Risk factors for anemia in children under 6 years of age in Ethiopia: analysis of the data from the cross-sectional Malaria IndicatorSurvey, 2007

Global warming may significantly increase childhood anemia burden in sub-Saharan Africa

Childhood anemia constitutes a global public health problem, especially in low- and middle-income countries (LMICs). However, it remains unknown whether global warming has an impact on childhood anemia. Here, we examined the association between annual temperatures and childhood anemia prevalence in sub-Saharan Africa and then projected childhood anemia burden attributable to climate change. Each 1°C increment in annual temperature was associated with increased odds of childhood anemia (odd ratio = 1.138, 95% confidence interval: 1.134-1.142). Compared with the baseline period (1985-2014), the attributable childhood anemia cases would increase by 7,597 per 100,000 person-years under a high-emission scenario in the 2090s, which would be almost 2-fold and over 3-fold more than those projected in moderate- and low-emission scenarios. Our results reveal the vulnerabilities and inequalities of children for the excess burden of anemia due to climate warming and highlight the importance of climate mitigation and adaptation strategies in LMICs.

Anemia and associated factors among 6 to 59 months age children attending health facilities in Kombolcha town, Northeast Ethiopia: a facility-based cross-sectional study

BACKGROUND

Childhood anemia is an important public health problem in Ethiopia. The northeast part of the country is among the areas affected by recurrent drought. Despite its significance, studies are scarce on childhood anemia particularly, in the study area. This study aimed to assess the proportion and factors associated with anemia among under-five children in Kombolcha town.

METHODS

A facility-based cross-sectional study was conducted among 409 systematically selected 6 to 59 months aged children visited health institutions in Kombolcha town. Data were collected using structured questionnaires from mothers/caretakers. The data entry and analysis were done using EpiData version 3.1 and SPSS version 26 respectively. Binary logistic regression was fitted to identify factors associated with anemia. Statistical significance was declared at p-value ≤ 0.05. The effect size was reported using the adjusted odds ratio with its 95% confidence interval.

RESULTS

Of the participants, 213(53.9%) were males with a mean age of 26 months (SD ± 15.2). The proportion of anemia was 52.2% (95% CI, 46.8-57%). Being in the age of 6-11 months (AOR = 6.23, 95% CI: 2.44, 15.95), 12-23 months (AOR = 3.74, 95%CI: 1.63, 8.60), having low dietary diversity score (AOR = 2.61, 95% CI: 1.55, 4.38), having a history of diarrhea (AOR = 1.87, 95% CI: 1.12, 3.12) and having the lowest family monthly income (AOR = 16.97, 95% CI: 4.95, 58.20) were positively associated with anemia. Whereas, maternal age ≥ 30 years (AOR = 0.37 (0.18, 0.77) and exclusive breastfeeding until six months (AOR = 0.27, 95% CI: 0.16, 0.45) were negatively associated with anemia.

CONCLUSIONS

Childhood anemia was a public health problem in the study area. Child age, maternal age, exclusive breastfeeding, dietary diversity score, diarrhea, and family income were significantly associated with anemia.

Individual, household and area predictors of anaemia among children aged 6–59 months in Nigeria

Objectives

This study aims to determine the prevalence of anaemia among children aged 6–59 months in all states of Nigeria, including the Federal Capital Territory (FCT), and to quantify the predicted probabilities by individual, household and area factors.

Study design

This study is a secondary analysis of data sets from two national representative cross-sectional surveys in Nigeria: the Nigeria Demographic and Health Survey (2018 NDHS) and the National Human Development Index (2018 NHDR). The state human development index (HDI) and the state multidimensional poverty index (MPI) from the 2018 NHDR were incorporated into the 2018 NDHS.

Methods

The study included a weighted sample of 10,222 children aged 6–59 months. Both univariate and bivariate analyses were computed to determine the prevalence and factors associated with anaemia status, respectively. Multiple binary logistic regression analyses with adjusted predicted probabilities (APPs) were performed to quantify the predictors’ probabilities.

