Browsing by Author "Bosomprah, S."

Now showing 1 - 20 of 64

A decomposition analysis of change in skilled birth attendants, 2003 to 2008, Ghana demographic and health surveys
(2014-12-24) Bosomprah, S.; Aryeetey, G.C.; Nonvignon, J.; Adanu, R.M.
Abstract Background The single most critical intervention to improve maternal and neonatal survival is to ensure that a competent health worker with midwifery skills is present at every birth, and transport is available to a referral facility for obstetric care in case of an emergency. This study aims to describe changes in percentage of skilled birth attendants in Ghana and to identify causes of the observed changes as well as the contribution of different categories of mother’s characteristics to these changes. Method This study uses two successive nationally representative household surveys: the 2003 and 2008 Ghana Demographic and Health Surveys (GDHS). The two datasets have comparable information on household characteristics and skilled attendants at birth at the time of the survey. The 2003 GDHS database includes information on 6,251 households and 3639 live births in the five years preceding the survey, whereas the 2008 GDHS database had information on11, 778 households and 2909 live births in the five years preceding the survey. A decomposition approach was used to explain the observed change in percentage of skilled birth attendants. Random-effects generalized least square regression was used to explore the effect of changes in population structure in respect of the mother’s characteristics on percentage of skilled birth attendants over the period. Results Overall, the data showed absolute gain in the proportion of births attended by a health professional from 47.1% in 2003 to 58.7% in 2008, which represents 21.9% of gap closed to reach universal coverage. The increase in skilled birth attendants was found to be caused by changes in general health behaviour. The gain is regardless of the mother’s characteristics. The structural change in the proportion of births in respect of birth order and mother’s education had little effect on the change in percentage of skilled birth attendants. Conclusion Improvement in general health behaviour can potentially contribute to an accelerated increase in proportion of births attended by skilled personnel in Ghana.
Anti-sporozoite antibodies as alternative markers for malaria transmission intensity estimation
(2014-03-17) Kusi, K.A.; Bosomprah, S.; Dodoo, D.; Kyei-Baafour, E.; Dickson, K.; Mensah, D.; Angov, E.; Dutta, S.; Sedegah, M.; Koram, K.A.
Abstract Background Reported malaria cases continue to decline globally, and this has been attributed to strategic implementation of multiple malaria control tools. Gains made would however need to be sustained through continuous monitoring to ensure malaria elimination and eradication. Entomological inoculation rate (EIR) is currently the standard tool for transmission monitoring but this is not sensitive enough, especially in areas of very low transmission. Transmission estimation models based on seroconversion rates (λ) of antibodies to Plasmodium falciparum blood stage antigens are gaining relevance. Estimates of λ, which is the measure of transmission intensity, correlate with EIR but are limited by long-term persistence of antibodies to blood stage antigens. Seroprevalence of antibodies to sporozoite antigens may be better alternatives since these antigens usually have shorter immune exposure times. The aim of this study was to develop transmission estimation models based on the seroprevalence of antibodies to two P. falciparum sporozoite antigens (CSP, CelTOS) and compare with models based on the classical blood stage antigen AMA1. Methods Antibody levels in archived plasma from three cross-sectional surveys conducted in 2009 in a low transmission area of Southern Ghana were assessed by indirect ELISA. Seroprevalence of antibodies against CSP, CelTOS and AMA1 were fitted to reversible catalytic models to estimate λ and corresponding seroreversion rates (ρ) for each antibody. Results Of the three models developed, the anti-CSP model predicted a 13-fold decrease in λ four years prior to the time of sampling (2009). Anti-AMA1 antibodies formed at a four-fold greater rate compared to that of anti-CelTOS antibodies, and anti-CSP antibodies during the period of decreased λ. In contrast, anti-AMA1 antibodies decayed at a five-fold slower rate relative to that of anti-CSP antibodies while anti-AMA1 and anti-CelTOS antibody decay rates were not significantly different. Anti-CSP antibodies were relatively short-lived as they formed at an 11.6-fold slower rate relative to their decay during the period of decreased λ. Conclusions These features of anti-CSP antibodies can be exploited for the development of models for predicting seasonal, short-term changes in transmission intensity in malaria-endemic areas, especially as the elimination phase of malaria control is approached.
Anti-sporozoite antibodies as alternative markers for malaria transmission intensity estimation
(Malaria Journal, 2014) Kusi, K.A.; Bosomprah, S.; Dodoo, D.; Kyei-Baafour, E.; Dickson, E.K.; Mensah, D.; Angov, E.; Dutta, S.; Sedegah, M.; Koram, K.A.
