Ethnic diversity and mortality in northwest Burkina Faso: An analysis of the Nouna health and demographic surveillance system from 2000 to 2012.

Ethnic diversity has been a topic of contention across the globe, contrasted with economic development, social security, and political stability. The link between health and ethnic diversity is not yet well established especially in low-middle- income countries. Our study aims to explore the association between ethnic diversity and all-cause mortality in rural areas of Burkina Faso. We used data from the Nouna Health & Demographic Surveillance System (HDSS) collected between 2000 and 2012. To derive Standardized Mortality Ratios (SMR), the observed number of deaths was compared to the expected deaths based on the entire HDSS taking into account sex, age, rainy season, calendar year, and village. SMR were calculated for ethnic and religious diversity on a village level (using the Simpson Index), sub-region, wealth, and distance to Healthcare Facilities (HCF). Furthermore, we modeled SMR with a multilevel random intercept Poisson regression considering individual ethnic and religious groups in addition to the above-mentioned village-level information. Village wealth (poorest fifth: SMR 1.07; 95% CI: 1.02-1.13, richest fifth: SMR 0.85; 95% CI: 0.82-0.88), distance to HCF (within the village: SMR 0.88; 95% CI: 0.85-0.91, further than 5km: SMR 1.13; 95% CI: 1.10-1.16), and sub-region showed significant associations with overall mortality. Villages belonging to the third with the highest ethnic diversity had lowered SMR (0.86; 95% CI: 0.84-0.89) compared to the entire HDSS, while those belonging to the lowest diversity third yielded elevated SMR (1.13; 95% CI: 1.09-1.17). The multilevel model confirmed the association. Our study showed that historically established ethnic diversity in rural areas of Burkina Faso was associated with lower all-cause mortality. Generally, the literature suffers from a lack of standardization in defining ethnic diversity, along with measuring it. More research is needed to understand this relation and to establish it in different settings.

Clustering of Infant Mortality Within Families in Rural Burkina Faso.

In this study, we analyze clustering of infant deaths within families living in a rural part of western Burkina Faso. The study included 9,220 infants, born between 1993 and 2009 in Nouna Health and Demographic Surveillance System (HDSS). A clustering of infant deaths in families was explored by calculating observed versus expected number of infant deaths within families for a given family size. In addition, risk ratios were calculated for infant death depending on the vital status of the previous sibling. We observed 470 infant deaths, yielding an overall infant mortality risk of 51/1,000 births. Clustering of infant deaths within families was observed (P = 0.004). In smaller families, the mortality of firstborns was higher than for the following siblings. The infant mortality risk was higher when the preceding sibling died in infancy (P = 0.03). The study supports the hypothesis of infant death clustering existing within rural families in West Africa. Further studies are needed to shed more light on these findings with the goal to develop effective interventions directed toward the families who already lost a child.

Ramadan Exposure In Utero and Child Mortality in Burkina Faso: Analysis of a Population-Based Cohort Including 41,025 Children.

Ramadan exposure in utero can be regarded as a natural experiment with which to study how nutritional conditions in utero influence susceptibility to disease later in life. We analyzed data from rural Burkina Faso on 41,025 children born between 1993 and 2012, of whom 25,093 were born to Muslim mothers. Ramadan exposure was assigned on the basis of overlap between Ramadan dates and gestation, creating 7 exclusive categories. We used proportional hazards regression with difference-in-differences analysis to estimate the association between Ramadan exposure at different gestational ages and mortality among children under 5 years of age. Under-5 mortality was 32 deaths per 1,000 child-years. Under-5 mortality among Muslims was 15% higher than that among non-Muslims (P < 0.001). In the difference-in-differences analysis, the occurrence of Ramadan during conception or the first or second trimester was associated with higher under-5 mortality rates among Muslims only. The mortality rates of children born to Muslim mothers were 33%, 29%, and 22% higher when Ramadan occurred during conception, the first trimester, and the second trimester, respectively, compared with children of non-Muslim mothers born at the same time (P = 0.01, P < 0.001, and P = 0.007). Having a Muslim mother was not associated with mortality when the child was not exposed to Ramadan, born during Ramadan, or exposed during the third trimester. Observance of Ramadan during early pregnancy can have detrimental consequences for the future health of the unborn child.

