Mucosal lactoferrin response to genital tract infections is associated with iron and nutritional biomarkers in young Burkinabé women

BACKGROUND/OBJECTIVES

The iron-binding affinity of vaginal lactoferrin (Lf) reduces iron available to genital pathogens. We describe host reproductive, nutritional, infection and iron biomarker profiles affecting vaginal Lf concentration in young nulliparous and primigravid women in Burkina Faso.

SUBJECTS/METHODS

Vaginal eluates from women who had participated in a randomized, controlled periconceptional iron supplementation trial were used to measure Lf using a competitive double-sandwich ELISA. For this analysis samples from both trial arms were combined and pregnant and non-pregnant cohorts compared. Following randomization Lf was measured after 18 months (end assessment) for women remaining non-pregnant, and at two antenatal visits for those becoming pregnant. Associations between log Lf levels and demographic, anthropometric, infection and iron biomarker variables were assessed using linear mixed models.

RESULTS

Lf samples were available for 712 non-pregnant women at end assessment and for 303 women seen at an antenatal visit. Lf concentrations of pregnant women were comparable to those of non-pregnant, sexually active women. Lf concentration increased with mid-upper-arm circumference, (P = 0.047), body mass index (P = 0.018), Trichomonas vaginalis (P < 0.001) infection, bacterial vaginosis (P < 0.001), serum C-reactive protein (P = 0.048) and microbiota community state types III/IV. Adjusted Lf concentration was positively associated with serum hepcidin (P = 0.047), serum ferritin (P = 0.018) and total body iron stores (P = 0.042). There was evidence that some women maintained persistently high or low Lf concentrations from before, and through, pregnancy.

CONCLUSION

Lf concentrations increased with genital infection, higher BMI, MUAC, body iron stores and hepcidin, suggesting nutritional and iron status influence homeostatic mechanisms controlling vaginal Lf responses.

Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen

OBJECTIVES

To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD).

METHODS

Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined.

RESULTS

Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1).

CONCLUSION

This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains.

Risk factors for fetal anaemia in a malarious area of Malawi

The prevalence of infants born with low cord haemoglobin (fetal anaemia) is high in areas where malaria and iron deficiency anaemia in pregnancy are common. The objective of the present study was to determine risk factors for fetal anaemia in an area of high malaria transmission in southern Malawi. A case control study was undertaken with fetal anaemia defined as cord haemoglobin (Hb) < 12.5 g/dl. Between March 1993 and July 1994, pregnant women attending the study hospitals for the first time in that pregnancy were enrolled. Data on socio-economic status, anthropometry, previous obstetric history and current pregnancy were collected. Malaria parasitaemia, Hb levels and iron status were measured in maternal blood at recruitment and delivery and in umbilical venous blood. Fetal anaemia occurred in 23.4% of babies. Mean (SD) cord Hb was 13.6 g/dl (1.83). Factors associated with fetal anaemia were: birth in the rainy season [adjusted odds ratio (AOR) 2.33, 95% CI 1.73-3.14], pre-term delivery (AOR 1.60, 1.03-2.49), infant Hb < 14 g/dl at 24 hours (AOR 2.35, 1.20-4.59), maternal Hb at delivery < 8 g/dl (AOR 1.61, 1.10-2.42) or <11 g/dl (AOR 1.60, 1.10-2.31). A higher prevalence of fetal anaemia occurred with increasing peripheral Plasmodium falciparum parasite density (p=0.03) and geometric mean placental parasite densities were higher in babies with fetal anaemia than in those without (3331 vs 2152 parasites/microl, p=0.07). Interventions should aim to reduce fetal anaemia by improving malaria and anaemia control in pregnancy and by addressing the determinants of pre-term delivery.

Utility of plasma transferrin receptor, ferritin and inflammatory markers in children with sickle cell disease

BACKGROUND

Soluble transferrin receptor (sTfR) is generally unaffected by inflammatory status, whereas ferritin increases along with acute-phase proteins. The utility of these iron biomarkers in relation to inflammatory markers in children with sickle cell disease (SCD) with differing grades of severity is unclear.

OBJECTIVES

To describe iron biomarker profiles and inflammatory responses in relation to disease severity in children with SCD.

METHODS

This cross-sectional study describes plasma levels of sTfR, ferritin, C-reactive protein (CRP) and serum amyloid A (SAA) among 102 Yemeni children with SCD in relation to clinical profiles and disease severity.

RESULTS

Median (IQR) sTfR was 58·5 mg/L (38-81), and concentration was positively correlated with reticulocyte count (r = +0·31, P = 0·002) and splenic enlargement (r = +0·20, P = 0·04), and was negatively correlated with Hb (r = -0·28, P = 0·004). Subcategories of children in a steady state were identified using ferritin and CRP cut-off values to discriminate iron status. In children in a steady state, the prevalence of iron deficiency was 25%, iron repletion 48% and marginal or normal status 27%. Ferritin concentration correlated positively with Hb and 23% of iron-deficient children had severe anaemia. CRP and SAA were increased in the steady state and were higher with acute disease complications (P<0·05 and <0·001, respectively). There was no association between sTfR or sTfR-ferritin index and inflammatory markers or disease severity score.

CONCLUSION

In SCD, elevated sTfR is related to hypererythropoietic activity and does not correlate with inflammatory status or disease severity. Iron deficiency prevalence was estimated to be 25%. A classification of iron status is proposed.

A case-control study of nutritional factors associated with chronic suppurative otitis media in Yemeni children

BACKGROUND/OBJECTIVES

Undernutrition and chronic suppurative otitis media (CSOM) in children are common in low resource settings, but there are few studies of their interactions. The aim is to evaluate nutritional factors associated with CSOM in Yemeni children.

SUBJECTS/METHODS

A case-control study of 75 children with CSOM and 74 healthy controls. Assessment included dietary history, anthropometry, haemoglobin (Hb) and serum analytes zinc (Zn), copper (Cu), selenium (Se), iron, calcium, phosphate (PO(4)) and total 25-hydroxy vitamin D (25(OH)D).

RESULTS

Cases had lower mean Z-scores for weight-for-age, weight-for-height, body mass index and mid-upper arm circumference (MUAC) (all P<0.05), and lower mean concentrations of serum Zn (P=0.032), Se (P<0.001) and calcium adjusted for albumin (P=0.026). Age-adjusted Hb and iron biomarkers did not differ between cases and controls. There was high prevalence of low serum Zn concentration (≥ 90%) and vitamin D deficiency in both cases (80%) and controls (96%). Duration of ear discharge was negatively correlated with total 25(OH)D (P=0.028), calcium adjusted for albumin (P<0.001), PO(4) (P=0.002), transferrin receptor/log ferritin ratio (P<0.001) and Cu (P<0.001), and positively correlated with child age and MUAC (both P<0.001).

CONCLUSIONS

Children with CSOM were more undernourished than controls with lower mean serum Zn, Se and calcium concentrations. Vitamin D-deficient and iron-replete children had longer duration of infection, although this association was lost with age adjustment. Trials evaluating specific micronutrients are required in order to investigate specific nutrient-infection interactions in CSOM.

Growth in children and adolescents with sickle cell disease in Yemen

BACKGROUND

Physical growth is known to be impaired in children with sickle cell disease (SCD) and the prevalence and severity vary with geographical location. The factors which contribute to this sub-optimal growth are poorly understood.

OBJECTIVES

To describe the growth status of children and adolescents with SCD in Yemen using the new WHO reference values and to assess correlation of growth indicators with disease severity and with haematological and biochemical parameters.

