Modelling the Ecological Comorbidity of Acute Respiratory Infection, Diarrhoea and Stunting among Children Under the Age of 5 Years in Somalia

Spatial joint hazard assessment of landslide susceptibility and intensity within a single framework: Environmental insights from the Wenchuan earthquake

To comprehensively assess regional landslide hazards, we propose a geospatial approach that jointly evaluates both the probability of occurrence (susceptibility) and potential destructive power (intensity) within a single framework, overcoming the limitations of previous studies that treated these two disaster scenarios independently. Focusing on the largest landslide event triggered by the Wenchuan earthquake in China, we collected landslide occurrence and count data at the slope unit level, alongside 18 environmental factors, including seismic data. To enable this multi-hazard single-framework evaluation, we employed two Bayesian spatial joint regressions: the spatial shared component model (SSCM) and the spatial shared hyperparameter model (SSHM). This joint assessment focuses on three key components: identifying shared influencing factors, capturing shared spatial autocorrelated random effects, and jointly predicting susceptibility and intensity maps. Additionally, we enhanced the traditional absolute intensity index into the relative intensity by accounting for slope unit size. Both Bayesian SSCM and SSHM, incorporating multiple environmental drivers (seismic, topographical, geological, hydrological, and human activities), successfully evaluated landslide susceptibility and intensity under a single analytical frame. SSHM outperformed SSCM in terms of model fit and predictive accuracy, as revealed by cross-validation. While SSCM overfitted the landslide distribution of spatial autocorrelated random effect, SSHM provided a smoother, more spatially diverse representation. Both models consistently identified slope as the shared key factor influencing susceptibility and intensity, with the top four additional environmental factors varying slightly but all related to seismic activity. The concurrent susceptibility and absolute intensity maps produced by both models exhibited similar patterns, while relative intensity mapping identified new high-hazard areas within smaller slope units that were previously overlooked by susceptibility and absolute intensity. We established a Bayesian-based single modeling framework for joint hazard assessment and prediction of regional susceptibility and intensity, providing a cutting-edge geospatial paradigm for multi-objective hazard assessment in global environmental disaster management.

Stature and Its Association With Physiological Stress Exposure in a Pediatric Autopsy Sample

INTRODUCTION AND BACKGROUND

Experiencing illnesses or other stressors may disrupt processes of growth and development throughout the different stages of prepubertal development. Stunted stature for age is one potential outcome from such disruption, with both the nature and timing of stressors playing a role in the development of stunting. This study explores whether stress events in utero or during birth, and prepubertal development have an impact on stature, by examining associations between experience of prenatal or birth issues, postnatal stressor exposure by severity, and stature at time-of-death, with the impact of different stress experiences compared.

METHODS

A coronial pediatric dataset of individuals aged 0-20.9 years (280 male, 195 female) who died in the state of New Mexico from years 2011 to 2019 was assessed for presence/absence of stunting associated with physiological stress exposure type whilst controlling for low socioeconomic status (as inferred by housing type) and sex using two multiple logistic regression models for ages < 12, and for ages 12+. Broad postnatal condition categories were then investigated, again controlling for socioeconomic status and sex for these two cohorts. A linear regression model was also used to assess relationships between stunting, physiological stress, low socioeconomic status housing, and age-at-death.

RESULTS AND DISCUSSION

For both groups aged < 12 and 12+, experiencing moderate to severe illness prior to 12 years of age increased the odds of being stunted at death. Only experience of prenatal or birth issues was associated with younger age-at-death, but stunting itself was not, potentially reflecting the prolonged exposure to severe stressors necessary for stunted growth.