Results

The prevalence of anaemia among children aged 6–59 months in Nigeria was 68.1% (6962/10,222). Zamfara state had the highest prevalence (84.0% [266/317]), while Kaduna state recorded the lowest (50.0% [283/572]). The APPs of being anaemic decreased from 82.9% (95% confidence interval [CI]: 80.0–85.8) for children aged 6–18 months to 60.6% (95% CI: 56.8–64.4) for children aged 43–59 months, when other predictors were held constant. The APP for a child of an anaemic mother is 10.2% points higher than the APP for a child whose mother is not anaemic. In addition, the APPs for children decreased as the age group of their mothers increased. A child from a state that is mildly deprived in the MPI has a lower APP (67.2% [95% CI: 62.2–72.2]) compared with a child from highly deprived MPI state (79.0% [95% CI: 73.4–84.5]).

Conclusions

Health strategies, including supplementation programmes, should be carried out at both ante-natal and post-natal clinics to reduce the prevalence of anaemia, especially in vulnerable population groups.

Bayesian network models with decision tree analysis for management of childhood malaria in Malawi

BACKGROUND

Malaria is a major cause of death in children under five years old in low- and middle-income countries such as Malawi. Accurate diagnosis and management of malaria can help reduce the global burden of childhood morbidity and mortality. Trained healthcare workers in rural health centers manage malaria with limited supplies of malarial diagnostic tests and drugs for treatment. A clinical decision support system that integrates predictive models to provide an accurate prediction of malaria based on clinical features could aid healthcare workers in the judicious use of testing and treatment. We developed Bayesian network (BN) models to predict the probability of malaria from clinical features and an illustrative decision tree to model the decision to use or not use a malaria rapid diagnostic test (mRDT).

METHODS

We developed two BN models to predict malaria from a dataset of outpatient encounters of children in Malawi. The first BN model was created manually with expert knowledge, and the second model was derived using an automated method. The performance of the BN models was compared to other statistical models on a range of performance metrics at multiple thresholds. We developed a decision tree that integrates predictions with the costs of mRDT and a course of recommended treatment.

RESULTS

The manually created BN model achieved an area under the ROC curve (AUC) equal to 0.60 which was statistically significantly higher than the other models. At the optimal threshold for classification, the manual BN model had sensitivity and specificity of 0.74 and 0.42 respectively, and the automated BN model had sensitivity and specificity of 0.45 and 0.68 respectively. The balanced accuracy values were similar across all the models. Sensitivity analysis of the decision tree showed that for values of probability of malaria below 0.04 and above 0.40, the preferred decision that minimizes expected costs is not to perform mRDT.

CONCLUSION

In resource-constrained settings, judicious use of mRDT is important. Predictive models in combination with decision analysis can provide personalized guidance on when to use mRDT in the management of childhood malaria. BN models can be efficiently derived from data to support clinical decision making.

Joint modelling of malaria and anaemia in children less than five years of age in Malawi

BACKGROUND

Malaria and anaemia jointly remain a public health problem in developing countries of which Malawi is one. Although there is an improvement along with intervention strategies in fighting against malaria and anaemia in Malawi, the two diseases remain significant problems, especially in children 6-59 months of age. The main objective of this study was to examine the association between malaria and anaemia. Moreover, the study investigated whether socio-economic, geographic, and demographic factors had a significant impact on malaria and anaemia.

DATA AND METHODOLOGY

The present study used a secondary cross-sectional data set from the 2017 Malawi Malaria Indicator Survey (MMIS) with a total number of 2 724 children 6-9 months of age. The study utilized a multivariate joint model within the ambit of the generalized linear mixed model (GLMM) to analyse the data. The two response variables for this study were: the child has either malaria or anaemia.

RESULTS

The prevalence of malaria was 37.2% of the total number of children who were tested using an RDT, while 56.9% were anaemic. The results from the multivariate joint model under GLMM indicated a positive association between anaemia and malaria. Furthermore, the same results showed that mother's education level, child's age, the altitude of the place of residence, place of residence, toilet facility, access to electricity and children who slept under a mosquito bed net the night before the survey had a significant effect on malaria and anaemia.

CONCLUSION

The study indicated that there is a strong association between anaemia and malaria. This is interpreted to indicate that controlling for malaria can result in a reduction of anaemia. The socio-economic, geographical and demographic variables have a significant effect on improving malaria and anaemia. Thus, improving health care, toilet facilities, access to electricity, especially in rural areas, educating the mothers of children and increasing mosquito bed nets would contribute in the reduction of malaria and anaemia in Malawi.