METHODS

A cross-sectional study of children <16 years with SCD was conducted at Al-Wahda General Teaching Hospital, Aden. Anthropometric measurements of weight, length/height, mid-upper-arm circumference (MUAC) and body mass index (BMI) were collected. Disease severity was assessed using a severity index (SI) score.

RESULTS

A total of 102 children (56 male) were included and their mean age was 7.2 years (range 6 months to 15 years). Low weight, height and BMI-for-age Z-scores (<-2 SD) were observed in 45%, 54% and 35% of children, respectively. Regression analyses indicated an association of low height-for-age with male gender (p=0.02), low weight-for-age and weight-for-height with increased age (both p<0.001), low weight-for-age with raised alkaline phosphatase (p=0.04), and low BMI with reduced plasma albumin (p=0.04). There was no correlation between growth deficits and SI or anaemia severity.

CONCLUSION

Growth is severely impaired in children and adolescents with SCD in Yemen. Growth monitoring and nutritional support should be included in their comprehensive care package.

Nutritional factors in the pathogenesis of ear disease in children: a systematic review

BACKGROUND

Ear disease is a major health problem in poorly resourced countries. The role of nutritional deficiencies in its pathogenesis and in relation to chronic suppurative otitis media (CSOM) has not been reviewed previously.

METHODS

A systematic review was undertaken using Pubmed, SCOPUS, Cinahl on Ovid, the Cochrane Database and selected medical journals, with no language restriction. Nutritional mechanisms potentially related to ear disease and CSOM risks were reviewed. All studies (observational, case-control, cohort and clinical trials including randomised controlled trials) with nutrition-related information were included. The titles and/or abstracts of all retrieved studies were reviewed and full articles were obtained for relevant studies. Exclusion criteria were multiple publication or studies which did not report nutritional information.

RESULTS

Supplementation studies using single micronutrients and vitamins to determine efficacy in reducing acute or chronic otitis media provided some evidence for an association of middle-ear pathology with deficiencies of zinc or vitamin A. Multi-micronutrient supplementation studies provided further support for a beneficial effect, although the number of studies was small and they were heterogeneous and uncontrolled. No human study was identified which specifically examined the association between copper, selenium or vitamin D status and middle-ear disease or infection.

CONCLUSION

Particularly in developing countries, research on micronutrient status and vitamin deficiency and their influence on middle-ear disease is required to improve knowledge of the pathogenesis of middle-ear infection and to determine the relevance of nutritional interventions in prevention and treatment.

Growth and nutritional status of children with homozygous sickle cell disease

BACKGROUND

Poor growth and under-nutrition are common in children with sickle cell disease (SCD). This review summarises evidence of nutritional status in children with SCD in relation to anthropometric status, disease severity, body composition, energy metabolism, micronutrient deficiency and endocrine dysfunction.

METHODS

A literature search was conducted on the Medline/PUBMED, SCOPUS, SciELO and LILACS databases to July 2007 using the keywords sickle cell combined with nutrition, anthropometry, growth, height and weight, body mass index, and specific named micronutrients.

RESULTS

Forty-six studies (26 cross-sectional and 20 longitudinal) were included in the final anthropometric analysis. Fourteen of the longitudinal studies were conducted in North America, the Caribbean or Europe, representing 78.8% (2086/2645) of patients. Most studies were observational with wide variations in sample size and selection of reference growth data, which limited comparability. There was a paucity of studies from Africa and the Arabian Peninsula, highlighting a large knowledge gap for low-resource settings. There was a consistent pattern of growth failure among affected children from all geographic areas, with good evidence linking growth failure to endocrine dysfunction, metabolic derangement and specific nutrient deficiencies.

CONCLUSIONS

The monitoring of growth and nutritional status in children with SCD is an essential requirement for comprehensive care, facilitating early diagnosis of growth failure and nutritional intervention. Randomised controlled trials are necessary to assess the potential benefits of nutritional interventions in relation to growth, nutritional status and the pathophysiology of the disease.

Community-based distribution of sulfadoxine-pyrimethamine for intermittent preventive treatment of malaria during pregnancy improved coverage but reduced antenatal attendance in southern Malawi

OBJECTIVE

To evaluate the impact of a 2-year programme for community-based delivery of sulfadoxine-pyrimethamine (SP) on intermittent preventive treatment during pregnancy coverage, antenatal clinic attendance and pregnancy outcome.

METHODS

Fourteen intervention and 12 control villages in the catchment areas of Chikwawa and Ngabu Government Hospitals, southern Malawi, were selected. Village-based community health workers were trained in information, education and counselling on malaria control in pregnancy and the importance of attending antenatal clinics and promoted these messages to pregnant women. In the intervention group community health workers also distributed SP to pregnant women.

RESULTS

In the control area, coverage of intermittent preventive treatment during pregnancy (>2 doses) was low before (44.1%) and during the intervention (46.1%). In the intervention area, coverage increased from 41.5% to 82.9% (P < 0.01). Antenatal clinic attendance (>2 visits) was maintained in control villages at above 90%, but fell in intervention villages from 87.3% to 51.5% (P < 0.01). Post-natal malaria parasitaemia prevalence fell in women from both study areas during the intervention phase (P < 0.05). Increasing the coverage of intermittent preventive treatment during pregnancy to >40% did not significantly improve maternal haemoglobin or reduce low birthweight prevalence.

CONCLUSIONS

Better coverage of community-based intermittent preventive treatment during pregnancy can lower attendance at antenatal clinics; thus its effect on pregnancy outcome and antenatal attendance need to be monitored.

A cohort study of haemoglobin and zinc protoporphyrin levels in term Zambian infants: effects of iron stores at birth, complementary food and placental malaria

OBJECTIVE

To examine zinc-protoporphyrin (ZPP) and haemoglobin levels, and to determine predictors of iron deficiency anaemia (IDA) in Zambian infants.

SUBJECTS AND METHODS

Ninety-one women and their normal birth weight (NBW) infants were followed bi-monthly during the first 6 months of life, and iron status, food intake, malaria parasitaemia and growth were monitored. At 4 months, the infants were divided into two groups, and the data were analysed according to whether or not they were exclusively breastfed.

RESULTS

Almost two-third of infants were born with low iron stores as defined by ZPP levels, and this proportion increased with age. Over 50% had developed IDA by 6 months. Exclusive breastfeeding at 4 months could be a protective factor for IDA (odds ratio (OR): 0.2; 95% confidence interval (CI): 0.0-1.1). Exclusively breastfed infants had higher haemoglobin values at 4 and 6 months (mean difference 0.6; 95% CI: 0.1-1.2 g/dl and mean difference 0.9; 95% CI: 0.2-1.7 g/dl, respectively), compared with infants with early complementary feeding. In univariate analysis, past or chronic placental malaria appeared to be a predictor of IDA at 4 and 6 months, but the significance was lost in multivariate analysis.

CONCLUSIONS

Zambian NBW infants are born with low iron stores and have a high risk to develop IDA in the first 6 months of life. Continuation of exclusive breastfeeding after 4 months is associated with a reduction of anaemia. The effect of placental malaria infection on increased risk of infant IDA could not be proven.

Maternal anaemia as an indicator for monitoring malaria control in pregnancy in sub-Saharan Africa

DESIGN

Malarial anaemia is a major problem in many developing countries and often occurs more frequently in first pregnancies, as primigravidae are more susceptible to Plasmodium falciparum malaria and are at excess risk of malarial anaemia.