Reported malaria cases continue to decline globally, and this has been attributed to strategic implementation of multiple malaria control tools. Gains made would however need to be sustained through continuous monitoring to ensure malaria elimination and eradication. Entomological inoculation rate (EIR) is currently the standard tool for transmission monitoring but this is not sensitive enough, especially in areas of very low transmission. Transmission estimation models based on seroconversion rates (λ) of antibodies to Plasmodium falciparum blood stage antigens are gaining relevance. Estimates of λ, which is the measure of transmission intensity, correlate with EIR but are limited by long-term persistence of antibodies to blood stage antigens. Seroprevalence of antibodies to sporozoite antigens may be better alternatives since these antigens usually have shorter immune exposure times. The aim of this study was to develop transmission estimation models based on the seroprevalence of antibodies to two P. falciparum sporozoite antigens (CSP, CelTOS) and compare with models based on the classical blood stage antigen AMA1. Methods. Antibody levels in archived plasma from three cross-sectional surveys conducted in 2009 in a low transmission area of Southern Ghana were assessed by indirect ELISA. Seroprevalence of antibodies against CSP, CelTOS and AMA1 were fitted to reversible catalytic models to estimate λ and corresponding seroreversion rates (ρ) for each antibody. Results: Of the three models developed, the anti-CSP model predicted a 13-fold decrease in λ four years prior to the time of sampling (2009). Anti-AMA1 antibodies formed at a four-fold greater rate compared to that of anti-CelTOS antibodies, and anti-CSP antibodies during the period of decreased λ. In contrast, anti-AMA1 antibodies decayed at a five-fold slower rate relative to that of anti-CSP antibodies while anti-AMA1 and anti-CelTOS antibody decay rates were not significantly different. Anti-CSP antibodies were relatively short-lived as they formed at an 11.6-fold slower rate relative to their decay during the period of decreased λ. Conclusions: These features of anti-CSP antibodies can be exploited for the development of models for predicting seasonal, short-term changes in transmission intensity in malaria-endemic areas, especially as the elimination phase of malaria control is approached. © 2014 Kusi et al.; licensee BioMed Central Ltd.
Antibody levels against GLURP R2, MSP1 block 2 hybrid and AS202.11 and the risk of malaria in children living in hyperendemic (Burkina Faso) and hypo-endemic (Ghana) areas
(BioMed Central Ltd, 2016) Adu, B.; Cherif, M.K.; Bosomprah, S.; Diarra, A.; Arthur, F.K.N.; Dickson, E.K.; Corradin, G.; Cavanagh, D.R.; Theisen, M.; Sirima, S.B.; Nebie, I.; Dodoo, D.
Background: Differences in parasite transmission intensity influence the process of acquisition of host immunity to Plasmodium falciparum malaria and ultimately, the rate of malaria related morbidity and mortality. Potential vaccines being designed to complement current intervention efforts therefore need to be evaluated against different malaria endemicity backgrounds. Methods: The associations between antibody responses to the chimeric merozoite surface protein 1 block 2 hybrid (MSP1 hybrid), glutamate-rich protein region 2 (GLURP R2) and the peptide AS202.11, and the risk of malaria were assessed in children living in malaria hyperendemic (Burkina Faso, n = 354) and hypo-endemic (Ghana, n = 209) areas. Using the same reagent lots and standardized protocols for both study sites, immunoglobulin (Ig) M, IgG and IgG sub-class levels to each antigen were measured by ELISA in plasma from the children (aged 6-72 months). Associations between antibody levels and risk of malaria were assessed using Cox regression models adjusting for covariates. Results: There was a significant association between GLURP R2 IgG3 and reduced risk of malaria after adjusting age of children in both the Burkinabe (hazard ratio 0.82; 95 % CI 0.74-0.91, p < 0.0001) and the Ghanaian (HR 0.48; 95 % CI 0.25-0.91, p = 0.02) cohorts. MSP1 hybrid IgM was associated (HR 0.85; 95 % CI 0.73-0.98, p = 0.02) with reduced risk of malaria in Burkina Faso cohort while IgG against AS202.11 in the Ghanaian children was associated with increased risk of malaria (HR 1.29; 95 % CI 1.01-1.65, p = 0.04). Conclusion: These findings support further development of GLURP R2 and MSP1 block 2 hybrid, perhaps as a fusion vaccine antigen targeting malaria blood stage that can be deployed in areas of varying transmission intensity. © 2016 Adu et al.
Antibody levels to multiple malaria vaccine candidate antigens in relation to clinical malaria episodes in children in the Kasena-Nankana district of Northern Ghana
(2011-05-01) Dodoo, D.; Atuguba, F.; Bosomprah, S.; Ansah, N.A.; Ansah, P.; Lamptey, H.; Egyir, B.; Oduro, A.R.; Gyan, B.; Hodgson, A.; Koram, K.A.
Abstract Background Considering the natural history of malaria of continued susceptibility to infection and episodes of illness that decline in frequency and severity over time, studies which attempt to relate immune response to protection must be longitudinal and have clearly specified definitions of immune status. Putative vaccines are expected to protect against infection, mild or severe disease or reduce transmission, but so far it has not been easy to clearly establish what constitutes protective immunity or how this develops naturally, especially among the affected target groups. The present study was done in under six year old children to identify malaria antigens which induce antibodies that correlate with protection from Plasmodium falciparum malaria. Methods In this longitudinal study, the multiplex assay was used to measure IgG antibody levels to 10 malaria antigens (GLURP R0, GLURP R2, MSP3 FVO, AMA1 FVO, AMA1 LR32, AMA1 3D7, MSP1 3D7, MSP1 FVO, LSA-1and EBA175RII) in 325 children aged 1 to 6 years in the Kassena Nankana district of northern Ghana. The antigen specific antibody levels were then related to the risk of clinical malaria over the ensuing year using a negative binomial regression model. Results IgG levels generally increased with age. The risk of clinical malaria decreased with increasing antibody levels. Except for FMPOII-LSA, (p = 0.05), higher IgG levels were associated with reduced risk of clinical malaria (defined as axillary temperature ≥37.5°C and parasitaemia of ≥5000 parasites/ul blood) in a univariate analysis, upon correcting for the confounding effect of age. However, in a combined multiple regression analysis, only IgG levels to MSP1-3D7 (Incidence rate ratio = 0.84, [95% C.I.= 0.73, 0.97, P = 0.02]) and AMA1 3D7 (IRR = 0.84 [95% C.I.= 0.74, 0.96, P = 0.01]) were associated with a reduced risk of clinical malaria over one year of morbidity surveillance. Conclusion The data from this study support the view that a multivalent vaccine involving different antigens is most likely to be more effective than a monovalent one. Functional assays, like the parasite growth inhibition assay will be necessary to confirm if these associations reflect functional roles of antibodies to MSP1-3D7 and AMA1-3D7 in this population.
