PhD defence Idalécia Cossa Moiane

Supervisors

• Prof. dr. Katja Polman (ITM)

• Prof. dr. Jean-Pierre Van geertruyden (University of Antwerp)

• Prof. dr. Nilsa de Deus (Instituto Nacional de Saúde, Maputo, Mozambique)

• Prof. dr. Colleen Doak (St. Ambrose University, Davenport, United States of America) 

Abstract

Introduction:

Child undernutrition remains one of the most pressing public health issues in low- and middle-income countries (LMICs), especially in sub-Saharan Africa. In Mozambique, the burden of undernutrition remains alarmingly high, having the highest rates of stunting in the sub-Saharan region among children under 5 years of age. While acute interventions often lead to weight gain, there is growing concern about the quality of this recovery, especially in terms of body composition. Recent evidence suggests that rapid weight gain may disproportionately consist of fat mass rather than lean mass, potentially increasing long-term metabolic risk. Consequently, it may lead to the development of overweight or obesity at a later age. This issue is particularly relevant and pressing in Mozambique and other LMICs, where obesity is also on the rise. This creates a “double burden of malnutrition” (DBM), with the country simultaneously affected by both undernutrition and overnutrition. The coexistence of these issues complicates public health efforts and underscores the need for interventions that promote not only weight gain but also healthy body composition.

The role of intestinal parasitic infections (IPIs) in changing body composition has so far been understudied. Nevertheless, IPIs are very common in LMICs and are known to be reciprocally associated with child undernutrition. Additionally, they have been linked to overweight/obesity. Mozambique is an example of a country in transition, with high parasite endemicity, high rates of child undernutrition, and rapidly emerging overweight, obesity, and related chronic disease risks.  

Objectives:

a) Main objective

To determine the role of intestinal parasitic infections and other factors in child undernutrition and changes in body composition in Mozambique. 

b) Specific objectives

• To determine the association between child undernutrition, intestinal parasite infection and body composition.

• To determine the short and long-term contribution of intestinal parasite infections and other factors to

  • the recovery process to normal weight and

  • changes in body composition after treatment of undernutrition in children.

• To explore how household environment relates to nutritional status and (changes in) body composition in children.

Methods:

1 Study design and setting

First, a scoping review was conducted, followed by fieldwork carried out both in hospital settings and through community follow-up. The hospital-based study took place at Hospital Geral de José Macamo, located in the Luís Cabral neighborhood, and at Hospital Geral de Mavalane, in the Mavalane neighborhood. Both hospitals serve populations from Maputo City and Maputo Province. 

a) Literature review

A literature review was conducted following a scoping review framework to identify both observational and experimental studies relevant to the research question. Observational studies were included to estimate cross-sectional associations between IPIs and body composition, whereas experimental studies were included to evaluate the effects of antiparasitic treatment on the rate of weight gain and subsequent changes in body composition. 

b) Fieldwork (hospital and community study)

Children aged 1 to 14 years with undernutrition were recruited from the pediatric wards of two hospitals in Maputo Province. Eligible participants were residents of Maputo City or Maputo Province. IPIs and other factors were investigated as exposures in relation to body composition outcomes, which were assessed at hospital admission,  hospital discharge, and during community follow up. Data were analyzed both cross-sectionally and longitudinally.

The cross-sectional analysis (chapter 3) involved a description of the profile of the undernourished children admitted to the hospital and of their caretakers[1]). The longitudinal analysis (chapter 4) focused on the assessment of the role of IPIs and other factors in changes in weight and body composition of undernourished children during their nutritional recovery process in the hospital and back home in their community. 

2 Data collection

2.1  Scoping review

Searches were conducted on MEDLINE, EMBASE and Cochrane Library. Search terms included several variations on body fat, BMI, body composition, overweight, obesity, parasitic infections, parasites, helminths, intestinal parasites, protozoa and names of IPIs species. 

2.2 Fieldwork

a) Stool Collection and Parasitological Examination

A single stool sample was collected from each participating child and/or caretaker and analyzed at the Laboratory of Parasitology of the Instituto Nacional de Saúde (INS). Samples were examined microscopically using the Kato-Katz (KK) method for helminth detection and the formol-ether concentration (FEC) method for protozoan identification, following standard procedures. Additionally, a modified Ziehl–Neelsen (mZN) stain was used to detect intestinal coccidian parasites such as Cryptosporidium sp., Cyclospora cayetanensis, and Cystoisospora belli.