A systematic review and meta-analysis of the prevalence and predictors of anemia among children in Ethiopia

Background

Anemia is a wide-spread public health problem characterized by a decrease in hemoglobin concentration and/ or red blood cell volume below an established cut-off value. In developing countries including Ethiopia, about half of children are estimated to be anemic. Therefore, the purpose of this study was to determine the pooled prevalence of anemia and its predictor factors among children in Ethiopia.

Method

The studies were identified through explicit and exhaustive search of reputable databases (PubMed, Google scholar, Science Direct, EMBASE, Cochrane library, and the hand search of reference lists of previous prevalence studies to retrieve more related articles. Thirty-nine studies were selected based on a comprehensive list of inclusion and exclusion criteria. Data were extracted using a standardized and pre-tested data extraction checklist, and the analysis was done using STATA 14 statistical software. To assess heterogeneity, the Cochrane Q test statistic and I2 tests were used. In our analysis, considerable heterogeneity was observed. Therefore, a random effect meta-analysis model was used to estimate the pooled prevalence of anemia. Moreover, the predictor factors of anemia were examined.

Results

The forest plot of 39 included studies revealed that the overall pooled prevalence of anemia among children in Ethiopia was 34.4% (95% CI: 29.1, 39.7%). Sub-group analysis showed that the highest anemia prevalence was observed in Somali Region with a prevalence of 49.4 % (95% CI: 20.9, 77.8). Also, anemia in children was found to be highest in the age group of less than five years (45.2, 95% CI: 39.6,50.8). Low literacy of families: 1.3 (95% CI: 1.1, 1.7), low family socioeconomic status: 1.9 (95% CI: 1.1,3.01.3), having housewife mothers or with no job: 1.5 (95% CI: 1.4, 1.9) and rural residence: 3.3 (95% CI: 1.7,6.1) were found to be predictors of anemia among children.

Conclusion

In this study, one in three children were anemic in Ethiopia. It is a moderate public health problem in children in this study. Low literacy, low socioeconomic status as well as rural residence of the families and helminthic infection of the children were found to be predictors of anemia in the children. Community and school-based interventions should be strengthened to improve the problem.

Anaemia and its determinants among young children aged 6-23 months in Ethiopia (2005-2016)

Anaemia in children remains a significant public health threat. Recent numbers from Ethiopia showed that more than two‐thirds of children under the age of 2 years were anaemic. This study aimed to investigate the determinants of anaemia throughout Ethiopia over 11 years, making use of the Ethiopian Demographic and Health Survey (EDHS) rounds 2005, 2011 and 2016. The EDHS made it possible to use data on blood tests and detailed questionnaires among infants and young children. Multivariable logistic regression was applied to assess the association of anaemia and different immediate and underlying determinants. A total of 7,324 children aged 6–23 months were included in the analysis, with prevalences of anaemia being 71% in 2005, 61% in 2011 and 72% in 2016. The following determinants were significantly associated with childhood anaemia throughout the entire period: children younger than 1 year, anaemic mothers and those growing up in pastoralist regions. Risk factors such as diet and infections were consistently not significantly associated with anaemia. Given the tremendous adverse health effects of anaemia in young children, urgent action is needed. Hence, this study recommends nationwide multisectoral interventions targeting pastoralist regions, maternal and child health, screening and treatment of risk groups that could reduce the prevalence of anaemia.

Adaptive interventions for optimizing malaria control: an implementation study protocol for a block-cluster randomized, sequential multiple assignment trial

Background

In the past two decades, the massive scale-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) has led to significant reductions in malaria mortality and morbidity. Nonetheless, the malaria burden remains high, and a dozen countries in Africa show a trend of increasing malaria incidence over the past several years. This underscores the need to improve the effectiveness of interventions by optimizing first-line intervention tools and integrating newly approved products into control programs. Because transmission settings and vector ecologies vary from place to place, malaria interventions should be adapted and readapted over time in response to evolving malaria risks. An adaptive approach based on local malaria epidemiology and vector ecology may lead to significant reductions in malaria incidence and transmission risk.

