Supplemental measles vaccine antibody response among HIV-infected and -uninfected children in Malawi after 1- and 2-dose primary measles vaccination schedules.

Background: The long-term antibody response to measles vaccine (MV) administered at age 6 months with or without subsequent doses is not well documented.

Methods: Measles serum antibody responses were evaluated after a supplemental dose of measles vaccine (sMV) administered at a median age of 20 months among Malawian children who had previously received 2 doses of measles vaccine (MV) at ages 6 and 9 months (HIV-infected and random sample of HIV-uninfected) or 1 dose at age 9 months (random sample of HIV-uninfected). We compared measles antibody seropositivity between groups by enzyme linked immunoassay and seroprotection by plaque reduction neutralization geometric mean concentrations.

Persistence of vaccine-induced measles antibody beyond age 12 months: a comparison of response to one and two doses of Edmonston-Zagreb measles vaccine among HIV-infected and uninfected children in Malawi.

Background: Previously, we demonstrated that measles antibody prevalence was lower at age 12 months among children infected with human immunodeficiency virus (HIV) than uninfected children following measles vaccination (MV) at ages 6 and 9 months. Among HIV-uninfected children, measles antibody prevalence was lower among 1- than 2-dose MV recipients. Here, we report results through age 24 months.

Epidemiology of rotavirus infection in children in Blantyre, Malawi, 1997-2007.

Acute gastroenteritis caused by rotavirus infection is an important cause of morbidity and mortality among infants and young children in Africa. From 1997 through 2007, we enrolled 3740 children <5 years of age with acute gastroenteritis who received hospital care at the Queen Elizabeth Central Hospital in Blantyre, Malawi. Group A rotavirus was detected in fecal specimens by enzyme immunoassay.

The effect of human immunodeficiency virus and breastfeeding on the nutritional status of African children.

Background: The risk of HIV-1 infection is high among breast-fed children in sub-Saharan Africa. Monitoring the nutritional status can provide useful information to determine the effect of HIV infection and breast-feeding on child growth and development. We longitudinally assessed the nutritional status and determined its association with HIV infection and breast-feeding among Malawian children.

The role of transplacental microtransfusions of maternal lymphocytes in HIV transmission to newborns.

Background: Perinatal HIV transmission could occur via microtransfused maternal blood during delivery. If so, detecting maternal cells in umbilical cord blood should correlate with infection risk.

Objective: To develop sensitive assays for maternal DNA in infant's blood stored as dried blood spots (DBS) and examine the correlation between microtransfusion and perinatal HIV infection risk.

Evaluation of the immune response to a 2-dose measles vaccination schedule administered at 6 and 9 months of age to HIV-infected and HIV-uninfected children in Malawi.

Background: The World Health Organization recommends that infants at high risk for developing measles before 9 months of age, including human immunodeficiency virus (HIV)-infected infants, receive measles vaccination (MV) at 6 and 9 months of age.

Methods: Children born to HIV-infected mothers received MV at 6 and 9 months, and children of HIV-uninfected mothers were randomized to receive MV at 6 and 9 months, MV at 9 months, or routine MV without follow-up. Blood samples were obtained before and 3 months after each MV.

Late postnatal transmission of HIV-1 and associated factors.

Background: The present study was undertaken to determine the risk and timing of late postnatal transmission (LPT) of human immunodeficiency virus type 1 (HIV-1).

Methods: Breast-fed infants previously enrolled in 2 trials of antiretroviral prophylaxis were monitored in Malawi. Kaplan-Meier and proportional hazard models assessed cumulative incidence and association of factors with LPT.

The impact of breastfeeding on the health of HIV-positive mothers and their children in sub-Saharan Africa.

Objective: We assessed the impact of breastfeeding by women infected with human immunodeficiency virus (HIV)-1 on their morbidity and risk of mortality and on the mortality of their children.

