Prevalence of nutritional defi cits among children under fi ve years of age in Angola

OBJECTIVE: To estimate the prevalence of nutritional defi ciencies in Angolan children. METHODS: A cross-sectional population based study. World Health Organization (2006) criteria were used to classify nutritional state. RESULTS: A high prevalence of low height for age, weight for height and weight for age was observed (22%, 13% and 7%, respectively) among the children. CONCLUSIONS: Nutritional defi ciencies in children represents a serious public health problem in Bom Jesus, Angola. DESCRIPTORS: Infant. Child. Defi ciency Diseases, epidemiology. Child Nutrition Disorders, epidemiology. Nutrition Surveys. Brief Communication DOI: 10.1590/S0034-8910.2013047004576 2 Prevalence of nutritional defi ciencies Fernandes ECB et al The worldwide prevalence of nutritional defi ciencies in children under five has decreased, although to differing extents between countries, due to exposure to unfavorable socio-environmental conditions in less developed regions.1 It is estimated that worldwide, in 2010, 115 million children under fi ve were underweight for their age (W/A). Higher prevalence was found in the CenterSouth region of Asia (30%) and in East, West and Central Africa, 22%, 22% and 21% respectively.1 In the same year, around 178 million children under fi ve had low height for their age (H/A). This defi cit may compromise development and cognitive ability when it affects a child under two, leading to lower productivity and human capital in adulthood.1 Children with nutritional defi ciencies are more prone to serious infections and death from diarrhea, measles, pneumonia and malaria. Those who survive may have a weakened immune system and develop a vicious cycle of recurrent infection and malnutrition.1 In addition, they may have impaired performance at school and are at greater risk of developing chronic illness in adulthood.1 Angola is a developing country in sub-Saharan Africa. Life expectancy at birth is 52 years and 34.4% of the population aged over 15 are illiterate. The socio-environmental conditions are precarious: 78.5% of the urban population live in dwellings constructed from materials not fi t for the purpose, without access to electricity (59.8%), drinking water (58%) or proper sanitation (40.4%).a The prevalence of low H/A was 29.2% in 2007, 12% severely so. A higher prevalence was observed in the West (34.3%), South (33.7%) and Center South (31.3%). The prevalence of low weight for height (W/H) was 8.2% and for low W/A, 15.6%.b Bom Jesus is a community in the municipality of Icolo e Bengo, in the province of Luanda, with rural characteristics, close to the capital. No studies were found on the prevalence of nutritional defi ciencies in children under fi ve in this area. This study aimed to estimate the prevalence of nutritional defi ciencies in Angolan children.

The worldwide prevalence of nutritional defi ciencies in children under five has decreased, although to differing extents between countries, due to exposure to unfavorable socio-environmental conditions in less developed regions. 1 It is estimated that worldwide, in 2010, 115 million children under fi ve were underweight for their age (W/A).Higher prevalence was found in the Center-South region of Asia (30%) and in East, West and Central Africa, 22%, 22% and 21% respectively. 1In the same year, around 178 million children under fi ve had low height for their age (H/A).This defi cit may compromise development and cognitive ability when it affects a child under two, leading to lower productivity and human capital in adulthood. 1ildren with nutritional defi ciencies are more prone to serious infections and death from diarrhea, measles, pneumonia and malaria.Those who survive may have a weakened immune system and develop a vicious cycle of recurrent infection and malnutrition. 1In addition, they may have impaired performance at school and are at greater risk of developing chronic illness in adulthood. 1gola is a developing country in sub-Saharan Africa.Life expectancy at birth is 52 years and 34.4% of the population aged over 15 are illiterate.The socio-environmental conditions are precarious: 78.5% of the urban population live in dwellings constructed from materials not fi t for the purpose, without access to electricity (59.8%), drinking water (58%) or proper sanitation (40.4%).a The prevalence of low H/A was 29.2% in 2007, 12% severely so.A higher prevalence was observed in the West (34.3%),South (33.7%) and Center South (31.3%).The prevalence of low weight for height (W/H) was 8.2% and for low W/A, 15.6%.b Bom Jesus is a community in the municipality of Icolo e Bengo, in the province of Luanda, with rural characteristics, close to the capital.No studies were found on the prevalence of nutritional defi ciencies in children under fi ve in this area.
This study aimed to estimate the prevalence of nutritional defi ciencies in Angolan children.

