Seth Owusu-Agyei

Kintampo Health Research Centre, Sunyani, Brong-Ahafo, Ghana

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Publications (142)928.36 Total impact

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    ABSTRACT: Oxytocin (10 IU) is the drug of choice for prevention of postpartum hemorrhage (PPH). Its use has generally been restricted to medically trained staff in health facilities. We assessed the effectiveness, safety, and feasibility of PPH prevention using oxytocin injected by peripheral health care providers without midwifery skills at home births. This community-based, cluster-randomized trial was conducted in four rural districts in Ghana. We randomly allocated 54 community health officers (stratified on district and catchment area distance to a health facility: ≥10 km versus <10 km) to intervention (one injection of oxytocin [10 IU] one minute after birth) and control (no provision of prophylactic oxytocin) arms. Births attended by a community health officer constituted a cluster. Our primary outcome was PPH, using multiple definitions; (PPH-1) blood loss ≥500 mL; (PPH-2) PPH-1 plus women who received early treatment for PPH; and (PPH-3) PPH-2 plus any other women referred to hospital for postpartum bleeding. Unsafe practice is defined as oxytocin use before delivery of the baby. We enrolled 689 and 897 women, respectively, into oxytocin and control arms of the trial from April 2011 to November 2012. In oxytocin and control arms, respectively, PPH-1 rates were 2.6% versus 5.5% (RR: 0.49; 95% CI: 0.27-0.88); PPH-2 rates were 3.8% versus 10.8% (RR: 0.35; 95% CI: 0.18-0.63), and PPH-3 rates were similar to those of PPH-2. Compared to women in control clusters, those in the intervention clusters lost 45.1 mL (17.7-72.6) less blood. There were no cases of oxytocin use before delivery of the baby and no major adverse events requiring notification of the institutional review boards. Limitations include an unblinded trial and imbalanced numbers of participants, favoring controls. Maternal health care planners can consider adapting this model to extend the use of oxytocin into peripheral settings including, in some contexts, home births. ClinicalTrials.gov NCT01108289 Please see later in the article for the Editors' Summary.
    PLoS Medicine 10/2013; 10(10):e1001524. DOI:10.1371/journal.pmed.1001524 · 14.00 Impact Factor
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    ABSTRACT: Malaria is a leading cause of morbidity and mortality among young children and is estimated to cause at least 1 million deaths each year especially among pregnant women and young children under the age of five years. Vitamin A supplementation is known to reduce morbidity and mortality in young children. Zinc is required for growth and immunity and we sought to replicate the study by Zeba et al. which showed 30% lower cases of clinical malaria in children on a combination of zinc and a large dose of vitamin A compared with children on vitamin A alone based on the hypothesis that combined vitamin A and zinc reduced symptomatic malaria compared to vitamin A alone. The primary objective was to determine the effect of vitamin A alone vs. vitamin A and zinc supplements on the incidence of clinical malaria and other anthropometric indices. It also sought to assess the effects on the incidence of anaemia, diarrhoea and pneumonia. The study was community-based and 200 children between the ages of 6-24 months were randomised to receive either vitamin A (100,000 IU for infants less than 12 months & 200,000 IU for children greater than 12 months and 10 mg daily zinc in the intervention group or vitamin A and zinc placebo for 6 months in the control group. The number of children who were diagnosed with uncomplicated malaria in the intervention group was 27% significantly lower compared with the children in the control group (p = 0.03). There were, however, no effects on severe malaria, pneumonia, anaemia and diarrhea. Our study confirms a significant role of vitamin A and zinc in reducing malaria morbidity.
