Risk factors for house-entry by malaria vectors in a rural town and satellite villages in The Gambia.

Background: In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry. Methods: Mosquitoes were sampled using CDC light traps in 976 houses, each on one night, in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia. Catches from individual houses were both (a) left unadjusted and (b) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period, to allow for night-to-night variation. Houses were characterized by location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. Results: 106,536 mosquitoes were caught, of which 55% were Anopheles gambiae sensu lato, the major malaria vectors in the region. There were seven fold higher numbers of An. gambiae s.l. in the villages (geometric mean per trap night = 43.7, 95% confidence intervals, CIs = 39.5–48.4) than in Farafenni town (6.3, 5.7–7.2) and significant variation between residential blocks (p < 0.001). A negative binomial multivariate model performed equally well using unadjusted or adjusted trap data. Using the unadjusted data the presence of nuisance mosquitoes was reduced if the house was located in the town (odds ratio, OR = 0.11, 95% CIs = 0.09–0.13), the eaves were closed (OR = 0.71, 0.60–0.85), a horse was tethered near the house (OR = 0.77, 0.73–0.82), and churai, a local incense, was burned in the room at night (OR = 0.56, 0.47–0.66). Mosquito numbers increased per additional person in the house (OR = 1.04, 1.02–1.06) or trapping room (OR = 1.19, 1.13–1.25) and when the walls were made of mud blocks compared with concrete (OR = 1.44, 1.10–1.87). Conclusion: This study demonstrates that the risk of malaria transmission is greatest in rural areas, where large numbers of people sleep in houses made of mud blocks, where the eaves are open, horses are not tethered nearby and where churai is not burnt at night. These factors need to be considered in the design and analysis of intervention studies designed to reduce malaria transmission in The Gambia and other parts of sub-Saharan Africa

Age Patterns of Mortality within Childhood in Sub-Saharan Africa

The age pattern of mortality in sub-Saharan Africa and how it varies across the continent remain poorly understood. The region lacks accurate registration statistics and assumptions about mortality patterns are needed to produce and smooth mortality estimates. These have had to be taken from model life table systems based on non-African data. Birth histories collected in national Demographic and Health Surveys are used to investigate age patterns of mortality in childhood in the sub-national regions of 26 countries of continental Sub-Saharan Africa. The majority of populations display a pattern of higher child relative to infant mortality than in any existing model system, including the Princeton "North" models. This reflects the existence of a "hump" of excess mortality in the late post-neonatal period and second year of life in more than three-quarters of sub-national populations. Age patterns of mortality vary markedly within and between countries, though adjacent parts of neighbouring countries sometimes have similar patterns. Particularly extreme relationships between infant and child mortality are most common in the Sahel, while a coastal belt exists adjoining the Indian Ocean with age patterns of mortality within the range of those in the Princeton models. A three-parameter model, which incorporates this "hump", is fitted to the data using Poisson regression and fitted national life tables are produced. Except for the southwest of Africa, no extensive areas exist with homogenous parameter values for the underlying downward slope of mortality with age in childhood and the size of the "hump" respectively. Thus, the scope for construction of "regional" childhood mortality models is limited. Nevertheless, age patterns of mortality in African populations tend to share features that differ from those of historical Western populations. Thus, using the national and regional average life tables in the indirect estimation of under-5 mortality yields more consistent series of estimates than are obtained using existing models

Achieving comprehensive childhood immunization: an analysis of obstacles and opportunities in The Gambia

INTRODUCTION: Immunization is a vital component in the drive to decrease global childhood mortality, yet challenges remain in ensuring wide coverage of immunization and full immunization, particularly in low- and middle-income countries. This study assessed immunization coverage and the determinants of immunization in a semi-rural area in The Gambia. METHODS: Data were drawn from the Farafenni Health and Demographic Surveillance System. Children born within the surveillance area between January 2000 and December 2010 were included. Main outcomes assessed included measles, BCG and DTP vaccination status and full immunization by 12 months of age as reported on child healthcards. Predictor variables were evaluated based on a literature review and included gender, ethnicity, area of residence, household wealth and mother's age. RESULTS: Of the 7363 children included in the study, immunization coverage was 73% (CI 72-74) for measles, 86% (CI 86-87) for BCG, 79% (CI 78-80) for three doses of DTP and 52% (CI 51-53) for full immunization. Coverage was significantly associated with area of residence and ethnicity, with children in urban areas and of Mandinka ethnicity being least likely to be fully immunized. CONCLUSIONS: Despite high levels of coverage of many individual vaccines, delivery of vaccinations later in the schedule and achieving high coverage of full immunization remain challenges, even in a country with a committed childhood immunization programme, such as The Gambia. Our data indicate areas for targeted interventions by the national Expanded Programme of Immunization

Risk factors for house-entry by culicine mosquitoes in a rural town and satellite villages in The Gambia

