Elevated iron stores are associated with HIV disease severity and mortality among postpartum women in Zimbabwe.

OBJECTIVES: The relationship between Fe status and HIV infection is complex and poorly understood. While anaemia is a major complication of HIV infection, higher Fe stores may be associated with disease progression. There is limited and conflicting data available from Africa. DESIGN: Cross-sectional and prospective cohort study. SETTING, SUBJECTS AND METHODS: We examined the association between postpartum Fe status (Hb, serum ferritin (SF) and transferrin receptor (TfR)) and viral load (VL) and HIV-related mortality in 643 HIV-positive Zimbabwean women over a period of 12 months. RESULTS: In non-anaemic women a log10 increase in SF was associated with a 2.3-fold increase in VL (P = 0.019); this association was absent in anaemic women. In prospective analyses, a log10 increase in SF was associated with a 4-fold increase in mortality by 12 months (P = 0.002). Hb was negatively associated with VL (P = 0.001) and mortality (P = 0.047). The adverse associations between SF and both VL and mortality were found at SF concentrations > 45 microg/l (P < 0.05). Controlling for alpha1 acid glycoprotein, a marker of inflammation, attenuated the association between both SF and VL and mortality, but these remained significant. CONCLUSIONS: These results are consistent with the hypothesis that high Fe stores have adverse consequences in HIV infection. If adverse consequences are real, our data suggest that they occur at SF concentrations exceeding those consistent with adequate Fe nutriture.

[Hepcidin and Plasmodium falciparum malaria in anemic school children in Mali]. / Hepcidine et infection due a Plasmodium falciparum chez un groupe d'ecoliers anémiés du Mali.

Hepcidin is a peptide produced by hepatocytes and detectable in blood and urine. Urinary hepcidin excretion appeared to be significantly increasing in humans with acute and chronic infections or inflammatory diseases. However, the effects of common tropical parasitic infections on hepcidin have not been sufficiently examined. We carried out a study in school children from Mali living in a neighborhood where Plasmodium falciparum malaria and Schistosoma haematobium infections are prevalent. Anemia (hemoglobin < 120 g/l) prevalence was very high among these children (68%); 24% had iron deficiency anemia. The prevalence of infections was also high (65% had at least one infection and 41% had C-reactive protein (CRP) levels > 10 mg/L). S. haematobium was diagnosed in 64%. We assessed first morning urine hepcidin excretion in a sub-sample of 15 children with either S. haematobium, P. falciparum malaria or none; 14 of these 15 children were included in the analyses. Children with P. falciparum malaria excreted significantly higher levels of hepcidin than those with S. haematobium (chi2 = 3.86; p = 0.05) or without any infection (chi2 = 5.95; p = 0.01). Urinary hepcidin correlated significantly with CRP (Spearman's r = 0.59; p = 0.001) and serum ferritin (Spearman's r = 0.73; p = 0.003). Our study confirms the still limited evidence of an association between human malaria and increased urinary hepcidin and points out the need for further studies to define the contribution of hepcidin to anemia associated with this disease.

Epidemiology of anemia among 4- to 17-month-old children living in south central Nepal.

OBJECTIVE: To describe the distribution of hemoglobin and prevalence of anemia in Nepali children living in the Terai region by potential risk factors for deficiency. DESIGN: This was a cross-sectional, community-based study of baseline characteristics of children enrolled in a randomized, placebo-controlled clinical trial between January and March 2002. Participants were weighed and measured and had their blood drawn. Their mothers contributed demographic, morbidity, and feeding data. SUBJECTS: There were 569 4- to 17-month-old children. Statistical models were based on 490 children. RESULTS: Anemia was prevalent: 58% of the children had a hemoglobin <105 g/l. Iron-deficiency anemia (anemia with erythrocyte protoporphyrin (EP) > or =90 micromol/mol heme) was present in 43% of the children. Severe anemia was rare: less than 2% of the children had a hemoglobin <70 g/l. The mean (s.d.) hemoglobin concentration was 101 (12.5) g/l. Stunting and wasting were prevalent: 30.8% were stunted (length-for-age Z-score <-2) and 18.1% were wasted (weight-for-length Z-score <-2). Bivariate analyses revealed that age, caste, socioeconomic status, dietary diversity, stunting, and underweight were associated with hemoglobin concentration and/or anemia. In multivariate models with and without EP, age and caste were found to be strong predictors of both hemoglobin concentration and anemia. CONCLUSIONS: Anemia and iron deficiency increased strongly with age and low-caste status among the study children. The data reveal the importance of targeting interventions to children in the first year of life before they become anemic and iron deficient.