    Nutrition Journal 09/2013; 12(1):131. DOI:10.1186/1475-2891-12-131 · 2.64 Impact Factor
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    ABSTRACT: In sub-Saharan Africa, malaria is a leading cause of childhood morbidity and iron deficiency is among the most prevalent nutritional deficiencies. In 2006, the World Health Organization and the United Nations Children's Fund released a joint statement that recommended limiting use of iron supplements (tablets or liquids) among children in malaria-endemic areas because of concern about increased malaria risk. As a result, anemia control programs were either not initiated or stopped in these areas. To determine the effect of providing a micronutrient powder (MNP) with or without iron on the incidence of malaria among children living in a high malaria-burden area. Double-blind, cluster randomized trial of children aged 6 to 35 months (n = 1958 living in 1552 clusters) conducted over 6 months in 2010 in a rural community setting in central Ghana, West Africa. A cluster was defined as a compound including 1 or more households. Children were excluded if iron supplement use occurred within the past 6 months, they had severe anemia (hemoglobin level <7 g/dL), or severe wasting (weight-for-length z score <-3). Children were randomized by cluster to receive a MNP with iron (iron group; 12.5 mg/d of iron) or without iron (no iron group). The MNP with and without iron were added to semiliquid home-prepared foods daily for 5 months followed by 1-month of further monitoring. Insecticide-treated bed nets were provided at enrollment, as well as malaria treatment when indicated. Malaria episodes in the iron group compared with the no iron group during the 5-month intervention period. In intention-to-treat analyses, malaria incidence overall was significantly lower in the iron group compared with the no iron group (76.1 and 86.1 episodes/100 child-years, respectively; risk ratio (RR), 0.87 [95% CI, 0.79-0.97]), and during the intervention period (79.4 and 90.7 episodes/100 child-years, respectively; RR, 0.87 [95% CI, 0.78-0.96]). In secondary analyses, these differences were no longer statistically significant after adjusting for baseline iron deficiency and anemia status overall (adjusted RR, 0.87; 95% CI, 0.75-1.01) and during the intervention period (adjusted RR, 0.86; 95% CI, 0.74-1.00). In a malaria-endemic setting in which insecticide-treated bed nets were provided and appropriate malaria treatment was available, daily use of a MNP with iron did not result in an increased incidence of malaria among young children. clinicaltrials.gov Identifier: NCT01001871.
    JAMA The Journal of the American Medical Association 09/2013; 310(9):938-47. DOI:10.1001/jama.2013.277129 · 30.39 Impact Factor
  • International Union of the Scientific Study of Populations (IUSSP), Busan, South Korea; 08/2013
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    ABSTRACT: Background. Whether the risk of malaria is increased in infants born to mothers who experience malaria during pregnancy is uncertain.Methods. We investigated malaria incidence among an infant cohort born to 355 primigravidae and 1500 multigravidae with or without placental malaria (PM) in a high malaria transmission area of Ghana. PM was assessed using placental histology.Results. The incidence of all episodes of malaria parasitemia or clinical malaria was very similar among three groups of infants, those born to multigravidae without PM, multigravidae with PM and primigravidae with PM. Infants born to primigravidae without PM experienced a lower incidence of malaria parasitemia or clinical malaria than the other three groups: adjusted hazard ratio 0.64 (95%CI 0.48-0.86, p<0.01) and 0.60 (95% CI 0.43-0.84, p<0.01) respectively. The incidence of malaria parasitemia or clinical malaria was about 2 times higher in most poor infants compared to least poor infants.Conclusion. There was no suggestion that exposure to PM directly increased incidence of malaria among infants of MG. In our study area, absence of placental malaria in PG is a marker of low exposure, and this probably explains the lower incidence of malaria-related outcomes among infants of PM negative PG.
    The Journal of Infectious Diseases 08/2013; DOI:10.1093/infdis/jit366 · 5.78 Impact Factor
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    ABSTRACT: Objective To evaluate whether the Newhints home visits intervention increased the adoption of skin-to-skin care (SSC), in particular, among low birthweight (LBW) (<2.5kg) babies. MethodsA cluster-randomised trial, with 49 Newhints zones and 49 control zones, was conducted in seven districts in the Brong Ahafo Region, Ghana. It included all live births between November 2008 and December 2009. In Newhints zones, existing community-based surveillance volunteers were trained to conduct home visits during which they weighed babies and counselled mothers of LBW babies on SSC. Performance of any SSC and SSC for more than 2h was evaluated. ResultsOf 15,615 live births, 68.5% had recorded birthweights; 10.1% were LBW. Any SSC was 19.4% higher among babies in Newhints vs. control zones (risk ratio, RR: 1.81; 95% confidence interval, CI: 1.40-2.35). Performance of SSC for more than 2h was, however, low, at only 7.5%, although more than double compared with control zones (RR: 2.72; 95% CI: 1.80-4.10). LBW babies visited and weighed by a volunteer were more likely to receive SSC (P-Any=0.005; P->2h=0.021), greater for LBW babies, particularly for more than 2h of SSC (P-interaction=0.050). Conclusion Newhints successfully promoted the uptake of SSC in rural Ghana. Although findings are encouraging, promotion in rural community settings in sub-Saharan Africa is challenging. Lessons learned can help shape SSC promotion in efforts to increase adoption and save newborn lives.