Methods/design

This study will use a longitudinal block-cluster sequential multiple assignment randomized trial (SMART) design with longitudinal outcome measures for a period of 3 years to develop an adaptive intervention for malaria control in western Kenya, the first adaptive trial for malaria control. The primary outcome is clinical malaria incidence rate. This will be a two-stage trial with 36 clusters for the initial trial. At the beginning of stage 1, all clusters will be randomized with equal probability to either LLIN, piperonyl butoxide-treated LLIN (PBO Nets), or LLIN + IRS by block randomization based on their respective malaria risks. Intervention effectiveness will be evaluated with 12 months of follow-up monitoring. At the end of the 12-month follow-up, clusters will be assessed for “response” versus “non-response” to PBO Nets or LLIN + IRS based on the change in clinical malaria incidence rate and a pre-defined threshold value of cost-effectiveness set by the Ministry of Health. At the beginning of stage 2, if an intervention was effective in stage 1, then the intervention will be continued. Non-responders to stage 1 PBO Net treatment will be randomized equally to either PBO Nets + LSM (larval source management) or an intervention determined by an enhanced reinforcement learning method. Similarly, non-responders to stage 1 LLIN + IRS treatment will be randomized equally to either LLIN + IRS + LSM or PBO Nets + IRS. There will be an 18-month evaluation follow-up period for stage 2 interventions. We will monitor indoor and outdoor vector abundance using light traps. Clinical malaria will be monitored through active case surveillance. Cost-effectiveness of the interventions will be assessed using Q-learning.

Discussion

This novel adaptive intervention strategy will optimize existing malaria vector control tools while allowing for the integration of new control products and approaches in the future to find the most cost-effective malaria control strategies in different settings. Given the urgent global need for optimization of malaria control tools, this study can have far-reaching implications for malaria control and elimination.

Trial registration

US National Institutes of Health, study ID NCT04182126. Registered on 26 November 2019.

LLIN Evaluation in Uganda Project (LLINEUP): factors associated with childhood parasitaemia and anaemia 3 years after a national long-lasting insecticidal net distribution campaign: a cross-sectional survey

Background

Recent reductions in malaria burden have been attributed largely to long-lasting insecticidal nets (LLINs). In March–June 2017, approximately 3 years after a national LLIN distribution campaign, a cross-sectional community survey was conducted to investigate factors associated with malaria parasitaemia and anaemia, in advance of Uganda’s 2017–2018 LLIN campaign.

Methods

Households from 104 clusters in 48 districts were randomly selected using two-staged cluster sampling; 50 households were enrolled per cluster. Eligible children aged 2–10 years had blood obtained for a thick blood smear and those aged 2–4 years had haemoglobin measured. Associations between outcomes and variables of interest were assessed using log-binomial regression with generalized estimating equations to adjust for household clustering.

Results

In total, 5196 households, 8834 children with blood smear results, and 3753 with haemoglobin results were included. Only 16% of children lived in households with adequate LLIN coverage. Overall, parasite prevalence was 26.0%, ranging from 8.0% in the South West to 53.1% in East Central. Limiting data to children 2–4 years of age, parasite prevalence was 21.4%, up from 16.9% in 2014–2015 following the national LLIN campaign. In a multivariate analysis, factors associated with parasitaemia included region (East-Central vs South-Western; adjusted prevalence ratio [aPR] 6.45, 95% CI 5.55–7.50; p < 0.001), older age (8–10 vs 2–3 years; aPR 1.57, 95% CI 1.43–1.72; p < 0.001), living in a poorer household (poorest vs least poor tercile; aPR 2.32, 95% CI 2.05–2.63; p < 0.001), one constructed of traditional materials (aPR 1.13, 95% CI 1.03–1.24; p = 0.008), or without adequate LLIN coverage (aPR 1.30, 95% CI 1.14–1.48; p < 0.001). Overall, the prevalence of anaemia (haemoglobin < 10 g/dL) was 15.1% and varied geographically. In a multivariate analysis, factors associated with anaemia included region, younger age, living in a traditional house, and parasitaemia, which was the strongest predictor (aPR 2.50, 95% CI 2.12–2.95; p < 0.001).

Conclusions

Three years after a national LLIN campaign, LLIN coverage was low and parasite prevalence had increased. Parasite prevalence varied widely across Uganda; older children, those living in poorer households, and those with inadequate LLIN coverage, were at highest risk of parasitaemia. LLINs may need to be distributed more frequently through mass campaigns or continuously through sustainable mechanisms. Targeting interventions to geographic areas and populations at highest risk should also be considered.