Antibody levels to multiple malaria vaccine candidate antigens in relation to clinical malaria episodes in children in the kasena-nankana district of northern ghana.
(2011) Dodoo, D.; Atuguba, F.; Bosomprah, S.; Ansah, N.A.; Ansah, P.; Lamptey, H.; Egyir, B.; Oduro, A.R.; Gyan, B.; Hodgson, A.; Koram, K.A.
Background: Considering the natural history of malaria of continued susceptibility to infection and episodes of illness that decline in frequency and severity over time, studies which attempt to relate immune response to protection must be longitudinal and have clearly specified definitions of immune status. Putative vaccines are expected to protect against infection, mild or severe disease or reduce transmission, but so far it has not been easy to clearly establish what constitutes protective immunity or how this develops naturally, especially among the affected target groups. The present study was done in under six year old children to identify malaria antigens which induce antibodies that correlate with protection from Plasmodium falciparum malaria. Methods. In this longitudinal study, the multiplex assay was used to measure IgG antibody levels to 10 malaria antigens (GLURP R0, GLURP R2, MSP3 FVO, AMA1 FVO, AMA1 LR32, AMA1 3D7, MSP1 3D7, MSP1 FVO, LSA-1and EBA175RII) in 325 children aged 1 to 6 years in the Kassena Nankana district of northern Ghana. The antigen specific antibody levels were then related to the risk of clinical malaria over the ensuing year using a negative binomial regression model. Results: IgG levels generally increased with age. The risk of clinical malaria decreased with increasing antibody levels. Except for FMPOII-LSA, (p = 0.05), higher IgG levels were associated with reduced risk of clinical malaria (defined as axillary temperature 37.5°C and parasitaemia of 5000 parasites/ul blood) in a univariate analysis, upon correcting for the confounding effect of age. However, in a combined multiple regression analysis, only IgG levels to MSP1-3D7 (Incidence rate ratio = 0.84, [95% C.I.= 0.73, 0.97, P = 0.02]) and AMA1 3D7 (IRR = 0.84 [95% C.I.= 0.74, 0.96, P = 0.01]) were associated with a reduced risk of clinical malaria over one year of morbidity surveillance. Conclusion: The data from this study support the view that a multivalent vaccine involving different antigens is most likely to be more effective than a monovalent one. Functional assays, like the parasite growth inhibition assay will be necessary to confirm if these associations reflect functional roles of antibodies to MSP1-3D7 and AMA1-3D7 in this population. © 2011 Dodoo et al; licensee BioMed Central Ltd.
Assessing capacity and readiness to manage NCDs in primary care setting: Gaps and opportunities based on adapted WHO PEN tool in Zambia
(PLoS ONE, 2018-08) Mutale, W.; Bosomprah, S.; Shankalala, P.; Mweemba, O.; Chilengi, R.; Kapambwe, S.; Chishimba, C.; Mukanu, M.; Chibutu, D.; Heimburger, D.
Introduction Sub-Saharan Africa is experiencing an epidemiological transition as the burden of NCDs overtake communicable diseases. However, it is unknown what capacity and gaps exist at primary care level to address the growing burden of NCDs. This study aimed to assess the Zambian health system’s capacity to address in NCDs, using an adapted WHO Essential Non Communicable Disease Interventions (WHO PEN) tool. Methodology This was a cross-sectional facility survey in the three districts conducted from September 2017 to October 2017. We defined facility readiness along five domains: basic equipment, essential services, diagnostic capacity, counseling services, and essential medicines. For each domain, we calculated an index as the mean score of items expressed as percentage. These indices were compared to an agreed cutoff at 70%, meaning that a facility index or district index below 70% off was considered as ‘not ready’ to manage NCDs at that level. All analysis were performed using Stata 15 MP. Results There appeared to be wide heterogeneity between facilities in respect of readiness to manage NCDs. Only 6 (including the three 1st level hospitals) out of the 46 facilities were deemed ready to manage NCDs. Only the first level hospitals scored a mean index higher than the 70% cut off; With regard to medications needed to manage NCDs, urban and rural health facilities were comparably equipped. However, there was evidence that calcium channel blockers (p = 0.013) and insulin (p = 0.022) were more likely to be available in urban and semi-urban health facilities compared to rural facilities. Conclusion Our study revealed gaps in primary health care capacity to manage NCDs in Zambia, with almost all health facilities failing to reach the minimum threshold. These results could be generalized to other similar districts in Zambia and the sub-region, where health systems remain focused on infectious rather than non-communicable Disease. These results should attract policy attention and potentially form the basis to review current approach to NCD care at the primary care level in Zambia and Sub-Saharan Africa.