    Tropical Medicine & International Health 06/2013; 18(8). DOI:10.1111/tmi.12134 · 2.30 Impact Factor
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    ABSTRACT: BACKGROUND: Malaria remains the leading cause of morbidity and mortality in sub-Saharan Africa despite tools currently available for its control. Making malaria vaccine available for routine use will be a major hallmark, but its acceptance by community members and health professionals within the health system could pose considerable challenge as has been found with the introduction of polio vaccinations in parts of West Africa. Some of these challenges may not be expected since decisions people make are many a time driven by a complex myriad of perceptions. This paper reports knowledge and perceptions of community members in the Kintampo area of Ghana where malaria vaccine trials have been ongoing as part of the drive for the first-ever licensed malaria vaccine in the near future. METHODS: Both qualitative and quantitative methods were used in the data collection processes. Women and men whose children were or were not involved in the malaria vaccine trial were invited to participate in focus group discussions (FGDs). Respondents, made up of heads of religious groupings in the study area, health care providers, traditional healers and traditional birth attendants, were also invited to participate in in-depth interviews (IDIs). A cross-sectional survey was conducted in communities where the malaria vaccine trial (Mal 047RTS,S) was carried out. In total, 12 FGDs, 15 IDIs and 466 household head interviews were conducted. RESULTS: Knowledge about vaccines was widespread among participants . Respondents would like their children to be vaccinated against all childhood illnesses including malaria. Knowledge of the long existing routine vaccines was relatively high among respondents compared to hepatitis B and Haemophilus influenza type B vaccines that were introduced more recently in 2002. There was no clear religious belief or sociocultural practice that will serve as a possible barrier to the acceptance of a malaria vaccine. CONCLUSION: With the assumption that a malaria vaccine will be as efficacious as other EPI vaccines, community members in Central Ghana will accept and prefer malaria vaccine to malaria drugs as a malaria control tool. Beliefs and cultural practices as barriers to the acceptance of malaria vaccine were virtually unknown in the communities surveyed.
    Malaria Journal 05/2013; 12(1):156. DOI:10.1186/1475-2875-12-156 · 3.49 Impact Factor
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    ABSTRACT: To assess the structural capacity for, and quality of, immediate and essential newborn care (ENC) in health facilities in rural Ghana, and to link this with demand for facility deliveries and admissions. Health facility assessment survey and population-based surveillance data. Seven districts in Brong Ahafo Region, Ghana. Heads of maternal/neonatal wards in all 64 facilities performing deliveries. Indicators include: the availability of essential infrastructure, newborn equipment and drugs, and personnel; vignette scores and adequacy of reasons given for delayed discharge of newborn babies; and prevalence of key immediate ENC practices that facilities should promote. These are matched to the percentage of babies delivered in and admitted to each type of facility. 70% of babies were delivered in health facilities; 56% of these and 87% of neonatal admissions were in four referral level hospitals. These had adequate infrastructure, but all lacked staff trained in ENC and some essential equipment (including incubators and bag and masks) and/or drugs. Vignette scores for care of very low-birth-weight babies were generally moderate-to-high, but only three hospitals achieved high overall scores for quality of ENC. We estimate that only 33% of babies were born in facilities capable of providing high quality, basic resuscitation as assessed by a vignette plus the presence of a bag and mask. Promotion of immediate ENC practices in facilities was also inadequate, with coverage of early initiation of breastfeeding and delayed bathing both below 50% for babies born in facilities; this represents a lost opportunity. Unless major gaps in ENC equipment, drugs, staff, practices and skills are addressed, strategies to increase facility utilisation will not achieve their potential to save newborn lives. http://clinicaltrials.gov NCT00623337.
