Browsing by Author "Lule, Swaib A."

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    Factors affecting the infant antibody response to measles immunisation in Entebbe-Uganda
    (BMC public health,, 2013) Kizito, Dennison; Tweyongyere, Robert; Namatovu, Alice; Webb, Emily L.; Muhangi, Lawrence; Lule, Swaib A.; Bukenya, Henry; Cose, Stephen; Elliott, Alison M.
    Background: Vaccine failure is an important concern in the tropics with many contributing elements. Among them, it has been suggested that exposure to natural infections might contribute to vaccine failure and recurrent disease outbreaks. We tested this hypothesis by examining the influence of co-infections on maternal and infant measles-specific IgG levels. Methods: We conducted an observational analysis using samples and data that had been collected during a larger randomised controlled trial, the Entebbe Mother and Baby Study (ISRCTN32849447). For the present study, 711 pregnant women and their offspring were considered. Helminth infections including hookworm, Schistosoma mansoni and Mansonella perstans, along with HIV, malaria, and other potential confounding factors were determined in mothers during pregnancy and in their infants at age one year. Infants received their measles immunisation at age nine months. Levels of total IgG against measles were measured in mothers during pregnancy and at delivery, as well as in cord blood and from infants at age one year. Results: Among the 711 pregnant women studied, 66% had at least one helminth infection at enrolment, 41% had hookworm, 20% M. perstans and 19% S. mansoni. Asymptomatic malaria and HIV prevalence was 8% and 10% respectively. At enrolment, 96% of the women had measles-specific IgG levels considered protective (median 4274 mIU/ml (IQR 1784, 7767)). IgG levels in cord blood were positively correlated to maternal measles-specific IgG levels at delivery (r = 0.81, p < 0.0001). Among the infants at one year of age, median measles-specific IgG levels were markedly lower than in maternal and cord blood (median 370 mIU/ml (IQR 198, 656) p < 0.0001). In addition, only 75% of the infants had measles-specific IgG levels considered to be protective. In a multivariate regression analysis, factors associated with reduced measles-specific antibody levels in infancy were maternal malaria infection, infant malaria parasitaemia, infant HIV and infant wasting. There was no association with maternal helminth infection. Conclusion: Malaria and HIV infection in mothers during pregnancy, and in their infants, along with infant malnutrition, may result in reduction of the antibody response to measles immunisation in infancy. This re-emphasises the importance of malaria and HIV control, and support for infant nutrition, as these interventions may have benefits for vaccine efficacy in tropical settings.
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    Impact of Anthelminthic Treatment in Pregnancy and Childhood on Immunisations, Infections and Eczema in Childhood: A Randomised Controlled Trial
    (PloS one, 2012) Ndibazza, Juliet; Mpairwe, Harriet; Webb, Emily L.; Mawa, Patrice A.; Nampijja, Margaret; Muhangi, Lawrence; Kihembo, Macklyn; Lule, Swaib A.; Rutebarika, Diana; Apule, Barbara; Akello, Florence; Akurut, Hellen; Oduru, Gloria; Naniima, Peter; Kizito, Dennison; Kizza, Moses; Kizindo, Robert; Tweyongere, Robert; Alcock, Katherine J.; Muwanga, Moses; Alison M., Elliott
    Helminth infections may modulate immune responses to unrelated pathogens and allergens; these effects may commence prenatally. We addressed the hypothesis that anthelminthic treatment in pregnancy and early childhood would improve responses to immunisation and modulate disease incidence in early childhood with both beneficial and detrimental effects. A randomised, double-blind, placebo-controlled trial was conducted in Entebbe, Uganda [ISRCTN32849447]. In three independent randomisations, 2507 pregnant women were allocated to receive single-dose albendazole or placebo, and praziquantel or placebo; 2016 of their offspring were randomised to receive quarterly singledose albendazole or placebo from age 15 months to 5 years. Primary outcomes were post-immunisation recall responses to BCG and tetanus antigens, and incidence of malaria, diarrhoea, and pneumonia; incidence of eczema was an important secondary outcome. Analysis was by intention-to-treat. Of 2345 live births, 1622 (69%) children remained in follow-up at age 5 years. 68% of mothers at enrolment, and 11% of five-year-olds, had helminth infections. Maternal hookworm and Schistosoma mansoni were effectively treated by albendazole and praziquantel, respectively; and childhood hookworm and Ascaris by quarterly albendazole. Incidence rates of malaria, diarrhoea, pneumonia, and eczema were 34, 65, 10 and 5 per 100 py, respectively. Albendazole during pregnancy caused an increased rate of eczema in the children (HR 1.58 (95% CI 1.15–2.17), p = 0.005). Quarterly albendazole during childhood was associated with reduced incidence of clinical malaria (HR 0.85 (95% CI 0.73–0.98), p = 0.03). There were no consistent effects of the interventions on any other outcome. Routine use of albendazole in pregnancy may not always be beneficial, even in tropical developing countries. By contrast, regular albendazole treatment in preschool children may have an additional benefit for malaria control where helminths and malaria are co-endemic. Given the low helminth prevalence in our children, the effect of albendazole on malaria is likely to be direct.
