Developmental effects of micronutrient supplementation and malaria in Zanzibari children.

BACKGROUND: Children's development is affected by the interplay of internal and external factors and changes in one factor can precipitate changes in multiple developmental domains. AIMS: The aim of this study was to test a theoretical model of children's development using structural equation modeling. STUDY DESIGN: This was designed as a substudy of a randomized, placebo-controlled, 2 × 2 factorial trial of the effects of daily supplementation with iron (12.5 mg) + folic acid (50 µg) (FeFA) with or without zinc (10 mg) (Zn) on child mortality. SUBJECTS: Zanzibari children aged 5-9 mo (n = 106) and 10-14 mo (n = 141) at baseline were included in this sub study. OUTCOME MEASURES: Longitudinal data on children's hemoglobin, growth, malaria infection, motor development, motor activity, and language development and caregiver behavior were used to test the fit of the theoretical model for two age groups and to examine the direct and indirect relationships among the variables in the model. RESULTS: The theoretical models were a good fit to the data for both age groups and revealed that FeFA with or without Zn had positive effects on motor development. FeFA alone had negative effects on language development in both age groups and Zn alone had negative effects on language development in children aged 10-14 mo. The incidence of malaria had negative effects on the majority of health and development outcomes in children aged 5-9 mo, and on motor development and hemoglobin in children aged 10-14 mo. CONCLUSIONS: These findings illustrate how nutrition and health factors can affect different domains of development and how these changes can precipitate changes in other domains. More work is needed to better understand the multiple impacts of internal and external factors on children's development and how changes in developmental domains interact with each other over time to determine children's overall developmental trajectory. The randomized, placebo-controlled study was registered as an International Standard Randomized Controlled Trial, number ISRCTN59549825.

Beyond food insecurity: how context can improve complementary feeding interventions.

BACKGROUND: The role of context has not been elaborated with respect to current recommendations for complementary feeding interventions, apart from a gross distinction based on food security. OBJECTIVE: Our objective was to compare two food-insecure settings in sub-Saharan Africa to determine how context (i.e., the set of local social, cultural, and physical circumstances) influences complementary feeding practices and nutrient intakes and how the results can help in the design of a suitable intervention strategy. METHODS: We conducted formative research using 24-hour dietary recalls, household interviews, and focus group discussions with mothers of 6- to 12-month-old infants in rural Zimbabwe (n = 32) and Pemba Island, Zanzibar, Tanzania (n = 44). RESULTS: In both settings, many infants had suboptimal nutrient intakes, poor dietary diversity, and poor hygiene. Breastfeeding practices were poor in Pemba, and the infants' diet had low energy density in Zimbabwe. Beyond food insecurity, contextual determinants of practices included inaccurate indigenous knowledge, time-consuming maternal livelihoods, family eating behaviors, local agriculture, and the local ecosystem. Both settings would require nutrition education, but it should target the broader indigenous ways of learning and family eating behaviors in order to achieve the necessary behavior change. A home-based fortificant would probably be enough for Pemban children, because the ecosystem of the island provides sufficient sources of macronutrients. However, Zimbabwean children appear to need a fortified food-based supplement to overcome the poor agricultural and economic context. CONCLUSIONS: Assessing context was essential to intervention design. A framework to guide future formative research is proposed.

Association of pica with anemia and gastrointestinal distress among pregnant women in Zanzibar, Tanzania.

The etiology of pica, the purposive consumption of non-food substances, is not understood, despite its ubiquity among gravidae. We examined correlates of pica in a representative obstetric population (n = 2,368) on Pemba Island, Zanzibar, Tanzania to examine proposed etiologies. Cross-sectional data were collected on socioeconomic characteristics, food intake, geophagy (earth consumption), amylophagy (raw starch consumption), anthropometry, iron status, parasitic burden, and gastrointestinal morbidities. Amylophagy was reported by 36.3%, geophagy by 5.2%, and any pica by 40.1%. There was a strong additive relationship of geophagy and amylophagy with lower hemoglobin (Hb) concentration and iron deficiency anemia. By multivariate logistic regression, any pica was associated with Hb level (odds ratio [OR] = 0.76, 95% confidence interval [CI] = 0.72-0.81), nausea (OR = 1.45, 95% CI = 1.20-1.73), and abdominal pain (OR = 1.22, 95% CI = 1.01-1.48). These striking results indicate that the nature of the relationship between pica, pregnancy, gastrointestinal distress, and iron deficiency anemia merits further investigation.

Incidence and risk factors for newborn umbilical cord infections on Pemba Island, Zanzibar, Tanzania.