Prevalence of abnormal birth weight and related factors in Northern region, Ghana.

BACKGROUND: Birth weight is a crucial determinant of the development potential of the newborn. Abnormal newborn weights are associated with negative effects on the health and survival of the baby and the mother. Therefore, this study was designed to determine the prevalence of abnormal birth weight and related factors in Northern region, Ghana. METHODS: The study was a facility-based cross-sectional survey in five hospitals in Northern region, Ghana. These hospitals were selected based on the different socio-economic backgrounds of their clients. The data on birth weight and other factors were derived from hospital records. RESULTS: It was observed that low birth weight is still highly prevalent (29.6%), while macrosomia (10.5%) is also increasingly becoming important. There were marginal differences in low birth weight observed across public hospitals but marked difference in low birth weight was observed in Cienfuegos Suglo Specialist Hospital (Private hospital) as compared to the public hospitals. The private hospital also had the highest prevalence of macrosomia (20.1%). Parity (0-1) (p < 0.001), female gender (p < 0.001) and location (rural) (p < 0.001) were significantly associated with decreased risk of macrosomic births. On the other hand, female infant sex (p < 0.001), residential status (rural) (p < 0.001) and parity (0-1) (p < 0.001) were significantly associated with increased risk of low birth weigh. CONCLUSIONS: Our findings show that under nutrition (low birth weight) and over nutrition (macrosomia) coexist among infants at birth in Northern region reflecting the double burden of malnutrition phenomenon, which is currently being experienced by developing and transition counties. Both low birth weight and macrosomia are risk factors, which could contribute considerably to the current and future burden of diseases. This may overstretch the already fragile health system in Ghana. Therefore, it is prudent to recommend that policies aiming at reducing diet related diseases should focus on addressing malnutrition during pregnancy and early life.

Safety of insecticide-treated mosquito nets for infants and their mothers: randomized controlled community trial in Burkina Faso.

BACKGROUND: Insecticide-treated bed nets (ITNs) are now the main tool for malaria prevention in endemic areas. Synthetic pyrethroids are the only group of insecticides recommended by the World Health Organization for the use on ITNs. There are only few studies which have specifically investigated potential adverse effects of frequent exposure to ITNs in the vulnerable group of young infants and their mothers. METHODS: This study was nested into a large randomized controlled ITN effectiveness trial. Ninety newborns and their mothers were selected from the study population for participation. Together with their mothers they were protected with ITNs from birth (group A, n = 45) or from age 6 months (group B, n = 45) and followed up for 18 weeks (daily visits in the first 4 weeks, weekly visits thereafter). Potential side effects related to synthetic pyrethroids (deltamethrin) exposure were systematically investigated by trained field staff. The frequency and duration of respective symptoms was compared between the two study groups. RESULTS: A total of 180 participants (90 mothers and 90 infants) were followed up over the study period without any loss to follow up. There were no significant differences in the frequency and duration of side effects between the two study groups, except that the frequency of headache was significantly higher in group A compared to group B mothers (p = 0.01). CONCLUSIONS: The study provides further evidence for ITNs being sufficiently safe in children and even in newborns. The association with headache in mothers could be explained by them handling the ITNs more intensely or it could be a chance finding.

Maternal Determinants of Birth Weight in Northern Ghana.