Assessment of the infuence of ABO blood groups on oral cholera vaccine immunogenicity in a cholera endemic area in Zambia
(BMC Public Health, 2023) Chisenga, C.C.; Bosomprah, S.; Chilyabanyama, O.N.; et al.
Background Histo-blood group antigens (HBGAs) which include the ABO and Lewis antigen systems have been known for determining predisposition to infections. For instance, blood group O individuals have a higher risk of severe illness due to V. cholerae compared to those with non-blood group O antigens. We set out to determine the infuence that these HBGAs have on oral cholera vaccine immunogenicity and seroconversion in individuals residing within a cholera endemic area in Zambia. Methodology We conducted a longitudinal study nested under a clinical trial in which samples from a cohort of 223 adults who were vaccinated with two doses of Shanchol™ and followed up over 4 years were used. We measured serum vibriocidal geometric mean titers (GMTs) at Baseline, Day 28, Months 6, 12, 24, 30, 36 and 48 in response to the vaccine. Saliva obtained at 1 year post vaccination was tested for HBGA phenotypes and secretor status using an enzyme-linked immunosorbent assay (ELISA). Results Of the 133/223 participants included in the fnal analysis, the majority were above 34 years old (58%) and of these, 90% were males. Seroconversion rates to V. cholerae O1 Inaba with non-O (23%) and O (30%) blood types were comparable. The same pattern was observed against O1 Ogawa serotype between non-O (25%) and O (35%). This trend continued over the four-year follow-up period. Similarly, no signifcant diferences were observed in seroconversion rates between the non-secretors (26%) and secretors (36%) against V. cholerae O1 Inaba. The same was observed for O1 Ogawa in non-secretors (22%) and the secretors (36%). Conclusion Our results do not support the idea that ABO blood grouping influence vaccine uptake and responses against cholera.
Association of biomarkers of enteric dysfunction, systemic inflammation, and growth hormone resistance with seroconversion to oral rotavirus vaccine: A lasso for inference approach
(PLOS ONE, 2023) Mwila-Kazimbaya, K.; Bosomprah, S.; Chilyabanyama, O.N.; et al.
Background Rotavirus gastroenteritis remains a leading cause of morbidity and mortality despite the introduction of vaccines. Research shows there are several factors contributing to the reduced efficacy of rotavirus vaccines in low- and middle-income settings. Proposed factors include environmental enteric dysfunction (EED), malnutrition, and immune dysfunction. This study aimed to assess the effect of these factors on vaccine responses using a machine learning lasso approach. Methods Serum samples from two rotavirus clinical trials (CVIA 066 n = 99 and CVIA 061 n = 124) were assessed for 11 analytes using the novel Micronutrient and EED Assessment Tool (MEEDAT) multiplex ELISA. Immune responses to oral rotavirus vaccines (Rotarix, Rota vac, and Rotavac 5D) as well as a parenteral rotavirus vaccine (trivalent P2-VP8) were also measured and machine learning using the lasso approach was then applied to investigate any associations between immune responses and environmental enteric dysfunction, sys temic inflammation, and growth hormone resistance biomarkers. Results Both oral and parenteral rotavirus vaccine responses were negatively associated with retinol binding protein 4 (RBP4), albeit only weakly for oral vaccines. The parenteral vaccine responses were positively associated with thyroglobulin (Tg) and histidine-rich protein 2 (HRP2) for all three serotypes (P8, P6 and P4), whilst intestinal fatty acid binding protein (I FABP) was negatively associated with P6 and P4, but not P8, and soluble transferrin recep tor (sTfR) was positively associated with P6 only. Conclusion MEEDAT successfully measured biomarkers of growth, systemic inflammation, and EED in infants undergoing vaccination, with RBP4 being the only analyte associated with both oral and parenteral rotavirus vaccine responses. Tg and HRP2 were associated with responses to all three serotypes in the parenteral vaccine, while I-FABP and sTfR results indicated pos sible strain specific immune responses to parenteral immunization.
Associations of inter-annual rainfall decreases with subsequent HIV outcomes for persons with HIV on antiretroviral therapy in Southern Africa: a collaborative analysis of cohort studies
(BMC Infectious Diseases, 2023) Trickey, A.; Bosomprah, S.; Chirimuta, L.; et al.