Methods: We analysed longitudinal data from two previous randomized clinical trials of mother-to-child transmission of HIV conducted between April 2000 and March 2003 in the Republic of Malawi, Africa. Mothers infected with HIV, and their newborns, were enrolled at the time of their child's birth; they then returned for follow-up visits when the child was aged 1 week, 6-8 weeks and then 3, 6, 9, 15, 18, 21 and 24 months.

Higher in utero and perinatal HIV infection risk in girls than boys.

Objective: This study analyzed mother-to-child HIV transmission rates by sex and exposure time for babies born to HIV-infected, untreated African women.

Methods: Data were analyzed from 2 independent studies done in Malawi during the 1990s. Infections were established by polymerase chain reaction on blood samples.

Status of carotenoids, vitamin A, and vitamin E in the mother-infant dyad and anthropometric status of infants in Malawi.

This prospective study was carried out during February 2000-April 2003 to characterize the relationship between the status of carotenoids, vitamin E, and retinol and anthropometric status in apparently healthy infants and their mothers in Blantyre, Malawi. Anthropometric status of infants and concentrations of carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, zeaxanthin, and lycopene), retinol, and alpha-tocopherol in plasma were measured in 173 infants at 12 months of age, and concentrations of carotenoids, retinol, and a-tocopherol in plasma were measured in their mothers two weeks postpartum. In multivariate analyses, concentrations of retinol, total carotenoids, non-provitamin A carotenoids, and alpha-tocopherol in infants were associated with under-weight (p = 0.

Detection and characterization of human caliciviruses in hospitalized children with acute gastroenteritis in Blantyre, Malawi.

The human caliciviruses (HuCVs), including Norovirus and Sapovirus, are recognized causes of acute gastroenteritis in children and adults. A 1-year study was undertaken in Blantyre, Malawi, to examine the prevalence, and genetic diversity, of human caliciviruses (HuCVs) amongst children under 5 years of age hospitalized with acute gastroenteritis. Using the reverse transcription-polymerase chain reaction (RT-PCR), combined with nucleotide sequencing of the RT-PCR products, HuCVs were detected in 34/398 (8.

Haematological changes in African children who received short-term prophylaxis with nevirapine and zidovudine at birth.

We assessed the safety of short-term antiretroviral prophylaxis to prevent mother-to-child transmission (MTCT) of HIV by monitoring haematological changes in children up to the age of 18 months. Babies of HIV-infected women were randomised at birth to receive a single dose of nevirapine (NVP) alone or with zidovudine (ZDV) twice daily for a week. Based on the time of presentation to the labour ward, mothers of these babies might or might not have received intrapartum NVP.

Gender differences in perinatal HIV acquisition among African infants.

Objective: We investigated gender-specific risks of mother-to-child transmission (MTCT) at birth and at 6 to 8 weeks among infants born to HIV-infected African women.

Design: Follow-up study of infants enrolled in 2 randomized, phase III, clinical trials to prevent MTCT, conducted in Blantyre, Malawi, in southeast Africa.

Methods: Infants were enrolled at birth and monitored postnatally, and their HIV status was assessed at birth and at 6 to 8 weeks (assessment beyond 6-8 weeks is ongoing).

The 2000 Burkitt lymphoma trial in Malawi.

Background: We previously reported 57% 12-month event free survival (EFS) in Malawian children with stage I to III Burkitt lymphoma (BL) with an intermediate dose chemotherapy protocol lasting 77 days. This protocol was shortened to 42 days and evaluated in children with stage I to IV disease for EFS and toxicity.

Methods: All Malawian children admitted to Queen Elizabeth Central Hospital, from 03/08/2000 to 12/03/2002 with confirmed BL were eligible.

HIV infection among paediatric in-patients in Blantyre, Malawi.

To investigate the impact of HIV infection on hospital admission and death we studied children admitted to paediatric medical and surgical wards in Blantyre, Malawi, in March 2000. Unselected children whose parents or guardians consented to HIV testing of the child were recruited and HIV infection was determined by serology, with confirmation in children aged 15 months or less by PCR. We assessed the prevalence of HIV infection by age, clinical diagnosis and outcome of admission.