OBJECTIVES: Weight at birth is usually considered as an indicator of the health status of a given society. As a result this study was designed to investigate the association between birth weight and maternal factors such as gestational weight gain, pre-pregnancy BMI and socio-economic status in Northern Ghana. METHODS: The study was a facility-based cross-sectional survey conducted in two districts in the Northern region of Ghana. These districts were purposively sampled to represent a mix of urban, peri-urban and rural population. The current study included 419 mother-infant pairs who delivered at term (37-42 weeks). Mother's height, pre-pregnancy weight and weight changes were generated from the antenatal records. Questionnaires were administered to establish socio-economic and demographic information of respondents. Maternal factors associated with birth weight were examined using multiple and univariate regressions. RESULTS: The mothers were generally well nourished before conception (Underweight 3.82%, Normal 57.76%, Overweight 25.06% and Obesity 13.37%) but approximately half of them could not gain adequate weight according to Institute of Medicine recommendations (Low weight gain 49.64%, Adequate weight gain 42.96% and Excessive weight gain 7.40%). Infants whose mothers had excess weight gain were 431g (95% CI 18-444) heavier compared to those whose mothers gained normal weight, while those whose mothers gained less were 479g (95% CI -682- (-276) lighter. Infants of mothers who were overweight and obese before conception were 246g (95% CI 87-405) and 595g (95% CI 375-815) respectively heavier than those of normal mothers, whereas those whose mothers were underweight were 305g (95% CI -565 -(-44) lighter. The mean birth weight observed was 2.98 ± 0.68 kg. CONCLUSION: Our findings show that pre-pregnancy body mass index and weight gain during pregnancy influence birth weight. Therefore, emphasis should be placed on counseling and assisting pregnant women to stay within the recommended weight gain ranges.

Decreasing disparities in infant survival using surveillance data from Burkina Faso.

We assessed changes in the effect size of risk factors for infant mortality comparing a birth cohort from 2005 to 2010 with a birth cohort from 1993 to 1999 in the Nouna Health and Demographic Surveillance System (HDSS) in Burkina Faso. Single- and three-level Cox proportional hazards regression models were used for analysis. Independent variables among others included year of birth, ethnicity, religion, age of the mother, birth order, death of the mother, being a twin, and distance to the closest health facility. We observed an infant mortality rate of about 51/1,000 person-years. The strongest risk factors were death of the mother and being a twin, which were also the strongest risk factors from the previous analysis period. Compared with the period 1993-1999, the effect of most risk factors decreased, notably ethnicity, religious affiliation, distance to the closest health facility, birth order, and season of birth. The strongest reduction in mortality occurred in the groups with the previously highest infant mortality rates in 1993-1999.

Childhood mortality and its association with household wealth in rural and semi-urban Burkina Faso.

BACKGROUND: This study aimed to investigate the relationship between household wealth and under-5 year mortality in rural and semi-urban Burkina Faso. METHODS: The study included 15 543 children born between 2005 and 2010 in the Nouna Health and Demographic Surveillance System. Information on household wealth was collected in 2009. Two separate wealth indicators were calculated by principal components analysis for the rural and the semi-urban households, which were then divided into quintiles accordingly. Multivariable Cox proportional hazards regression was used to study the effect of the respective wealth measure on under-5 mortality. RESULTS: We observed 1201 childhood deaths, corresponding to 5-year survival probability of 93.6% and 88% in the semi-urban and rural area, respectively. In the semi-urban area, household wealth was significantly related to under-5 mortality after adjustment for confounding. There was a similar but non-significant effect of household wealth on infant mortality, too. There was no effect of household wealth on under-5 mortality in rural children. CONCLUSIONS: Results from this study indicate that the more privileged children from the semi-urban area with access to piped water and electricity have an advantage in under-5 survival, while under-5 mortality in the rural area is rather homogeneous and still relatively high.

Public and private maternal health service capacity and patient flows in Southern Tanzania: using a geographic information system to link hospital and national census data.

BACKGROUND: Strategies to improve maternal health in low-income countries are increasingly embracing partnership approaches between public and private stakeholders in health. In Tanzania, such partnerships are a declared policy goal. However, implementation remains challenging as unfamiliarity between partners and insufficient recognition of private health providers prevail. This hinders cooperation and reflects the need to improve the evidence base of private sector contribution. OBJECTIVE: To map and analyse the capacities of public and private hospitals to provide maternal health care in southern Tanzania and the population reached with these services. DESIGN: A hospital questionnaire was applied in all 16 hospitals (public n=10; private faith-based n=6) in 12 districts of southern Tanzania. Areas of inquiry included selected maternal health service indicators (human resources, maternity/delivery beds), provider-fees for obstetric services and patient turnover (antenatal care, births). Spatial information was linked to the 2002 Population Census dataset and a geographic information system to map patient flows and socio-geographic characteristics of service recipients. RESULTS: The contribution of faith-based organizations (FBOs) to hospital maternal health services is substantial. FBO hospitals are primarily located in rural areas and their patient composition places a higher emphasis on rural populations. Also, maternal health service capacity was more favourable in FBO hospitals. We approximated that 19.9% of deliveries in the study area were performed in hospitals and that the proportion of c-sections was 2.7%. Mapping of patient flows demonstrated that women often travelled far to seek hospital care and where catchment areas of public and FBO hospitals overlap. CONCLUSIONS: We conclude that the important contribution of FBOs to maternal health services and capacity as well as their emphasis on serving rural populations makes them promising partners in health programming. Inclusive partnerships could increase integration of FBOs into the public health care system and improve coordination and use of scarce resources.