    BMJ Open 05/2013; 3(5). DOI:10.1136/bmjopen-2012-002326 · 2.06 Impact Factor
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    ABSTRACT: BACKGROUND: In 2009, on the basis of promising evidence from trials in south Asia, WHO and UNICEF issued a joint statement about home visits as a strategy to improve newborn survival. In the Newhints trial, we aimed to test this home-visits strategy in sub-Saharan Africa by assessing the effect on all-cause neonatal mortality rate (NMR) and essential newborn-care practices. METHODS: The Newhints cluster randomised trial was undertaken in 98 zones in seven districts in the Brong Ahafo Region, Ghana. 49 zones were randomly assigned to the Newhints intervention and 49 to the control intervention by use of restricted randomisation with stratification to ensure comparability between interventions. Community-based surveillance volunteers (CBSVs) in Newhints zones were trained to identify pregnant women in their community and to make two home visits during pregnancy and three in the first week of life to promote essential newborn-care practices, weigh and assess babies for danger signs, and refer as necessary. Primary outcomes were NMR and coverage of key essential newborn-care practices. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00623337. FINDINGS: 16 168 (99%) of 16 329 deliveries between November, 2008, and December, 2009, were livebirths; the status at 1 month was known for 15 619 (97%) livebirths. 482 neonatal deaths were recorded. Coverage data were available from 6029 women in Newhints zones; of these 4358 (72%) reported having CBSV visits during pregnancy and 3815 (63%) reported having postnatal visits. This coverage increased substantially from June, 2009, after the introduction of new implementation strategies and reached almost 90% for pregnancy visits by the end of the trial and 75% for postnatal visits. The Newhints intervention significantly increased coverage of key essential newborn-care behaviours, except for four or more antenatal-care visits (5975 [76%] of 7859 vs 5988 [74%] of 8121, respectively; relative risk 1·02, 95% CI 0·96-1·09; p=0·52) and baby delivered in a facility (5373 [68%] vs 5539 [68%], respectively; 0·97, 0·81-1·14; p=0·69). The largest increase was for care-seeking, with 102 (77%) of 132 sick babies in Newhints zones taken to a hospital or clinic compared with 77 (55%) of 139 in control zones (1·43, 1·17-1·76; p=0·001). Increases were also noted in bednet use during pregnancy (5398 [69%] of 7859 vs 5135 [63%] of 8121, respectively; 1·12, 1·03-1·21; p=0·005), money saved for delivery or emergency (5730 [86%] of 6681 vs 5525 [80%] of 6941, respectively; 1·09, 1·05-1·12; p<0·0001), transport arranged in advance for facility (2496 [37%] vs 2061 [30%], respectively; 1·30, 1·12-1·49; p=0·0004), birth assistant for home delivery washed hands with soap (1853 [93%] of 1992 vs 1817 [87%] of 2091, respectively; 1·05, 1·02-1·09; p=0·001), initiation of breastfeeding in less than 1 h of birth (3743 [49%] of 7673 vs 3280 [41%] of 7921, respectively; 1·22, 1·07-1·40; p=0·004), skin to skin contact (3355 [44%] vs 1931 [24%], respectively; 2·30, 1·85-2·87; p=0·0002), first bath delayed for longer than 6 h (3131 [41%] vs 2269 [29%], respectively; 1·65, 1·27-2·13; p<0·0001), exclusive breastfeeding for 26-32 days (1217 [86%] of 1414 vs 1091 [80%] of 1371; 1·10, 1·04-1·16; p=0·001), and baby sleeping under bednet for 8-56 days (4548 [79%] of 5756 vs 4291 [73%] of 5846; 1·09, 1·03-1·15; p=0·002). There were 230 neonatal deaths in the Newhints zones compared with 252 in the control zones. The overall NMRs per 1000 livebirths were 29·8 and 31·9, respectively (0·92, 0·75-1·12; p=0·405). INTERPRETATION: The reduction in NMR with Newhints is consistent with the reductions achieved in three trials undertaken in programme settings in south Asia. Because there is no suggestion of any heterogeneity (p=0·850) between these trials and Newhints, the meta-analysis summary estimate of a reduction of 12% (95% CI 5-18) provides the best evidence for the likely effect of the home-visits strategy delivered within programmes in sub-Saharan Africa and in south Asia. Improvements in the quality of delivery and neonatal care in health facilities and development of innovative, effective strategies to increase coverage of home visits on the day of birth could lead to the achievement of more substantial reductions. FUNDING: WHO, Bill & Melinda Gates Foundation, and UK Department for International Development.
    The Lancet 04/2013; DOI:10.1016/S0140-6736(13)60095-1 · 45.22 Impact Factor
  • Population Association of America (PAA), New Orleans, LA; 04/2013
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    ABSTRACT: Background Malaria diagnosis is largely dependent on the demonstration of parasites in stained blood films by conventional microscopy. Accurate identification of the infecting Plasmodium species relies on detailed examination of parasite morphological characteristics, such as size, shape, pigment granules, besides the size and shape of the parasitized red blood cells and presence of cell inclusions. This work explores misclassifications of four Plasmodium species by conventional microscopy relative to the proficiency of microscopists and morphological characteristics of the parasites on Giemsa-stained blood films. Case description Ten-day malaria microscopy remedial courses on parasite detection, species identification and parasite counting were conducted for public health and research laboratory personnel. Proficiency in species identification was assessed at the start (pre) and the end (post) of each course using known blood films of Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax infections with densities ranging from 1,000 to 30,000 parasites/μL. Outcomes were categorized as false negative, positive without speciation, P. falciparum, P. malariae, P. ovale, P. vivax and mixed infections. Discussion and evaluation Reported findings are based on 1,878 P. falciparum, 483 P. malariae, 581 P. ovale and 438 P. vivax cumulative results collated from 2008 to 2010 remedial courses. Pre-training false negative and positive misclassifications without speciation were significantly lower on P. falciparum infections compared to non-falciparum infections (p < 0.0001). Post-training misclassifications decreased significantly compared to pre- training misclassifications which in turn led to significant improvements in the identification of the four species. However, P. falciparum infections were highly misclassified as mixed infections, P. ovale misclassified as P. vivax and P. vivax similarly misclassified as P. ovale (p < 0.05). Conclusion These findings suggest that the misclassification of malaria species could be a common occurrence especially where non-falciparum infections are involved due to lack of requisite skills in microscopic diagnosis and variations in morphological characteristics within and between Plasmodium species. Remedial training might improve reliability of conventional light microscopy with respect to differentiation of Plasmodium infections.