Measurement of blood loss at childbirth and postpartum.

OBJECTIVE: To accurately measure blood loss during childbirth in a developing country. METHOD: The alkaline hematin technique was used to quantify blood lost during delivery and 24 h postpartum in 158 women in Pemba Island, Zanzibar. RESULT: Women were found to lose less blood during childbirth and 24 h postpartum than previously reported. Compared with laboratory values, nurse-midwives approximated blood loss accurately (mean difference, i.e., mean underestimation by nurse-midwives, 4.90 mL); however, their imprecision was greater for higher laboratory values. CONCLUSION: This study may prompt further investigation, as no comparable data exist for developing countries where maternal mortality is high and severe anemia prevalent.

Delta-aminolevulinic Acid dehydratase genotype and its relationship with blood lead and zinc protoporphyrin levels in lead-exposed children living in a smelter community in northern Mexico.

The implications of delta-aminolevulinic acid dehydratase (ALAD) polymorphism for lead kinetics and toxicity have been mainly studied in occupationally exposed adults. Therefore, our purpose was to evaluate the distribution of ALAD genotype and its association with biomarkers of exposure (PbB levels) and effect (Blood ZPP) among children living in a smelter community in Mexico. We recruited 569 children from nine elementary schools close to a smelter site. PbB was determined by electrothermal atomic absorption spectrometry. A polymerase chain reaction (PCR)-based protocol was used for ALAD genotyping. Zinc protoporphyrin (ZPP) in blood was measured by direct fluorometry. Most children (93.15%) were homozygous for ALAD (1-1), 6.67% were heterozygous for ALAD for (1-2), and one child was homozygous for ALAD (2-2). There was an increased proportion of ALAD (1-2/2-2) genotype with respect to PbB levels. The ZPP geometric mean was slightly higher in ALAD (1-1) genotype children (63.48 mu mol ZPP/mol Hb) than in those having the ALAD-2 genotype (58.22 mu mol ZPP/mol Hb; p = 0.051). Linear and quadratic models showed significant relationships between ZPP and PbB. A significant increase in the odds ratio (OR) for the effect of lead exposure on ZPP levels was observed for ALAD (1-1) children having PbB values above 20 mu g/dL, as compared to those having PbB levels below 10 mu g/dL (OR = 2.95, 95% CI = 1.45-5.97; p = 0.003), whereas no significant increases were observed for the ALAD (1-2/2-2) children. In summary, our results suggest that heme biosynthesis was less affected in ALAD (1-2/2-2) lead-exposed children than in those carrying the ALAD (1-1) genotype.

Hyporetinolemia, illness symptoms, and acute phase protein response in pregnant women with and without night blindness.

We examined the association among elevations in acute phase proteins, reported illness, and hyporetinolemia in 234 pregnant Nepali women with (cases) and without (controls) night blindness. Serum alpha1-acid glycoprotein (AGP) and C-reactive protein (CRP) were inversely associated with serum retinol concentrations. Elevations in the concentration of CRP in both cases and controls and of AGP in cases were associated with significant reductions (approximately 0.2-0.3 micromol/L) in serum retinol. The risk of a low serum retinol concentration (< 0.7 micromol/L) with elevated AGP (> or = 1 g/L) and CRP (> or = 5 mg/L) concentrations was significantly higher in cases (odds ratios = 8.6 and 4.3, respectively) than in controls (odd ratios = 1.9 and 2.4, respectively). A 7-d morbidity history indicated that cases were significantly more likely than controls to report symptoms of infections of the urinary, reproductive, and gastrointestinal tracts. Only a few of these symptoms (diarrhea, nausea, and vomiting) were significantly associated with low serum retinol concentrations. Illness in the previous week and elevated CRP or AGP concentrations were synergistically associated with lower serum retinol. For example, the reduction in serum retinol in women with diarrhea and elevated AGP was 0.54 micromol/L, compared with a reduction of 0.03 micromol/L in those with diarrhea only. AGP and CRP may provide useful information about the effect of reported illness on hyporetinolemia in pregnancy. Infection-related hyporetinolemia may predispose women to night blindness during pregnancy in Nepal.