BACKGROUND: Screening doors, windows and eaves of houses should reduce house entry by eusynanthropic insects, including the common African house mosquito Culex pipiens quinquefasciatus and other culicines. In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against mosquito house entry, a multi-factorial risk factor analysis study was used to identify factors influencing house entry by culicines of nuisance biting and medical importance. These factors were house location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. RESULTS: 40,407 culicines were caught; the dominant species were Culex thalassius, Cx. pipiens s.l., Mansonia africanus, M. uniformis and Aedes aegypti. There were four times more Cx. pipiens s.l. in Farafenni town (geometric mean/trap/night = 8.1, 95% confidence intervals, CIs = 7.2–9.1) than in surrounding villages (2.1, 1.9–2.3), but over five times more other culicines in the villages (25.1, 22.1–28.7) than in town (4.6, 4.2–5.2). The presence of Cx. pipiens s.l. was reduced in both settings if the house had closed eaves (odds ratios, OR town = 0.62, 95% CIs = 0.49–0.77; OR village = 0.49, 0.33–0.73), but increased per additional person in the trapping room (OR town = 1.16, 1.09–1.24; OR village = 1.10, 1.02–1.18). In the town only, Cx. pipiens s.l. numbers were reduced if houses had a thatched roof (OR = 0.70, 0.51–0.96), for each additional cow tethered near the house (OR = 0.73, 0.65–0.82) and with increasing distance from a pit latrine (OR = 0.97, 0.95–0.99). In the villages a reduction in Cx. pipiens s.l. numbers correlated with increased horses in the compound (OR = 0.90, 0.82–0.99). The presence of all other culicines was reduced in houses with closed eaves (both locations), with horses tethered outside (village only) and with increasing room height (town only), but increased with additional people in the trapping room and where cows were tethered outside (both locations). CONCLUSION: The findings of this study advocate eave closure and pit latrine treatment in all locations, and zooprophylaxis using horses in rural areas, as simple control measures that could reduce the number of culicines found indoors

The role of leadership in people-centred health systems: a sub-national study in The Gambia

Recently, increasing attention has been given to behavioural and relational aspects of the people who both define and shape health systems, placing them at the core. A growing refrain includes the assertion that important decisions determining health system performance, including agenda setting, policy formulation and policy implementation, are made by people. Within this actor-oriented approach, good leadership has been identified as a key contributing factor in health systems strengthening. However, leadership remains ill-defined and under-researched, especially in resource-limited settings, and understanding the links between leadership and health outcomes remains a challenge. We explore the concept and practice of healthcare leadership at sub-national level in a low-income country setting, using a people-centric research methodology. In June and July 2013, 15 in-depth interviews were conducted with key informants in formal healthcare leadership roles across urban, peri-urban and rural settings of The Gambia, West Africa. Participants included the entire spectrum of Regional Health Team (RHT) Directors and Chief Executive Officers of all government hospitals, as well as one clinical officer-in-charge in a secondary-level major health centre. We found reference to several important aspects of, and approaches to, leadership, including (i) setting a clear vision; (ii) engendering shared leadership; and (iii) paying attention to human relations in management. Participants described attending to constituencies in government, international development agencies and civil society, as well as to the populations they serve. By illuminating the multi-polar networks within which these leaders are embedded, and through which they operate, we provide insight into the complex ‘organizational ecology’ of the Gambian health system. There is a need to further research and develop healthcare leadership across all levels, within various political, socio-economic and cultural contexts, in order to better work with a range of health actors and to engage them in identifying and acting upon opportunities for health systems strengthening

Preventive measures in infancy to reduce under-five mortality: a case-control study in The Gambia.

OBJECTIVE: To investigate the relationship between child mortality and common preventive interventions: vaccination, trained birthing attendants, tetanus toxoid during pregnancy, breastfeeding and vitamin A supplementation. METHODS: Case-control study in a population under demographic surveillance. Cases (n = 141) were children under five who died. Each was age and sex-matched to five controls (n = 705). Information was gathered by interviewing primary caregivers. RESULTS: All but one of the interventions - whether the mother had received tetanus toxoid during pregnancy - were protective against child mortality after multivariate analysis. Having a trained person assisting at child birth (OR 0.2 95% CI 0.1-0.4), receiving all vaccinations by 9 months of age (OR 0.1; 95% CI 0.01-0.3), being breastfed for more than 12 months (Children breastfed between 13 and 24 months OR 0.1 95% CI 0.03-0.3, more than 25 months OR 0.1 95% CI 0.01-0.5) and receiving vitamin A supplementation at or after 6 months of age (OR 0.05; 95% CI 0.01-0.2) were protective against child death. CONCLUSIONS: This study confirms the value of at least four available interventions in the prevention of under-five death in The Gambia. It is now important to identify those who are not receiving them and why, and to intervene to improve coverage across the population

Disease-specific mortality burdens in a rural Gambian population using verbal autopsy, 1998-2007.