    Malaria Journal 03/2013; 12(1):113. DOI:10.1186/1475-2875-12-113 · 3.49 Impact Factor
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    ABSTRACT: This study was conducted at the Kintampo Municipal Hospital in Ghana to determine whether there was any benefit (or otherwise) in basing the management of cases of suspected malaria solely on laboratory confirmation (microscopy or by RDT) as compared with presumptive diagnosis. Children under five years who reported at the Out-Patient Department of the Hospital with axillary temperature ≥37.5°C or with a 48 hr history of fever were enrolled and had malaria microscopy and RDT performed. The attending clinician was blinded from laboratory results unless a request for these tests had been made earlier. Diagnosis of malaria was based on three main methods: presumptive or microscopy and/or RDT. Cost implication for adopting laboratory diagnosis or not was determined to inform malaria control programmes. In total, 936 children were enrolled in the study. Proportions of malaria diagnosed presumptively, by RDT and microscopy were 73.6% (689/936), 66.0% (618/936) and 43.2% (404/936) respectively. Over 50% (170/318) of the children who were RDT negative and 60% (321/532) who were microscopy negative were treated for malaria when presumptive diagnoses were used. Comparing the methods of diagnoses, the cost of malaria treatment could have been reduced by 24% and 46% in the RDT and microscopy groups respectively; the reduction was greater in the dry season (43% vs. 50%) compared with the wet season (20% vs. 45%) for the RDT and microscopy confirmed cases respectively. DISCUSSIONCONCLUSION: Over-diagnosis of malaria was prevalent in Kintampo during the period of the study. Though the use of RDT for diagnosis of malaria might have improved the quality of care for children, it appeared not to have a cost saving effect on the management of children with suspected malaria. Further research may be needed to confirm this.
    PLoS ONE 03/2013; 8(3):e58107. DOI:10.1371/journal.pone.0058107 · 3.53 Impact Factor
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    ABSTRACT: BACKGROUND: The efficacy of RTS,S/AS01 as a vaccine for malaria is being tested in a phase 3 clinical trial. Early results show significant, albeit partial, protection against clinical malaria and severe malaria. To ascertain variations in vaccine efficacy according to covariates such as transmission intensity, choice of adjuvant, age at vaccination, and bednet use, we did an individual-participant pooled analysis of phase 2 clinical data. METHODS: We analysed data from 11 different sites in Africa, including 4453 participants. We measured heterogeneity in vaccine efficacy by estimating the interactions between covariates and vaccination in pooled multivariable Cox regression and Poisson regression analyses. Endpoints for measurement of vaccine efficacy were infection, clinical malaria, severe malaria, and death. We defined transmission intensity levels according to the estimated local parasite prevalence in children aged 2-10 years (PrP2-10), ranging from 5% to 80%. Choice of adjuvant was either AS01 or AS02. FINDINGS: Vaccine efficacy against all episodes of clinical malaria varied by transmission intensity (p=0·001). At low transmission (PrP2-10 10%) vaccine efficacy was 60% (95% CI 54 to 67), at moderate transmission (PrP2-10 20%) it was 41% (21 to 57), and at high transmission (PrP2-10 70%) the efficacy was 4% (-10 to 22). Vaccine efficacy also varied by adjuvant choice (p<0·0001)-eg, at low transmission (PrP2-10 10%), efficacy varied from 60% (95% CI 54 to 67) for AS01 to 47% (14 to 75) for AS02. Variations in efficacy by age at vaccination were of borderline significance (p=0·038), and bednet use and sex were not significant covariates. Vaccine efficacy (pooled across adjuvant choice and transmission intensity) varied significantly (p<0·0001) according to time since vaccination, from 36% efficacy (95% CI 24 to 45) at time of vaccination to 0% (-38 to 38) after 3 years. INTERPRETATION: Vaccine efficacy against clinical disease was of limited duration and was not detectable 3 years after vaccination. Furthermore, efficacy fell with increasing transmission intensity. Outcomes after vaccination cannot be gauged accurately on the basis of one pooled efficacy figure. However, predictions of public-health outcomes of vaccination will need to take account of variations in efficacy by transmission intensity and by time since vaccination. FUNDING: Medical Research Council (UK); Bill & Melinda Gates Foundation Vaccine Modelling Initiative; Wellcome Trust.
