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.

Malaria incidence during early childhood in rural Burkina Faso: Analysis of a birth cohort protected with insecticide-treated mosquito nets.

BACKGROUND: Even in the high transmission areas of sub-Saharan Africa (SSA), the incidence of falciparum malaria varies greatly depending on factors such as age, rainfall pattern, distance to breeding places, quality of houses, and existing vector control measures. Insecticide-treated mosquito nets (ITN) have now become the vector control standard in nearly all of SSA. This study aims to describe and analyse the incidence of malaria in a cohort of young children protected with ITN in rural West Africa. METHODS: Data of a subsample from a large community trial in rural north-western Burkina Faso consisting of 420 children were analysed. The main aim of the trial was to evaluate the long-term effects of ITNs in two groups of new-borns; Group A was protected with ITN from birth onwards while Group B was protected only from month six onwards. The primary objective of this study was to describe malaria incidence in detail with an analysis of the impact of potentially relevant determinants of malaria incidence, in particular age, sex, ITN protection, village, month and season as secondary objective. Bivariate negative binomial regression analysis was used to calculate incidence rate ratios of malaria incidence. Moreover, relevant variables were included in a multivariate negative binomial regression model to examine possible risk factors for malaria. RESULTS: Out of the 420 study children 387 (92.1%) developed a total of 1822 falciparum malaria episodes; the malaria incidence rate was 7.6 per 1000 child days. Group A children had lower malaria incidence rates compared to group B, but only in early infancy. Malaria incidence varied significantly between villages and increased with age, but no sex-specific differences were observed; these findings were confirmed in the multi-variate analysis. Malaria incidence peaked sharply towards the end of the rainy season in September but there were no differences in the seasonal pattern by study group. CONCLUSIONS: The study, carried out in a high-transmission West African area, shows that malaria incidence remains high in spite of maximum ITN coverage.

Decreasing child mortality, spatial clustering and decreasing disparity in North-Western Burkina Faso.

Within relatively small areas, there exist high spatial variations of mortality between villages. In rural Burkina Faso, with data from 1993 to 1998, clusters of particularly high child mortality were identified in the population of the Nouna Health and Demographic Surveillance System (HDSS), a member of the INDEPTH Network. In this paper, we report child mortality with respect to temporal trends, spatial clustering and disparity in this HDSS from 1993 to 2012. Poisson regression was used to describe village-specific child mortality rates and time trends in mortality. The spatial scan statistic was used to identify villages or village clusters with higher child mortality. Clustering of mortality in the area is still present, but not as strong as before. The disparity of child mortality between villages has decreased. The decrease occurred in the context of an overall halving of child mortality in the rural area of Nouna HDSS between 1993 and 2012. Extrapolated to the Millennium Development Goals target period 1990-2015, this yields an estimated reduction of 54%, which is not too far off the aim of a two-thirds reduction.

The Health and Demographic Surveillance System (HDSS) in Nouna, Burkina Faso, 1993-2007.

The Nouna Health and Demographic Surveillance System (HDSS) is located in rural Burkina Faso and has existed since 1992. Currently, it has about 78,000 inhabitants. It is a member of the International Network for the Demographic Evaluation of Populations and Their Health in Developing Countries (INDEPTH), a global network of members who conducts longitudinal health and demographic evaluation of populations in low- and middle-income countries. The health facilities consist of one hospital and 13 basic health centres (locally known as CSPS). The Nouna HDSS has been used as a sampling frame for numerous studies in the fields of clinical research, epidemiology, health economics, and health systems research. In this paper we review some of the main findings, and we describe the effects that almost 20 years of health research activities have shown in the population in general and in terms of the perception, economic implications, and other indicators. Longitudinal data analyses show that childhood, as well as overall mortality, has significantly decreased over the observation period 1993-2007. The under-five mortality rate dropped from about 40 per 1,000 person-years in the mid-1990s to below 30 per 1,000 in 2007. Further efforts are needed to meet goal four of the Millennium Development Goals, which is to reduce the under-five mortality rate by two-thirds between 1990 and 2015.

Apparent bias for P. falciparum parasites carrying the wild-type pfcrt allele in the placenta.

Resistance to chloroquine has been linked to polymorphisms within the pfcrt gene of the human malarial parasite Plasmodium falciparum. Here, we have investigated the prevalence of the pfcrt allele associated with chloroquine resistance in the peripheral blood and the placenta of pregnant women diagnosed with a P. falciparum infection. Our molecular epidemiological data show an unequal distribution with a significant under-representation of parasites carrying the mutated pfcrt allele in the placenta, as compared to the peripheral blood. In comparison, no differences were seen with regard to pfmdr1 polymorphisms of these parasites. Our data suggest a selective disadvantage of the polymorphic and a selective advantage of the wild-type pfcrt haplotype in the placenta, supporting the model that the human host provides various microenvironments that favor genetically distinct P. falciparum populations.

Malaria in a holoendemic area of Burkina Faso: a cross-sectional study.

A malaria survey of the entire population of a village in Western Burkina Faso (n=1,561) was conducted to assess malaria endemicity. The study population was examined for symptoms characteristic of malaria including fever, anaemia, splenomegaly and parasites present in thick blood films. In the overall study population, the prevalence of Plasmodium spp. infection by microscopic examination of thick blood films was 79.0% (1,233/1,561). In a subcohort with 201 individuals, PCR techniques found a prevalence rate for all Plasmodium spp. of 92.0% (185/201), while microscopy found one of 80.6% (162/201). A combination of both methods gives a rate of 95.5% (192/201). Though univariate logistic analyses of elevated body temperature, anaemia, splenomegaly and age showed them all to be predictors of or risk factors for an infection, only elevated body temperature and age were predictors in multivariate logistic analysis. However, the symptom of splenomegaly did show a highly significant association with infection by multiple species of Plasmodium.