BACKGROUND: Few community-based data exist on the frequency of cord infection signs in low resource settings, especially in Sub-Saharan Africa. We developed simple sign-based definitions of omphalitis and estimated incidence and risk factors for infection over a range of severity among neonates in Pemba, Zanzibar, Tanzania. METHODS: Infants' umbilical stump was assessed on days 1, 3, 5, 7, 10, and 14 after birth for presence of pus, redness, swelling, and foul odor. Infection incidence and proportion of affected infants was estimated for 6 separate combinations of these signs. Two definitions were examined for associations between infection and selected potential risk factors using multivariate analysis. RESULTS: Nine thousand five hundred fifty cord assessments (in 1653 infants) were conducted. The proportion of affected infants ranged from 16 (1.0%, moderate to severe redness with pus discharge) to 199 (12.0%, pus and foul odor), while single signs were observed in >20% of infants. Median time to onset of infection was 3 to 4 days; 90% of infections occurred by age 7 days. Breast-feeding within the first hour after birth was associated with lower risk of infection in multivariate analyses, while other maternal, and infant and care practices were generally not associated. CONCLUSIONS: Signs of omphalitis occur frequently and predominantly in the first week of life among newborns in Pemba, Tanzania. Infection definitions relying on single signs without classifying severity level may overestimate burden. Redness with pus or redness at the moderate or severe level if pus is absent is more appropriate for estimating burden or during evaluation of interventions to reduce infection.

The effects of iron and/or zinc supplementation on maternal reports of sleep in infants from Nepal and Zanzibar.

BACKGROUND: There is some evidence that sleep patterns may be affected by iron deficiency anemia but the role of iron in sleep has not been tested in a randomized iron supplementation trial. OBJECTIVE: We investigated the effect of iron supplementation on maternal reports of sleep in infants in 2 randomized, placebo-controlled trials from Pemba Island, Zanzibar, and Nepal. DESIGN: In both studies, which had parallel designs and were carried out in years 2002 to 2003, infants received iron-folic acid with or without zinc daily for 12 months, and assessments of development were made every 3 months for the duration of the study. Eight hundred seventy-seven Pemban (12.5 +/- 4.0 months old) and 567 Nepali (10.8 +/- 4.0 months) infants participated. Maternal reports of sleep patterns (napping frequency and duration, nighttime sleep duration, frequency of night waking) were collected. RESULTS: Mean Hb concentration was 9.2 +/- 1.1 for Pemban and 10.1 +/- 1.2 g/dL for Nepali infants. Approximately, one-third of the children were stunted. Supplemental iron was consistently associated with longer night and total sleep duration. The effects of zinc supplementation also included longer sleep duration. CONCLUSIONS: Micronutrient supplementation in infants at high risk for iron deficiency and iron deficiency anemia was related to increased night sleep duration and less night waking.

Development of nutritionally at-risk young children is predicted by malaria, anemia, and stunting in Pemba, Zanzibar.

Nutritionally at-risk children suffer delays in physical growth and motor and language development. Infectious diseases such as malaria pose an additional risk. We examined the cross-sectional relationships among malaria infection, hemoglobin (Hb) concentration, length-for-age Z-scores (LAZ), motor activity, behavior, and motor and language development in 841 Zanzibari children 5-19 mo old. We used structural equation modeling to test the fit of the data to a theoretical model and to examine the relationships among the variables in 3 age groups (5-9, 10-14, and 15-19 mo). The model fit the data for all age groups. In the youngest and oldest groups, children with higher malaria parasite densities had significantly lower Hb and LAZ. Higher LAZ significantly predicted higher total motor activity, and motor and language development scores in all age groups. In the oldest group, children who had higher Hb had higher motor development and activity scores. Malaria was directly and indirectly related to motor activity in the 10- to 14-mo-old group [standardized total effects, -0.14; direct, -0.10 (P = 0.015); and indirect, -0.038]. The significant fit of the models to the data and the statistical significance of many of the specific pathways highlight the complexities of the relationships between health and nutrition and child development outcomes in this population. In addition, the results suggest that multiple interventions are likely necessary to improve child development outcomes in this population of nutritionally at-risk children and that the potential effectiveness of interventions may differ according to age (i.e. prevention and treatment of anemia, stunting, and malaria).

Association between anaemia during pregnancy and blood loss at and after delivery among women with vaginal births in Pemba Island, Zanzibar, Tanzania.