Examining comorbidities in children with diarrhea across four provinces of Mozambique: A cross-sectional study (2015 to 2019)

Comorbidities are defined as the simultaneous occurrence of two or more diseases within the same individual. Comorbidities can delay a patient's recovery and increase the costs of treatment. Assessing comorbidities can provide local health care policy-makers with evidence of the most common multi-health impairments in children. This could aid in redirecting and integrating care and treatment services by increasing health facilities the awareness and readiness of health facilities. The present analysis aims to determine the frequency and associated factors of comorbidities in children with diarrhea in Mozambique. A cross-sectional hospital-based analysis was conducted between January 2015 and December 2019 in children up to 59 months of age who were admitted with diarrhea in six reference hospitals in Mozambique. These hospitals are distributed across the country's three regions, with at least one hospital in each province from each region. Sociodemographic and clinical data were obtained through semi-structured interviews and by reviewing the child clinical process. Descriptive statistics, and Mann-Whitney-U tests were used. Crude and adjusted logistics regression models were built. P-values < 0.05 were considered statistically significant. Comorbidities were observed in 55.5% of patients (389/701; 95%CI: 51.8-59.1). Wasting was the most common comorbidity (30.2%; 212/701) and pneumonia was the least common (1.7%; 12/701). Children born with a low birth weight were 2.420 times more likely to have comorbidities, adjusted odds ratio: 2.420 (95% CI: 1.339-4374). The median (interquartile range) duration of hospitalization was significantly higher in children with comorbidities than without comorbidities, 5 days (3-7) and 4 days (3-6), respectively (p-value < 0.001). One in every two children with diarrhea in Mozambique has an additional health impairment, and this increases the length of their hospital stay.

Copula based trivariate spatial modeling of childhood illnesses in Western African countries

Acute respiratory infections (ARI), diarrhea, and fever are three common childhood illnesses, especially in sub-Saharan Africa. This study investigates the marginal and pairwise correlated effects of these diseases across Western African countries in a single analytical framework. Using data from nationally representative cross-sectional Demographic and Health Surveys, the study analyzed specific and correlated effects of each pair of childhood morbidity from ARI, diarrhea, and fever using copula regression models in fourteen contiguous Western African countries. Data concerning childhood demographic and socio-economic conditions were used as covariates. In this cross-sectional analysis of 152,125 children aged 0-59 months, the prevalence of ARI was 6.9%, diarrhea, 13.8%, and fever 19.6%. The results showed a positive correlation and geographical variation in the prevalence of the three illnesses across the study region. The estimated correlation and 95% confidence interval between diarrhea and fever is 0.431(0.300,0.539); diarrhea and ARI is 0.270(0.096,0.422); and fever and ARI is 0.502(0.350,0.614). The marginal and correlated spatial random effects reveal within-country spatial dependence. Source of water and access to electricity was significantly associated with any of the three illnesses, while television, birth order, and gender were associated with diarrhea or fever. The place of residence and access to newspapers were associated with fever or ARI. There was an increased likelihood of childhood ARI, diarrhea, and fever, which peaked at about ten months but decreased substantially thereafter. Mother's age was associated with a reduced likelihood of the three illnesses. The maps generated could be resourceful for area-specific policy-making to speed up mitigation processes.

A Systematic Review of Areal Units and Adjacency Used in Bayesian Spatial and Spatio-Temporal Conditional Autoregressive Models in Health Research

Advancements in Bayesian spatial and spatio-temporal modelling have been observed in recent years. Despite this, there are unresolved issues about the choice of appropriate spatial unit and adjacency matrix in disease mapping. There is limited systematic review evidence on this topic. This review aimed to address these problems. We searched seven databases to find published articles on this topic. A modified quality assessment tool was used to assess the quality of studies. A total of 52 studies were included, of which 26 (50.0%) were on infectious diseases, 10 (19.2%) on chronic diseases, 8 (15.5%) on maternal and child health, and 8 (15.5%) on other health-related outcomes. Only 6 studies reported the reasons for using the specified spatial unit, 8 (15.3%) studies conducted sensitivity analysis for prior selection, and 39 (75%) of the studies used Queen contiguity adjacency. This review highlights existing variation and limitations in the specification of Bayesian spatial and spatio-temporal models used in health research. We found that majority of the studies failed to report the rationale for the choice of spatial units, perform sensitivity analyses on the priors, or evaluate the choice of neighbourhood adjacency, all of which can potentially affect findings in their studies.