Conjunctival impression cytology as an indicator of vitamin A status in lactating Indonesian women.

Conjunctival impression cytology (CIC) has been used to assess the vitamin A status of children but not women. We used CIC in a randomized controlled trial of high-dose vitamin A supplementation in Indonesian women. We report its association with biochemical indicators and evaluate its usefulness for several assessment functions, using two definitions for abnormal CIC. Serum retinol concentrations of all women and milk vitamin A concentrations of unsupplemented women decreased with worsening CIC category. CIC indicated risk of low milk vitamin A and low infant serum retinol with low sensitivity and high specificity. CIC did not identify women who benefited from supplementation. The usefulness of CIC to measure response to supplementation was limited by the low prevalence of abnormal status in these women. CIC may be a useful indicator of vitamin A deficiency in women or their breast-fed infants, or to measure response to supplementation, when a more sensitive cutoff point for abnormal status is used.

Epidemiology of iron deficiency anemia in Zanzibari schoolchildren: the importance of hookworms.

Anemia is estimated to affect one-half of school-age children in developing countries. The school years are an opportune time to intervene, and interventions must be based on sound epidemiologic understanding of the problem in this age group. We report on the distribution of iron deficiency and anemia across age, sex, anthropometric indexes, and parasitic infections in a representative sample of 3595 schoolchildren from Pemba Island, Zanzibar. Iron status was assessed by hemoglobin, erythrocyte protoporphyrin (EP), and serum ferritin concentrations from a venous blood sample. Overall, 62.3% of children were anemic (hemoglobin < 110 g/L), and 82.7% of anemia was associated with iron deficiency. The overall prevalence of iron-deficient erythropoiesis (EP > 90 mumol/mol heme) was 48.5%, and the prevalence of exhausted iron stores (serum ferritin < 12 micrograms/L) was 41.3%. In bivariate analyses, iron status was slightly better in girls than in boys, and was better in children aged 7-11 y than in those older or younger. Hemoglobin but not EP or serum ferritin concentrations were lower in stunted children. Infection with malaria, Trichuris trichiura, Ascaris lumbricoides, and hookworms were all associated with worse iron status; the association with hookworms was strongest by far. In multivariate analyses, hookworm infection intensity was the strongest explanatory variable for hemoglobin, EP, and serum ferritin. Sex, malarial parasitemia, A. lumbricoides infection, and stunting were also retained in the multivariate model for hemoglobin. Twenty-five percent of all anemia, 35% of iron deficiency anemia, and 73% of severe anemia were attributable to hookworm infection; < 10% of anemia was attributable to A. lumbricoides, malaria infection, or stunting. We conclude that anthelminthic therapy is an essential component of anemia control in schoolchildren in whom hookworms are endemic, and should be complemented with school-based iron supplementation.

Effects of the Zanzibar school-based deworming program on iron status of children.

We evaluated the effects of the Zanzibar school-based deworming program on the iron status of primary school children. Parasitologic and nutritional assessments were carried out at baseline, 6 mo, and 12 mo in 4 nonprogram schools (n = 1002), 4 schools in which students received twice-yearly deworming (n = 952), and 4 schools in which students received thrice-yearly deworming (n = 970) with 500 mg generic mebendazole. Schools were randomly selected for evaluation and allocated to program groups. Relative to no treatment, thrice-yearly deworming caused significant decreases in protoporphyrin concentrations and both deworming regimens caused marginally significant increases in serum ferritin concentrations. The average annual changes in protoporphyrin concentrations were -5.9 and -23.5 micromol/mol heme in the control and thrice-yearly deworming groups, respectively (P < 0.001). The average changes in ferritin concentration were 2.8 and 4.5 microg/L, respectively (P = 0.07). Deworming had no effect on annual hemoglobin change or prevalence of anemia. However, the relative risk of severe anemia (hemoglobin < 70 g/L) was 0.77 (95% confidence limits: 0.39, 1.51) in the twice-yearly deworming group and 0.45 (0.19, 1.08) in the thrice-yearly deworming group. The effects on prevalence of high protoporphyrin values and incidence of moderate-to-severe anemia (hemoglobin < 90 g/L) were significantly greater in children with > 2000 hookworm eggs/g feces at baseline. We estimate that this deworming program prevented 1260 cases of moderate-to-severe anemia and 276 cases of severe anemia in a population of 30,000 schoolchildren in 1 y. Where hookworm is heavily endemic, deworming programs can improve iron status and prevent moderate and severe anemia, but deworming may be needed at least twice yearly.