The study sought to identify determinants of blood loss at childbirth and 24 hours postpartum. The study was nested in a community-based randomized trial of treatments for anaemia during pregnancy in Wete Town, Pemba Island, Zanzibar, United Republic of Tanzania. Status of anaemia during pregnancy, nutritional information, obstetric history, and socioeconomic status were assessed at enrollment during routine antenatal care. Pregnant women presented for spontaneous vaginal delivery, and nurse-midwives collected information on labour and delivery via partograph. Blood-stained sanitary napkins and pads from childbirth and 24 hours postpartum were quantified using the alkaline hematin method. Moderate-to-severe anaemia (Hb <90 g/L) at enrollment was strongly associated with blood loss at delivery and the immediate postpartum period, after adjusting for maternal covariates and variables of biological relevance to blood loss. Greater blood loss was associated (p<0.10) with duration of the first stage of labour, placental weight, receipt of oxytocin, preterm birth, and grand multiparity. The findings provide unique evidence of a previously-suspected link between maternal anaemia and greater blood loss at childbirth and postpartum. Further research is needed to confirm these findings on a larger sample of women to determine whether women with moderate-to-severe anaemia are more likely to experience postpartum haemorrhage and whether appropriate antenatal or peripartum care can affect the relationships described here.

Young Zanzibari children with iron deficiency, iron deficiency anemia, stunting, or malaria have lower motor activity scores and spend less time in locomotion.

Motor activity improves cognitive and social-emotional development through a child's exploration of his or her physical and social environment. This study assessed anemia, iron deficiency, hemoglobin (Hb), length-for-age Z-score (LAZ), and malaria infection as predictors of motor activity in 771 children aged 5-19 mo. Trained observers conducted 2- to 4-h observations of children's motor activity in and around their homes. Binary logistic regression assessed the predictors of any locomotion. Children who did not locomote during the observation (nonmovers) were excluded from further analyses. Linear regression evaluated the predictors of total motor activity (TMA) and time spent in locomotion for all children who locomoted during the observation combined (movers) and then separately for crawlers and walkers. Iron deficiency (77.0%), anemia (58.9%), malaria infection (33.9%), and stunting (34.6%) were prevalent. Iron deficiency with and without anemia, Hb, LAZ, and malaria infection significantly predicted TMA and locomotion in all movers. Malaria infection significantly predicted less TMA and locomotion in crawlers. In walkers, iron deficiency anemia predicted less activity and locomotion, whereas higher Hb and LAZ significantly predicted more activity and locomotion, even after controlling for attained milestone. Improvements in iron status and growth and prevention or effective treatment of malaria may improve children's motor, cognitive, and social-emotional development either directly or through improvements in motor activity. However, the relative importance of these factors is dependent on motor development, with malaria being important for the younger, less developmentally advanced children and Hb and LAZ becoming important as children begin to attain walking skills.

Unexpectedly low prevalence of Helicobacter pylori infection among pregnant women on Pemba Island, Zanzibar.

Helicobacter pylori is strongly associated with peptic ulcer and gastric cancer and may be the most common human bacterial infection. The epidemiology of H. pylori has been poorly studied in Africa, where its relevance to disease has not been fully appreciated. Following a cross-sectional study design, H. pylori infection was measured by (13)C-urea breath test among 857 pregnant women attending antenatal care clinics. Location, water use practices, anthropometry, and social and demographic variables were assessed as covariates. The prevalence of H. pylori infection was 17.5%. Multiple logistic regression showed that H. pylori was positively associated with location of enrollment clinic along the main road leading from the southern seaport (odds ratio (OR)=2.5), presence of costlier household lighting in the home (OR=1.6) and height (10 cm) (OR=1.5). The prevalence of H. pylori infection was unexpectedly low for a developing country population, where prevalence is typically very high. Higher prevalence along the road from the southern seaport suggests that infection was imported from the mainland. The reason for very low prevalence should be investigated further because the discovery of bacterial or dietary factors that limit infection in this population could have useful public health applications.

Geophagia is not associated with Trichuris or hookworm transmission in Zanzibar, Tanzania.

Geophagia may be harmful as a method for the transmission of geohelminths. In this study, we pose two questions in a representative sample of 970 pregnant women from Pemba Island, Zanzibar, Tanzania. Can consumed earth be a vector for geohelminth infection? And do geophagists have differential parasitic infection? The parasitological content of 59 non-food substance samples was analysed. Cross-sectional data regarding pica behaviour were collected through interviews conducted by local researchers. Ascaris, Trichuris and hookworm status was ascertained through Kato-Katz smears. The prevalence of geophagia at baseline was 5.6% and the overall prevalence of Ascaris, Trichuris and hookworm infection was 5.6%, 33.2% and 32.9%, respectively. No consumed soil samples contained infectious parasitic stages, and only one of the consumed pica substances (charcoal) contained parasites of potential risk to human health. In bivariate analyses, neither the prevalence nor the intensity of infection with Ascaris, Trichuris or hookworm differed significantly by geophagia status. Furthermore, in multivariate models, geophagia was not a significant predictor of helminth infection status. We conclude that geophagia is not a source of Trichuris or hookworm infection among pregnant women in Pemba (insufficient power to evaluate the effect of Ascaris), which is in contrast to existing findings of helminth infection and geophagia.