Association between extreme rainfall and acute respiratory infection among children under-5 years in sub-Saharan Africa: an analysis of Demographic and Health Survey data, 2006-2020

OBJECTIVE

Despite an increase in the number of studies examining the association between extreme weather events and infectious diseases, evidence on respiratory infection remains scarce. This study examined the association between extreme rainfall and acute respiratory infection (ARI) in children aged <5 years in sub-Saharan Africa.

SETTING

Study data were taken from recent (2006-2020) Demographic and Health Survey data sets from 33 countries in sub-Saharan Africa.

PARTICIPANTS

280 157 children aged below 5 years were included.

OUTCOME MEASURES

The proportions of ARI according to individual, household and geographical characteristics were compared using the χ² test. The association between extreme rainfall (≥90th percentile) and ARI was examined using multivariate logistic regression for 10 of 33 countries with an adequate sample size of ARI and extreme rainfall events. The model was adjusted for temperature, comorbidity and sociodemographic factors as covariates. Stratification analyses by climate zone were also performed.

RESULTS

The prevalence of ARI in children aged <5 years ranged from 1.0% to 9.1% across sub-Saharan Africa. By country, no significant association was observed between extreme rainfall and ARI, except in Nigeria (OR: 2.14, 95% CI 1.06 to 4.31). Larger effect estimates were observed in the tropical zone (OR: 1.13, 95% CI 0.69 to 1.84) than in the arid zone (OR: 0.72, 95% CI 0.17 to 2.95), although the difference was not statistically significant.

CONCLUSION

We found no association between extreme rainfall and ARI in sub-Saharan Africa. Effect estimates tended to be larger in the tropical zone where intense rainfall events regularly occur. Comprehensive studies to investigate subsequent extreme climate events, such as flooding, are warranted in the future.

A Systematic Review of Joint Spatial and Spatiotemporal Models in Health Research

With the advancement of spatial analysis approaches, methodological research addressing the technical and statistical issues related to joint spatial and spatiotemporal models has increased. Despite the benefits of spatial modelling of several interrelated outcomes simultaneously, there has been no published systematic review on this topic, specifically when such models would be useful. This systematic review therefore aimed at reviewing health research published using joint spatial and spatiotemporal models. A systematic search of published studies that applied joint spatial and spatiotemporal models was performed using six electronic databases without geographic restriction. A search with the developed search terms yielded 4077 studies, from which 43 studies were included for the systematic review, including 15 studies focused on infectious diseases and 11 on cancer. Most of the studies (81.40%) were performed based on the Bayesian framework. Different joint spatial and spatiotemporal models were applied based on the nature of the data, population size, the incidence of outcomes, and assumptions. This review found that when the outcome is rare or the population is small, joint spatial and spatiotemporal models provide better performance by borrowing strength from related health outcomes which have a higher prevalence. A framework for the design, analysis, and reporting of such studies is also needed.

Comorbidities of Child Malnutrition in Low- and Medium-Income Countries: A Systematic Review

The study intended to review the best evidence on prevalence, diagnosis, and treatment outcomes of comorbidities associated with child malnutrition. The study design was a systematic review of quantitative studies. Critical appraisal tools were used to assess the methodological quality of the studies. Data were extracted according to the predetermined data extraction table. Data were further analyzed narratively according to the set study objectives and main concepts. Fifteen studies were eligible to include in the review. All 15 studies reported on the prevalence of 4 child malnutrition-associated comorbidities. Five (n = 5/15) studies reported on length of hospitalization/stay, 10 (n = 10) studies on recovery rate, and 9 (n = 9/15) studies on mortality rate as treatment outcomes of child malnutrition associated comorbidities. The most prevalent child malnutrition associated comorbidities were tuberculosis, pneumonia, gastroenteritis, and anemia. The treatment outcomes identified included the length of hospitalization/stay, recovery rate, and mortality rate. Screening of prevalent comorbidities in children admitted with malnutrition should be standard procedure in practice. More research needs to be done on the diagnosis of under-5 child malnutrition associated comorbidities.

