Maternal Malaria and Perinatal HIV Transmission, Western Kenya1,2

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 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 malaria (<10,000 parasites/μL) was associated with reduced risk (adjusted relative risk [ARR] 0.4). Among women dually infected with malaria and HIV, high-density malaria (>10,000 parasites/μL) 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

Workgroup report: Public health strategies for reducing aflatoxin exposure in developing countries

10.1289/ehp.9302Environmental Health Perspectives114121898-190

SARS-CoV-2 seroprevalence in three Kenyan health and demographic surveillance sites, December 2020-May 2021

Background Most of the studies that have informed the public health response to the COVID-19 pandemic in Kenya have relied on samples that are not representative of the general population. We conducted population-based serosurveys at three Health and Demographic Surveillance Systems (HDSSs) to determine the cumulative incidence of infection with SARS-CoV-2. Methods We selected random age-stratified population-based samples at HDSSs in Kisumu, Nairobi and Kilifi, in Kenya. Blood samples were collected from participants between 01 Dec 2020 and 27 May 2021. No participant had received a COVID-19 vaccine. We tested for IgG antibodies to SARS-CoV-2 spike protein using ELISA. Locally-validated assay sensitivity and specificity were 93% (95% CI 88–96%) and 99% (95% CI 98–99.5%), respectively. We adjusted prevalence estimates using classical methods and Bayesian modelling to account for the sampling scheme and assay performance. Results We recruited 2,559 individuals from the three HDSS sites, median age (IQR) 27 (10–78) years and 52% were female. Seroprevalence at all three sites rose steadily during the study period. In Kisumu, Nairobi and Kilifi, seroprevalences (95% CI) at the beginning of the study were 36.0% (28.2–44.4%), 32.4% (23.1–42.4%), and 14.5% (9.1–21%), and respectively; at the end they were 42.0% (34.7–50.0%), 50.2% (39.7–61.1%), and 24.7% (17.5–32.6%), respectively. Seroprevalence was substantially lower among children (&lt;16 years) than among adults at all three sites (p≤0.001). Conclusion By May 2021 in three broadly representative populations of unvaccinated individuals in Kenya, seroprevalence of anti-SARS-CoV-2 IgG was 25–50%. There was wide variation in cumulative incidence by location and age. </jats:sec

Human immunodeficiency virus seropositivity and malaria as risk factors for third-trimester anemia in asymptomatic pregnant women in western Kenya

To assess risk factors for anemia in late pregnancy, we studied healthy pregnant women with a singleton uncomplicated pregnancy of > or = 32 weeks attending the prenatal clinic in the Provincial Hospital in Kisumu, Kenya. Between June 1996 and December 1998, 4,608 pregnant women had a blood sample collected for hemoglobin (Hb) measurement, malaria smear, and testing for human immunodeficiency virus (HIV). The mean +/- standard deviation of Hb was 9.58 +/- 1.8 g/dL; 21% had malaria in their blood; and 25% of the women were HIV seropositive. Plasmodium falciparum parasitemia was more common among HIV-seropositive women in all gravidities compared with HIV-seronegative women (risk ratio, 1.71; 95% confidence interval, 1.53-1.92). In a multivariate analysis, for primi- and secundigravidae women, the factors malaria, belonging to the Luo tribe, and HIV seropositivity were significantly associated with any anemia (Hb < 11 g/dL), and HIV seropositivity and documented fever were associated with severe anemia (Hb < 7 g/dL). In women of higher gravidities, HIV seropositivity was the only statistically significant factor associated with any anemia or with severe anemia. Asymptomatic HIV seropositivity is an important risk factor to be considered in the differential diagnosis of maternal anemia, independent of P. falciparum parasitemi

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

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. 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. 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. 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 roo

Effectiveness of intermittent preventive treatment with sulphadoxine-pyrimethamine for control of malaria in pregnancy in western Kenya: a hospital-based study

OBJECTIVE To monitor the effectiveness of intermittent preventive treatment (IPT) with sulphadoxine-pyrimethamine (SP) for the control of malaria in pregnancy at delivery in the Provincial Hospital in Kisumu, Kenya, and to assess the effect of IPT in participants in a cohort study. METHODS Between June 1999 and June 2000, information on IPT and birth outcome was collected in 2302 consecutive deliveries. A group of 889 women, who were enrolled in a cohort to assess the interaction between malaria and HIV, were analysed separately because of the enrolment criteria and different access to health care. RESULTS The prevalence of placental malaria was 13.8% and of low birthweight (LBW) was 12.2%. In multivariable analysis, IPT (greater than or equal to1 dose of SP) was associated with a reduction in placental malaria and LBW [adjusted odds ratio (OR) 0.56, 95% confidence interval (CI) 0.39-0.83 and OR 0.65, 95% CI 0.45-0.95, respectively]. An adjusted mean increase in birthweight of 61 g was seen (95% CI 22-101 g) for each increment in number of SP doses (greater than or equal to2 doses grouped together). IPT was associated with a reduction in placental malaria in HIV-seronegative women (OR 0.49, 95% CI 0.28-0.86) but this was not significant among HIV-seropositive women (OR 0.45, 95% CI 0.20-1.05). A significant effect on birthweight could not be detected among participants in the HIV-cohort. CONCLUSIONS This evaluation confirms that IPT with SP is effective in reducing placental malaria and LBW. It will be important to increase coverage of IPT and to extend IPT to antenatal clinics in peri-urban and rural area

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 gravid ity-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. (C) 2003 Lippincott Williams Wilkin

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. (C) 2003 Lippincott Williams Wilkin

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 greater than or equal to 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 HPV-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 periurban 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 pregnanc