clinic in the Provincial Hospital. Between June 1996 and March 1999, malaria and human immunodeficiency virus (HIV) infection were examined in 5093 pregnant women: 20.1% of the women were parasitaemic and 24.9% were HIV-seropositive. 2502 women delivered in the hospital and a smear was obtained: the prevalence of placental malaria, maternal peripheral parasitaemia, and HIV infection was respectively 19.0%, 15.2% and 24.5%. HIV infection (risk ratio [RR] 1.58, 95% confidence interval [95% CI] 1.32-1.89), young age (< 21 years: RR 1.51, 95% CI 1.19-1.91), being a primigravidae (RR 1.41, 95% CI 1.05-1.88), a peri-urban residence (RR 1.50, 95% CI 1.21-1.88), and Luo ethnicity (RR 1.74, 95% CI 1.35-2.24) were risk factors for malaria at delivery. Use of sulfadoxine-pyrimethamine (SP), reported by 2.1% of the women, was a protective factor (RR 0.44, 95% CI 0.18-1.06). Results were similar in the third trimester. In this urban/peri-urban setting, preventing HIV infection, delaying the first pregnancy until after adolescence, and applying an effective antimalarial strategy such as intermittent therapy with SP will reduce the prevalence of malaria in pregnancy.

Preventing mother-to-child transmission of HIV in Western Kenya: operational issues.

OBJECTIVES: To improve uptake in a program to prevent mother-to-child HIV transmission and describe lessons relevant for prevention of mother-to-child transmission programs in resource-poor settings. METHODS: Implementation of a pilot project that evaluates approaches to increase program uptake at health facility level at New Nyanza Provincial General Hospital, a public hospital in western Kenya, an area with high HIV prevalence. Client flow was revised to integrate counseling, HIV testing, and dispensing of single-dose nevirapine into routine antenatal services. The number of facilities providing PMCT services was expanded to increase district-wide coverage. Main outcome measures were uptake of counseling, HIV testing, nevirapine, and estimated program impact. RESULTS: Uptake of counseling and testing improved from 55 to 68% (P < 0.001), nevirapine uptake from 57% to 70% (P < 0.001), and estimated program impact from 15% to 23% (P = 0.03). Aggregate reports compare well with computer-entered data. CONCLUSION: Addressing institutional factors can improve uptake, but expected program impact remains low for several reasons, including relatively low efficacy of the intervention and missed opportunities in the labor room.

Implementation of intermittent preventive treatment with sulphadoxine-pyrimethamine for control of malaria in pregnancy in Kisumu, western Kenya.

OBJECTIVE: In 1998, the Kenyan Ministry of Health introduced intermittent preventive treatment (IPT) with sulphadoxine-pyrimethamine (SP), one treatment dose in the second trimester (16-27 weeks) and one treatment dose between 28 and 34 weeks of gestational age, for the control of malaria in pregnancy. We evaluated the coverage and determinants of receipt of IPT after its introduction in the Provincial Hospital in Kisumu, western Kenya. METHODS: Information on the use of IPT in pregnancy was collected from women who attended the antenatal clinic (ANC) and delivered in the same hospital. In exit interviews, we assessed patterns of IPT use in the ANC. RESULTS: Of 1498 women who delivered between June 1999 and June 2000, 23.7%, 43.4% and 32.9% received > or =2, 1 or no dose of SP, respectively. Late first ANC attendance was the most important factor contributing to incomplete IPT; 45% of the women started attending ANC in the third trimester. More women received at least one tetanus toxoid immunization than at least one dose of IPT (94%vs. 67%, P < 0.05). In exit interviews, 74% correctly associated IPT with treatment of malaria; however, knowledge on the need for the second dose was poor. Three per cent of the administrations were given despite contraindications. The agreement between gestational age by date of last menstrual period and by palpation was low (kappa = 0.1). CONCLUSIONS: Education of pregnant women and ANC staff to increase earlier attendance for ANC has the potential to substantially increase the proportion of women receiving two doses of IPT with SP.

Maternal malaria and perinatal HIV transmission, western Kenya.

To determine whether maternal placental malaria is associated with an increased risk for perinatal mother-to-child HIV transmission (MTCT), we studied HIV-positive women in western Kenya. We enrolled 512 mother-infant pairs; 128 (25.0%) women had placental malaria, and 102 (19.9%) infants acquired HIV perinatally. Log10 HIV viral load and episiotomy or perineal tear were associated with increased perinatal HIV transmission, whereas low-density placental malaria (<10,000 parasites/mL) was associated with reduced risk (adjusted relative risk [ARR] 0.4). Among women dually infected with malaria and HIV, high-density placental malaria (>10,000 parasites/mL) was associated with increased risk for perinatal MTCT (ARR 2.0), compared to low-density malaria. The interaction between placental malaria and MTCT appears to be variable and complex: placental malaria that is controlled at low density may cause an increase in broad-based immune responses that protect against MTCT; uncontrolled, high-density malaria may simultaneously disrupt placental architecture and generate substantial antigen stimulus to HIV replication and increase risk for MTCT.