Male and undernourished children were at high risk of anemia in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Anemia is one of the global public health problems affecting more than one-third of the world population. It has been strongly associated with limited psychomotor development; and poor growth and performance in cognitive, social, and emotional function in children. Despite published data revealed that anemia is a public health problem among children in Ethiopia, there is no a pooled national estimate on the prevalence and associated risk factors of anemia.

METHODS

Published articles until December 31, 2017, were searched using comprehensive search strings through PubMed/Medline, EMBASE, SCOPUS, HINARI, Web of Science, Google Scholar and Google. Reference probing of published articles and hand searching were employed for grey literature. Two groups of review authors independently appraised the studies for eligibility and extracted the data. The quality of articles was assessed using Joana Brigg's institute critical appraisal checklist for prevalence and analytical studies. The pooled estimates were determined using random effect model. Heterogeneity between the included studies was assessed using the I2 statistics. Subgroup analysis was employed in the evidence of heterogeneity. Publication bias was assessed by visual inspection of the funnel plot and Egger's regression test statistic.

RESULTS

Of the total 871 articles retrieved, 34 articles which involved 61,748 children were eligible for meta-analysis. The overall pooled prevalence of anemia using random effect model was 31.14% (95% CI: 24.62, 37.66%). In subgroup analysis, the pooled prevalence of anemia was higher among preschool-aged children (44.17%; 95% CI: 37.19, 51.15%) than school-aged children (22.19%; 95% CI: 17.54, 26.83%). Furthermore, the odds of anemia was higher among children who were male (OR = 1.11; 95% CI: 1.03, 1.19), stunted (OR = 1.95; 95% CI: 1.52, 2.51), and wasted (OR = 2.05; 95% CI: 1.36, 3.10).

CONCLUSION

The pooled prevalence of anemia among children was high, indicating that it had been continuing to be a public health problem. Therefore, there is a need to design a comprehensive prevention and control strategies to reduce its burden.

Individual, maternal and household risk factors for anaemia among young children in sub-Saharan Africa: a cross-sectional study

OBJECTIVE

Anaemia affects the majority of children in sub-Saharan Africa (SSA). Previous studies of risk factors for anaemia have been limited by sample size, geography and the association of many risk factors with poverty. In order to measure the relative impact of individual, maternal and household risk factors for anaemia in young children, we analysed data from all SSA countries that performed haemoglobin (Hb) testing in the Demographic and Health Surveys.

DESIGN AND SETTING

This cross-sectional study pooled household-level data from the most recent Demographic and Health Surveys conducted in 27 SSA between 2008 and 2014.

PARTICIPANTS

96 804 children age 6-59 months.

RESULTS

The prevalence of childhood anaemia (defined as Hb <11 g/dL) across the region was 59.9%, ranging from 23.7% in Rwanda to 87.9% in Burkina Faso. In multivariable regression models, older age, female sex, greater wealth, fewer household members, greater height-for-age, older maternal age, higher maternal body mass index, current maternal pregnancy and higher maternal Hb, and absence of recent fever were associated with higher Hb in tested children. Demographic, socioeconomic factors, family structure, water/sanitation, growth, maternal health and recent illnesses were significantly associated with the presence of childhood anaemia. These risk factor groups explain a significant fraction of anaemia (ranging from 1.0% to 16.7%) at the population level.

CONCLUSIONS

The findings from our analysis of risk factors for anaemia in SSA underscore the importance of family and socioeconomic context in childhood anaemia. These data highlight the need for integrated programmes that address the multifactorial nature of childhood anaemia.

Prevalence and associated determinants of malaria parasites among Kenyan children

Background

Approximately 80% of deaths attributed to malaria worldwide occurred mainly in Africa in 2015. Kenya is one of the major malaria endemic countries, making malaria the leading public health concern in this country. This study intended to document the prevalence of malaria and determine associated factors including socioeconomic status among children aged 6 months to 14 years in Kenya.

Methods

This study analyzed the secondary data extracted from the 2015 Kenya Malaria Indicator Survey (KMIS), a cross-sectional country representative survey. Associations of demographic, socioeconomic, community-based, and behavioral factors with the prevalence of malaria in children were analyzed using multivariable logistic regression analysis.