The challenges of developing an instrument to assess health provider motivation at primary care level in rural Burkina Faso, Ghana and Tanzania.

BACKGROUND: The quality of health care depends on the competence and motivation of the health workers that provide it. In the West, several tools exist to measure worker motivation, and some have been applied to the health sector. However, none have been validated for use in sub-Saharan Africa. The complexity of such tools has also led to concerns about their application at primary care level. OBJECTIVE: To develop a common instrument to monitor any changes in maternal and neonatal health (MNH) care provider motivation resulting from the introduction of pilot interventions in rural, primary level facilities in Ghana, Burkina Faso, and Tanzania. DESIGN: Initially, a conceptual framework was developed. Based upon this, a literature review and preliminary qualitative research, an English-language instrument was developed and validated in an iterative process with experts from the three countries involved. The instrument was then piloted in Ghana. Reliability testing and exploratory factor analysis were used to produce a final, parsimonious version. RESULTS AND DISCUSSION: This paper describes the actual process of developing the instrument. Consequently, the concepts and items that did not perform well psychometrically at pre-test are first presented and discussed. The final version of the instrument, which comprises 42 items for self-assessment and eight for peer-assessment, is then shown. This is followed by a presentation and discussion of the findings from first use of the instrument with MNH providers from 12 rural, primary level facilities in each of the three countries. CONCLUSIONS: It is possible to undertake work of this nature at primary health care level, particularly if the instruments are kept as straightforward as possible and well introduced. However, their development requires very lengthy preparatory periods. The effort needed to adapt such instruments for use in different countries within the region of sub-Saharan Africa should not be underestimated.

Direct manipulation of malaria parasites with optical tweezers reveals distinct functions of Plasmodium surface proteins.

Plasmodium sporozoite motility is essential for establishing malaria infections. It depends on initial adhesion to a substrate as well as the continuous turnover of discrete adhesion sites. Adhesion and motility are mediated by a dynamic actin cytoskeleton and surface proteins. The mode of adhesion formation and the integration of adhesion forces into fast and continuous forward locomotion remain largely unknown. Here, we use optical tweezers to directly trap individual parasites and probe adhesion formation. We find that sporozoites lacking the surface proteins TRAP and S6 display distinct defects in initial adhesion; trap(-) sporozoites adhere preferentially with their front end, while s6(-) sporozoites show no such preference. The cohesive strength of the initial adhesion site is differently affected by actin filament depolymerization at distinct adhesion sites along the parasite for trap(-) and s6(-) sporozoites. These spatial differences between TRAP and S6 in their functional interaction with actin filaments show that these proteins have nonredundant roles during adhesion and motility. We suggest that complex protein-protein interactions and signaling events govern the regulation of parasite gliding at different sites along the parasite. Investigating how these events are coordinated will be essential for our understanding of sporozoite gliding motility, which is crucial for malaria infection. Laser tweezers will be a valuable part of the toolset.

ITN protection, MSP1 antibody levels and malaria episodes in young children of rural Burkina Faso.