Nevirapine and zidovudine at birth to reduce perinatal transmission of HIV in an African setting: a randomized controlled trial.

Context: Antenatal counseling and human immunodeficiency virus (HIV) testing are not universal in Africa; thus, women often present in labor with unknown HIV status without receiving the HIVNET 012 nevirapine (NVP) regimen (a single oral dose of NVP to the mother at the start of labor and to the infant within 72 hours of birth).

Objective: To determine risk of mother-to-child transmission of HIV when either standard use of NVP alone or in combination with zidovudine (ZDV) was administered to infants of women tested at delivery.

Design, Setting, And Participants: A randomized, open-label, phase 3 trial conducted between April 1, 2000, and March 15, 2003, at 6 clinics in Blantyre, Malawi, Africa.

Post-neonatal infant mortality in Malawi: the importance of maternal health.

In a cohort study of mothers and their infants, information was collected from women attending the antenatal services of two hospitals in a rural area of Malawi and 561 of their babies were enrolled in a follow-up study. There were 128 with a low birthweight (LBW, <2500 g), 138 with fetal anaemia (FA, cord haemoglobin <12.5 g/dl), 42 with both and 228 with a normal birthweight and no FA.

Whole-body leucine kinetics and the acute phase response during acute infection in marasmic Malawian children.

This study compared leucine kinetics and acute-phase protein and cytokine concentrations in three groups of Malawian children who were fed an isoenergetic, isonitrogenous diet: children with marasmus with (n = 25) and without (n = 17) infection and well-nourished children with infection (n =13). The hypotheses tested were that whole-body leucine kinetics will be less in marasmic acutely infected children than in well-nourished acutely infected children but greater than in marasmic uninfected children. Children were studied after 24 h of therapy using standard (13)C-leucine stable isotope tracer techniques.

Molecular epidemiology of cryptosporidiosis in children in Malawi.

Few studies have examined the molecular epidemiology of cryptosporidiosis in developing countries. In this study, DNA of 69 microscopy-positive human fecal samples collected from Malawi were examined by multilocus genetic analyses. From 43, 27 and 28 of the samples, the SSU rRNA, 70 kDa heat shock protein (HSP70) and 60 kDa glycoprotein (GP60) genes, respectively, were successfully PCR-amplified.

Malawi pilot study of Burkitt lymphoma treatment.

Background: Burkitt lymphoma (BL) accounts for 50% of childhood cancer in Malawi. Lack of resources precludes the use of new successful treatment approaches such as the LMB 89 group B protocol, which cures >80% of children with stage III BL with high dose chemotherapy and matching supportive care. Our objective was to achieve a good cure rate in Murphy stage I-III BL with manageable toxicity in Malawi at a drug cost of <1000 US dollars per patient.

Short postexposure prophylaxis in newborn babies to reduce mother-to-child transmission of HIV-1: NVAZ randomised clinical trial.

Background: In sub-Saharan Africa, most women present late for delivery with unknown HIV status, which limits the use of intrapartum nevirapine to prevent mother-to-child transmission of HIV. We aimed to determine whether post-exposure prophylaxis of nevirapine plus zidovudine given to babies only reduced transmission of HIV more than did a regimen of nevirapine alone.

Methods: We randomly assigned 1119 babies of Malawian women with HIV-1 who presented late (ie, within 2 h of expected delivery) to either nevirapine alone or nevirapine and zidovudine.

The risk of human immunodeficiency virus-1 infection in twin pairs born to infected mothers in Africa.

We examined birth order and delivery route as risk factors for mother-to-child transmission of human immunodeficiency virus (HIV)-1 in 315 twin pairs born in Malawi during 1994-1998. No antiretroviral drugs were administered to these subjects. Infections were detected by polymerase chain reaction and were stratified as having occurred either in utero, perinatally, or postnatally.