Background Periods of droughts can lead to decreased food security, and altered behaviours, potentially afecting outcomes on antiretroviral therapy (ART) among persons with HIV (PWH). We investigated whether decreased rainfall is associated with adverse outcomes among PWH on ART in Southern Africa. Methods Data were combined from 11 clinical cohorts of PWH in Lesotho, Malawi, Mozambique, South Africa, Zambia, and Zimbabwe, participating in the International epidemiology Databases to Evaluate AIDS Southern Africa (IeDEA-SA) collaboration. Adult PWH who had started ART prior to 01/06/2016 and were in follow-up in the year prior to 01/06/2016 were included. Two-year rainfall from June 2014 to May 2016 at the location of each HIV centre was summed and ranked against historical 2-year rainfall amounts (1981–2016) to give an empirical relative percentile rainfall estimate. The IeDEA-SA and rainfall data were combined using each HIV centre’s latitude/longitude. In individ ual-level analyses, multivariable Cox or generalized estimating equation regression models (GEEs) assessed associa tions between decreased rainfall versus historical levels and four separate outcomes (mortality, CD4 counts<200 cells/mm3 , viral loads>400 copies/mL, and>12-month gaps in follow-up) in the two years following the rainfall period. GEEs were used to investigate the association between relative rainfall and monthly numbers of unique visi tors per HIV centre. Results Among 270,708 PWH across 386 HIV centres (67% female, median age 39 [IQR: 32–46]), lower rainfall than usual was associated with higher mortality (adjusted Hazard Ratio: 1.18 [95%CI: 1.07–1.32] per 10 percen tile rainfall rank decrease) and unsuppressed viral loads (adjusted Odds Ratio: 1.05 [1.01–1.09]). Levels of rainfall were not strongly associated with CD4 counts<200 cell/mm3 or>12-month gaps in care. HIV centres in areasBackground Periods of droughts can lead to decreased food security, and altered behaviours, potentially afecting outcomes on antiretroviral therapy (ART) among persons with HIV (PWH). We investigated whether decreased rainfall is associated with adverse outcomes among PWH on ART in Southern Africa. Methods Data were combined from 11 clinical cohorts of PWH in Lesotho, Malawi, Mozambique, South Africa, Zambia, and Zimbabwe, participating in the International epidemiology Databases to Evaluate AIDS Southern Africa (IeDEA-SA) collaboration. Adult PWH who had started ART prior to 01/06/2016 and were in follow-up in the year prior to 01/06/2016 were included. Two-year rainfall from June 2014 to May 2016 at the location of each HIV centre was summed and ranked against historical 2-year rainfall amounts (1981–2016) to give an empirical relative percentile rainfall estimate. The IeDEA-SA and rainfall data were combined using each HIV centre’s latitude/longitude. In individ ual-level analyses, multivariable Cox or generalized estimating equation regression models (GEEs) assessed associa tions between decreased rainfall versus historical levels and four separate outcomes (mortality, CD4 counts<200 cells/mm3 , viral loads>400 copies/mL, and>12-month gaps in follow-up) in the two years following the rainfall period. GEEs were used to investigate the association between relative rainfall and monthly numbers of unique visi tors per HIV centre. Results Among 270,708 PWH across 386 HIV centres (67% female, median age 39 [IQR: 32–46]), lower rainfall than usual was associated with higher mortality (adjusted Hazard Ratio: 1.18 [95%CI: 1.07–1.32] per 10 percen tile rainfall rank decrease) and unsuppressed viral loads (adjusted Odds Ratio: 1.05 [1.01–1.09]). Levels of rainfall were not strongly associated with CD4 counts<200 cell/mm3 or>12-month gaps in care. HIV centres in areas with less rainfall than usual had lower numbers of PWH visiting them (adjusted Rate Ratio: 0.80 [0.66–0.98] per 10 percentile rainfall rank decrease). Conclusions Decreased rainfall could negatively impact on HIV treatment behaviours and outcomes. Further research is needed to explore the reasons for these efects. Interventions to mitigate the health impact of severe weather events are required.
Barriers to healthcare workers reporting adverse events following immunization in four regions of Ghana
(Vaccine, 2019-11-29) Bosomprah, S.; Gidudu, J.F.; Shaum, A.; Dodoo, A.; Bonsu, G.; Amponsa-Achiano, K.; Darko, D.M.; Sabblah, G.; Opare, J.; Nyaku, M.; Owusu-Boakye, B.; Oduro, A.; Aborigo, R.; Conklin, L.; Welaga, P.; Ampadu, H.H.
Despite didactic training on adverse events following immunization (AEFI) in Ghana, the reporting ratio of AEFI was 1.56 per 100,000 surviving infants in 2015, below the minimum reporting ratio of 10. We aimed to estimate the proportion of health care workers (HCWs) reporting AEFI and to identify barriers to reporting. We conducted a cross-sectional survey of HCWs in four regions in Ghana. A simple random sample of 176 health facilities was selected and up to two HCWs were randomly selected per facility. We used the Rao-Scott Chi-squared test to compare factors associated with reporting of AEFI in the last year. We used an open-ended question to identify reasons for low reporting. One supervisor from each facility, responsible for overall reporting and management of AEFI, was also interviewed. A total of 306 HCWs from 169 facilities were interviewed. Of these, 176 (57.5%) reported they had ever encountered an AEFI. Of the 120 who had encountered an AEFI in the last year, 66 (55.0%) indicated they had reported the AEFI, and 38 (31.7%) completed a reporting form. HCWs (n = 120) reported multiple barriers to reporting of AEFI; the most common barriers were fear of personal consequences (44.1%), lack of knowledge or training (25.2%), and not believing an AEFI was serious enough to report (22.2%). Discussion of AEFI during the last supervisory visit was significantly associated with reporting in the past year (OR 7.39; p < .001). Of 172 supervisors interviewed, 65 (37.8%) mentioned their facilties had ever encountered an AEFI; over 90% of facilities had reporting forms. We identified low reporting of AEFI and multiple barriers to reporting among HCWs in the four selected regions of Ghana. Discussing AEFI during supervisory visits with HCWs might improve reporting. Additionally, strategies to address fear of personal consequences as a barrier to reporting of AEFI are needed.
