Causes of deaths using verbal autopsy among adolescents and adults in rural western Kenya.

OBJECTIVE: To establish causes and patterns of deaths among adolescents and adults (age >11 years) using verbal autopsy (VA) in a rural area of western Kenya where malaria and HIV are common. METHODS: Village reporters reported all deaths in Asembo and Gem (population 135 000), an area under routine demographic surveillance. After an interval of >/=1 month, a trained interviewer used a structured questionnaire to ask the caretaker about signs and symptoms that preceded death. Three clinical officers independently reviewed the interviews and assigned two unranked causes of death; a common cause was designated as the cause of death. RESULTS: In 2003, 1816 deaths were reported from residents; 48% were male and 72% were between 20 and 64 years of age. Most residents (97%) were ill before death, with 60% of illnesses lasting more than 2 months; 87% died at home. Care was sought by 96%; a health facility was the most common source, visited by 73%. For 1759 persons (97%), a common cause of death was designated. Overall, 74% of deaths were attributed to infectious causes. HIV (32%) and tuberculosis (TB) (16%) were the most frequent, followed by malaria, respiratory infections, anaemia and diarrhoeal disease (approximately 6% each). Death in a health facility was associated with young age, higher education, higher SES, a non-infectious disease cause and a shorter duration of illness. CONCLUSION: In this area, the majority of adult and adolescent deaths were attributed to potentially preventable infectious diseases. Deaths in health facilities were not representative of deaths in the community. Programmes to prevent HIV and TB infection and to decrease mortality have started. Their impact can be evaluated against this baseline information.

The effect of health care worker training on the use of intermittent preventive treatment for malaria in pregnancy in rural western Kenya.

BACKGROUND: In 1998, Kenya adopted intermittent preventive treatment (IPTp) with sulphadoxine-pyrimethamine (SP) for malaria prevention during pregnancy. We conducted a survey in 2002 among women who had recently delivered in the rural neighbouring areas Asembo and Gem and reported coverage of 19% of at least one dose and 7% of two or more doses of SP. Health care workers (HCW) in Asembo were retrained on IPTp in 2003. OBJECTIVES: To evaluate if IPTp coverage increased and if the training in Asembo led to better coverage than in Gem, and to identify barriers to the effective implementation of IPTp. METHODS: Community-based cross-sectional survey among a simple random sample of women who had recently delivered in April 2005, interviews with HCW of antenatal clinics (ANC) in Asembo and Gem. RESULTS: Of the 724 women interviewed, 626 (86.5%) attended the ANC once and 516 (71.3%) attended two or more times. Overall IPTp coverage was 41% for at least one dose, and 21% for at least two doses of SP. In Asembo, coverage increased from 19% in 2002 to 61% in 2005 for at least one dose and from 7% to 17% for two doses of SP. In Gem, coverage increased from 17% to 28% and 7% to 11%, respectively. Interviews of HCW in both Asembo and Gem revealed confusion about appropriate timing, and lack of direct observation of IPTp. CONCLUSION: Training of HCW and use of simplified IPTp messages may be a key strategy in achieving Roll Back Malaria targets for malaria prevention in pregnancy in Kenya.

Use of intermittent preventive treatment for malaria in pregnancy in a rural area of western Kenya with high coverage of insecticide-treated bed nets.

Kenya established intermittent preventive treatment (IPT) with sulfadoxine-pyrimethamine (SP) for malaria in pregnancy as national policy in 1998. We assessed the coverage of IPT among women who had recently delivered in a rural area of western Kenya with perennial malaria transmission and high coverage with insecticide treated nets (ITNs) through a cross-sectional, community-based survey in December 2002. Antenatal clinic (ANC) attendance was high (89.9% of the 635 participating women); 77.5% of attendees visited an ANC before the third trimester and 91.9% made more than one visit. Delivery of SP by the ANC was reported by 19.1% of all women but only 6.8% reported receiving more than one dose. Given the high rate of use of ANC services, if SP were given at each visit after the first trimester, the potential coverage of IPT (two doses of SP) would be 80.3% in this study population. ITNs were used by 82.4% of women during pregnancy, and almost all mothers (98.5%) who slept under an ITN shared the nets with their newborns after delivery. Women who thought malaria in pregnancy caused foetal problems were more likely to have used an ITN (adjusted odds ratio [AOR] 1.6, 95% confidence interval [CI] 1.0-2.4), and to have visited ANC more than once (AOR 2.4, 95% CI 1.2-4.7) compared to women who thought malaria in pregnancy was either not a problem or caused problems for the mother only. These findings illustrate the need for improved IPT coverage in this rural area. Identification and removal of the barriers to provision of IPT during ANC visits can help to increase coverage. In this area of Kenya, health messages stressing that foetal complications of malaria in pregnancy may occur in the absence of maternal illness may improve the demand for IPT.

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 enrollment 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 (> or =1 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 (> or =2 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 areas.

Does infection with Human Immunodeficiency Virus affect the antibody responses to Plasmodium falciparum antigenic determinants in asymptomatic pregnant women?