Helicobacter pylori infection is associated with severe anemia of pregnancy on Pemba Island, Zanzibar.

Helicobacter pylori infection has recently been associated with iron deficiency and anemia in developed countries. To determine the association of H. pylori and anemia in a tropical region, we measured hemoglobin concentration (Hb) and H. pylori infection by the 13C urea breath test among 857 pregnant women attending antenatal care clinics. Parasitology, anthropometry, obstetric history, sociodemographic and dietary variables were also assessed. Logistic regression showed an odds ratio of 7.63 (95% confidence interval=1.73-33.55) for H. pylori infection comparing women with and without severe anemia (Hb<7 g/dL), controlling for hookworm infection, body mass index and parity, but only among women with a diet low in foods containing heme iron. Infection with H. pylori with low bacterial load was associated with lower Hb concentration while high bacterial load was associated with higher Hb concentration. Further research is needed to establish causality because high worldwide prevalence means that even a small associated risk would be of public health significance.

Combined iron and folic acid supplementation with or without zinc reduces time to walking unassisted among Zanzibari infants 5- to 11-mo old.

Iron and zinc deficiencies have been associated with delayed motor development in nutritionally at-risk children, albeit inconsistently. In this community-based, randomized double-blind trial, iron+folic acid (FeFA) (12.5 mg Fe + 50 mug folic acid), zinc (Zn) (10 mg), and iron+folic acid+zinc (FeFA+Zn) supplements or a placebo were given daily for 1 y to nutritionally at-risk children in Pemba, Zanzibar. The effects of these treatments on attaining unassisted walking were evaluated using survival analysis for 354 children aged 5-11 mo at the start of supplementation. Treatment effects on changes in hemoglobin (Hb) and zinc protoporphyrin (ZPP) and height-for-age (HAZ) and weight-for-age (WAZ) Z scores were evaluated using linear regression. Attained motor milestone was recorded every 2 wk for 1 y. Hb, ZPP, HAZ, and WAZ were measured at baseline and after 6 mo of treatment. FeFA with or without Zn reduced the time it took for children to walk assisted. Children who received any iron walked unassisted sooner than those who received no iron [median difference approximately 15 d, P = 0.035, risk ratio (RR) = 1.28, 95% CI = 1.02, 1.61] and this effect was stronger in those who had iron deficiency anemia (IDA) at baseline (median difference was approximately 30 d; P = 0.002; RR = 1.68; 95% CI = 1.21, 2.32). FeFA alone and Zn alone improved Hb and ZPP compared with placebo. There were no significant treatment effects on changes in HAZ or WAZ. The effects of treatment on time to walking may have been mediated by improvements in iron status or hemoglobin, but were not mediated through improvements in growth.

Iron deficiency and physical growth predict attainment of walking but not crawling in poorly nourished Zanzibari infants.

Locomotion allows infants to explore their environment, promoting development in other domains. Motor progression involves biological systems and experiential factors. Nutritional deficiencies could interfere with systems involved in locomotion. This study examined the associations between height-for-age (HAZ), weight-for-height (WHZ) Z-scores and anemia-iron status on locomotion in 646 Zanzibari infants. Motor milestones were assessed by trained observers using a 14-item scale. Two mutually exclusive samples were created. The crawling sample (n = 167, 6-18 mo old) included infants that crawled only or did not crawl; the walking sample (n = 479, 9-18 mo old) included children that walked alone or did not walk alone. Of the crawling and walking samples, 82.6 and 83.9% respectively, were iron deficient and/or anemic (hemoglobin < 100 g/L; zinc protoporphyrin > or = 90 micromol/mol heme). Stunting (HAZ less than -2) occurred in 30.5% of the crawling sample and 38.4% of the walking sample. Logistic regression models estimated the influence of factors on crawling vs. not crawling or walking vs. not walking. Two models were tested: 1) included sex, age, SES, HAZ and WHZ; 2) added anemia-iron status category to Model 1. HAZ improved the odds of crawling by 30%, but was not significant in either model. Model 2 fit the walking sample data best (P < 0.0001); an increase in HAZ doubled the odds of walking and nonanemic, noniron deficient children were 66% more likely to walk than those with anemia and/or iron deficiency. In this sample of poorly nourished infants, growth and anemia-iron status are significant predictors of walking, but not crawling.