Malaria blood-stage vaccines are in an early phase of clinical development with MSP1 being a major antigen candidate. There are limited data on the protective efficacy of antibodies against subunits of MSP1 in the malaria endemic areas of sub-Saharan Africa. This prospective cohort study was nested into a large insecticide-treated mosquito net (ITN) trial during which neonates were individually randomised to ITN protection from birth vs. protection from month six onwards in rural Burkina Faso. A sub sample of 120 children from three villages was followed for 10 months with six measurements of MSP1(42) antibodies (ELISA based on recombinant 42kDa fragment) and daily assessment of malaria episodes. Time to the next malaria episode was determined in relation to MSP1(42) antibody titres. MSP1(42) antibody titres were dependent on age, season, ITN-group, number of previous malaria episodes and parasitaemia. There were no significant differences in time until the next malaria episode in children with low compared to children with high MSP1(42) antibody titres at any point in time (101 vs. 97 days in May, p=0.6; 58 vs. 84 days in September, p=0.3; 144 vs. 161 days in March, p=0.5). The findings of this study support the short-lived nature of the humoral immune response in infants of malaria endemic areas. The study provides no evidence for antibodies against a subunit of MSP1 being protective against new malaria episodes in infants.

Seasonal patterns of cardiovascular disease mortality of adults in Burkina Faso, West Africa.

OBJECTIVE: To evaluate seasonal patterns of cardiovascular death in adults, which are possibly influenced by hot and dry climate, in a rural setting of Burkina Faso. METHODS: Cause of death was ascertained by verbal autopsy. Age-specific death rates (cardiovascular death and all-cause) by month of death were calculated. Seasonal trends and temperature effects were modelled with Poisson regression. RESULTS: In 11,174 adults (40+), 1238 deaths were recorded for the period 1999-2003. All-cause mortality in adults (40-64 years) and the elderly (65+ years) was 1269 per 100,000 (95% CI 1156-1382) and 7074 (95% CI 6569-7579), respectively. Cardiovascular death was the fourth most frequent cause of death in adults (40+), with a mortality of 109.9 (95% CI 76.6-143.1) for ages 40-64 and 544.9 (95% CI 404.6-685.1) for ages 65+. For all-causes, the mortality was highest in March and for cardiovascular death highest in April, the hot dry season (March-May). Mean monthly temperature was significantly related to mortality in old ages. CONCLUSIONS: Cardiovascular mortality varies by season, with higher mortality rates in the hot dry season. The pattern seems to be consistent with other studies suggesting association between hot weather and cardiovascular disease. A 'heat-wave' effect appears to be observable also in areas with hot average temperatures.

Step-wedge cluster-randomised community-based trials: an application to the study of the impact of community health insurance.

BACKGROUND: We describe a step-wedge cluster-randomised community-based trial which has been conducted since 2003 to accompany the implementation of a community health insurance (CHI) scheme in West Africa. The trial aims at overcoming the paucity of evidence-based information on the impact of CHI. Impact is defined in terms of changes in health service utilisation and household protection against the cost of illness. Our exclusive focus on the description and discussion of the methods is justified by the fact that the study relies on a methodology previously applied in the field of disease control, but never in the field of health financing. METHODS: First, we clarify how clusters were defined both in respect of statistical considerations and of local geographical and socio-cultural concerns. Second, we illustrate how households within clusters were sampled. Third, we expound the data collection process and the survey instruments. Finally, we outline the statistical tools to be applied to estimate the impact of CHI. CONCLUSION: We discuss all design choices both in relation to methodological considerations and to specific ethical and organisational concerns faced in the field. On the basis of the appraisal of our experience, we postulate that conducting relatively sophisticated trials (such as our step-wedge cluster-randomised community-based trial) aimed at generating sound public health evidence, is both feasible and valuable also in low income settings. Our work shows that if accurately designed in conjunction with local health authorities, such trials have the potential to generate sound scientific evidence and do not hinder, but at times even facilitate, the implementation of complex health interventions such as CHI.

Patterns of malaria: cause-specific and all-cause mortality in a malaria-endemic area of west Africa.

Information on cause-specific mortality is sparse in sub-Saharan Africa. We present seasonal patterns of malaria and all-cause mortality from a longitudinal study with 60,000 individuals in rural northwestern Burkina Faso. The study is based on a demographic surveillance system and covers the period 1999-2003. Overall, 3,492 deaths were observed. Cause of death was ascertained by verbal autopsy. Age-specific death rates by cause and month of death were calculated. Seasonal and temporal trends were modeled with parametric Poisson regression. Infant and children less than 5 years of age mortality was 60.6 (95% CI, 56.2-65.3) and 31.9 (95% CI, 30.4-33.5) per 1,000 for all causes and 23.4 (95% CI, 20.7-26.4) and 13.3 (95% CI, 12.3-14.3) for malaria, respectively. Mortality was significantly higher in the rainy season. It is well described parametrically with a sinusoidal function. In adults, the highest all-cause mortality rates were observed in the dry season. Here, HIV/AIDS has become a leading cause of mortality.