OBJECTIVE AND METHODS

To analyse the excess risk of anaemia in primigravidae as a potential indicator of malaria control and exposure in pregnant women living in sub-Saharan Africa. The sensitivity, specificity and predictive values for anaemia in first compared with later pregnancies are calculated for 27 studies from malarious and 7 studies from nonmalarious areas.

SETTING

Surveys of pregnancy anaemia reported for highly malarious and nonmalarious areas.

RESULTS

In malarious areas, the weighted odds ratio for excess anaemia (haemoglobin [Hb] <11 g/dl) in primigravidae compared with multigravidae for all studies was 1.34 (95% CI 1.14-1.58). At an Hb cutoff below 8 g/dl, the weighted odds ratio was 1.79 (95% CI 1.52-2.10). In nonmalarious areas, there was no increased risk of anaemia in primigravidae with Hb below 11 g/dl (OR 0.80; 95% CI 0.63-1.90) or below 8 g/dl (OR 0.82, 95% CI 0.51-1.28).

CONCLUSIONS

In view of the consistency of results across highly malarious areas compared with nonmalarious areas, maternal anaemia has the potential to be used for surveillance of malaria control in pregnancy. Based on the analysis, an anaemia nomogram is developed for use as a surveillance indicator in malarious areas in sub-Saharan Africa.

Population attributable risk for adverse pregnancy outcomes related to smoking in adolescents and adults

BACKGROUND

Little is known about how population-attributable risks (PAR) for adverse birth outcomes due to smoking differ in adolescent and adult pregnancies.

METHODS

An analysis of community and hospital-based cross-sectional studies in Liverpool was undertaken to estimate the PAR values of low birthweight (LBW), preterm birth, and small for gestational age (SGA) births resulting from pregnancy smoking covering the period between 1983 and 2003. Maternal smoking status and pregnancy outcomes were available for a sample of 12631 women.

RESULTS

The prevalence of maternal pregnancy smoking was 40% in the community sample and 33% in adults and 40% among adolescent pregnancies in the hospital sample. The PAR values (95% CI) associated with LBW, preterm birth and SGA outcomes due to maternal pregnancy smoking in the community sample were 27% (25-30), 13% (11-15) and 25% (23-27), respectively. The PAR values in adults in the hospital sample were 29% (27-31) for LBW, 16% (14-19) for preterm birth and 28% (26-31) for SGA. The corresponding PAR values in adolescents were 39% (34-43), 12% (7-18) and 31% (23-40). The LBW risk attributed to pregnancy smoking in adolescents was significantly higher than for adults (P=0.05).

CONCLUSION

About one-third of LBW, one-quarter of SGA and one-sixth of preterm births could be attributed to maternal smoking during pregnancy. The magnitude of the problem was greater among adolescent pregnancies, among whom a sub-group of mothers with very high risk for adverse birth outcomes due to pregnancy smoking was identified.

Increased postpartum blood loss in pregnancies associated with placental malaria

OBJECTIVE

To determine the relationship of placental malaria and parity with postpartum blood loss in a malarious area of Tanzania.

METHODS

A total of 706 uncomplicated vaginal deliveries were studied at Muhimbili University Hospital, Dar es Salaam, Tanzania. Maternal age, parity, date of delivery, birth weight, presence of placental malaria, stillbirths, and delivery complications were noted. Collection and measurement of vaginal blood loss commenced immediately following birth using a plastic vinyl sheet placed underneath the mother. The bed was divided in the middle to allow the blood to drain into a bucket. Blood loss was measured for a period of 2 h following delivery.

RESULTS

In singleton births the mean postpartum blood loss was 170 mL in nulliparas and 187 mL in multiparas (p=0.017). Blood loss was 400 mL or greater in 23 women (3.4%) and 500 mL or greater in 10 women (1.5%). Mean postpartum bleeding tended to increase with maternal age, parity, and birth weight. In logistic regression the odds ratio for a blood loss of 400 mL or greater was significantly increased for women with placental malaria (3.2; 95% confidence interval, 1.1-9.0; p=0.028), after adjusting for a birth weight greater than 4000 g. Placental malaria showed a marked seasonal pattern, which corresponded to the months of peak prevalence for a postpartum blood loss of 400 mL or greater (p=0.007).

CONCLUSION

A postpartum blood loss of 400 mL or greater should be considered a possible complication of placental malaria.

Maternal smoking during pregnancy and possible effects of in utero testosterone: evidence from the 2D:4D finger length ratio

OBJECTIVES

Maternal smoking during pregnancy is linked to high fetal testosterone (FT), and an increased risk in offspring for autism, ADHD, conduct disorder, antisocial behaviour and criminal outcomes. The ratio of the length of the 2nd and 4th fingers (2D:4D) is thought to be negatively related to FT concentration, and is related to autism, hyperactivity, poor social behaviour, and physical aggression. We compare the 2D:4D ratio of children whose mothers smoked during pregnancy with the 2D:4D of children whose mother did not smoke.

METHOD

Cross-sectional survey in two primary schools. Questionnaires were distributed to 710 children and 546 were returned. Of these the 2nd and 4th digits of 520 children (259 females and 261 males) were measured. The main outcome measures were 2nd and 4th digit length, smoking history of mother and father.

RESULTS

Boys had lower mean 2D:4D than girls and right 2D:4D was lower than left. Among boys, those whose mother's smoked during pregnancy had lower right hand 2D:4D ratio than those whose mother did not smoke. The difference remained significant after the effects of age, height, weight and birth weight were removed. Other household smoking patterns were not associated with male offspring 2D:4D. Female offspring 2D:4D did not differ on the basis of maternal smoking.

CONCLUSIONS

Maternal smoking during pregnancy was associated with low right 2D:4D in children, but the effect was restricted to boys. A link between maternal smoking during pregnancy and 2D:4D supports a causal association between FT and such behaviours as hyperactivity and conduct disorder.

Estimation of effectiveness of interventions for malaria control in pregnancy using the screening method

BACKGROUND

The evaluation of the effectiveness of antimalarial drugs and bed net use in pregnant women is an important aspect of monitoring and surveillance of malaria control in pregnancy. In principle the screening method for assessing vaccine efficacy can be applied in non-vaccine settings for assessing interventions for malaria control in pregnancy.

METHODS

In this analysis field data on the proportion of placental malaria cases treated with two doses of sulphadoxine-pyrimethamine (SP) and the uptake of two doses of SP in the antenatal clinic was used in a case-coverage method to assess the protective effectiveness (PE) of intermittent preventive treatment with SP for malaria control in pregnancy. PE was assessed using placental malaria, low birthweight and maternal anaemia at delivery as outcome variables. The method was also applied to an evaluation of the protective effectiveness of self-reported use of impregnated bed nets (ITNs).

RESULTS

Effectiveness was highest for reduction of low birthweight in multigravidae (87.2%, 95% CI, 83.2-91.3%). PE was lower for placental malaria (61.6% primigravidae, 28.5% multigravidae), and maternal anaemia (Hb < 8.0 g/dl, 37.8% primigravidae, 29.6% multigravidae). Estimates for PE of self-reported use of ITNs gave values for all three outcome parameters that were much lower than for SP use. For women of all parties effectiveness estimates for reduction of low birthweight were 22% (95% CI, 17.7-26.4), prevention of placental malaria (all types) 7.1% (95% CI, 4.4-9.8), prevention of active placental infection 38.9% (95% CI, 27.4-50.4), and for maternal anaemia 8.8% (95% CI, 0-20.0).

