Zeba Rasmussen

Diarrhea in Early Childhood: Short-term Association With Weight and Long-term Association With Length

The short-term association between diarrhea and weight is well-accepted, but the long-term association between diarrhea and growth is less clear. Using data from 7 cohort studies (Peru, 1985-1987; Peru, 1989-1991; Peru, 1995-1998; Brazil, 1989-1998; Guinea-Bissau, 1987-1990; Guinea-Bissau, 1996-1997; and Bangladesh, 1993-1996), we evaluated the lagged relationship between diarrhea and growth in the first 2 years of life. Our analysis included 1,007 children with 597,638 child-days of diarrhea surveillance and 15,629 anthropometric measurements. We calculated the associations between varying diarrhea burdens during lagged 30-day periods and length at 24 months of age. The cumulative association between the average diarrhea burden and length at age 24 months was -0.38 cm (95% confidence interval: -0.59, -0.17). Diarrhea during the 30 days prior to anthropometric measurement was consistently associated with lower weight at most ages, but there was little indication of a short-term association with length. Diarrhea was associated with a small but measurable decrease in linear growth over the long term. These findings support a focus on prevention of diarrhea as part of an overall public health strategy for improving child health and nutrition; however, more research is needed to explore catch-up growth and potential confounders.

Wasting Is Associated with Stunting in Early Childhood

The longitudinal relationship between stunting and wasting in children is poorly characterized. Instances of wasting or poor weight gain may precede linear growth retardation. We analyzed longitudinal anthropometric data for 1599 children from 8 cohort studies to determine the effect of wasting [weight-for-length Z-score (WLZ) < -2] and variability in WLZ in the first 17 mo on length-for-age Z-score (LAZ) at 18-24 mo of age. In addition, we considered the effects of change in WLZ during the previous 6-mo period on length at 18 and 24 mo. Wasting at 6-11 or 12-17 mo was associated with decreased LAZ; however, children who experienced wasting only at 0-5 mo did not suffer any long-term growth deficits compared with children with no wasting during any period. Children with greater WLZ variability (≥0.5 SD) in the first 17 mo of life were shorter [LAZ = -0.51 SD (95% CI: -0.67, -0.36 SD)] at 18-24 mo of age than children with WLZ variability <0.5. Change in WLZ in the previous 6-mo period was directly associated with greater attained length at 18 mo [0.33 cm (95% CI: 0.11, 0.54 cm)] and 24 mo [0.72 cm (95% CI: 0.52, 0.92 cm)]. Children with wasting, highly variable WLZ, or negative changes in WLZ are at a higher risk for linear growth retardation, although instances of wasting may not be the primary cause of stunting in developing countries.

Catch-Up Growth Occurs after Diarrhea in Early Childhood

Diarrhea and linear growth faltering continue to burden low-income countries and are among the most important contributors to poor health during early childhood. Diarrhea is thought to adversely affect linear growth, but catch-up growth can occur if no additional insults are experienced. We sought to characterize catch-up growth in relation to diarrhea burden in a multisite dataset of 1007 children. Using longitudinal anthropometry and diarrheal surveillance data from 7 cohort studies in 4 countries, we examined the relation between diarrhea prevalence and growth in 3- to 6-mo periods using linear mixed-effect models. Growth during each period was calculated as a function of age using linear splines. We incorporated the longitudinal prevalence of diarrhea in both current and previous periods into the model. Diarrhea during the current period was associated with slower linear and ponderal growth. Faster (catch-up) growth in length was observed in children with no diarrhea in age groups immediately after an age group in which diarrhea was experienced [age group >6-12 mo: 0.03 mm/mo for each percentage diarrhea prevalence in the previous period (95% CI: 0.007, 0.06) relative to 11.3 mm/mo mean growth rate; age group >12-18 mo: 0.04 mm/mo (95% CI: 0.02, 0.06) relative to 8.9 mm/mo mean growth rate; age group >18-24 mo: 0.04 mm/mo (95% CI: 0.003, 0.09) relative to 7.9 mm/mo mean growth rate]. The associations were stronger in boys than in girls when separate models were run. Similar results were observed when weight was the outcome variable. When diarrheal episodes are followed by diarrhea-free periods in the first 2 y of life, catch-up growth is observed that may allow children to regain their original trajectories. The finding of a greater effect of diarrhea on linear growth in boys than in girls was unexpected and requires additional study. Diarrhea burdens are high throughout the first 2 y of life in these study sites, therefore reducing the likelihood of catch-up growth. Extending diarrhea-free periods may increase the likelihood of catch-up growth and decrease the prevalence of stunting.