Spatial Co-Morbidity of Childhood Acute Respiratory Infection, Diarrhoea and Stunting in Nigeria

In low- and middle-income countries, children aged below 5 years frequently suffer from disease co-occurrence. This study assessed whether the co-occurrence of acute respiratory infection (ARI), diarrhoea and stunting observed at the child level could also be reflected ecologically. We considered disease data on 69,579 children (0–59 months) from the 2008, 2013, and 2018 Nigeria Demographic and Health Surveys using a hierarchical Bayesian spatial shared component model to separate the state-specific risk of each disease into an underlying disease-overall spatial pattern, common to the three diseases and a disease-specific spatial pattern. We found that ARI and stunting were more concentrated in the north-eastern and southern parts of the country, while diarrhoea was much higher in the northern parts. The disease-general spatial component was greater in the north-eastern and southern parts of the country. Identifying and reducing common risk factors to the three conditions could result in improved child health, particularly in the northeast and south of Nigeria.

Factors associated with adverse nutritional status of children in sub-Saharan Africa: Evidence from the Demographic and Health Surveys from 31 countries

Undernutrition is linked to almost half of all deaths in under-five children. In 2019, 144 million under-five children suffered from stunting and 47 million suffered from wasting. This study examined the factors that influence adverse nutritional status of children in sub-Saharan Africa. The study used data from the Demographic and Health Surveys (DHS) of 31 countries, which involved 189,195 children under age 5. Binary logistic regression was used to examine the relationships between the independent variables and adverse nutritional status of children. About 26% of the children in the 31 countries in sub-Saharan Africa considered in this study are stunted, 6% are wasted and 21% are underweight. Close to 31% of children whose mothers have no education are stunted, 9% are wasted and 28% are underweight. Adverse nutritional status of children is significantly associated with maternal age, education, household wealth, residence, antenatal care attendance, mass media exposure, child's sex and size of child at birth. This study has shown that adverse nutritional status of children is a major challenge in sub-Saharan Africa. Efforts at improving nutritional status of children should include poverty alleviation initiatives at individual and household levels, increase in women's educational level and improvement in living conditions in rural areas.

Spectrum of nutrition-specific and nutrition-sensitive determinants of child undernutrition: a multisectoral cross-sectional study in rural Mozambique

Background

Despite an increasing need for multisectoral interventions and coordinations for addressing malnutrition, evidence-based multisectoral nutrition interventions have been rarely developed and implemented in low-income and middle-income countries. To identify key determinants of undernutrition for effectively designing a multisectoral intervention package, a nutrition survey was conducted, by comprehensively covering a variety of variables across sectors, in Niassa province, Mozambique.

Methods

A cross-sectional household survey was conducted in Niassa province, August–October 2019. Anthropometric measurements, anaemia tests of children under 5 years of age and structured interviews with their mothers were conducted. A total of 1498 children under 5 years of age participated in the survey. We employed 107 background variables related to possible underlying and immediate causes of undernutrition, to examine their associations with being malnourished. Both bivariate (χ2 test and Mann-Whitney’s U test) and multivariate analyses (logistic regression) were undertaken, to identify the determinants of being malnourished.

Results

Prevalence rates of stunting, underweight and wasting were estimated at 46.2%, 20.0% and 7.1%, respectively. Timely introduction of solid, semi-solid or soft foods to children of 6–8 months of age was detected as a determinant of being not stunted. Mother–child cosleeping and ownership of birth certificate were a protective factor from and a promoting factor for being underweight, respectively. Similarly, availability and consumption of eggs at the household level and cough during the last 2 weeks among children were likely to be a protective factor from and a promoting factor for being wasted, respectively.