Evaluation of serum retinol, the modified-relative-dose-response ratio, and breast-milk vitamin A as indicators of response to postpartum maternal vitamin A supplementation.

BACKGROUND: Conflicting results have been reported regarding the relative performance of serum retinol, the modified-relative-dose-response (MRDR) ratio, and breast-milk vitamin A concentrations in detecting changes in maternal vitamin A status. OBJECTIVE: We used receiver operating characteristic analyses and standardized differences to compare the ability of these indicators to detect a response to postpartum vitamin A supplementation in lactating Bangladeshi women. DESIGN: At 2 wk postpartum, women were randomly assigned to receive either a single dose of vitamin A [200000 IU (60000 retinol equivalents); n = 74] or placebo (n = 73). Data from maternal serum and breast milk collected 3 mo postpartum and from infant serum collected 6 mo postpartum were used to examine the ability of serum retinol, the MRDR ratio, and breast-milk vitamin A to discriminate between individuals in the supplemented and unsupplemented groups. Breast milk was collected by expressing the entire contents of one breast that had not been used to feed an infant for > or =2 h (full samples) or without controlling the time since the last breast-feeding episode (casual samples). RESULTS: Casual breast-milk samples performed better than full breast-milk samples in detecting a response to maternal supplementation. The MRDR ratio performed better than serum retinol in both the women and their infants. Overall, the most responsive indicator was the measurement of breast-milk vitamin A per gram of fat in casual breast-milk samples. CONCLUSIONS: Breast-milk vitamin A and the MRDR ratio are responsive indicators of vitamin A status, especially in women with mild vitamin A deficiency.

Vitamin A supplementation selectively improves the linear growth of indonesian preschool children: results from a randomized controlled trial.

BACKGROUND: Vitamin A deficiency is associated with stunting and wasting in preschool children, but vitamin A supplementation trials have not shown a consistent effect on growth. OBJECTIVE: We examined the effect of vitamin A supplementation on height and weight increments among Indonesian preschool children. DESIGN: Data were obtained from a randomized, double-masked, placebo-controlled trial of rural Javanese children aged 6-48 mo. Children received 206000 IU vitamin A (103000 IU if aged <12 mo) or placebo every 4 mo. RESULTS: High-dose vitamin A supplementation modestly improved the linear growth of the children by 0.16 cm/4 mo. The effect was modified by age, initial vitamin A status, and breast-feeding status. Vitamin A supplementation improved height by 0.10 cm/4 mo in children aged <24 mo and by 0.22 cm/4 mo in children aged >/=24 mo. The vitamin A-supplemented children with an initial serum retinol concentration <0.35 micromol/L gained 0.39 cm/4 mo more in height and 152 g/4 mo more in weight than did the placebo group. No growth response to vitamin A was found among children with an initial serum retinol concentration >/=0.35 micromol/L. In non-breast-fed children, vitamin A supplementation improved height by 0.21 cm/4 mo regardless of age. In breast-fed children, vitamin A supplementation improved linear growth by approximately 0.21 cm/4 mo among children aged >/=24 mo, but had no significant effect on the growth of children aged <24 mo. CONCLUSION: High-dose vitamin A supplementation improves the linear growth of children with very low serum retinol and the effect is modified by age and breast-feeding.

Evaluation of indicators for use in vitamin A intervention trials targeted at women.

This paper examines the ability of three indicators to detect changes in women's vitamin A status. Serum retinol concentration, milk vitamin A concentration, and milk vitamin A per gram milk fat were used to assess the vitamin A status of mildly deficient Indonesian women before and after supplementation in a randomized intervention trial. Choice of indicator made a fourfold difference in the sample size required to measure a statistically significant change in vitamin A status. Milk vitamin A per gram milk fat was the best indicator of response, milk vitamin A concentration was intermediate, and serum retinol concentration performed most poorly. Serum retinol concentration was equally responsive across the range of vitamin A status in this population. The milk indicators were more responsive among women of lower status than women of higher status. Milk vitamin A is an efficient indicator for monitoring the effects of vitamin A interventions in women.