OBJECTIVES: HIV-seropositive pregnant women are more susceptible to malaria than HIV-seronegative women. We assessed whether HIV infection alters maternal and cord plasma malarial antibody responses and the mother-to-infant transfer of malaria antibodies. METHODS: We determined plasma levels of maternal and cord antibodies [Immunoglobulin (IgG)] to recombinant malarial proteins [merozoite surface protein 1 (MSP-1(19kD)), the erythrocyte binding antigen (EBA-175)], the synthetic peptides [MSP-2, MSP-3, rhoptry associated protein 1 (RAP-1), and the pre-erythrocytic stage, circumsporozoite protein (NANP)(5)] antigenic determinants of Plasmodium falciparum; and tetanus toxoid (TT) by ELISA among samples of 99 HIV-seropositive mothers, 69 of their infants, 102 HIV-seronegative mothers and 62 of their infants. RESULTS: The prevalence of maternal antibodies to the malarial antigenic determinants ranged from 18% on MSP3 to 91% on EBA-175; in cord plasma it ranged from 13% to 91%, respectively. More than 97% of maternal and cord samples had antibodies to TT. In multivariate analysis, HIV infection was only associated with reduced antibodies to (NANP)(5) in maternal (P=0.001) and cord plasma (P=0.001); and reduced mother-to-infant antibody transfer to (NANP)(5) (P=0.012). This effect of HIV was independent of maternal age, gravidity and placental malaria. No consistent HIV-associated differences were observed for other antigenic determinants. CONCLUSION: An effect of HIV infection was only observed on one malarial antigenic determinant, suggesting that the increased susceptibility to malaria among HIV-infected pregnant women may not be explained on the basis of their reduced antibody response to malaria antigens.

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 parasitemia.

Risk factors for HIV infection among asymptomatic pregnant women attending an antenatal clinic in western Kenya.

Our objective was to evaluate HIV prevalence and identify risk factors for HIV infection among women attending the antenatal clinic (ANC) at a large public hospital in Kisumu town, western Kenya. Between June 1996 and November 1997, in the context of a study to determine the effect of placental malaria on mother-to-child transmission of HIV in western Kenya, HIV-1 antibody testing was offered to women with a singleton uncomplicated pregnancy of > or =32 weeks' gestation attending the ANC. Women were interviewed using a structured questionnaire and had a fingerstick blood sample collected for haemoglobin (Hb), malaria smears, and HIV antibody testing. Overall HIV seroprevalence was 26.1% (743/2844) (95% confidence interval (CI): 24.5-27.7) and in bivariate evaluation was significantly associated with anaemia (Hb <11 g/dl) (risk ratio (RR) 1.8), malarial parasitaemia (RR 1.6), fever (axillary temperature > or =37.5 degrees C at screening) (RR 1.6), a history of being treated for either vaginal discharge (RR 1.5) or tuberculosis (RR 1.6), reported alcohol consumption (RR 1.6), being an unmarried multigravida (RR 2.2) or a history of the most recent child having died (RR 2.0). Poisson regression analysis for all women identified 5 significant factors independently associated with HIV seropositivity: anaemia (adjusted RR 1.7; 95% CI 1.3-2.0), malarial parasitaemia (adjusted RR 1.7; 95% CI 1.4-2.0), a history of being treated for vaginal discharge (adjusted RR 1.5; 95% CI 1.1-2.0), fever (adjusted RR 2.0; 95% CI 1.3-3.2) and reported alcohol consumption (adjusted RR 1.6; 95% CI 1.1-2.5). Multigravidae women whose most recent child had died were also more likely to be HIV seropositive (adjusted RR 1.9; 95% CI 1.7-2.8). Only 5.5% (156/2844) of the women had none of these risk factors, of whom 12% (18/156) were HIV(+). Even though the model containing the 5 identified factors fitted the data well (goodness-of-fit chi2=18.41, P=0.10), its collective capacity to predict HIV infection was poor; while 74% of the truly positive women were correctly predicted positive by the model, 52% of the truly negative women were misclassified. Among pregnant women attending the ANC in western Kenya, we were unable to identify a subgroup at risk of HIV infection using non-serological information, indicating that wherever possible universal access to voluntary HIV counselling and testing would be preferable to targeted screening.

PIP: This study evaluated the HIV prevalence and identified the risk factors for HIV infection among women attending the antenatal clinic at a public hospital in Kisumu, western Kenya. Also, the effect of placental malaria on vertical HIV transmission were determined using structured interviews and HIV-1 antibody testing and hemoglobin malaria smears were offered to the respondents. Overall, HIV seroprevalence was 26.1% (743/2844) (95% confidence interval [CI]: 24.5-27.7) and in bivariate evaluation was significantly associated with anemia (risk ratio [RR] 1.8), malarial parasitemia (RR 1.6), fever (RR 1.6), a history of being treated for either vaginal discharge (RR 1.5) or tuberculosis (RR 1.6), alcohol consumption (RR 1.6), being an unmarried multigravida (RR 2.2), or a history of the most recent child having died (RR 2.0). Using the Poisson regression analysis, 5 significant factors associated with HIV seropositivity were identified: anemia, malarial parasitemia, and history of being treated for vaginal discharge, fever, and reported alcohol consumption. Among the pregnant women, the researchers were unable to identify a subgroup at risk of HIV infection using nonserological information, indicating that universal access to voluntary HIV counseling and testing would be preferable to targeted screening.

Pulsed heterodyne CO(2) laser rangefinder and velocimeter with chirp correction.

A pulsed hybrid CO(2) transversely excited atmosphere (TEA) laser has been used in a bistatic laser rangefinder-velocimeter system with heterodyne detection. Several techniques have been applied to improve the performance of the system. These include the stabilization of the hybrid CO(2) TEA-laser and the stabilization of the frequency offset of the local oscillator (better than ±74 kHz peak to peak), phase-front matching at the detector surface resulting in a heterodyne beat efficiency of 0.4-0.6, and chirp correction. With this system, targets at distances of up to 25 km can be detected with an accuracy of 15 m. The velocity of the targets can be estimated with an accuracy of approximately ±0.5 m/s.