Bayesian and Non-Bayesian Inference for Survival Data Using Generalised Exponential Distribution
(Hindawi Publishing Corporation, 2013-08) Guure, B.C.; Bosomprah, S.
A two-parameter lifetime distribution was introduced by Kundu and Gupta known as generalised exponential distribution. This distribution has been touted to be an alternative to the well-known 2-parameter Weibull and gamma distributions. We seek to determine the parameters and the survival function of this distribution. The survival function determines the probability that a unit under investigation will survive beyond a certain specified time, say, (). We have employed different data sets to estimate the parameters and see how well the distribution can be used to analyse survival data. A comparison is made about the estimators used in this study. Standard errors of the estimators are determined and used for the comparisons. A simulation study is also carried out, and the mean squared errors and absolute bias are obtained for the purpose of comparison.
Bayesian parameter and reliability estimate of weibull failure time distribution
(Bulletin of the Malaysian Mathematical Sciences Society, 2013-06) Guure, C.B.; Ibrahim, N.A.; Adam, M.B.; Ahmed, A.O.M.; Bosomprah, S.
Bayes and frequentist estimators are obtained for the two-parameter Weibull failure time distribution with uncensored observations as well as the survival/reliability and hazard function. The Weibull distribution is used extensively in life testing and reliability/ survival analysis. The Bayes approach is obtained using Lindleys approximation technique with standard non-informative (vague) prior and a proposed generalisation of the noninformative prior. A simulation study is carried out to compare the performances of the methods. It is observed from the study that the unknown parameters, the reliability and hazard functions are best estimated by Bayes using linear exponential loss with the proposed prior followed by general entropy loss function.
Bayesian statistical inference of the loglogistic model with interval-censored lifetime data
(Journal of Statistical Computation and Simulation, 2014-01) Guure, C.B.; Ibrahim, N.A.; Dwomoh, D.; Bosomprah, S.
Interval-censored data arise when a failure time say, T cannot be observed directly but can only be determined to lie in an interval obtained from a series of inspection times. The frequentist approach for analysing interval-censored data has been developed for some time now. It is very common due to unavailability of software in the field of biological, medical and reliability studies to simplify the interval censoring structure of the data into that of a more standard right censoring situation by imputing the midpoints of the censoring intervals. In this research paper, we apply the Bayesian approach by employing Lindley's 1980, and Tierney and Kadane 1986 numerical approximation procedures when the survival data under consideration are interval-censored. The Bayesian approach to interval-censored data has barely been discussed in literature. The essence of this study is to explore and promote the Bayesian methods when the survival data been analysed are is interval-censored. We have considered only a parametric approach by assuming that the survival data follow a loglogistic distribution model. We illustrate the proposed methods with two real data sets. A simulation study is also carried out to compare the performances of the methods. © 2014, Taylor & Francis.
Burden of chronic kidney diseases and underlying causes in Zambia: evidence from the global burden of disease study 2019
(BMC Nephrology, 2023) Bosomprah, S.; Bjonstad, E.C.; Musuku, J.; Siyumbwa, N.; Ngandu, M.; Chisunka, M.; Banda, P.; Goma, F.; Mweemba, A.
Introduction Chronic kidney disease (CKD) has been a global public health problem and a major source of sufering and poor quality of life for those aficted. Using data from the global burden of disease (GBD) study 2019, we esti mated the magnitude of the burden of CKD as well as the underlying causes of CKD in the Zambian population. Method The data used for this study were extracted from the GBD 2019 study. The GBD 2019 provides estimates of several metrics of disease burden including the commonly used disability-adjusted life year (DALYs) for over 369 diseases and injuries, and 87 risk factors and combinations of these in 204 countries and territories from 1990 to 2019. We estimated the burden of CKD as the number and rates (per 100,000 population) of DALYs, disaggregated by year, sex, and age group. We examined the underlying causes of CKD by estimating the population attributable fraction as the percentage contributions of risk factors to CKD DALY. Results The number of DALYs for CKD was estimated as 76.03 million (95% UI: 61.01 to 93.36) in 2019 compared to 39.42 million (95% UI: 33.09 to 45.90) in 1990, representing 93% increase whereas the DALYs rate per 100,000 popu lation was estimated as 416.89 (95% UI: 334.53 to 511.93) in 2019 compared to 496.38 (95% UI: 416.55 to 577.87) in 1990, representing 16% reduction. CKD due to hypertension accounted for 18.7% of CKD DALYs and CKD due to dia betes (types 1 and 2) accounted for 22.7%, while CKD from glomerulonephritis accounted for the most DALYs at 33%. The age group most impacted from CKD were adolescents and young adults. Conclusion The burden of CKD remains high in the Zambian population with diabetes, high blood pressure, and glomerulonephritis as important causes. The results highlight the need to develop a comprehensive action plan to prevent and treat kidney disease. Increasing the awareness of CKD among the public as well as adaptation of guide lines for treating patients with end stage kidney disease are important considerations
Clinic-based evaluation of point-of-care dual HIV/syphilis rapid diagnostic tests at primary healthcare antenatal facilities in South Africa and Zambia
(BMC Infectious Diseases, 2024) Kularatne, R.; Blondeel, K.; Bosomprah, S.