Results

Data from 7040 children aged 6 months to 14 years were analyzed. The prevalence of malaria showed an upward trend in terms of age, with the highest prevalence among children aged 11–14 years. Prevalence was also higher among rural children (10.16%) compared to urban children (2.93%), as well as poor children (11.05%) compared to rich children (3.23%). The likelihood of having malaria was higher among children aged 10–14 years (AOR = 4.47, 95% CI = 3.33, 6.02; P < 0.001) compared with children aged under 5 years. The presence of anemia (AOR = 3.52, 95% CI = 2.78, 4.45; P < 0.001), rural residence (AOR = 1.71, 95% CI = 1.31, 2.22; P < 0.001), lack of a hanging mosquito net (AOR = 2.38, 95% CI = 1.78, 3.19; P < 0.001), primary education level of the household head (AOR = 1.15, 95% CI = 1.08, 2.25; P < 0.05), and other factors, such as the household having electricity and access to media such as television or radio, were also associated with the likelihood of infection.

Conclusion

This study demonstrated the need to focus on awareness programs to prevent malaria and to use existing knowledge in practice to control the malaria burden in Kenya. Furthermore, this study suggests that improving the information available through the mass media and introducing behavior change communication and intervention program specifically for those of poor socioeconomic status will help to reduce malaria cases.

Safety of primaquine given to people with G6PD deficiency: systematic review of prospective studies

Background

Haemolysis risk with single dose or short course primaquine was evaluated in glucose-6-phosphate dehydrogenase (G6PD) deficient people.

Methods

Major electronic databases (to August 2016) were searched for single or short course 8-aminoquinolines (8-AQ) in (1) randomized comparisons against placebo in G6PD deficient people; and (2) observational comparisons in G6PD deficient compared to replete people. Two authors independently assessed eligibility, risk-of-bias, and extracted data.

Results

Five randomized controlled trials and four controlled observational cohorts were included. In G6PD deficient individuals, high-dose (0.75 mg/kg) PQ resulted in lower average haemoglobin levels at 7 days (mean difference [MD] −1.45 g/dl, 95% CI −2.17 to −0.74, 2 trials) and larger percentage fall from baseline to day 7 (MD −10.31%, 95% CI −17.69 to −2.92, 3 trials) compared to placebo. In G6PD deficient compared to replete people, average haemoglobin was lower at 7 days (MD −1.19 g/dl, 95% CI −1.94 to −0.44, 2 trials) and haemoglobin change from baseline to day 7 was greater (MD −9.10%, 95% CI −12.55 to −5.65, 5 trials). One small trial evaluated mid-range PQ dose (0.4–0.5 mg/kg) in G6PD deficient people, with no difference detected in average haemoglobin at day 7 compared to placebo. In one cohort comparing G6PD deficient and replete people there was a greater fall with G6PD deficiency (MD −4.99%, 95% CI −9.96 to −0.02). For low-dose PQ (0.1–0.25 mg/kg) in G6PD deficient people, haemoglobin change from baseline was similar to the placebo group (MD 1.72%, 95% CI −1.89 to 5.34, 2 trials). Comparing low dose PQ in G6PD deficient with replete people, the average haemoglobin was lower in the G6PD deficient group at 7 days (−0.57 g (95% CI −0.97 to −0.17, 1 trial)); although change from baseline was similar (MD −1.45%, 95% CI −5.69 to 2.78, 3 trials).

Conclusions

Falls in average haemoglobin are less marked with the 0.1 to 0.25 mg/kg PQ than with the 0.75 mg/kg dose, and severe haemolytic events are not common. However, data were limited and the evidence GRADE was low or very low certainty.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1989-3) contains supplementary material, which is available to authorized users.

Freedom from Infection: Confirming Interruption of Malaria Transmission

The global reductions in disease burden and the continued spread of drug and insecticide resistance make malaria elimination both viable and imperative, although this may be more easily achieved in some settings compared to others. Whilst the focus has been on optimal approaches to achieve elimination, less attention has been paid to how to measure the absence of malaria. Measuring the absence of transmission poses a specific challenge in that it involves proving a negative. The concept of freedom from infection, routinely used in veterinary epidemiology, can provide quantitative and reproducible estimates that, if infections were present above a predefined (low) threshold, they would be detected with a known uncertainty. Additionally, these methods are adaptable for both passively and actively collected data as well as combining information when multiple surveillance streams are available. Here we discuss the potential application of this approach to malaria.