CONCLUSIONS

The case-coverage method could provide a useful and practical approach to routine monitoring and evaluation of drug interventions to control malaria in pregnancy and has potentially wide applications. Effectiveness estimates related to reported ITN use in pregnancy may be less reliable. The method should be further evaluated using currently available data sets.

Breast and complementary feeding practices in relation to morbidity and growth in Malawian infants

OBJECTIVES

The objective of this study was to compare growth, morbidity incidence and risk factors for undernutrition between infants receiving complementary feeding early, before 3 months of age, with those receiving complementary foods after 3 months in a poor rural Malawian community.

METHODS

A cohort of babies was enrolled at birth for follow-up to 12 months of age. Weight, length, morbidity and feeding patterns were recorded at 4 weekly intervals from birth to 52 weeks.

RESULTS

Mean age at introduction of water was 2.5 months (range 0-11.8), complementary foods 3.4 months (range, 1.0-10.7) and solids 4.5 months (range 1.2-13.8). Over 40% of infants had received complementary foods by 2 months and 65% by 3 months. The proportion of exclusively breast-fed infants, which included those receiving supplemental water, was 13% at 4 months, 6.3% at 5 months and 1.5% at 6 months. Infants with early complementary feeding had lower weight for age at 3 and 6 months (P<0.05), and at 9 months (P=0.07) and at 2 months they were approximately 200 g lighter. Early complementary feeding was significantly associated with increased risk for respiratory infection (P<0.05), and marginally increased risk for eye infection and episodes of malaria. Maternal illiteracy was associated with early complementary feeding (OR=2.1, 95% CI 1.3, 3.2), while later complementary feeding was associated with reduced infant morbidity and improved growth.

CONCLUSION

Breast-feeding promotion programmes should target illiterate women. Greater emphasis is required to improve complementary feeding practices.

Size and morbidity in Malawian twins

OBJECTIVE

Twins in developing countries may be disadvantaged due to their small size at birth, compromised nutrition and high infection risk. Although twinning is common in Africa, there are few longitudinal studies of growth and morbidity in this high-risk group. The aim of the present paper was to describe growth and morbidity of Malawian twins compared to singletons.

METHODS

Morbidity episodes were recorded at 4 weekly intervals and at extra visits made to health centres for illness. Weight, length, head and arm circumference were recorded at birth and weight, length and MUAC at 4 weekly intervals to 52 weeks of age.

RESULTS

Twins showed reduced fetal growth compared to singletons, with increasing fall-off in percentiles from 33 weeks gestation. Infant growth percentiles for twins were below those for singletons at all ages, but showed no fall-off from singleton percentile values. There were no differences in morbidity incidence during infancy between twins and singletons.

CONCLUSION

Malawian twins showed no catch-up growth during infancy, their smaller size was not associated with higher morbidity incidence compared to singletons.

Placental malaria and immunity to infant measles

The efficiency of transplacental transfer of measles specific antibody was assessed in relation to placental malaria. Infection at delivery was associated with a 30% decrease in expected cord measles antibody titres. Uninfected women who received anti-malarial drugs during pregnancy transmitted 30% more antibody than those who received no antimalarial drugs.

Anthropometry of Malawian live births between 35 and 41 weeks of gestation

The aim of this analysis was to construct cross-sectional gestational age specific percentile curves for birthweight, length, head and mid-arm circumference for Malawian babies, and to compare these percentiles with reference values for babies born to women with normal pregnancies, from a developed country. A cross-sectional study which enrolled pregnant women attending two study hospitals between March 1993 and July 1994 was undertaken. Data on maternal socio-economic status, newborn anthropometry, previous obstetric history and current pregnancy were collected. Smoothed percentile values were derived using the LMS method. Malawian reference percentiles were constructed for fetal growth from 35 weeks' gestation for singleton births. Mean birthweight, length and head circumference were lower at all gestational ages for Malawian compared with Swedish newborns. Fetal growth per completed gestational week was higher by 60 g in weight, 0.5 cm in length and 0.2 cm in head circumference in Swedish compared with Malawian babies. Growth restriction was present from 35 to 41 weeks' gestation. The pattern for the 10th percentile suggested that this was occurring from well before 35 weeks' gestation in a proportion of babies.

The association of anti-phospholipid antibodies with parity in placental malaria

Anti-phospholipid antibodies (aPL) are autoantibodies associated with both infections and the pathogenesis of certain pregnancy complications. In the latter, but not the former, aPL are dependent on a co-factor, beta(2) glycoprotein I (beta2GPI), which can also be used as an antigen for detection of such aPL in pregnancy. A cross-sectional study was carried out on serum samples from Kumasi, Ghana, to determine the occurrence and beta2GPI-dependence of aPL in placental malaria. Anti-cardiolipin, anti-phosphatidylserine and anti-beta2GPI enzyme-linked immunosorbent assays (ELISAs) were performed on sera from 103 HIV-non-infected gravid women. Placental malaria, both active and past infection, was diagnosed in 33/103 (32%) based on placental histology. In multiparae, beta2GPI-independent IgM antibodies to cardiolipin (P = 0.018) and phosphatidylserine (P = 0.009) were observed, which were most pronounced in past placental malaria infection. In primiparae, no association emerged between aPL and placental malaria. Trends for improved clinical parameters were identified in infected women with levels of anti-cardiolipin beyond the 99th multiple of the median for a healthy, non-malarious population. This study in placental malaria reports parity associations of beta2GPI-independent aPL profiles, and does not support a role for beta2GPI-dependent aPL. It is of significance in the context of the known parity differences in pregnancy malaria immunity.

Passive cigarette smoke exposure in primary school children in Liverpool

OBJECTIVE

To assess environmental tobacco smoke (ETS) exposure amongst primary school children.

METHODS

A descriptive, community-based, cross-sectional study of self-reported parental smoking patterns and children's salivary cotinine concentrations in 245 children aged 5-11 years attending 10 primary schools in Liverpool.

RESULTS

The mean age was 7.4 years. The percentage of children living in smoking households was higher than the average reported for England (61.4% vs 53.0%). The average daily number of cigarettes smoked was similar for fathers (15.8) and mothers (16.4). The mean salivary cotinine concentration (+/-SD) was 1.6+/-0.4 ng/ml, and was higher in boys than girls (1.9+/-0.4 vs 1.2+/-0.2 ng/ml, P=0.006). The mean cotinine concentration was higher amongst children less than 7 years of age compared with older children (1.9+/-0.9 vs 1.4+/-0.6 ng/ml, P=0.01). Children from disadvantaged socio-economic households (Townsend score > + 6) had a mean cotinine level of 1.9+/-0.4 ng/ml, and a higher risk of a positive cotinine-validated level (>or=1 ng/ml) [crude odds ratio (OR) 3.5, 95% confidence interval (CI) 1.6-5.2). Maternal, but not paternal, cigarette smoke exposure was significantly associated with the salivary cotinine-validated level in children (adjusted OR 2.5, 95%CI 1.8-3.4).

CONCLUSIONS

Maternal smoking, age less than 7 years, child's gender (male) and low socio-economic status were significant risk factors associated with ETS exposure in young school children in Liverpool. The level of childhood ETS exposure in this area demonstrates a major public health concern that creates a challenge for innovative interactive strategies.

Catch-up growth in Malawian babies, a longitudinal study of normal and low birthweight babies born in a malarious endemic area

INTRODUCTION

Infant growth has not been studied in developing countries in relation to maternal factors related to malaria in pregnancy and maternal illiteracy.