Background Southern African countries have the largest global burden of HIV and syphilis, with a high prevalence among women of reproductive age. Although antenatal screening is standard of care, syphilis screening has generally lagged behind HIV screening. We aimed to evaluate the performance and operational characteristics of two commercial dual HIV/syphilis point-of-care tests (POCTs) for simultaneous maternal HIV/syphilis screening. Methods A clinic-based evaluation of dual HIV/syphilis POCTs (SD Bioline and Chembio) was conducted at five primary healthcare centres (PHCs) in South Africa and Zambia. POCT results using capillary fingerprick blood were compared to reference laboratory syphilis and HIV serological assays. Results Three thousand four hundred twelve consenting pregnant women aged≥18 years were enrolled. The prevalence of treponemal antibody seropositivity and HIV infection ranged from 3.7 to 9.9% (n=253) and 17.8 to 21.3% (n=643), respectively. Pooled sensitivity for syphilis compared to the reference assay was 66.0% (95%CI 57.7– 73.4) with SD Bioline and 67.9% (95%CI 58.2–76.3) with Chembio. Pooled specificity for syphilis was above 98% with both POCTs. The sensitivities of SD Bioline and Chembio assays were 78.0% (95%CI 68.6–85.7) and 81.0% (95%CI 71.9–88.2), respectively compared to an active syphilis case definition of treponemal test positive with a rapid plasma reagin titre of ≥8. The negative predictive values (NPVs) based on various prevalence estimates for syphilis lis with both assays ranged from 97 to 99%. The pooled sensitivity for HIV was 92.1% (95%CI 89.4–94.2) with SD Bioline; and 91.5% (95%CI 88.2–93.9) with Chembio. The pooled specificities for HIV were 97.2% (95%CI 94.8–98.5) with SD Bioline and 96.7% (95%CI 95.1–97.8) with Chembio. The NPV based on various prevalence estimates for HIV with both assays was approximately 98%. Most participating women (91%) preferred dual POCTs over two single POCTs for HIV and syphilis, and healthcare providers gave favourable feedback on the utility of both assays at PHC level. Conclusions Based on the need to improve antenatal screening coverage for syphilis, dual HIV/syphilis POCTs could be effectively incorporated into antenatal testing algorithms to enhance efforts towards elimination of mother-to-child transmission of these infections
Cohort study of the association of antibody levels to AMA1, MSP119, MSP3 and GLURP with protection from clinical malaria in Ghanaian children
(2008-07-29) Dodoo, D.; Aikins, A.; Kusi, K.A.; Lamptey, H.; Remarque, E.; Milligan, P.; Bosomprah, S.; Chilengi, R.; Osei, Y.D.; Akanmori, B.D.; Theisen, M.
Abstract Background Antigen-specific antibody-mediated immune responses play an important role in natural protection against clinical malaria, but conflicting estimates of this association have emerged from immuno-epidemiological studies in different geographical settings. This study was aimed at assessing in a standardized manner the relationship between the antibody responses to four malaria vaccine candidate antigens and protection from clinical malaria, in a cohort of Ghanaian children. Methods Standardized ELISA protocols were used to measure isotype and IgG subclass levels to Apical Membrane Antigen 1 (AMA1), Merozoite Surface Protein 1–19 (MSP119), Merozoite Surface Protein 3 (MSP3) and Glutamate Rich Protein (GLURP) antigens in plasma samples from 352 Ghanaian children, aged three to 10 years with subsequent malaria surveillance for nine months. This is one of a series of studies in different epidemiological settings using the same standardized ELISA protocols to permit comparisons of results from different laboratories. Results The incidence rate of malaria was 0.35 episodes per child per year. Isotype and IgG subclasses for all antigens investigated increased with age, while the risk of malaria decreased with age. After adjusting for age, higher levels of IgG to GLURP, MSP119, MSP3 and IgM to MSP119, MSP3 and AMA1 were associated with decreased malaria incidence. Of the IgG subclasses, only IgG1 to MSP119 was associated with reduced incidence of clinical malaria. A previous study in the same location failed to find an association of antibodies to MSP119 with clinical malaria. The disagreement may be due to differences in reagents, ELISA and analytical procedures used in the two studies. When IgG, IgM and IgG subclass levels for all four antigens were included in a combined model, only IgG1 [(0.80 (0.67–0.97), p = 0.018)] and IgM [(0.48 (0.32–0.72), p < 0.001)] to MSP119 were independently associated with protection from malaria. Conclusion Using standardized procedures, the study has confirmed the importance of antibodies to MSP119 in reducing the risk of clinical malaria in Ghanaian children, thus substantiating its potential as a malaria vaccine candidate.
Cohort study of the association of antibody levels to AMA1, MSP119, MSP3 and GLURP with protection from clinical malaria in Ghanaian children
(Malaria Journal (7): 142, 2008) Dodoo, D.; Kusi, K.A.; Aikins, A.; Lamptey, H.; Remarque, E.; Milligan, P.; Bosomprah, S.; Chilengi, R.; Osei, Y.D.; Akanmori, B.D.; Theisen, M.