Conclusion

Timely introduction of solid, semi-solid or soft foods could serve as an entry point for the three sectors to start making joint efforts, as it requires the interventions from all health, agriculture and water sectors. To enable us to make meaningful interprovincial, international and inter-seasonal comparisons, it is crucially important to develop a standard set of variables related to being malnourished.

The incidence of stunting, the frequency/duration of diarrhea and Acute Respiratory Infection in toddlers

Background: Infectious diseases such as diarrhea and Acute Respiratory Infection (ARI) lead to loss of appetite in children and stunting growth. This study analyzes the relationship between the incidence of stunting and the frequency/duration of diarrhea and ARI in children under five years.

Design and Methods: The stratified random sampling method was used to obtain data from 152 children in 4 villages in Surabaya, East Java, Indonesia.

Results: The results showed that children under the age of five, experience higher stunting duration and longer frequency of diarrhea. The Rho Spearmen Test showed differences in the incidence of stunting with the frequency of diarrhea P = 0.005 (P<α = 0.05), P = 0.003 (P<α = 0.05), with ARI of P =0.001 (P<α = 0.05).

Conclusions: In conclusion, stunting is related to the frequency and duration of diarrheal diseases and ARI, therefore, community- integrated health center need to carryout counseling activities on children less than five years to determine their health status.

Prevalence of pneumonia and its associated factors among under-five children in East Africa: a systematic review and meta-analysis

Background

Pneumonia is defined as an acute inflammation of the Lungs’ parenchymal structure. It is a major public health problem and the leading cause of morbidity and mortality in under-five children especially in developing countries. In 2015, it was estimated that about 102 million cases of pneumonia occurred in under-five children, of which 0.7 million were end up with death. Different primary studies in Eastern Africa showed the burden of pneumonia. However, inconsistency among those studies was seen and no review has been conducted to report the amalgamated magnitude and associated factors. Therefore, this review aimed to estimate the national prevalence and associated factors of pneumonia in Eastern Africa

Methods

Using PRISMA guideline, we systematically reviewed and meta-analyzed studies that examined the prevalence and associated factors of pneumonia from PubMed, Cochrane library, and Google Scholar. Heterogeneity across the studies was evaluated using the Q and the I² test. A weighted inverse variance random-effects model was applied to estimate the national prevalence and the effect size of associated factors. The subgroup analysis was conducted by country, study design, and year of publication. A funnel plot and Egger’s regression test were used to see publication bias. Sensitivity analysis was also done to identify the impact of studies.

Result

A total of 34 studies with 87, 984 participants were used for analysis. The pooled prevalence of pneumonia in East Africa was 34% (95% CI; 23.80–44.21). Use of wood as fuel source (AOR = 1.53; 95% CI:1.30–1.77; I² = 0.0%;P = 0.465), cook food in living room (AOR = 1.47;95% CI:1.16–1.79; I² = 0.0%;P = 0.58), caring of a child on mother during cooking (AOR = 3.26; 95% CI:1.80–4.72; I² = 22.5%;P = 0.26), Being unvaccinated (AOR = 2.41; 95% CI:2.00–2.81; I² = 51.4%;P = 0.055), Child history of Acute Respiratory Tract Infection (ARTI) (AOR = 2.62; 95% CI:1.68–3.56; I² = 11.7%;P = 0.337) were identified factors of pneumonia.

Conclusion

The prevalence of pneumonia in Eastern Africa remains high. This review will help policy-makers and program officers to design pneumonia preventive interventions.