OBJECTIVE

To describe growth patterns in infants with low and normal birthweight and determine maternal risk factors for infant undernutrition.

METHODS

Babies born in a rural district of southern Malawi were recruited. An infant cohort was selected on the basis of low or normal birthweight. Weight and length were recorded at birth and at 4-weekly intervals until at 52 weeks after birth. Maternal characteristics at first antenatal attendance and delivery were obtained. Odds ratios in univariate analysis were adjusted for birthweight. Factors included in the multivariate regression included maternal illiteracy, season of birth, maternal iron deficiency and number of infant illness episodes.

RESULTS

Low birthweight infants were shorter and lighter throughout infancy than either normal birthweight or international reference values. At 12 months, placental or peripheral malaria at delivery (adjusted odds 1.8; 1.0, 3.1), number of infant illness episodes (AOR = 2.1; 1.2, 3.6) and maternal illiteracy (AOR = 2.7; 1.5, 4.9) were independently associated with low weight for age. Maternal short stature (AOR = 1.8; 1.1. 3.2), male sex (AOR = 2.4; 1.4, 4.1), number of infant illness episodes (AOR = 2.6; 1.5, 4.4), and birth in the rainy season (2.1; 1.2, 3.7) were independently associated with stunting. Placental or peripheral malaria at delivery (AOR = 2.2; 1.1, 4.4) and number of illness episodes (AOR = 2.2; 1.1, 4.5) were independently associated with thinness.

CONCLUSION

Malaria during pregnancy and maternal illiteracy are important maternal characteristics associated with infant undernutrition. Innovative health/literacy strategies are required to address malaria control in pregnancy in order to reduce the magnitude of its effects on infant undernutrition.

Trends in childhood and parental asthma prevalence in Merseyside, 1991-1998

OBJECTIVE

To determine changes in childhood and parental asthma prevalence in Merseyside between 1991 and 1998.

METHODS

Three standardized cross-sectional respiratory health surveys using a parent-completed questionnaire were completed in 1991 (n = 1171), 1993 (n = 2368) and 1998 (n = 1964) amongst primary school children (5-11 years) attending the same 10 schools. The main outcome measures were prevalence of reported doctor diagnosed asthma, the symptom triad of cough, wheeze and breathlessness (C+W+B+) and parental asthma.

RESULTS

Significant changes in prevalence for all respiratory variables occurred between 1991 and 1998, except for the symptom triad C+W+B+. Between 1991 and 1998 the prevalence of reported doctor diagnosed asthma increased from 17.7 to 29.8 per cent (p < 0.001), history of wheezing increased from 22.5 to 29.4 per cent (p < 0.001). The symptom triad of C+W+B+ changed from 9.6 to 9.9 per cent (p = 0.78). Childhood reported hospital admissions for respiratory illness increased from 5.5 to 10.7 per cent (p < 0.001). Paternal asthma increased from 6.5 per cent in 1991, to 8.6 per cent in 1998 (p = 0.031), and maternal asthma almost doubled in the same period from 6.6 to 11.2 per cent (p < 0.001). Children living in poorer areas (Townsend score 8-11) were more likely to have doctor diagnosed asthma (OR = 2.99, 95 per cent CI, 2.06 to 4.33) and C+W+B+ (OR = 2.17, CI 1.13 to 4.18). Childhood obesity was significantly associated with increased risk of both doctor diagnosed asthma (OR = 1.74, 95 per cent CI, 1.29 to 2.37) and C+W+B+ (OR = 1.88, 95 per cent CI, 1.21 to 2.90).

CONCLUSION

A rising prevalence of reported doctor diagnosed asthma, but not C+W+B+ was observed during the 1990s in a low socio-economic area of Liverpool. Asthma prevalence was related to socio-economic deprivation and was associated with obesity. The rising prevalence of reported doctor diagnosed asthma is likely to be attributable to several factors, including changes in diagnostic labelling and the distribution of factors related to socio-economic status.

Iron contents of Malawian foods when prepared in iron cooking pots

The aim of this study was to determine the iron content of Malawian foods prepared in iron pots and to examine the effects of continuous cooking time and added oil on the iron content of the food prepared. Foods prepared, which included a staple (Nsima), relish vegetables, and beans, had an increased iron content when prepared in an iron compared to a glass pot. For these three foods, iron content per gram increased by 3.15 micrograms, 35.8 micrograms, and 147.32 micrograms, respectively. Continuous use of the iron pot for cooking could have a positive effect on the amount of iron added to the food, as the three foods' iron content increased by a further 2.9 micrograms iron/g, 7.6 micrograms iron/g and 20.1 micrograms iron/g, respectively. This effect needs more study. Food pH was significantly negatively correlated with food iron content. The use of oil reduced the amount of iron added to stir-fried vegetables by 52.37 micrograms/g and increased iron added to Nsima (1.2 micrograms/g). Malawian foods increased their iron content when cooked in iron pots. This method of food preparation potentially provides a low-cost sustainable means of improving the iron intakes of families and communities where this traditional method of food preparation is acceptable.

Anthropometry of fetal growth in rural Malawi in relation to maternal malaria and HIV status

OBJECTIVE

To describe fetal growth centiles in relation to maternal malaria and HIV status, using cross sectional measurements at birth.

DESIGN

A cross sectional study of pregnant women and their babies. Data on maternal socioeconomic status and current pregnancy, including HIV status and newborn anthropometry, were collected. Malaria parasitaemia was assessed in maternal peripheral and placental blood, fetal haemoglobin was measured in cord blood, and maternal HIV status was determined.

SETTING

Two district hospitals in rural southern Malawi, between March 1993 and July 1994.

OUTCOME VARIABLES

Newborn weight, length, Rohrer's ponderal index.

RESULTS

Maternal HIV (adjusted odds ratio (AOR) 1.76 (95% confidence interval 1.04 to 2.98)) and first pregnancy (AOR 1.83 (1.10 to 3.05)) were independently associated with low weight for age. Placental or peripheral parasitaemia at delivery (AOR 1.73 (1.02 to 2.88)) and primigravidae (AOR 2.13 (1.27 to 3.59)) were independently associated with low length for age. Maternal malaria at delivery and primiparity were associated with reduced newborn weight and length but not with disproportionate growth. Maternal HIV infection was associated only with reduced birth weight. The malaria and parity effect occurred throughout gestational weeks 30-40, but the HIV effect primarily after 38 weeks gestation.

CONCLUSION

Fetal growth retardation in weight and length commonly occurs in this highly malarious area and is present from 30 weeks gestation. A maternal HIV effect on fetal weight occurred after 38 weeks gestation.

The sick placenta-the role of malaria

The human placenta is an ideal site for the accumulation of Plasmodium falciparum malaria parasites, and as a consequence serious health problems arise for the mother and her baby. The pathogenesis of placental malaria is only partially understood, but it is clear that it leads to a distinct epidemiological pattern of malaria during pregnancy. The objectives of this review are: (1) To review recent data on the epidemiology of malaria in pregnancy, with emphasis on placental malaria; (2) to describe the pathological changes and immunological factors related to placental malaria; and (3) to discuss briefly the functional consequences of this infection for the mother and her baby. The review attempts to bring together local events at the maternal-fetal interface which encompass immunological and pathological processes which relate to the epidemiological pattern of malaria in pregnancy in areas of both high and low malaria transmission. An integrated understanding of the epidemiological, immunological and pathological processes must be achieved in order to understand how to control malaria in pregnancy. The yearly exposure of at least 50 million pregnancies to malaria infection makes it the commonest and most recurrent parasitic infection directly affecting the placenta. These statistics and our limited understanding of its pathogenesis suggest the research priorities on this subject.