PIP: Vitamin A deficiency adversely affects child survival. In order to develop and evaluate vitamin A interventions, however, good indicators of vitamin A status are needed. The authors used serum retinol concentration, milk vitamin A concentration, and milk vitamin A per gram milk fat to assess the vitamin A status of 153 lactating, mildly deficient Indonesian women before and after supplementation in a randomized intervention trial. Milk vitamin A per gram milk fat was the best indicator of response, milk vitamin A concentration was the 2nd best, and serum retinol concentration was equally responsive across the range of vitamin A status in the population. Furthermore, these milk indicators were more responsive among women of lower status than among women of higher status. The authors conclude on the basis of these findings that milk vitamin A is an efficient indicator for monitoring the effects of vitamin A intervention is women.

A controlled evaluation of two school-based anthelminthic chemotherapy regimens on intensity of intestinal helminth infections.

BACKGROUND: School-based deworming programmes have been promoted as a cost-effective strategy for control of nematode infection in developing countries. While numerous efficacy studies have been conducted, there is little information on actual programme effectiveness in areas of intense transmission. METHODS: A randomized trial of a school-based deworming programme was conducted in 12 primary schools on Pemba Island, Zanzibar. Four schools each were randomized to control, twice a year deworming with single dose mebendazole or three times a year deworming. Baseline and 12-month follow-up data on helminth infection using the Kato-Katz technique, demographic information and nutritional status were collected on 3028 children from March 1994 to May 1995. RESULTS: Intensity of infection measured as eggs per gram of faeces (epg) declined significantly for Ascaris lumbricoides, Trichuris trichiura and hookworm infections in both treatment groups. A. lumbricoides infection intensity declined 63.1% and 96.7% in the twice and three times per year treatment groups compared to the controls. T. trichiura infection intensity declined 40.4% and 75.9% respectively and hookworm intensity declined 35.3% and 57.2% respectively compared to control schools. CONCLUSIONS: These results suggest that school-based programmes can be a cost-effective approach for controlling the intensity of intestinal helminth infection even in environments where transmission is high.

Respiratory infections reduce the growth response to vitamin A supplementation in a randomized controlled trial.

BACKGROUND: Studies on the effect of vitamin A supplementation on growth have yielded various results. It is possible that such growth is dependent on the burden of infectious diseases in the population. METHODS: We analysed data from a randomized, double-masked, placebo-controled trial to examine the role of respiratory infections and diarrhoea in modifying the growth response to vitamin A supplementation. A single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months, and 4430 child treatment cycles were used in this analysis. RESULTS: Vitamin A supplementation modestly improved linear but not ponderal growth of children who experienced little respiratory infection and especially of those who had vitamin A intake below the normative requirement (<400 RE/day). Children who received vitamin A and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height than the placebo group, but those with > or =21.5% of days of respiratory infection did not show a significant growth response to vitamin A supplementation. Children who experienced no respiratory infection and had vitamin A intake <400 RE/day benefited most, gaining 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height compared to the placebo group. Diarrhoea was associated with poorer growth, but did not significantly modify the effect of vitamin A supplementation on growth. CONCLUSIONS: Vitamin A supplementation improves the linear growth of children who have a low intake of vitamin A but this impact is muted with increasing levels of respiratory infections.

PIP: This randomized, double-masked, placebo-controlled trial study examined the role of respiratory infections and diarrhea in modifying the growth response to vitamin A supplementation. A total of 1405 children aged 6-48 months were given a single high dose of vitamin A or placebo every 4 months, and 4430 child treatment cycles were used in this analysis. The study was conducted in two rural subdistricts located on the southern coast of central Java, Indonesia. Analytic findings indicate that vitamin A supplementation resulted in a modest improvement in the linear and not in the ponderal growth of children. Those who had an adequate intake of 400 RE/day and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height. Conversely, there were no significant growth responses to vitamin A supplementation among children with 21.5% of days or higher of respiratory infection. In addition, children who experienced no respiratory infection and had vitamin A intake below the normative requirement (400 RE/day) gained 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height than the placebo group. Moreover, diarrhea was associated with poorer growth but did not modify the effect of vitamin A supplementation on growth. In conclusion, vitamin A supplementation improves linear growth in children but not among those with a high prevalence of respiratory infections.

Epidemiological evidence for a differential effect of hookworm species, Ancylostoma duodenale or Necator americanus, on iron status of children.