Correlates of childhood morbidity in Nigeria: Evidence from ordinal analysis of cross-sectional data

BACKGROUND

Child mortality records show that 1 in every 13 children dies before age five in sub-Saharan Africa with diseases such as pneumonia, diarrhoea and malaria considered to be the leading causes of such deaths. In Nigeria where 50% of all under-five deaths are attributed to morbidity, much attention has been directed to single health conditions. This study aims at examining the factors that are associated with single health conditions and comorbidity among children in Nigeria.

MATERIALS AND METHODS

This study was based on data from 2013 Nigeria Demographic and Health Survey (DHS) which involved 27,571 under-five children who suffered from acute respiratory infection, diarrhoea or fever within two weeks of data collection exercise. Descriptive statistics and generalized ordinal logistic regression model were used for the analysis.

RESULTS

About 14% of children suffered from a single health condition and 9% suffered from comorbidity. The likelihood of suffering from a single health condition and comorbidity is higher for children who are of third order birth or more (OR = 1.24, 95% CI = 1.11-1.39 & OR = 1.31, 95% CI = 1.12-1.55) compared to those who are of first order birth. The likelihood also increased for children whose mothers live in Northeast (OR = 3.19, 95% CI = 2.86-3.55 & OR = 3.88, 95% CI = 3.30-4.57) compared to children whose mothers live in North Central. The odds of suffering from a single health condition and comorbidity reduced for children who are from richest households, aged 3 years and above and were of average size at birth. Children of women who obtained water from improved source are less likely to experience any morbidity (OR = 0.93, 95% CI = 0.87-0.99) compared to children whose mothers obtained water from non-improved source.

CONCLUSIONS

The study has demonstrated that children in Nigeria are not only exposed to the risk of single health conditions but they are also exposed to the risk of comorbidity. Efforts should be made to design appropriate health care models that would facilitate a considerable reduction in childhood morbidity in the country.

A Scoping Review of Spatial Analysis Approaches Using Health Survey Data in Sub-Saharan Africa

Spatial analysis has become an increasingly used analytic approach to describe and analyze spatial characteristics of disease burden, but the depth and coverage of its usage for health surveys data in Sub-Saharan Africa are not well known. The objective of this scoping review was to conduct an evaluation of studies using spatial statistics approaches for national health survey data in the SSA region. An organized literature search for studies related to spatial statistics and national health surveys was conducted through PMC, PubMed/Medline, Scopus, NLM Catalog, and Science Direct electronic databases. Of the 4,193 unique articles identified, 153 were included in the final review. Spatial smoothing and prediction methods were predominant (n = 108), followed by spatial description aggregation (n = 25), and spatial autocorrelation and clustering (n = 19). Bayesian statistics methods and lattice data modelling were predominant (n = 108). Most studies focused on malaria and fever (n = 47) followed by health services coverage (n = 38). Only fifteen studies employed nonstandard spatial analyses (e.g., spatial model assessment, joint spatial modelling, accounting for survey design). We recommend that for future spatial analysis using health survey data in the SSA region, there must be an improve recognition and awareness of the potential dangers of a naïve application of spatial statistical methods. We also recommend a wide range of applications using big health data and the future of data science for health systems to monitor and evaluate impacts that are not well understood at local levels.

Structured additive distributional zero augmented beta regression modeling of mortality in Nigeria

Child mortality has remained persistently high in most sub-Saharan African countries. Majority of the effort in analyzing the determinants, or covariables did not consider the duration of exposure to mortality risks. In addition, covariates are usually linked to the mean of the response variable, thereby neglecting the possible association with other higher moments. In this paper, we account for the duration of exposure via the child mortality index, defined as the ratio of observed to expected child death, for all women captured in the 2013 Nigeria Demographic and Health Survey. Based on this index, a structured additive distributional beta regression model was adopted to examine covariate effects on the probability of a woman experiencing no child mortality, the conditional expectation of mortality, and the mortality spread, controlling for latent spatial associations. Our inferential framework is Bayesian inference, powered by generic MCMC tools based on iterative weighted least squares. Results confirm the existence of significant variation in the likelihood of a woman experiencing no child mortality, and in the spread of mortality, across Nigerian states. Findings also show that although mortality is fairly spread among women aged ≥30 years, it is concentrated among the younger women.

