Title Factors associated with malaria parasitaemia , malnutrition , and anaemia among HIV-exposed and unexposed Ugandan infants : a cross-sectional survey Permalink

Background: Malaria, malnutrition and anaemia are major causes of morbidity and mortality in African children. The interplay between these conditions is complex and limited data exist on factors associated with these conditions among infants born to HIV-uninfected and infected women. Methods: Two hundred HIV-exposed (HIV-uninfected infants born to HIV-infected mothers) and 400 HIV-unexposed infants were recruited from an area of high malaria transmission in rural Uganda. A cross-sectional survey was performed at enrolment to measure the prevalence of malaria parasitaemia, measures of malnutrition (z-scores <2 standard deviations below mean) and anaemia (haemoglobin <8 gm/dL). Multivariate logistic regression was used to measure associations between these conditions and risk factors of interest including household demographics, malaria prevention practices, breastfeeding practices, household structure and wealth index. Results: The prevalence of malaria parasitaemia was 20%. Factors protective against parasitaemia included female gender (OR = 0.66, p = 0.047), mother’s age (OR = 0.81 per five-year increase, p = 0.01), reported bed net use (OR = 0.63, p = 0.03) and living in a well-constructed house (OR = 0.25, p = 0.01). Although HIV-unexposed infants had a higher risk of parasitaemia compared to HIV-exposed infants (24% vs 14%, p = 0.004), there was no significant association between HIV-exposure status and parasitaemia after controlling for the use of malaria preventative measures including bed net use and trimethoprim-sulphamethoxazole prophylaxis. The prevalence of stunting, underweight, and wasting were 10%, 7%, and 3%, respectively. HIV-exposed infants had a higher odds of stunting (OR = 2.23, p = 0.005), underweight (OR = 1.73, p = 0.09) and wasting (OR = 3.29, p = 0.02). The prevalence of anaemia was 12%. Risk factors for anaemia included older infant age (OR = 2.05 per one month increase, p = 0.003) and having malaria parasitaemia (OR = 5.74, p < 0.001). Conclusions: Compared to HIV-unexposed infants, HIV-exposed infants had a higher use of malaria preventative measures and lower odds of malaria parasitaemia. Having a better constructed house was also protective against malaria parasitaemia. HIV-exposure was the primary risk factor for measures of malnutrition. The primary risk factor for anaemia was malaria parasitaemia. These findings suggest the need to better target existing interventions for malaria, malnutrition and anaemia as well as the need to explore further the mechanisms behind the observed associations. * Correspondence: osterbauerb@php.ucsf. edu Department of Medicine, University of California, San Francisco General Hospital, 1001 Potrero Avenue, Building 30, Room 3420, San Francisco, CA 94110, USA Full list of author information is available at the end of the article © 2012 Osterbauer et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Osterbauer et al. Malaria Journal 2012, 11:432 Page 2 of 6 http://www.malariajournal. com/content/11/1/432 Background Malaria, malnutrition, and anaemia are among the major causes of childhood morbidity and mortality in subSaharan Africa [1,2]. Not only are these disease entities of major public health importance, they may also be interrelated in terms of causality, severity of illness, and underlying associated factors. In 2009, malaria was estimated to account for 16% of all deaths in children under five years of age in Africa [3]. Malnutrition has been estimated to be a contributing factor in more than half of childhood deaths related to major infectious diseases, including malaria [3,4]. Malnutrition has also been shown to influence both the manifestation of and susceptibility to malaria [5-7]. Malaria and malnutrition are causally associated with anaemia and underlying anaemia may contribute to the severity of malaria and malnutrition [6]. African infants under one year may be at particularly high risk of malaria, malnutrition and anaemia, both in terms of the prevalence and severity of these illnesses [2]. Adding to the complexity of this high-risk group is a rising population of HIV-exposed but uninfected infants born to HIV-infected mothers, due in large part to the successful implementation of prevention of mother-tochild transmission (PMTCT) programmes in Africa [7]. Exposure to HIV may have a direct or indirect role on child health and limited data exist on the prevalence and factors associated with malaria, malnutrition, and anaemia in this novel population. For example, infants born to HIV-infected mothers may have better access to health care services compared to infants born to HIV-uninfected mothers. Alternatively, infants born to HIV-infected mothers may have excess morbidity due to maternal HIVrelated illness, exposure to opportunistic infections, the mother’s ability to breastfeed, or socioeconomic factors [8]. A better understanding of factors associated with malaria, malnutrition and anaemia in African infants both exposed and unexposed to HIV could help elucidate their complex relationship and consequently inform the design of interventions aimed at reducing disease burden. To address some of these issues a cross-sectional survey was performed at enrolment in a cohort of HIV-exposed and unexposed infants living in a rural area of Eastern Uganda with high malaria transmission intensity and high prevalence of malnutrition [9,10]. The goals of this study were to describe the prevalence of malaria, malnutrition, and anaemia, examine the relationship between these disease entities, and generate plausible hypotheses regarding variables that could possibly be associated with these outcomes, including HIV exposure status.