The effect of weekly iron and vitamin A supplementation on hemoglobin levels and iron status in adolescent schoolgirls in western Kenya.

BACKGROUND/OBJECTIVES: Iron deficiency anemia is a major public health problem in developing countries and may affect school performance and physical work capacity in nonpregnant adolescents, and may increase the risk of anemia during subsequent teenage pregnancies. We assessed the effect of weekly iron (120 mg elemental iron) and vitamin A (25 000 IU) supplementation on hemoglobin, iron status and malaria and nonmalaria morbidity in adolescent schoolgirls. SUBJECTS/METHODS: A total of 279 schoolgirls aged 12-18 years from public primary schools in Kisumu, western Kenya. Double-blind randomized placebo-controlled trial using a factorial design. RESULTS: Five months of iron supplementation was associated with a 0.52 g dl(-1) (0.21, 0.82) greater increase in hemoglobin relative to iron placebo. The effect was only observed in girls with iron deficiency on enrollment (1.34 g dl(-1) (0.79, 1.88)), but not in iron-replete girls (-0.20 g dl(-1) (-0.59, 0.18)). Similar differences in treatment effect were seen between menstruating and nonmenstruating girls. The effect of iron was independent of vitamin A. The baseline prevalence of vitamin A deficiency was low (6.7%) and no sustained increase in hemoglobin was seen with weekly vitamin A (-0.07 g dl(-1) (-0.38, 0.25)). Incidence of malaria parasitemia was higher in the iron than iron-placebo groups (Rate ratio 1.33 (0.94, 1.88)). CONCLUSIONS: Weekly iron supplementation results in substantial increases in hemoglobin concentration in adolescent schoolgirls in western Kenya, which may outweigh possible risks caused by malaria, but only in iron-deficient or menstruating girls and not in iron-replete and nonmenstruating girls.

Prevalence and severity of malnutrition and age at menarche; cross-sectional studies in adolescent schoolgirls in western Kenya.

OBJECTIVE: Nutritional status is an important marker of overall health and linear growth retardation has serious long-term physiological and economic consequences. Approximately 35 and 29% of preschool children in sub-Saharan Africa are stunted and underweight, respectively. There is relatively little information available about the nutritional status in adolescents, the age group with the highest growth velocity after infancy. We conducted a series of cross-sectional surveys to determine the prevalence and main risk groups for malnutrition and to describe the associations between age, sexual maturation and nutritional status in adolescent schoolgirls in western Kenya. DESIGN: Three cross-sectional surveys; one in Mumias, using random sampling in all schools, and two surveys in Asembo, using a multi-stage random sample design. SETTING: Public primary schools in two different rural malaria endemic areas in western Kenya with high levels of malnutrition in preschool children. SUBJECTS: In all, 928 randomly selected adolescent schoolgirls aged 12-18 y. RESULTS: Overall prevalence of stunting and thinness was 12.1 and 15.6%, respectively. Of the total, 2% were severely stunted. Menarche and start of puberty were delayed by approximately 1.5-2 y compared to a US reference population. The prevalence of stunting and thinness decreased with age and mean height for age z-scores converged towards the median of the US reference curve. Girls who had not yet started menstruating were more likely to be stunted than the girls of the same age who were post-menarche. CONCLUSIONS: Stunting and thinness are common in young adolescent schoolgirls in these poor rural settings in western Kenya, but the prevalence decreases with age, providing observational support that children catch up on incomplete growth attained earlier in life due to a maturational delay of 1.5-2 y allowing prolonged growth.

Prevalence and severity of anemia and iron deficiency: cross-sectional studies in adolescent schoolgirls in western Kenya.

OBJECTIVE: Anemia is a major public health concern in preschool children and pregnant women in the developing world. While many studies have examined these two at-risk groups, there is a paucity of data on anemia in adolescents living in developing countries in the complex ecologic context of poverty, parasitism, and malnutrition. We evaluated the prevalence, severity, and risk factors of anemia in adolescent schoolgirls in an area with intense malaria transmission in western Kenya. DESIGN: Two cross-sectional surveys were conducted, using a multistage random sample design. SETTING: Public primary schools in an area with intense malaria transmission in western Kenya. SUBJECTS: A total of 648 randomly selected adolescent schoolgirls aged 12-18 y. RESULTS: The prevalence of anemia (Hb <120 g/l) was 21.1%; only one girl had an Hb less than 70 g/l. Ferritin levels were available from a subsample of 206 girls. The prevalence of iron deficiency (ferritin <12 microg/l) was 19.8, and 30.4% of anemic girls were iron deficient. Malaria and schistosomiasis were the main risk factors for anemia in younger girls (12-13 y), while menstruation was the principal risk factor in older girls (14-18 y). CONCLUSIONS: Iron deficiency and anemia in school-attending girls in western Kenya were more prevalent than in developed countries, but considerably less prevalent than in preschool children and pregnant women from the same study area. Our findings are consistent with other recent school-based surveys from western Kenya, but not with recent community- and school-based cross-sectional surveys from other parts of sub-Saharan Africa. It deserves further study to determine if adolescent girls not attending school are at higher risk of anemia.

Recognition of pallor associated with severe anaemia by primary caregivers in western Kenya.

OBJECTIVES: To explore which pallor signs and symptoms of severe anaemia could be recognized by primary caregivers following minimal instructions. METHODS: Data from three community-based cross-sectional surveys were used. Test characteristics to predict haemoglobin (Hb) concentrations < 5 and < 7 g/dl were compared for different combinations of pallor signs (eyelid, tongue, palmar and nailbed) and symptoms. RESULTS: Pallor signs and haemoglobin levels were available for 3782 children under 5 years of age from 2609 households. Comparisons of the sensitivity and specificity at a range of haemoglobin cut-offs showed that Hb < 5 g/dl was associated with the greatest combined sensitivity and specificity for pallor at any anatomical site (sensitivity = 75.6%, specificity = 63.0%, Youden index = 38.6). Higher or lower haemoglobin cut-offs resulted in more children being misclassified. Similar results were obtained for all individual pallor sites. Combining a history of soil eating with pallor at any site improved the sensitivity (87.8%) to detect Hb < 5 g/dl with a smaller reduction in specificity (53.3%; Youden index 41.1). Other combinations including respiratory signs or poor feeding resulted in lower accuracy. CONCLUSION: Primary caregivers can recognize severe anaemia (Hb < 5 g/dl) in their children, but only with moderate accuracy. Soil eating should be considered as an additional indicator of severe anaemia. The effect of training caretakers to improve recognition of severe anaemia and care-seeking behaviour at the household level should be assessed in prospective community-based studies.