BACKGROUND: The hookworms, Ancylostoma duodenale and Necator americanus, cause significant gastrointestinal blood loss. In clinical studies, greater blood losses have been reported with A. duodenale. However, there has been no evidence that endemic A. duodenale infection has greater impact than N. americanus infection on the iron status of populations. METHODS: In a sample of 525 school children in Pemba Island, Tanzania, we compared the degree of anaemia and iron deficiency associated with the two hookworm species at the individual and community (i.e. school) levels. Multiple regression was used to control for infection intensities and other child characteristics. RESULTS: In the 492 children with hookworm positive faecal cultures, haemoglobin and ferritin concentrations decreased with increasing proportions of A. duodenale. Among children with only N. americanus larvae, the prevalence of anaemia was 60.5 % and the prevalence of ferritin <12 microg/l was 33.1%, while in children with > or =50% A. duodenale larvae, the respective prevalences were 80.6% and 58.9%. When children were grouped by the prevalence of A. duodenale at the school level, children from high prevalence (> or =20%) schools had significantly worse iron deficiency and anaemia than children from low prevalence schools. CONCLUSIONS: The species of hookworm being transmitted in a community influences the burden of iron deficiency anaemia in the community, and should be considered in prioritizing and planning programmes for hookworm and anaemia control.

PIP: Hookworms infect 1.3 billion people annually. Iron-deficiency anemia caused or exacerbated by intestinal blood loss is the major feature of hookworm infection, with such loss caused by the feeding of hookworms upon the intestinal mucosa. The hookworms Ancylostoma duodenale and Necator americanus cause major gastrointestinal blood loss. While relatively greater blood loss has been reported in clinical studies due to infection with A. duodenale, there has been no evidence that endemic A. duodenale infection has a greater impact than N. americanus infection upon the iron status of populations. The authors compared the degree of anemia and iron deficiency associated with these 2 hookworm species at the individual and community levels using a sample of 525 school children in grades 1-4 in Pemba Island, Tanzania, and controlling for infection intensities and other child characteristics through multiple regression. In the 492 children with hookworm-positive fecal cultures, hemoglobin and ferritin concentrations decreased with increasing proportions of A. duodenale. Among children with only N. americanus larvae, the prevalence of anemia was 60.5% and the prevalence of ferritin under 12 mcg/l was 33.1%. In children with 50% or higher proportions of A. duodenale larvae, the respective prevalences were 80.6% and 58.9%. Children from schools with high prevalences of A. duodenale infection had significantly worse iron deficiency and anemia than did children from low prevalence schools.

Hookworm control as a strategy to prevent iron deficiency.

The hookworms Necator americanus and Ancylostoma duodenale infect approximately 1 billion people worldwide. The prevalence of hookworm infection increases with age in children, typically reaching a plateau in late adolescence, whereas the intensity of infection may continue to increase throughout adulthood. Hookworms cause intestinal blood loss in amounts proportional to the number of adult worms in the gut. The relationship between hookworm infection intensity and hemoglobin concentration is evident in epidemiologic studies, but may be apparent only above a threshold worm burden that is related to the iron stores of the population. Current hookworm control efforts are focused on reducing infection load and transmission potential through periodic anthelminthic chemotherapy. Several controlled trials have demonstrated a positive impact of anthelminthic treatment on hemoglobin levels, with best results obtained in settings where iron intakes were also increased. Evidence suggests that anthelminthic programs will have modest impacts on iron deficiency anemia in the short term, with greater impacts on more severe anemia. Hookworms are an important cause of anemia in women, who are often overlooked by current helminth control programs. Current WHO recommendations for use of anthelminthics in schoolchildren and women are reviewed. There is a need to clarify whether hookworms are an important etiology of iron deficiency anemia in preschool children.

Determinants of gestational weight gain outside the recommended ranges among black and white women.

OBJECTIVES: To identify factors influencing risk of gaining outside the Institute of Medicine recommendations for pregnancy weight gain, and to determine whether these factors differ by race. METHODS: Multivariate methods were used to identify risk factors for under- and over-gain among 2617 black and 1253 white women delivering at the Johns Hopkins Hospital during 1987-1989. RESULTS: Only 28.2% of black women and 32.5% of white women gained the recommended amounts of weight during pregnancy. Maternal pre-pregnancy body mass index (BMI), height, parity, education, smoking, hypertension, duration of pregnancy, and fetal sex influenced risk for under-gain or over-gain. Black women were 1.51 (95% confidence interval [CI] 1.23-1.85) times more likely to under-gain, but 0.89 (95% CI 0.74-1.08) times less likely to over-gain than white women. No interactions were found between any factor examined and BMI or race. CONCLUSION: Only about one-third of women are gaining the recommended amounts of weight during pregnancy. Black women are at increased risk for gaining less weight than recommended, and selected maternal characteristics associated with race do not explain this difference. Further, risk factors for under-or over-gain do not differ between black and white women.