A Venue-Based Survey of Malaria, Anemia and Mobility Patterns among Migrant Farm Workers in Amhara Region, Ethiopia

BACKGROUND

Mobile populations present unique challenges to malaria control and elimination efforts. Each year, a large number of individuals travel to northwest Amhara Region, Ethiopia to seek seasonal employment on large-scale farms. Agricultural areas typically report the heaviest malaria burden within Amhara thereby placing migrants at high risk of infection. Yet little is known about these seasonal migrants and their malaria-related risk factors.

METHODS AND FINDINGS

In July 2013, a venue-based survey of 605 migrant laborers 18 years or older was conducted in two districts of North Gondar zone, Amhara. The study population was predominantly male (97.7%) and young (mean age 22.8 years). Plasmodium prevalence by rapid diagnostic test (RDT) was 12.0%; One quarter (28.3%) of individuals were anemic (hemoglobin <13 g/dl). Nearly all participants (95.6%) originated from within Amhara Region, with half (51.6%) coming from within North Gondar zone. Around half (51.2%) slept in temporary shelters, while 20.5% regularly slept outside. Only 11.9% of participants had access to a long lasting insecticidal net (LLIN). Reported net use the previous night was 8.8% overall but 74.6% among those with LLIN access. Nearly one-third (30.1%) reported having fever within the past two weeks, of whom 31.3% sought care. Cost and distance were the main reported barriers to seeking care. LLIN access (odds ratio [OR] = 0.30, P = 0.04) and malaria knowledge (OR = 0.50, P = 0.02) were significantly associated with reduced Plasmodium infection among migrants, with a similar but non-significant trend observed for reported net use the previous night (OR = 0.16, P = 0.14).

CONCLUSIONS

High prevalence of malaria and anemia were observed among a young population that originated from relatively proximate areas. Low access to care and low IRS and LLIN coverage likely place migrant workers at significant risk of malaria in this area and their return home may facilitate parasite transport to other areas. Strategies specifically tailored to migrant farm workers are needed to support malaria control and elimination activities in Ethiopia.

Effect of early and current Helicobacter pylori infection on the risk of anaemia in 6.5-year-old Ethiopian children

BACKGROUND

Epidemiological and clinical studies in high income countries have suggested that Helicobacter pylori (H. pylori) may cause anaemia, but evidence is lacking from low income countries.We examined associations between H. pylori infection in early childhood and anaemia at the age of 6.5 years in an Ethiopian birth cohort.

METHODS

In 2011/12, 856 children (85.1 % of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Haemoglobin level and red cell indices were examined using an automated haematological analyzer (Cell Dyn 1800, Abbott, USA), and stool samples analyzed for H. pylori antigen. The independent effects of H. pylori infection (measured at age 3.5 and 6.5 years) on anaemia, haemoglobin level, and red cell indices (measured at age 6.5 years) were determined using multiple logistic and linear regression.

RESULTS

The prevalence of anemia was 34.8 % (257/739), and the mean (SD) haemoglobin concentration was 11.8 (1.1) gm/dl. Current H. pylori infection at age 6.5 years was positively, though not significantly related to prevalence of anaemia (adjusted OR, 95 % CI, 1.15; 0.69, 1.93, p = 0.59). Any H. pylori infection up to age 6.5 years was significantly associated with an increased risk of anaemia at age 6.5 (adjusted OR, 95 % CI, 1.68; 1.22, 2.32, p = 0.01). A significant reduction in haemoglobin concentration and red cell indices was also observed among children who had any H. pylori infection up to age 6.5 (Hb adjusted β = -0.19, 95 % CI, -0.35 to -0.03, p = 0.01; MCV adjusted β = -2.22, 95 % CI, -3.43 to -1.01, p = 0.01; MCH adjusted β = -0.63, 95 % CI, -1.15 to - 0.12, p = 0.01; and MCHC adjusted β = -0.67, 95 % CI, -1.21 to -0.14, p = 0.01), respectively.