Haematological profiles of the people of rural southern Malawi: an overview

An integrative review of the results of two published and two unpublished studies of anaemia in children, adolescent females, pregnant women and adults living in southern Malawi is presented. Anaemia was universally present in all age-groups, with the higher prevalences in infants (100%) and adolescent primigravidae (93.8%). Nutritional deficits of iron and vitamin A were major contributory factors but chronic malarial haemolysis also significantly contributed to the anaemia. Among boys, anaemia was more common among those with glucose-6-phosphate-dehydrogenase (G6PD) deficiency than in those without this deficiency (P<0.002). This enzymopathy, which occurred in 23.5% [95% confidence interval (CI)=16.7%-30.1%] of the male and 30% (CI=17.3%-42.7%) of the female infants examined, was also associated with neonatal jaundice. The overall prevalences of the-alpha(3.7)/alphaalpha and -alpha(3.7)/-alpha(3.7) thalassaemia genotypes were estimated at 41.0% (CI=28.3%-53.7%) and 8.7% (CI=1.5%-15.9%), respectively. Haemoglobin AS was present in 18.1% (CI=12.8%-23.4%) of the infants and haemoglobin SS in 2.5% (CI=1.4%-3.6%). As the prevalence of infection with Plasmodium falciparum was significantly higher in infants with haemoglobin AS than in those with AA (21.4% v. 6.7%; P<0.001), an increased risk of early-onset moderate parasitaemias in young infants probably stimulates the development of immunity, protecting older heterozygotes from severe malarial infection. Innovative community approaches are required to break the cycle of ill health that anaemia supports in those living in rural areas of southern Malawi. Interventions in adolescent girls could be of particular importance, as they could break the cycle in both pregnant women and their infants.

Food prepared in iron cooking pots as an intervention for reducing iron deficiency anaemia in developing countries: a systematic review

OBJECTIVE

To complete a systematic review of the effect of preparing food cooked in iron pots on haemoglobin concentrations and to assess compliance with pot use. DESIGN AND SEARCH STRATEGY: We searched The Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness, The Cochrane Controlled trials Register, The Cochrane Methodology Register, Health Technology Assessment Database and NHS Economic Evaluation Database (Cochrane Library, Issue 3, 2002). Medline (1966 to May 2002) and EMBASE (1988 to May 2002). Reference lists of published trials were examined for other potentially relevant trials and authors of selected trials were contacted to obtain information about ongoing or unpublished trials. Selection criteria included randomized trials which compared the effect of food cooked in cast iron pots with food cooked in noncast iron pots on participants of a minimum age of 4 months. One reviewer applied inclusion criteria to potentially relevant trials. Two reviewers assessed trial quality and extracted data.

RESULTS

Three trials were eligible for inclusion in the review. There is some evidence from these studies that eating food prepared in iron pots increases the haemoglobin concentration of anaemic/iron deficient individuals. This effect seems to be modified by compliance, users age, and the presence of malaria and hookworm. Compliance with pot use varies considerably between countries depending on several factors, including: size of the cooking pot, targeted user group, whether the pot is used as an extra or replacement pot, and familiarity with cast iron pots.

CONCLUSION

The introduction of iron pots or improving their use in communities in developing countries for the preparation of food maybe a promising innovative intervention for reducing iron deficiency and iron deficiency anaemia. Further research is required to monitor the use and effectiveness of this intervention.

Comparison of screening methods for anaemia in pregnant women in Awassa, Ethiopia

Screening for anaemia in pregnancy is essential for implementing and monitoring effective antenatal programmes. We compared the diagnostic accuracy of invasive and non-invasive screening methods in a cross-sectional survey of 403 pregnant women attending an urban health centre in Awassa, southern Ethiopia. Overall anaemia prevalence [haemoglobin (Hb): <11 g/dl] was 15.1% (95% CI: 12.1-19.9), mild anaemia (Hb: 10-10.9 g/dl) 10.4%, moderate anaemia (Hb: 7-9.9 g/dl) 4.2% and severe anaemia (Hb < 7 g/dl) 0.3%. Sensitivity, specificity and predictive values of conjunctival pallor and the WHO Hb colour scale were calculated for Hb cut-off points <11, <10 and <9 g/dl. All methods in combination with the symptoms and complaints reported by the mothers were entered into a predictive scoring system. None of the methods tested or models predicted anaemia with suitable accuracy in this population. The diagnosis of anaemia based on clinical signs and symptoms remains unreliable despite attempts to develop predictive models.

Epidemiology of measles in Blantyre, Malawi: analyses of passive surveillance data from 1996 to 1998

Measles surveillance data in Blantyre, Malawi were reviewed for 1996-8 to describe the epidemiology of infection and to estimate vaccine efficacy (VE) by the screening method. A total of 674 measles cases were reported to the Blantyre District Health Office during this period. Age distribution showed that 108 (16.1%) of the cases were aged less than 1 year. The median age was 5 years. Eighty percent of the cases between 1 and 19 years had been previously vaccinated. VE was 68.6% (95% CI, 527-792) for children 12-23 months of age and 67.3% (95% CI, 48.3-79.3) for infants 9-11 months of age. Reasons for this low vaccine efficacy are discussed. Previous vaccination history was negatively associated with the risk for developing cough during measles infection (odds ratio (OR), 0.30; 95% CI, 0.09-0.91), diarrhoea (OR, 0.64; CI, 0.44-0.95) and pneumonia (OR, 0.40; CI, 0.25-0.62). Logistic regression analysis showed that pneumonia in adults was negatively associated with vaccination history. The passive surveillance system for measles in Malawi was useful to describe the epidemiology of measles.

Changes in haemoglobin levels in infants in Malawi: effect of low birth weight and fetal anaemia

OBJECTIVES

To examine the effect of low birth weight (LBW) and fetal anaemia (FA) on haemoglobin (Hb) patterns in infancy. To study the additional contribution of other risk factors known at birth. To examine the effect of iron supplementation during infancy on Hb levels.

METHODS

A stratified cohort of infants in Malawi (83 with LBW (< 2500 g), 111 with FA (cord Hb < 125 g/l), 31 with both LBW and FA, and 176 controls) was followed during infancy. Hb levels were measured at about 2, 4, 6, 9, and 12 months of age. Repeated measures models were used to describe the changes in Hb levels over time.

RESULTS

The mean Hb concentration in the control group was 95.5 g/l (95% confidence interval (CI) 92.5 to 98.5) at 2 months, 86.9 g/l (95% CI 84.4 to 89.4) at 9 months, and 898 g/l (95% CI 874 to 92.2) at 12 months. Differences between LBW infants and controls increased over time (difference at 12 months: 5.5 g/l (95% CI 1.3 to 9.7)). Infants with FA had borderline significantly lower Hb at 2 months (p = 0.07), but at 6 months their levels were similar to those of controls. The LBW infants and those with FA had the lowest Hb levels (difference from controls at 12 months 7.9 g/l). Parity, placental and maternal malaria at delivery, and sex significantly affected Hb levels after adjustment for LBW and FA. After iron supplementation, Hb significantly increased.

CONCLUSIONS

Antimalarial control and iron supplementation throughout pregnancy should be increased to reduce the incidence of infant anaemia and improve child development and survival.