Influence of maternal anthropometric status and birth weight on the risk of cesarean delivery.

OBJECTIVE: To determine whether greater weight gain during pregnancy is associated with an increased risk of cesarean delivery, and, if so, whether this effect is explained by the positive influence of weight gain on birth weight and if there is a threshold of pregnancy weight gain above which the risk of cesarean delivery is increased differentially. METHODS: We analyzed live births at Johns Hopkins Hospital for the period 1987-1989. A multiple logistic regression model was used to evaluate the risk of cesarean delivery, recorded in the hospital's perinatal data base. RESULTS: The study sample contained 4346 patients, 1086 of whom delivered by cesarean. Associated independently with an increased risk of cesarean delivery were the following: 1) greater weight gain during pregnancy, 2) older maternal age, 3) greater maternal prepregnant body mass index, 4) maternal height of 1.57 m or less, 5) the diagnosis of preeclampsia during current pregnancy, and 6) carrying a fetus weighing more than 3591 g at birth. An additional risk factor for cesarean delivery was a fetus less than 2847 g at birth, with the risk more marked the lower the gestational age. Maternal height of 1.73 m or more and a history of at least one previous viable pregnancy were associated independently with a decreased risk of cesarean delivery. CONCLUSION: The risk of cesarean delivery increases linearly with pregnancy weight gain, independent of birth weight. No specific threshold of weight gain can be determined above which the cesarean risk climbs more rapidly.

Hemoquant determination of hookworm-related blood loss and its role in iron deficiency in African children.

Iron deficiency remains the most prevalent form of human malnutrition, and current interventions to control it have not decreased the global prevalence. Hookworm control activities are becoming more widely implemented, but the importance of these efforts to prevent anemia in populations is not well-defined. We studied the relationships among hookworm infection, intestinal blood loss, and iron status of 203 Zanzibari school children. Helminth infection intensity was quantified by fecal egg counts, and iron deficiency anemia was defined by low hemoglobin and serum ferritin concentrations. Intestinal blood loss was quantified by measuring fecal heme and heme breakdown products as porphyrin, a noninvasive method that has not been used previously to assess hookworm blood loss. Intestinal blood loss was strongly and linearly related to hookworm egg counts. The degree of degradation of fecal heme indicated that blood loss occurred in the upper gastrointestinal tract, compatible with the behavior of hookworms. Trichuris trichiura and Ascaris lumbricoides infections were also common, but did not contribute significantly to intestinal blood loss in this population. The prevalence of iron deficiency anemia increased steadily as hookworm infection intensity and intestinal blood loss increased. In the context of a poor diet, as exists in Zanzibar and many tropical countries, hookworm-related blood loss contributes dramatically to anemia. In such contexts, hookworm control is a feasible and essential component of anemia control. Determination of fecal heme is relatively simple and noninvasive and may be a useful tool for measuring the impact of hookworm control activities.

Ancylostoma duodenale is responsible for hookworm infections among pregnant women in the rural plains of Nepal.

Fecal specimens from 292 pregnant women (ages 15-40 yr) and 129 infants (ages 10-20 wk) were examined for helminth eggs by the Kato-Katz method and cultured for helminth larvae identification using a modified Harada Mori method. These specimens were collected from June 1995 through July 1996 in Sarlahi District in the southern rural plains of Nepal. Among pregnant women, the prevalence of helminth infection by the Kato-Katz method was 78.8%, 56.2%, and 7.9% for hookworm, Ascaris lumbricoides, and Trichuris trichiura, respectively. Using the modified Harada-Mori method, 66.1% and 2.0% of women's fecal cultures were positive for hookworm and Strongyloides stercoralis, respectively. All of the cultured hookworm larvae were identified as Ancylostoma duodenale. Among infants, 1 specimen was positive for hookworm and 1 for A. lumbricoides using the Kato-Katz method. The modified Harada Mori method detected no larvae in specimens from infants. There was 81.8% agreement between the 2 methods for the detection of hookworm infection. Ancylostoma duodenale is endemic in this study population and highly prevalent in pregnant women.