OBJECTIVE: To estimate and evaluate the cause-of-death structure and disease-specific mortality rates in a rural area of The Gambia as determined using the InterVA-4 model. DESIGN: Deaths and person-years of observation were determined by age group for the population of the Farafenni Health and Demographic Surveillance area from January 1998 to December 2007. Causes of death were determined by verbal autopsy (VA) using the InterVA-4 model and ICD-10 disease classification. Assigned causes of death were classified into six broad groups: infectious and parasitic diseases; cancers; other non-communicable diseases; neonatal; maternal; and external causes. Poisson regression was used to estimate age and disease-specific mortality rates, and likelihood ratio tests were used to determine statistical significance. RESULTS: A total of 3,203 deaths were recorded and VA administered for 2,275 (71%). All-age mortality declined from 15 per 1,000 person-years in 1998-2001 to 8 per 1,000 person-years in 2005-2007. Children aged 1-4 years registered the most marked (74%) decline from 27 to 7 per 1,000 person-years. Communicable diseases accounted for half (49.9%) of the deaths in all age groups, dominated by acute respiratory infections (ARI) (13.7%), malaria (12.9%) and pulmonary tuberculosis (10.2%). The leading causes of death among infants were ARI (5.59 per 1,000 person-years [95% CI: 4.38-7.15]) and malaria (4.11 per 1,000 person-years [95% CI: 3.09-5.47]). Mortality rates in children aged 1-4 years were 3.06 per 1,000 person-years (95% CI: 2.58-3.63) for malaria, and 1.05 per 1,000 person-years (95% CI: 0.79-1.41) for ARI. The HIV-related mortality rate in this age group was 1.17 per 1,000 person-years (95% CI: 0.89-1.54). Pulmonary tuberculosis and communicable diseases other than malaria, HIV/AIDS and ARI were the main killers of adults aged 15 years and over. Stroke-related mortality increased to become the leading cause of death among the elderly aged 60 years or more in 2005-2007. CONCLUSIONS: Mortality in the Farafenni HDSS area was dominated by communicable diseases. Malaria and ARI were the leading causes of death in the general population. In addition to these, diarrhoeal disease was a particularly important cause of death among children under 5 years of age, as was pulmonary tuberculosis among adults aged 15 years and above

Comparison of all-cause and malaria-specific mortality from two West African countries with different malaria transmission patterns

BACKGROUND: Malaria is a leading cause of death in children below five years of age in sub-Saharan Africa. All-cause and malaria-specific mortality rates for children under-five years old in a mesoendemic malaria area (The Gambia) were compared with those from a hyper/holoendemic area (Burkina Faso). METHODS: Information on observed person-years (PY), deaths and cause of death was extracted from online search, using key words: "Africa, The Gambia, Burkina Faso, malaria, Plasmodium falciparum, mortality, child survival, morbidity". Missing person-years were estimated and all-cause and malaria-specific mortality were calculated as rates per 1,000 PY. Studies were classified as longitudinal/clinical studies or surveys/censuses. Linear regression was used to investigate mortality trends. RESULTS: Overall, 39 and 18 longitudinal/clinical studies plus 10 and 15 surveys and censuses were identified for The Gambia and Burkina Faso respectively (1960-2004). Model-based estimates for under-five all-cause mortality rates show a decline from 1960 to 2000 in both countries (Burkina Faso: from 71.8 to 39.0), but more markedly in The Gambia (from 104.5 to 28.4). The weighted-average malaria-specific mortality rate per 1000 person-years for Burkina Faso (15.4, 95% CI: 13.0-18.3) was higher than that in The Gambia (9.5, 95% CI: 9.1-10.1). Malaria mortality rates did not decline over time in either country. CONCLUSION: Child mortality in both countries declined significantly in the period 1960 to 2004, possibly due to socio-economic development, improved health services and specific intervention projects. However, there was little decline in malaria mortality suggesting that there had been no major impact of malaria control programmes during this period. The difference in malaria mortality rates across countries points to significant differences in national disease control policies and/or disease transmission patterns

Assessing levels and trends of adult mortality in Sub Saharan Africa using INDEPTH health and demographic surveillance systems

International audienceThere is still a considerable dearth of knowledge regarding adult mortality and premature deaths in Sub-Saharan Africa (SSA). Attempts to measure adult mortality using censuses and cross-sectional surveys rely mainly on indirect techniques that are affected by common biases. The growing number of Health and Demographic Surveillance Systems (HDSSs) offer a mediumterm solution to the dearth of knowledge regarding adult mortality and the main causes in Africa. This paper compares adult mortality estimates from 16 HDSSs in nine countries in SSA based on publicly available data on INDEPTHStats. We use Life Table techniques to examine differences in adult mortality trends and to identify mortality clusters and sex differentials. Results reveal distinctive mortality trends for the three regions of Africa with the Southern and Eastern African regions having relatively higher mortality than the West African region