Hepatitis B prevalence and risk factors for HBsAg carriage amongst Somali households in Liverpool

The prevalence of hepatitis B core antibody (anti-HBc) and surface antigen (HBsAg) in the Somali population in Liverpool is described and groups who may benefit from vaccination are identified. A cross-sectional descriptive study was undertaken. A total of 439 subjects, aged between 10 months and 80 years, from 151 households, were screened for anti-HBc and HBsAg. One hundred ninety-four (44.2%) were children aged less than 15 years. Three hundred and nine (69%) of enrolled subjects were born in Somalia, 122 (27.2%) were born in the UK and 8 were born elsewhere. Of the study population, 5.7% were carriers of HBsAg, with the highest prevalence in adults aged 20 to 44 years (9.4%). A history of circumcision (RR 95% CI; 1.2, 1.1-1.5) was the most significant risk factor for HBsAg carriage, but was not significant on multivariate analysis. Prevalence of anti-HBc was 27.5%, and increased with age over the first four decades. Univariate analysis showed that a history of living in a refugee camp (RR 95% CI; 3.1, 1.7-5.7), receiving an injection in Somalia (2.1, 1.7-2.5), a history of circumcision or other surgical procedure in Somalia (1.4, 1.3-1.6) and being born in Somalia (1.3, 1.2-1.4) were significant risk factors for anti-HBc positivity. On multivariate analysis, only circumcision (OR 95% CI; 4.3, 1.8-10.3) and receiving an injection in Somalia (2.5, 1.5-4.4) remained significant. Seven of 80 (8.7%) children born in the UK and aged five years or less had evidence of exposure to hepatitis B, of whom only one had a close family member identified to be HBsAg seropositive. Previous infection with hepatitis B is common in this population. Horizontal transmission may be continuing at an early age within the UK, suggesting a population of at risk individuals who would benefit from surveillance and immunisation. Community circumcision is a risk factor for hepatitis B transmission and best practice should be followed when this procedure is undertaken.

An analysis of intra-uterine growth retardation in rural Malawi

OBJECTIVE

(1) To describe the sex-specific, birth weight distribution by gestational age of babies born in a malaria endemic, rural area with high maternal HIV prevalence; (2) to assess the contribution of maternal health, nutritional status and obstetric history on intra-uterine growth retardation (IUGR) and prematurity.

METHODS

Information was collected on all women attending antenatal services in two hospitals in Chikwawa District, Malawi, and at delivery if at the hospital facilities. Newborns were weighed and gestational age was assessed through post-natal examination (modified Ballard). Sex-specific growth curves were calculated using the LMS method and compared with international reference curves.

RESULTS

A total of 1423 live-born singleton babies were enrolled; 14.9% had a birth weight <2500 g, 17.3% were premature (<37 weeks) and 20.3% had IUGR. A fall-off in Malawian growth percentile values occurred between 34 and 37 weeks gestation. Significantly associated with increased IUGR risk were primiparity relative risk (RR) 1.9; 95% CI 1.4--2.6), short maternal stature (RR 1.6; 95% CI 1.0--2.4), anaemia (Hb<8 g/dl) at first antenatal visit (RR 1.6; 95% CI 1.2--2.2) and malaria at delivery (RR 1.4; 95% CI 1.0--1.9). Prematurity risk was associated with primiparity (RR 1.7; 95% CI 1.3--2.4), number of antenatal visits (RR 2.2; 95% CI 1.6--2.9) and arm circumference <23 cm (RR 1.9; 95% CI 1.4--2.5). HIV infection was not associated with IUGR or prematurity.

CONCLUSION

The birth-weight-for-gestational-age, sex-specific growth curves should facilitate improved growth monitoring of newborns in African areas where low birth weight and IUGR are common. The prevention of IUGR requires improved malaria control, possibly until late in pregnancy, and reduction of anaemia.

An analysis of anemia and pregnancy-related maternal mortality

The relationship of anemia as a risk factor for maternal mortality was analyzed by using cross-sectional, longitudinal and case-control studies because randomized trials were not available for analysis. The following six methods of estimation of mortality risk were adopted: 1) the correlation of maternal mortality rates with maternal anemia prevalence derived from national statistics; 2) the proportion of maternal deaths attributable to anemia; 3) the proportion of anemic women who die; 4) population-attributable risk of maternal mortality due to anemia; 5) adolescence as a risk factor for anemia-related mortality; and 6) causes of anemia associated with maternal mortality. The average estimates for all-cause anemia attributable mortality (both direct and indirect) were 6.37, 7.26 and 3.0% for Africa, Asia and Latin America, respectively. Case fatality rates, mainly for hospital studies, varied from <1% to >50%. The relative risk of mortality associated with moderate anemia (hemoglobin 40-80 g/L) was 1.35 [95% confidence interval (CI): 0.92-2.00] and for severe anemia (<47 g/L) was 3.51 (95% CI: 2.05-6.00). Population-attributable risk estimates can be defended on the basis of the strong association between severe anemia and maternal mortality but not for mild or moderate anemia. In holoendemic malarious areas with a 5% severe anemia prevalence (hemoglobin <70 g/L), it was estimated that in primigravidae, there would be 9 severe-malaria anemia-related deaths and 41 nonmalarial anemia-related deaths (mostly nutritional) per 100,000 live births. The iron deficiency component of these is unknown.

An analysis of anemia and child mortality

The relationship of anemia as a risk factor for child mortality was analyzed by using cross-sectional, longitudinal and case-control studies, and randomized trials. Five methods of estimation were adopted: 1) the proportion of child deaths attributable to anemia; 2) the proportion of anemic children who die in hospital studies; 3) the population-attributable risk of child mortality due to anemia; 4) survival analyses of mortality in anemic children; and 5) cause-specific anemia-related child mortality. Most of the data available were hospital based. For children aged 0-5 y the percentage of deaths due to anemia was comparable for reports from highly malarious areas in Africa (Sierra Leone 11.2%, Zaire 12.2%, Kenya 14.3%). Ten values available for hemoglobin values <50 g/L showed a variation in case fatality from 2 to 29.3%. The data suggested little if any dose-response relating increasing hemoglobin level (whether by mean value or selected cut-off values) with decreasing mortality. Although mortality was increased in anemic children with hemoglobin <50 g/L, the evidence for increased risk with less severe anemia was inconclusive. The wide variation for mortality with hemoglobin <50 g/L is related to methodological variation and places severe limits on causal inference; in view of this, it is premature to generate projections on population-attributable risk. A preliminary survival analysis of an infant cohort from Malawi indicated that if the hemoglobin decreases by 10 g/L at age 6 mo, the risk of dying becomes 1.72 times higher. Evidence from a number of studies suggests that mortality due to malarial severe anemia is greater than that due to iron-deficiency anemia. Data are scarce on anemia and child mortality from non-malarious regions. Primary prevention of iron-deficiency anemia and malaria in young children could have substantive effects on reducing child mortality from severe anemia in children living in malarious areas.