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    The impact of maternal infection with Mycobacterium tuberculosis on the infant response to bacille Calmette–Gue´rin immunization
    (Philosophical Transactions of the Royal Society B: Biological Sciences, 2015) Mawa, Patrice A.; Nkurunungi, Gyaviira; Egesa, Moses; Webb, Emily L.; Smith, Steven G.; Kizindo, Robert; Akello, Mirriam; Lule, Swaib A.; Muwanga, Moses; Dockrell, Hazel M.; Cose, Stephen; Elliott, Alison M.
    Bacille Calmette–Gue´rin (BCG) immunization provides variable protection against tuberculosis. Prenatal antigen exposure may have lifelong effects on responses to related antigens and pathogens. We therefore hypothesized that maternal latent Mycobacterium tuberculosis infection (LTBI) influences infant responses to BCG immunization at birth. We measured antibody (n ¼ 53) and cellular (n ¼ 31) responses to M. tuberculosis purified protein derivative (PPD) in infants of mothers with and without LTBI, in cord blood and at one and six weeks after BCG. The concentrations of PPD-specific antibodies declined between birth (median [interquartile range (IQR)]) 5600 ng ml21 [3300–11 050] in cord blood) and sixweeks (0.00 ng ml21 [0–288]). Frequencies of PPD-specific IFN-g-expressing CD4þT cells increased at one week and declined between one and six weeks ( p ¼ 0.031). Frequencies of IL-2- and TNF-a-expressing PPD-specific CD4þT cells increased between one and six weeks ( p ¼ 0.019, p ¼ 0.009, respectively). At one week, the frequency of PPD-specific CD4þT cells expressing any of the three cytokines, combined, was lower among infants of mothers with LTBI, in crude analyses ( p ¼ 0.002) and after adjusting for confounders (mean difference, 95% CI 20.041% (20.082, 20.001)). In conclusion, maternal LTBI was associated with lower infant anti-mycobacterial T-cell responses immediately following BCGimmunization. These findings are being explored further in a larger study.
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    Maternal HIV infection and other factors associated with growth outcomes of HIV-uninfected infants in Entebbe, Uganda
    (Public health nutrition, 2013) Muhangi, Lawrence; Lule, Swaib A.; Mpairwe, Harriet; Ndibazza, Juliet; Kizza, Moses; Nampijja, Margaret; Nakazibwe, Esther; Kihembo, Macklyn; Elliott, Alison M.; Webb, Emily L.
    To assess the associations between maternal HIV infection and growth outcomes of HIV-exposed but uninfected infants and to identify other predictors for poor growth among this population. Within a trial of de-worming during pregnancy, the cohort of offspring was followed from birth. HIV status of the mothers and their children was investigated and growth data for children were obtained at age 1 year. Lengthfor- age, weight-for-age and weight-for-length Z-scores were calculated for each child; Z-scores ,22 were defined as stunting, underweight and wasting, respectively. Setting: The study was conducted in Entebbe municipality and Katabi subcounty, Uganda. Subjects: The sample consisted of 1502 children aged 1 year: HIV-unexposed (n 1380) and HIV-exposed not infected (n 122). Results: Prevalence of stunting, underweight and wasting was 14?2%, 8?0% and3?9%, respectively. There was evidence for an association between maternal HIV infection and odds of being underweight (adjusted OR52?32; 95% CI 1?32, 4?09; P50?006) but no evidence for an association with stunting or with wasting. Young maternal age, low maternal education, low birth weight, early weaning and experiencing a higher number of episodes of malaria during infancy were independent predictors for stunting and underweight. A higher number of living children in the family was associated with wasting. Conclusions: Maternal HIV infection was associated with being underweight in HIV-exposed uninfected infants. The success of programmes for prevention of mother-to-child HIV transmission means that an increasing number of infants will be born to HIV-infected women without acquiring HIV. Therefore, viable nutritional interventions need to be identified for this population.
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    Maternal Recall of Birthweight and Birth Size in Entebbe, Uganda
    (Tropical medicine & international health, 2012) Lule, Swaib A.; Webb, Emily L.; Ndibazza, Juliet; Nampijja, Margaret; Muhangi, Lawrence; Akello, Florence; Kakande, Muhammed; Kizindo, Robert; Elliott, Alison M.
    To assess the reliability of maternally recalled birthweight and size in Entebbe, Uganda. The study population comprised 404 mothers, who were participants in the Entebbe Mother and Baby Study (EMaBS). Mothers were recruited to EMaBS during antenatal care, maternal characteristics were recorded during pregnancy, and birthweight was recorded at delivery. Four to seven years after delivery, mothers were asked to recall the child’s birthweight and size. Their responses were compared with the birthweight recorded in the EMaBS database. Of 404 interviewed mothers, 303 (75%) were able to give an estimate of birthweight and for 265 of these EMaBS data on recorded birthweights were available. Women who were educated and whose children had low birth order were more likely to be able to give an estimate: 37 (14%) recalled the exact recorded birthweight; a further 52 (20%) were accurate to within 0.1 kg of the recorded weight. On average, mothers overestimated birthweight by 0.06 kg (95% CI: 0.00–0.13 kg, P = 0.04). Recalled and recorded birthweights showed moderate agreement with an intraclass correlation coefficient of 0.64. Four hundred mothers gave an estimate of birth size: the sensitivity and specificity of recalled birth size for classifying low birthweight were 76%(95%CI: 50–93%) and 70%(95%CI: 65–75%), respectively. Mothers’ recall of birthweight was not precise but in absence of other data, recall of birthweight and size may have some value in epidemiological studies in these settings.