Microscopy was selected as the standard diagnostic method (gold standard) according to WHO guidelines/national guidelines.

b) Clinical Data

Clinical information was extracted from hospital records filled by a medical doctor at admission. Data included socio-demographic characteristics, type of undernutrition, presence of comorbidities (e.g., malaria, pneumonia, HIV), vitamin A intake, and presence of nutritional edema.

At hospital discharge (Time 1) and community (Time 2), anthropometry measurements and stool sample were collected for follow-up. 

c) Nutritional Status and Body Composition Assessment

Anthropometric measurements were obtained from children and their caretakers to assess nutritional status and body composition. The following anthropometric measurements were taken: height, weight, MUAC, WC, and four SKs. The SKs measurements were taken from the triceps, biceps, subscapular, and suprailiac, using standardized WHO procedures and calibrated Seca equipment.

Collectively, these complementary anthropometric indicators enhance diagnostic precision by capturing multiple dimensions of nutritional status. Height and weight describe linear growth and overall mass; MUAC reflects combined muscle and fat reserves and is indispensable for detecting undernutrition; whereas WC and SK quantify fat distribution and potential metabolic risk. The integration of these methods provides a multidimensional understanding of nutritional recovery and allows examination of how IPIs and other factors influence body composition, the fat-to-lean mass ratio, growth trajectories, and overall child health outcomes.

Particular attention was given to children presenting with edema. Specifically, any child with edema was classified as having severe acute malnutrition (SAM) and was treated as having a Z-score < −3 standard deviations (SD) for all weight-related indices (BAZ and WHZ). SK measurements were attempted in all children, including those with edema; however, in cases of severe edema and/or when the child was too frail to be measured safely, SK was not performed. In such instances, the corresponding site value was recorded as missing for that time point. Consequently, when one or more SK sites were missing, the sum of SKs and percentage of body fat (%BF) were not calculated for that time point. 

Results:

The findings of the scoping review revealed that direct measures of body composition are rarely assessed in clinical practice, with most studies relying on proxies such as weight-for-height, Body Mass-Index (BMI) or skinfold thickness (SK). The cross-sectional study in Maputo showed that children with undernutrition often present to the hospital in critical condition, and many suffer from co-infections with IPIs and/or HIV. The longitudinal study confirmed that HIV infection is a strong negative predictor of both weight and fat recovery, whereas edema at hospital admission is associated with improved weight and skinfold outcomes. Age and sex also emerged as significant predictors of body composition changes. Noteworthy is that IPIs were significantly associated with body fat in univariate analysis, but this association attenuated after adjusting for other variables. SKs in addition to mid-upper arm circumference (MUAC), height and weight provided valuable insights into the body composition changes during nutritional recovery. 

Conclusions:

These findings underscore the complexity of nutritional recovery and illustrate the importance of adopting a more refined approach to monitoring and intervention. This includes the prioritization of more proximal actions, such as providing close follow-up care for children in their home environment after hospital discharge, in addition to the care provided during hospitalization. The findings demonstrate the need for a shift towards integrated strategies that consider body composition, particularly body fat. It also calls for reflection on the integration of child healthcare, simultaneously considering nutrition, infectious diseases and a family-centered approach. Ultimately, this research aligns with global efforts to achieve the Sustainable Development Goals (SDGs), particularly SDG 2 (Zero Hunger) and SDG 3 (Good Health and Well-being). It challenges policymakers and health systems to move beyond treating undernutrition as a condition of weight deficiency and to recognize the importance of weight recovery.  Attention should be paid to infection management, body composition outcomes, continued follow-up of the child (particularly when back home), as well as education of household members on nutritional behaviors and prevention of IPIs.

[1] The caretaker is the legal guardian named to take care of the child. It should be someone who lives with the child, and not someone who is hired to look after the child such as a nanny or housemaid. It can be a grandmother, grandfather, uncle, aunt, etc, someone related to the child or with a close personal relationship to the family.