METHODS
A cross-sectional population-based study of 744 children aged under fi ve in the community of Bom Jesus, province of Luanda, in 2010.
The sample was selected using the systematic sampling technique, with the household used as the sampling unit.The fi rst household was randomly selected, and then every third household from there, in an anti-clockwise, eastern direction.Children living in the households selected were deemed to be units of analysis, excluding those who were absent, who were suffering from long-term illness and those whose data presented discrepancies.
The data were collected between May and August 2010, carried out by students in the fi nal year of the medicine degree at the Faculty of Medicine, Universidade Agostinho Neto, under the supervision of a researcher.
The interviewers were trained and those who obtained the best precision in taking anthropometric measurements were scheduled to carry out the fi eldwork.Weight was measured using portable Salter scales, model CMS, with a capacity of 25 kg and precise to 100 g, calibrated daily with standard weights.For children under 24 months, length was measured lying down and those aged over 24 months were measured in a supine position, c using portable anthropometers, model AHRTAG, precise to 1 mm.The data were collected in duplicate, with the mean used as the fi nal value, as long as the difference between measurements was < 100 g for weight and 0.7 cm for height. 2 The interviews were conducted preferably with the child's mother or guardian.A structured, previously codifi ed questionnaire was applied, which included data about the child: age, sex, date of birth, birth weight, birth order and morbidity in the preceding 15 days.
Nutritional status was calculated according to the anthropometric indices H/A, W/H and W/A and expressed in Z scores (Z), carried out using the WHO Anthro program version 3.1.0,using World Health Organization growth curves 2 for children under fi ve as a standard of reference, the cutoff point considered was -2 Z. Thirty-four children were excluded: 2.2% as they were absent during the data collection period, 0.9% due to long term illness and 1.3% for having extreme Z values, i.e., W/A < -6 or > 5; H/A < -6 or > 6; and W/H < -5 or > 5.
The Epilnfo program version 3.5.1 was used to compare defi ciencies according to the characteristics of the children.Pearson's Chi-squared test was used to test heterogeneity, with the level of signifi cance of 0.05.After clearing up any doubts, the children's mothers or guardians agreed to participate in the study and signed a informed consent form.Those children who had nutritional defi ciencies or other morbidities received advice and were referred to the local health care service for treatment and monitoring.

RESULTS
In 2010 there were 2,088 households in the community of Bom Jesus.There were 696 (around ⅓) randomly selected to take part; children under fi ve lived in 23.3% of these.In these households there were 498 families and 778 children were identifi ed.
Among the 744 children observed, the prevalence of nutritional defi ciencies was high for the three indices: 22.0%, 6.6% and 13.3% for low H/A, W/H and W/A, respectively.There was a greater proportion of children with low H/A in the 24 to 35 months age group, whereas low W/H and W/A were more prevalent in the age groups of zero to fi ve months and 12 to 23 months, respectively.A higher prevalence of low H/A was observed in children with diarrhea containing mucus and blood, and parasites, whereas the proportion of low W/A was higher in those who reported passing parasites and anal itching (Table ).

DISCUSSION
A high prevalence of nutritional deficiency was observed among the children in the community of Bom Jesus, posing a serious public health problem.
Low H/A continues to be the most common worldwide, compared with low W/H and W/A. 1 Although Bom Jesus has rural characteristics, the prevalence of low H/A (22%) was lower than that verifi ed in rural Angola (33.0%) and in the province of Bengo, b probably due to the establishment of industries, which may have led to an increase in household income.A higher prevalence of low H/A was observed from two years old onwards, with the greatest proportion in the 24 to 47 month old age group.Low H/A indicates a chronic condition due to a continuous process of malnutrition at a young age.Maternal malnutrition, which can lead to low birth weights, and poor nutrition for young and breastfeeding children are some of the causes of malnutrition in the early years. 1 Although the prevalence of low W/A in Bom Jesus was considered high (13.3%), it was lower than that found in rural Angola (18.0%).b A third of children aged six to 23 months have acute malnutrition, which may be a refl ection of maternal malnutrition, insuffi cient nutrition from breastfeeding and precarious food situations, especially at the time of weaning. 1 Illiteracy, especially on the part of the mother, and precarious environmental, sanitary and social conditions may be subjacent causes of the link between low H/A and W/A and intestinal parasites and diarrhea, immediate causes of infant malnutrition. 1A high proportion of households in Bom Jesus, in 2010, lived in one-roomed homes constructed of material which is unfi t for the purpose, without access to treated water.There was no toilet/sewer and rubbish was dumped in the open air in more than ⅔ of households.Approximately ⅔ of mothers were illiterate or had between one and four years of schooling (data not shown).
Although the results cannot be extrapolated to all Angolan children, the fi ndings show an elevated prevalence of nutritional defi ciencies, especially with regards to low H/A.Other studies are necessary to identify the determinants of infant malnutrition with the aim of establishing preventative measures.
The research was approved by the Provincial Health Care directorate of Bengo, Angola (Process No. 26/ DPSB/2009); by the Independent Ethics Committee of the Faculty of Medicine, Universidade Agostinho Neto, INTRODUCTION Angola; and by the Research Ethics Committee of the Centro de Saúde-Escola of the Faculty of Medicine, of Ribeirao Preto, Universidade de São Paulo, (Process No. 267/09/COORD.CEP/CSE-FMRP-USP).

Table .
Prevalence of nutritional defi ciencies according to characteristics of children aged under fi ve.Bom Jesus, Angola, 2010.
NI: No information; H/A: Height for age; W/H: Weight for height; W/A: Weight for agee a According to the Chi-squared test for heterogeneity