    The Lancet Infectious Diseases 02/2013; 13(4). DOI:10.1016/S1473-3099(13)70005-7 · 19.45 Impact Factor
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    ABSTRACT: BACKGROUND: Clinical research participants often express concerns about blood draw because of misconceptions about the uses to which the blood will be put. Their comments can generate rumours in their communities, thereby affecting rates of recruitment to research studies and increasing losses to follow-up. This study sought to identify community perceptions about blood draw for clinical research. METHODS: Between September 2010 and March 2011, 12 focus group discussions and eight in-depth interviews were conducted among community members in the Kintampo district of Ghana, to determine what cultural beliefs and traditional practices might affect attitudes to blood draw. RESULTS: Most of the study participants did not mention any cultural beliefs prohibiting blood draw but were of the opinion that collecting blood from children and pregnant women could lead to serious health consequences. They could not understand why blood would be taken from participants who were not sick. Some were of the opinion that blood samples could be used for rituals and others recounted unpleasant experiences following blood draws. CONCLUSION: To facilitate clinical research that entails blood draw, it is important to address concerns and rumours through intensive community sensitisation.
    Transactions of the Royal Society of Tropical Medicine and Hygiene 02/2013; DOI:10.1093/trstmh/trt012 · 1.93 Impact Factor
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    ABSTRACT: BACKGROUND: The relationship between entomological measures of malaria transmission intensity and mortality remains uncertain. This is partly because transmission is heterogeneous even within small geographical areas. Studying this relationship requires high resolution, spatially structured, longitudinal entomological data. Geostatistical models that have been used to analyse the spatio-temporal heterogeneity have not considered the uncertainty in both sporozoite rate (SR) and mosquito density data. This study analysed data from Kassena-Nankana districts in northern Ghana to obtain small area estimates of malaria transmission rates allowing for this uncertainty. METHODS: Independent Bayesian geostatistical models for sporozoite rate and mosquito density were fitted to produce explicit entomological inoculation rate (EIR) estimates for small areas and short time periods, controlling for environmental factors. RESULTS: Mosquitoes were trapped from 2,803 unique locations for three years using mainly CDC light traps. Anopheles gambiae constituted 52%, the rest were Anopheles funestus. Mean biting rates for An. funestus and An. gambiae were 32 and 33 respectively. Most bites occurred in September, the wettest month. The sporozoite rates were higher in the dry periods of the last two years compared with the wet period. The annual EIR varied from 1,132 to 157 infective bites. Monthly EIR varied between zero and 388 infective bites. Spatial correlation for SR was lower than that of mosquito densities. CONCLUSION: This study confirms the presence of spatio-temporal heterogeneity in malaria transmission within a small geographical area. Spatial variance was stronger than temporal especially in the SR. The estimated EIR will be used in mortality analysis for the area.
    Malaria Journal 02/2013; 12(1):63. DOI:10.1186/1475-2875-12-63 · 3.49 Impact Factor
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    ABSTRACT: BACKGROUND: The prevalence of epilepsy in sub-Saharan Africa seems to be higher than in other parts of the world, but estimates vary substantially for unknown reasons. We assessed the prevalence and risk factors of active convulsive epilepsy across five centres in this region. METHODS: We did large population-based cross-sectional and case-control studies in five Health and Demographic Surveillance System centres: Kilifi, Kenya (Dec 3, 2007-July 31, 2008); Agincourt, South Africa (Aug 4, 2008-Feb 27, 2009); Iganga-Mayuge, Uganda (Feb 2, 2009-Oct 30, 2009); Ifakara, Tanzania (May 4, 2009-Dec 31, 2009); and Kintampo, Ghana (Aug 2, 2010-April 29, 2011). We used a three-stage screening process to identify people with active convulsive epilepsy. Prevalence was estimated as the ratio of confirmed cases to the population screened and was adjusted for sensitivity and attrition between stages. For each case, an age-matched control individual was randomly selected from the relevant centre's census database. Fieldworkers masked to the status of the person they were interviewing administered questionnaires to individuals with active convulsive epilepsy and control individuals to assess sociodemographic variables and historical risk factors (perinatal events, head injuries, and diet). Blood samples were taken from a randomly selected subgroup of 300 participants with epilepsy and 300 control individuals from each centre and were screened for antibodies to Toxocara canis, Toxoplasma gondii, Onchocerca volvulus, Plasmodium