Malaria in pregnancy and its consequences for the infant in rural Malawi

Maternal malaria and anaemia, pregnancy and infant outcomes are reviewed among a cohort of mothers and their babies living in Chikwawa district, southern Malawi. Overall, 4104 women were screened at first antenatal visit and 1523 at delivery. Factors independently associated with moderately severe anaemia (MSA; < 8 g haemoglobin/dl) in primigravidae were malaria (relative risk = 1.9; 95% confidence interval = 1.6-2.3) and iron deficiency (relative risk = 4.2; 95% confidence interval = 3.5-5.0). Only iron deficiency was associated with MSA in multigravidae. After controlling for antimalarial use, parasitaemia was observed in 56.3% of the HIV-infected primigravidae and 36.5% of the non-infected (P = 0.04). The corresponding figures for multigravidae were 23.8% and 11.0%, respectively (P = 0.002). Over 33% of the infants born alive to primigravidae were of low birthweight (LBW; < 2500 g), and 23.3% of all newborns had foetal anaemia (< 12.5 g haemoglobin/dl cord blood). LBW was significantly associated in primigravidae with pre-term delivery, placental malaria and frequency of treatment with sulfadoxine-pyrimethamine (SP), and in multigravidae with pre-term delivery, adolescence, short stature and MSA. LBW was significantly reduced with a second SP treatment in primigravidae, and with iron-folate supplementation in multigravidae. Mean haemoglobin concentrations were significantly lower in the infant who had been LBW babies than in the others, and significantly associated with parity, peripheral parasitaemia at delivery and placental malaria. At 1 year post-delivery, life status was known for 364 (80.7%) of the 451 infants enrolled in the follow-up study. Independent risk factors for post-neonatal mortality were maternal HIV infection, LBW, and iron deficiency at delivery. This study identifies priorities for improving the health of pregnant women and their babies in this rural area of Malawi.

A birthweight nomogram for Africa, as a malaria-control indicator

Low birthweight (LBW) attributable to malaria in pregnancy is a significant risk for millions in Africa. Infants born to primigravidae are at greatest risk and it is proposed that this excess risk can be used as a simple indicator of malaria transmission and exposure in pregnant women in Africa. Birthweight data from different regions in 11 malarious and three non-malarious African countries were investigated. A regression analysis of the excess risk of low birthweight in first pregnancies, compared with later ones, was completed and interpreted in relation to malaria-transmission intensities. The aim was to develop a simple birthweight chart (nomogram) as a tool for monitoring malaria transmission or malaria control in pregnancy. Low-birthweight risk in first pregnancies was associated with levels of malaria-transmission intensity amongst different African countries. The nomogram distinguished longitudinal changes in malaria exposure, related to season and changes in antimalarial-drug policy. Malaria is one of the most important causes of LBW in first pregnancies in Africa. As birthweight and parity are routinely recorded in many delivery centres across Africa, the nomogram provides a simple, available and inexpensive tool for monitoring malaria transmission and exposure in pregnant women and the effectiveness of malaria-control activities for this high-risk group.

An analysis of the determinants of anaemia in pregnant women in rural Malawi--a basis for action

Haematological data are presented on 4104 pregnant women attending the antenatal-care facilities of two hospitals in a rural area in southern Malawi. In this area, malaria transmission is perennial and there is a high prevalence of HIV infection. The local women are exposed to drought and food shortages but experience high fertility rates. Mean (S.D.) haemoglobin (Hb) concentration was significantly lower in the primigravidae [8.7 (1.60 g/dl] than in the secundigravidae [9.1 (1.5) g/dl; P < 0.0001] or multigravidae [9.2 (1.5) g/dl; P < 0.0001]. Primigravidae also experienced significantly more iron deficiency and malaria than secundi- or multi-gravidae. For all parity groups, the lowest mean Hb levels were observed between 26-30 weeks' gestation. In primigravidae peak prevalence of malaria occurred between 16-20 weeks' gestation (38.6%) and peak prevalence of moderately severe anaemia (< 8 g Hb/dl) between 26-30 weeks' (35.7%). Multigravidae showed little variation in the prevalence of anaemia, iron deficiency and malaria with gestational age. Peak prevalences of malaria were observed in April, in the post-rainy season, with values of 51.4%, 56.0% and 25.3% for primi-, secundi- and multi-gravidae, respectively. Peak prevalences of iron deficiency occurred between April and May and those of moderately severe anaemia between May and June. Mean Hb was lower in adolescent primigravidae than in any other group of pregnant women [8.6 (1.5) g/dl], including the non-adolescent primigravidae [8.9 (1.6) g/dl; P = 0.008]. Other factors significantly associated with increased risk of moderately severe anaemia in primigravidae were illiteracy and poor nutritional status (i.e. body mass index < 18.5 kg/m2 and mid-upper-arm circumference < 23 cm). After forward, step-wise, regression analysis of relative risk (RR) factors and their 95% confidence intervals (CI), variables associated with an increased risk for moderately severe anaemia were iron deficiency (RR = 4.2; CI = 3.0-6.0) and malaria parasitaemia (RR = 1.9; CI = 1.3-2.7) in primigravidae, iron deficiency (RR = 4.1; CI = 2.7-6.3) and mid-upper-arm-circumference < 23 cm (RR = 1.8; CI = 1.1-3.0) in secundigravidae, and iron deficiency in multigravidae (RR = 3.1; CI = 4.3-6.9).

Increased prevalence of malaria in HIV-infected pregnant women and its implications for malaria control

OBJECTIVES

To examine in pregnant women the relationship between HIV infection and malaria prevalence and to determine, in relation to HIV infection, the effectiveness of sulphadoxine-pyrimethamine in clearing P. falciparum infection.

METHOD

Descriptive cross-sectional analysis of P. falciparum prevalence in pregnant women at first antenatal visit and of women at delivery who had received two sulphadoxine-pyrimethamine treatments for malaria. HIV status was assessed in 621 women who attended for antenatal care and for delivery at two rural hospitals in southern Malawi in 1993-94. Information was collected on maternal age, parity and gestational age. Prevalence of P. falciparum was measured at first antenatal visit and delivery. Women were given two routine treatment doses of sulphadoxine-pyrimethamine (SP), at first antenatal visit and between 28 and 34 weeks gestation, conforming to Malawi government policy on antimalarial control during pregnancy.

RESULTS

Prevalence of HIV infection was 25.6% and all infections were HIV type-1. In primigravidae malaria prevalence at recruitment was 56.3% in HIV-infected and 36.5% in HIV-uninfected women (P=0.04). The corresponding figures for multigravidae were 23.8% and 11.0%, respectively (P<0.01). HIV-infected primigravidae had increased malaria prevalence at all gestational ages. Peak parasite prevalence occurred earlier in gestation in HIV-infected primigravidae (16-19 weeks if HIV-infected; 20-23 weeks if HIV-uninfected). The relative risk for parasitaemia in HIV-infected compared to HIV-uninfected women was significantly increased in three of five parity groups, including the two highest ones (parity>3), indicating parity-specific immunity to malaria was impaired. Malaria prevalence at delivery remained high in HIV-infected women despite prior routine treatment with sulphadoxine-pyrimethamine in pregnancy There was no significant difference in parasite prevalence at delivery between women who did or did not use sulphadoxine-pyrimethamine.

CONCLUSIONS

HIV infection is associated with a significant increase in malaria prevalence in pregnant women of all parities with the effect apparent from early in gestation. Two treatment doses of sulphadoxine-pyrimethamine were inadequate to clear parasitaemia in many women by the time of delivery and this occurred independently of HIV status and despite high sensitivity to SP in this area. There is a need to undertake longitudinal studies to determine the incidence of P. falciparum infection in HIV-infected and uninfected pregnant women and to reassess the frequency and timing of sulphadoxine-pyrimethamine treatment doses in these women. Late pregnancy re-infections with P. falciparum probably explain the high parasite prevalence at delivery following sulphadoxine-pyrimethamine treatment at 28-34 weeks gestation.