Assessing Comorbidity of Diarrhea and Acute Respiratory Infections in Children Under 5 Years: Evidence From Kenya's Demographic Health Survey 2014

Background: Kenya is one among the 15 countries that account for three-quarters of the global mortality burden due to diarrhea and respiratory tract infections (RTIs). Comorbidity of diarrhea and acute respiratory infection (ARI) can either be simultaneous (both occurring at the same time) or sequential (where the occurrence of one leads to the occurrence of the other. This study aimed to determine the shared risks that influence comorbidity of diarrhea and RTIs among Kenya's children younger than 5 years. Methods: The study entailed an analysis of secondary data from the Kenya Demographic Health Survey (DHS) 2014 using STATA Corp 2010. Descriptive analysis of independent variables and logistic regression model was used to analyze risk factors associated with comorbidity from diarrhea and ARI in children <5 years. Results: A total of 18 702 children <5 years were in the study out of whom 411 had comorbidity from diarrhea and ARI in the 2 weeks prior to the survey. Comorbidity peaked at 6 to 11 months (4.6%). Child's age between 6 and 11 months (adjusted odds ratio [aOR] = 3.48, 95% CI = 2.02-5.99) and caregivers with incomplete primary education (aOR = 1.66, 95% CI = 1.11-2.50) were associated with higher odds of comorbidity from diarrhea and ARI. The main determinants associated with lower odds of combined morbidity from diarrhea and ARI were high wealth quintile (aOR = 0.58, 95% CI = 0.39-0.85) and older aged caregivers (aOR = 0.47, 95% CI = 0.23-0.95). However, we found no association between nutritional status of a child, sex, residence, exclusive breastfeeding between 0 and 6 months, and combined morbidity from diarrhea and ARI. Conclusion: Programs aimed at reducing comorbidity should target children between 6 and 11 months and deliberate emphasis should be placed on addressing barriers to wealth and caregivers' education.

Joint spatial mapping of childhood anemia and malnutrition in sub-Saharan Africa: a cross-sectional study of small-scale geographical disparities

BACKGROUND

In epidemiological studies, several diseases share common risk factors or co-exist in their spatial prevalence. Disease mapping allows the health practitioners and epidemiologists to hypothesize the disease aetiology and gain better understanding of the geographical prevalence of the disease risks.

OBJECTIVE

This paper investigates the differences in small scale geographical variations and the underlying risk factors of child's health outcomes (anemia, stunting and wasting) in Sub-Saharan Africa using spatial epidemiology.

METHOD

The study first carried out an independent univariate analysis on each malnutrition indicator to identify underlying risk factors. A multivariate conditional autoregressive prior was explored to jointly model the spatial correlation between the undernutrition indicators and the small area-geographical disparities at sub-national levels in two sub-Saharan African countries.

RESULTS

The approach was implemented on data from National cross-sectional household- based demographic and health surveys conducted in 17,307 under-five children in Burkina Faso and Mozambique in 2010-012. Out of these children, 31.8% are found to be stunted, 15.5% wasted and 30.9% had anemia among Burkina Faso children, while 42.5% of Mozambican children were stunted, 5.9% wasted and 30.9% suffered from iron-deficiency anemia. The multivariate analysis revealed that the spatial prevalence existed across regions in Burkina Faso with geographical variations in stunting estimated as: 0.7549, CI (0.4693, 1.264); wasting 0.9197; (95%CI: 0.535, 1.591)and anemia: 0.734; (0.4606, 1.214). In additin, the spatial correlation between stunting and wasting was negatively correlated: -0.998; 95% CI (-1.000, -0.984), and a perfect negative correlation;(-1) between stunting and anemia, and positive for wasting and anemia: 0.997; (0.978, 1.000). The spatial occurrence across provinces in Mozambique indicated that there was strong positive correlation between stunting and wasting; 0.986; (0.899, 1.000) and a significant negative correlation between stunting and anemia: -0.720, (-0.934, -0.308) and wasting and anemia: -0.640; (-0.903 -0.174) with individual geographical variability in child stunting: 1427, (913.6, 2268); wasting:1751, (1117, 2803) and anemia: 556, (279.5, 978.9). These extra random effect parameters computed in our multivariate approach would outperform a univariate analysis in similar studies. Our model further detected high prevalent of malnutrition and anemia in the northern Burkina Faso, but high anemia prevalent found in central Mozambique, and high stunting and wasting identified Southern Mozambique. In addition, the risk factors of malnutrition and iron deficiency anemia included household poverty, morbidity, short birth interval (less 18 months), breast feeding, antenatal attendance and maternal literacy.