falciparum, Taenia solium, and HIV. We estimated odds ratios (ORs) with logistic regression, adjusted for age, sex, education, employment, and marital status. RESULTS: 586 607 residents in the study areas were screened in stage one, of whom 1711 were diagnosed as having active convulsive epilepsy. Prevalence adjusted for attrition and sensitivity varied between sites: 7·8 per 1000 people (95% CI 7·5-8·2) in Kilifi, 7·0 (6·2-7·4) in Agincourt, 10·3 (9·5-11·1) in Iganga-Mayuge, 14·8 (13·8-15·4) in Ifakara, and 10·1 (9·5-10·7) in Kintampo. The 1711 individuals with the disorder and 2032 control individuals were given questionnaires. In children (aged <18 years), the greatest relative increases in prevalence were associated with difficulties feeding, crying, or breathing after birth (OR 10·23, 95% CI 5·85-17·88; p<0·0001); abnormal antenatal periods (2·15, 1·53-3·02; p<0·0001); and head injury (1·97, 1·28-3·03; p=0·002). In adults (aged ≥18 years), the disorder was significantly associated with admission to hospital with malaria or fever (2·28, 1·06-4·92; p=0·036), exposure to T canis (1·74, 1·27-2·40; p=0·0006), exposure to T gondii (1·39, 1·05-1·84; p=0·021), and exposure to O volvulus (2·23, 1·56-3·19; p<0·0001). Hypertension (2·13, 1·08-4·20; p=0·029) and exposure to T solium (7·03, 2·06-24·00; p=0·002) were risk factors for adult-onset disease. INTERPRETATION: The prevalence of active convulsive epilepsy varies in sub-Saharan Africa and that the variation is probably a result of differences in risk factors. Programmes to control parasitic diseases and interventions to improve antenatal and perinatal care could substantially reduce the prevalence of epilepsy in this region. FUNDING: Wellcome Trust, University of the Witwatersrand, and South African Medical Research Council.
    The Lancet Neurology 01/2013; 12(3). DOI:10.1016/S1474-4422(13)70003-6 · 21.82 Impact Factor
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    ABSTRACT: Background Malaria is the most important cause of mortality and morbidity in children living in the Kintampo districts in the middle part of Ghana. This study has investigated the multiplicity of infection (MOI) within asymptomatic residents of the Kintampo districts, and the influence of age and seasonality on MOI, by studying the distribution of the polymorphic Plasmodium falciparum antigen merozoite surface protein 2 (MSP2). Methods DNA was extracted from an asymptomatic cohort of children and adults infected with P. falciparum during the period November 2003 to October 2004. Polymerase chain reaction was carried out and multiplicity of infection (MOI) was determined. Results Children under 10 years of age had an average MOI of 2.3 while adults 18 years and above had an average MOI of 1.4. Children below five years had high and low average MOIs of 2.8 in the March/April survey and 0.9 in the May/June survey respectively. A similar trend in the monthly distribution of MOI was observed for the entire cohort. IC/3D7 strains outnumbered the FC27 strains throughout the year by a ratio of about 4:1 with the difference between the prevalence of the two strains being least marked in the March/April survey, at the beginning of the rainy season. MOI was not linked to the level of malaria transmission as measured by the entomological inoculation rate. Discussion/conclusion The impact of interventions, introduced since this baseline study was carried out on the parasite diversity of asymptomatic residents will be the subject of further investigations.
    Malaria Journal 01/2013; 12(1):22. DOI:10.1186/1475-2875-12-22 · 3.49 Impact Factor
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    ABSTRACT: To determine the effect of weekly low-dose vitamin A supplementation on cause-specific mortality in women of reproductive age in Ghana. A cluster-randomized, triple-blind, placebo-controlled trial was conducted in seven districts of the Brong Ahafo region of Ghana. Women aged 15-45 years who were capable of giving informed consent and intended to live in the trial area for at least 3 months were enrolled and randomly assigned, according to their cluster of residence, to receive oral vitamin A (7500 μg) or placebo once a week. Randomization was blocked, with two clusters in each fieldwork area allocated to vitamin A and two to placebo. Every 4 weeks, fieldworkers distributed capsules and collected data during home visits. Verbal autopsies were conducted by field supervisors and reviewed by physicians, who assigned a cause of death. Cause-specific mortality rates in both arms were compared by means of random-effects Poisson regression models to allow for the cluster randomization. Analysis was by intention-to-treat, based on cluster of residence, with women eligible for inclusion once they had consistently received the supplement or placebo capsules for 6 months. The analysis was based on 581 870 woman-years and 2624 deaths. Cause-specific mortality rates were found to be similar in the two study arms. Low-dose vitamin A supplements administered weekly are of no benefit in programmes to reduce mortality in women of childbearing age.