Pattern of cause-specific childhood mortality in a malaria endemic area of Burkina Faso.

BACKGROUND: Reliable mortality data are a prerequisite for planning health interventions, yet such data are often not available in developing countries, particularly in sub-Saharan Africa (SSA). Demographic surveillance systems (DSS) implementing the verbal autopsy (VA) method are the only possibility to observe cause-specific mortality of a population on a longitudinal basis in many countries. METHODS: This paper reports all-cause and cause-specific mortality rates in children under the age of five years from 1999 until 2003 in a malaria holoendemic area of north-western Burkina Faso. The DSS of the Nouna Health Research Centre, in which VA data were analysed, covers a rural population of about 30,000 (41 villages) and an urban population of about 25,000 (Nouna town). RESULTS: A total of 1,544 deaths were analysed, 87 (6%), 225 (14%), 317 (21%) and 915 (59%) of which occurred in the periods < 1 month, 1-5 months, 6-11 months and 1-4 years respectively. All cause mortality rates of children under five years were higher in the rural than the urban area (34 vs 24 per 1,000 person-years) and in the rainy than the dry season (35 vs 29 per 1,000 person-years). Malaria was the most frequent diagnosis (42%) with peak mortality rates in infants aged 6-11 months. CONCLUSION: Malaria is the most important cause of death in this remote area of SSA, even considering the low specificity of malaria diagnosis in young children. Strengthening the existing malaria control tools is of prime importance to reduce the high childhood mortality in the endemic areas of SSA.

Seroprevalence of six different viruses among pregnant women and blood donors in rural and urban Burkina Faso: A comparative analysis.

A seroprevalence study was carried out of six different human pathogenic viruses, namely human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell leukemia virus (HTLV), human herpesvirus type 8 (HHV-8), and dengue virus among pregnant women and blood donors from rural (Nouna) and urban (Ouagadougou) Burkina Faso, West Africa. A total of 683 samples from blood donors (n = 191) and pregnant women (n = 492) were collected from both sites and screened for the different virus infection markers resulting in the following prevalence values for Nouna or Ouagadougou, respectively: HIV 3.6/4.6, anti-HBV core (anti-HBc) 69.6/76.4, HBV surface antigen (HBsAg)14.3/17.3, HCV 2.2/1.5, HTLV 1.4/0.5, HHV-8 11.5/13.5, dengue virus 26.3/36.5. Individuals aged > or =25 years were more likely to be infected with HIV than those below 24 years (P < 0.05). Infection with HIV increased the likelihood of co-infection with other viruses, such as HHV-8, HBV and HTLV. Co-infection studies involving five viruses (HBV-HBsAg, HHV-8, HIV, HCV, and HTLV) showed that 4.8% (33/683) of the studied population were dually infected, with HBsAg+ HHV-8 (13/33), HBsAg+HIV (8/33) and HIV+HHV-8 (8/33) being the most common co-infections. Of the population studied 0.6% (4/683) was triply infected, the most common infection being with HBV+HIV+HHV-8 (3/4). There was no difference in the prevalence of HIV, anti-HBc, HBsAg, HCV, HTLV, and HHV-8 either among blood donors or pregnant women in urban or rural setting, while dengue virus prevalence was relatively lower in rural (26.3%) than in urban (36.5%) Burkina Faso.

Multiple pregnancy in rural Burkina Faso: frequency, survival, and use of health services.