CONCLUSION

The statistical relevance of the identified risk factors in this study is useful to target specific individual interventions and the maps of the geographical inequalities in sub-national region can be used for designing nutrition interventions and allocation of scarce health resources.

Co-morbidity of malnutrition with falciparum malaria parasitaemia among children under the aged 6-59 months in Somalia: a geostatistical analysis

Background

Malnutrition and malaria are both significant causes of morbidity and mortality in African children. However, the extent of their spatial comorbidity remains unexplored and an understanding of their spatial correlation structure would inform improvement of integrated interventions. We aimed to determine the spatial correlation between both wasting and low mid upper arm circumference (MUAC) and falciparum malaria among Somalian children aged 6–59 months.

Methods

Data were from 49 227 children living in 888 villages between 2007 to 2010. We developed a Bayesian geostatistical shared component model in order to determine the common spatial distributions of wasting and falciparum malaria; and low-MUAC and falciparum malaria at 1 × 1 km spatial resolution.

Results

The empirical correlations with malaria were 0.16 and 0.23 for wasting and low-MUAC respectively. Shared spatial residual effects were statistically significant for both wasting and low-MUAC. The posterior spatial relative risk was highest for low-MUAC and malaria (range: 0.19 to 5.40) and relatively lower between wasting and malaria (range: 0.11 to 3.55). Hotspots for both wasting and low-MUAC with malaria occurred in the South Central region in Somalia.

Conclusions

The findings demonstrate a relationship between nutritional status and falciparum malaria parasitaemia, and support the use of the relatively simpler MUAC measurement in surveys. Shared spatial distribution and distinct hotspots present opportunities for targeted seasonal chemoprophylaxis and other forms of malaria prevention integrated within nutrition programmes.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0449-9) contains supplementary material, which is available to authorized users.

Modelling the Ecological Comorbidity of Acute Respiratory Infection, Diarrhoea and Stunting among Children Under the Age of 5 Years in Somalia

The aim of this study was to assess spatial co-occurrence of acute respiratory infections (ARI), diarrhoea and stunting among children of the age between 6 and 59 months in Somalia. Data were obtained from routine biannual nutrition surveys conducted by the Food and Agriculture Organization 2007-2010. A Bayesian hierarchical geostatistical shared component model was fitted to the residual spatial components of the three health conditions. Risk maps of the common spatial effects at 1×1 km resolution were derived. The empirical correlations of the enumeration area proportion were 0.37, 0.63 and 0.66 for ARI and stunting, diarrhoea and stunting and ARI and diarrhoea, respectively. Spatially, the posterior residual effects ranged 0.03-20.98, 0.16-6.37 and 0.08-9.66 for shared component between ARI and stunting, diarrhoea and stunting and ARI and diarrhoea, respectively. The analysis showed clearly that the spatial shared component between ARI, diarrhoea and stunting was higher in the southern part of the country. Interventions aimed at controlling and mitigating the adverse effects of these three childhood health conditions should focus on their common putative risk factors, particularly in the South in Somalia.