    Bulletin of the World Health Organisation 01/2013; 91(1):19-27. DOI:10.2471/BLT.11.100412 · 5.11 Impact Factor
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    ABSTRACT: Background: The dearth of health and demographic data in sub-Saharan Africa from vital registration systems and its impact on effective planning for health and socio-economic development is widely documented. Health and Demographic Surveillance Systems have the capacity to address the dearth of quality data for policy making in resource-poor settings. Objective: This article demonstrates the utility of the Kintampo Health and Demographic Surveillance System (KHDSS) by showing the patterns and trends of population change from 2005 to 2009 in the Kintampo North Municipality and Kintampo South districts of Ghana through data obtained from the KHDSS biannual update rounds. Design: Basic demographic rates for fertility, mortality, and migration were computed by year. School enrolment was computed as a percentage in school by age and sex for 6-18 year-olds. Socio-economic status was derived by use of Principal Components Analysis on household assets. Results: Over the period, an earlier fertility decline was reversed in 2009; mortality declined slightly for all age-groups, and a significant share of working-age population was lost through out-migration. Large minorities of children of school-going age are not in school. Socio-economic factors are shown to be important determinants of fertility and mortality. Conclusion: Strengthening the capacity of HDSSs could offer added value to evidence-driven policymaking at local level.
    Global Health Action 12/2012; 5:1-11. DOI:10.3402/gha.v5i0.19033 · 1.65 Impact Factor
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    ABSTRACT: Background The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe malaria in children 5 to 17 months of age by approximately 50% in an ongoing phase 3 trial. We studied infants 6 to 12 weeks of age recruited for the same trial. Methods We administered RTS,S/AS01 or a comparator vaccine to 6537 infants who were 6 to 12 weeks of age at the time of the first vaccination in conjunction with Expanded Program on Immunization (EPI) vaccines in a three-dose monthly schedule. Vaccine efficacy against the first or only episode of clinical malaria during the 12 months after vaccination, a coprimary end point, was analyzed with the use of Cox regression. Vaccine efficacy against all malaria episodes, vaccine efficacy against severe malaria, safety, and immunogenicity were also assessed. Results The incidence of the first or only episode of clinical malaria in the intention-to-treat population during the 14 months after the first dose of vaccine was 0.31 per person-year in the RTS,S/AS01 group and 0.40 per person-year in the control group, for a vaccine efficacy of 30.1% (95% confidence interval [CI], 23.6 to 36.1). Vaccine efficacy in the per-protocol population was 31.3% (97.5% CI, 23.6 to 38.3). Vaccine efficacy against severe malaria was 26.0% (95% CI, −7.4 to 48.6) in the intention-to-treat population and 36.6% (95% CI, 4.6 to 57.7) in the per-protocol population. Serious adverse events occurred with a similar frequency in the two study groups. One month after administration of the third dose of RTS,S/AS01, 99.7% of children were positive for anti-circumsporozoite antibodies, with a geometric mean titer of 209 EU per milliliter (95% CI, 197 to 222). Conclusions The RTS,S/AS01 vaccine coadministered with EPI vaccines provided modest protection against both clinical and severe malaria in young infants. (Funded by GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative; RTS,S ClinicalTrials.gov number, NCT00866619.)
    New England Journal of Medicine 12/2012; 367(367):2284-2295. · 54.42 Impact Factor

Publication Stats

2k Citations
928.36 Total Impact Points

Institutions

  • 2008–2015
    • Kintampo Health Research Centre
      Sunyani, Brong-Ahafo, Ghana
  • 2007–2014
    • London School of Hygiene and Tropical Medicine
      • • Faculty of Epidemiology and Population Health
      • • Faculty of Infectious and Tropical Diseases
      Londinium, England, United Kingdom
  • 2013
    • Ministry of Health, Ghana
      Akra, Greater Accra, Ghana
    • Johns Hopkins Bloomberg School of Public Health
      Baltimore, Maryland, United States
    • Ghana Health Service
      Akra, Greater Accra, Ghana
    • INDEPTH
      Madina, Greater Accra, Ghana
  • 2012
    • Swiss Tropical and Public Health Institute
      • Department of Epidemiology and Public Health
      Bâle, Basel-City, Switzerland
  • 2011
    • University of Tuebingen
      • Department of Tropical Medicine
      Tübingen, Baden-Württemberg, Germany
  • 2003–2007
    • Naval Medical Research Unit 3
      Al Qāhirah, Al Qāhirah, Egypt
  • 2001–2004
    • Navrongo Health Research Centre
      Navrongo, Upper East, Ghana