Antigen-specific antibody-mediated immune responses play an important role in natural protection against clinical malaria, but conflicting estimates of this association have emerged from immuno-epidemiological studies in different geographical settings. This study was aimed at assessing in a standardized manner the relationship between the antibody responses to four malaria vaccine candidate antigens and protection from clinical malaria, in a cohort of Ghanaian children. Methods: Standardized ELISA protocols were used to measure isotype and IgG subclass levels to Apical Membrane Antigen 1 (AMA1), Merozoite Surface Protein 1-19 (MSP119), Merozoite Surface Protein 3 (MSP3) and Glutamate Rich Protein (GLURP) antigens in plasma samples from 352 Ghanaian children, aged three to 10 years with subsequent malaria surveillance for nine months. This is one of a series of studies in different epidemiological settings using the same standardized ELISA protocols to permit comparisons of results from different laboratories. Results: The incidence rate of malaria was 0.35 episodes per child per year. Isotype and IgG subclasses for all antigens investigated increased with age, while the risk of malaria decreased with age. After adjusting for age, higher levels of IgG to GLURP, MSP119, MSP3 and IgM to MSP119, MSP3 and AMA1 were associated with decreased malaria incidence. Of the IgG subclasses, only IgG1 to MSP119 was associated with reduced incidence of clinical malaria. A previous study in the same location failed to find an association of antibodies to MSP119 with clinical malaria. The disagreement may be d.
Comparing growth velocity of HIV exposed and non-exposed infants: An observational study of infants enrolled in a randomized control trial in Zambia
(PLOS ONE, 2021) Chilyabanyama, O.N.; Chilengi, R.; Laban, N.M.; Chirwa, M.; Simunyandi, M.; Hatyoka, L.M.; Ngaruye, I.; Talat Iqba, N.; Bosomprah, S.
Background Impaired growth among infants remains one of the leading nutrition problems globally. In this study, we aimed to compare the growth trajectory rate and evaluate growth trajectory characteristics among children, who are HIV exposed uninfected (HEU) and HIV unexposed uninfected (HUU), under two years in Zambia. Method Our study used data from the ROVAS II study (PACTR201804003096919), an open-label randomized control trial of two verses three doses of live, attenuated, oral RotarixTM administered 6 &10 weeks or at 6 &10 weeks plus an additional dose at 9 months of age, conducted at George clinic in Lusaka, Zambia. Anthropometric measurements (height and weight) were collected on all scheduled and unscheduled visits. We defined linear growth velocity as the rate of change in height and estimated linear growth velocity as the first derivative of the mixed effect model with fractional polynomial transformations and, thereafter, used the second derivative test to determine the peak height and age at peak heigh. Results We included 212 infants in this study with median age 6 (IQR: 6–6) weeks of age. Of these 97 (45.3%) were female, 35 (16.4%) were stunted, and 59 (27.6%) were exposed to HIV at baseline. Growth velocity was consistently below the 3rd percentile of the WHO linear growth standard for HEU and HUU children. The peak height and age at peak height among HEU children were 74.7 cm (95% CI = 73.9–75.5) and 15.5 months (95% CI = 14.7–16.3) respectively and those for HUU were 73 cm (95% CI = 72.1–74.0) and 15.6 months (95% CI = 14.5–16.6) respectively. Conclusion We found no difference in growth trajectories between infants who are HEU and HUU. However, the data suggests that poor linear growth is universal and profound in this cohort and may have already occurred in utero.
A decomposition analysis of change in skilled birth attendants, 2003 to 2008, Ghana demographic and health surveys
(BMC Pregnancy and Childbirth, 2014-12) Bosomprah, S.; Aryeetey, G.C.; Nonvignon, J.; Adanu, R.M.
Background: The single most critical intervention to improve maternal and neonatal survival is to ensure that a competent health worker with midwifery skills is present at every birth, and transport is available to a referral facility for obstetric care in case of an emergency. This study aims to describe changes in percentage of skilled birth attendants in Ghana and to identify causes of the observed changes as well as the contribution of different categories of mother's characteristics to these changes. Method: This study uses two successive nationally representative household surveys: the 2003 and 2008 Ghana Demographic and Health Surveys (GDHS). The two datasets have comparable information on household characteristics and skilled attendants at birth at the time of the survey. The 2003 GDHS database includes information on 6,251 households and 3639 live births in the five years preceding the survey, whereas the 2008 GDHS database had information on11, 778 households and 2909 live births in the five years preceding the survey. A decomposition approach was used to explain the observed change in percentage of skilled birth attendants. Random-effects generalized least square regression was used to explore the effect of changes in population structure in respect of the mother's characteristics on percentage of skilled birth attendants over the period. Results: Overall, the data showed absolute gain in the proportion of births attended by a health professional from 47.1% in 2003 to 58.7% in 2008, which represents 21.9% of gap closed to reach universal coverage. The increase in skilled birth attendants was found to be caused by changes in general health behaviour. The gain is regardless of the mother's characteristics. The structural change in the proportion of births in respect of birth order and mother's education had little effect on the change in percentage of skilled birth attendants. Conclusion: Improvement in general health behaviour can potentially contribute to an accelerated increase in proportion of births attended by skilled personnel in Ghana. © 2014 Bosomprah et al.