OBJECTIVE: To assess the birth of twins in rural Burkina Faso with respect to prevalence, mortality, and provision of obstetric care. METHODS: A descriptive demographic analysis of population-based and health service data was performed with multivariate modeling by Poisson regression. Health service data were derived from a document review in health facilities in the Nouna District for the years 1994-2001. The district hospital provides obstetric care for the entire district with its 252,000 population (1998). Population-based data (deliveries, live births, deaths) were derived from the demographic surveillance system in the surveillance area within the Nouna District, Burkina Faso (population under surveillance: 30,988 in 1998). All births in the period from January 1, 1993 to December 31, 1998 (9457 recorded deliveries with 9,610 live births) were included and followed up until April 30, 2002. The main outcome measures were the prevalence of twin delivery as well as age- and sex-specific mortality risks. RESULTS: Mortality of twins is high, with one out of three dying before reaching the age of five years--2.5 times the mortality risk of singletons. Among twins, mortality is particularly high in the neonatal period (RR 5.16; CI: 3.6-7.5) and in twins born to mothers above the age of 35 (RR 5.12; CI: 3.5-7.6). The overall population-based prevalence of twin delivery is 1.6% (CI: 1.4-1.9) versus a hospital-based prevalence of 2.8% (CI: 2.2-3.1). Despite this moderate trend towards hospital-based obstetric care, most twins (90.5%) are still delivered outside a hospital setting. CONCLUSIONS: The high neonatal mortality in twins points to the need for special care in pregnancy, child birth, and postpartum. Maternity services fail to adequately cover the vast majority of multiple pregnancies and deliveries.

Season of death and birth predict patterns of mortality in Burkina Faso.

BACKGROUND: Mortality in developing countries has multiple causes. Some of these causes are linked to climatic conditions that differ over the year. Data on season-specific mortality are sparse. METHODS: We analysed longitudinal data from a population of approximately 35,000 individuals in Burkina Faso. During the observation period 1993-2001, a total number of 4,098 deaths were recorded. The effect of season on mortality was investigated separately by age group as (i) date of death and (ii) date of birth. For (i), age-specific death rates by month of death were calculated. The relative effect of each month was assessed using the floating relative risk method and modelled continuously. For (ii), age-specific death rates by month of birth were calculated and the mean date of birth among deaths and survivors was compared. RESULTS: Overall mortality was found to be consistently higher during the dry season (November to May). The pattern was seen in all age groups except in infants where a peak was seen around the end of the rainy season. In infants we found a strong association between high mortality and being born during the time period September to February. No effect was seen for the other age groups. CONCLUSIONS: The observed excess mortality in young children at or around the end of the rainy season can be explained by the effects of infectious diseases and, in particular, malaria during this time period. In contrast, the excess mortality seen in older children and adults during the early dry season remains largely unexplained although specific infectious diseases such as meningitis and pneumonia are possible main causes. The association between high infant mortality and being born at around the end of the rainy season is probably explained by most of the malaria deaths in areas of high transmission intensity occurring in the second half of infancy.

Risk factors of infant and child mortality in rural Burkina Faso.

OBJECTIVE: The aim of the study was to quantify the effect of risk factors for childhood mortality in a typical rural setting in sub-Saharan Africa. METHODS: We performed a survival analysis of births within a population under demographic surveillance from 1992 to 1999 based on data from a demographic surveillance system in 39 villages around Nouna, western Burkina Faso, with a total population of about 30000. All children born alive in the period 1 January 1993 to 31 December 1999 in the study area (n = 10 122) followed-up until 31 December 1999 were included. All-cause childhood mortality was used as outcome variable. FINDINGS: Within the observation time, 1340 deaths were recorded. In a Cox regression model a simultaneous estimation of hazard rate ratios showed death of the mother and being a twin as the strongest risk factors for mortality. For both, the risk was most pronounced in infancy. Further factors associated with mortality include age of the mother, birth spacing, season of birth, village, ethnic group, and distance to the nearest health centre. Finally, there was an overall decrease in childhood mortality over the years 1993-99. CONCLUSION: The study supports the multi-causation of childhood deaths in rural West Africa during the 1990s and supports the overall trend, as observed in other studies, of decreasing childhood mortality in these populations. The observed correlation between the factors highlights the need for multivariate analysis to disentangle the separate effects. These findings illustrate the need for more comprehensive improvement of prenatal and postnatal care in rural sub-Saharan Africa.