CONCLUSION

This study provides further evidence from a low income country that any H. pylori infection up to age 6.5 is associated with higher prevalence of anaemia, and reduction of haemoglobin level and red cell indices at age 6.5.

Factors associated with malaria parasitemia, anemia and serological responses in a spectrum of epidemiological settings in Uganda

Background

Understanding the current epidemiology of malaria and the relationship between intervention coverage, transmission intensity, and burden of disease is important to guide control activities. We aimed to determine the prevalence of anemia, parasitemia, and serological responses to P. falciparum antigens, and factors associated with these indicators, in three different epidemiological settings in Uganda.

Methods and Findings

In 2012, cross-sectional surveys were conducted in 200 randomly selected households from each of three sites: Walukuba, Jinja district (peri-urban); Kihihi, Kanungu district (rural); and Nagongera, Tororo district (rural) with corresponding estimates of annual entomologic inoculation rates (aEIR) of 3.8, 26.6, and 125.0, respectively. Of 2737 participants, laboratory testing was done in 2227 (81.4%), including measurement of hemoglobin, parasitemia using microscopy, and serological responses to P. falciparum apical membrane antigen 1 (AMA-1) and merozoite surface protein 1, 19 kilodalton fragment (MSP-1₁₉). Analysis of laboratory results was restricted to 1949 (87.5%) participants aged ≤ 40 years. Prevalence of anemia (hemoglobin < 11.0 g/dL) was significantly higher in Walukuba (18.9%) and Nagongera (17.4%) than in Kihihi (13.1%), and was strongly associated with decreasing age for those ≤ 5 years at all sites. Parasite prevalence was significantly higher in Nagongera (48.3%) than in Walukuba (12.2%) and Kihihi (12.8%), and significantly increased with age to 11 years, and then significantly decreased at all sites. Seropositivity to AMA-1 was 53.3% in Walukuba, 63.0% in Kihihi, and 83.7% in Nagongera and was associated with increasing age at all sites. AMA-1 seroconversion rates strongly correlated with transmission intensity, while serological responses to MSP-1₁₉ did not.

Conclusion

Anemia was predominant in young children and parasitemia peaked by 11 years across 3 sites with varied transmission intensity. Serological responses to AMA-1 appeared to best reflect transmission intensity, and may be a more accurate indicator for malaria surveillance than anemia or parasitemia.

Malaria and anaemia in pregnancy: a cross-sectional study of pregnant women in rural communities of Southeastern Nigeria

BACKGROUND

Several strategies are used in the care of pregnant women accessing antenatal care in primary health centres in Nigeria, with the aim of reducing the burden of malaria and anaemia. The objective of the study was to appraise the prevalence of malaria parasitaemia and anaemia in pregnant women attending antenatal clinics in rural communities of Southeastern Nigeria where malaria preventive strategies are in place.

METHODS

We undertook a cross-sectional study of 300 pregnant women receiving antenatal care in randomly selected primary health centres in the Nkanu West local government area (LGA), Enugu state, Nigeria from August to September 2010.

RESULTS

The prevalence of malaria parasitaemia was 92.0% (276/300) (mild in 86.7% [260/300] and moderate in 15.3% [16/300]). The prevalence of anaemia was 49.3% (148/300) (mild in 29.3% [88/300] and moderate in 20% [60/300]). There were no severe cases of malaria parasitaemia or anaemia. The educational status and occupation of participants were significantly associated with the occurrence of peripheral parasitaemia and anaemia respectively (p<0.05).

CONCLUSION

The prevalence of malaria and anaemia is very high in the Nkanu West LGA of Enugu State, Nigeria. Efforts to reduce the prevalence of malaria parasitaemia and anaemia in pregnancy should be intensified in rural settings of Enugu state and Nigeria as a whole.

The relationship between anaemia and malaria: apparently simple, yet controversial

Among many other factors, malaria plays a major causative role of anaemia globally. The mechanisms leading to anaemia in the course of malaria are extremely diverse, involving immunological factors that act differently according to age and malaria epidemiology. The malaria-attributable fraction of anaemia may then differ in different settings. While tremendous efforts are being made to control malaria, the availability of a simple and reliable biomarker of impact is of the upmost importance. Promising data are accumulating that Hb levels could be used as a proxy of malaria even in hypo-endemic areas, even if many grey areas still deserve research efforts.