The MAL-ED Cohort Study: Methods and Lessons Learned When Assessing Early Child Development and Caregiving Mediators in Infants and Young Children in 8 Low- and Middle-Income Countries

More epidemiological data are needed on risk and protective factors for child development. In The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study, we assessed child development in a harmonious manner across 8 sites in Bangladesh, Brazil, India, Nepal, Pakistan, Peru, South Africa, and Tanzania. From birth to 24 months, development and language acquisition were assessed via the Bayley Scales of Infant and Toddler Development and a modified MacArthur Communicative Development Inventory. Other measures were infant temperament, the childs environment, maternal psychological adjustment, and maternal reasoning abilities. We developed standard operating procedures and used multiple techniques to ensure appropriate adaptation and quality assurance across the sites. Test adaptation required significant time and human resources but is essential for data quality; funders should support this step in future studies. At the end of this study, we will have a portfolio of culturally adapted instruments for child development studies with examination of psychometric properties of each tool used.

Postpartum depressive symptoms across time and place: Structural invariance of the Self-Reporting Questionnaire among women from the international, multi-site MAL-ED study

BACKGROUND The Self-Reporting Questionnaire (SRQ) is a screening instrument that has been shown to be an effective measure of depression in postpartum women and is widely used in developing nations. METHODS The SRQ was administered to 2028 mothers from eight nations at two time points: one and six months postpartum. All data were obtained from the Interactions of Malnutrition and Enteric Infections: Consequences for Child Health and Development (MAL-ED) study. The sample included women from MAL-ED sites in Bangladesh, Brazil, India, Nepal, Pakistan, Peru, South Africa, and Tanzania. This study examined three aspects of validity of SRQ scores including (a) structural validity, (b) cross-cultural invariance, and (c) invariance over time. RESULTS A 16-item, one-factor structure with items reflecting somatic symptoms removed was deemed to be superior to the original structure in this postpartum population. Although differential item functioning (DIF) across sites was evident the one-factor model was a good fit to the data from seven sites, and the structure was invariant across the one- and six-month time points. LIMITATIONS Findings are based on data from self-report scales. No information about the clinical status of the participants was available. CONCLUSIONS Overall, findings support the validity of a modified model of the SRQ among postpartum women. Somatic symptoms (e.g., headaches, not sleeping well) may not reflect internalizing problems in a postpartum population. Implications for researchers and practitioners are discussed.

Learning from disasters to save lives every day in Pakistan

Pakistan faces a challenging array of complex humanitarian crises. Political instability, confl ict, entrenched poverty, and natural disasters are all too common and devastating. Threats to public health, particularly after large-scale disasters such as the earthquake in 2005 and fl ooding in 2010, have been well publicised. However, there is a striking lack of evidence for a direct negative eff ect of disasters on major health indicators in Pakistan. Post-disaster disease epidemics have been successfully averted and health service indicators have even improved. Although it might seem intuitive that ongoing instability and frequent natural disasters negatively aff ect health outcomes, this is not necessarily the case. Nepal, for example, with far fewer resources per person than Pakistan, has achieved improved health indicators in the face of humanitarian disasters and unstable governance. By far the most devastating and large-scale public health and humanitarian crisis Pakistan faces is in child survival: about 423 000 children younger than and ferret models of A(H5N1) infection indicate that higher and prolonged oseltamivir dosing improve outcomes. Resistance emerged in one patient infected with A(H7N9) despite increased dose oseltamivir, but further systematically collected data are needed. For now initial use of higher dose oseltamivir or, if available, intravenous NA inhibitor therapy would be reasonable in serious A(H7N9) infections. The development of A(H7N9) variants resistant to both classes of available antiviral drugs emphasises the importance of development of drugs with diff erent mechanisms of action, including therapeutic antibodies, and especially of testing antiviral combinations in severe infl uenza to enhance potency and reduce emergence of resistance.

Relationships among Common Illness Symptoms and the Protective Effect of Breastfeeding in Early Childhood in MAL-ED: An Eight-Country Cohort Study

Abstract. Children in low-income countries experience multiple illness symptoms in early childhood. Breastfeeding is protective against diarrhea and respiratory infections, and these illnesses are thought to be risk factors of one another, but these relationships have not been explored simultaneously. In the eight-site MAL-ED study, 1,731 infants were enrolled near birth and followed for 2 years. We collected symptoms and diet information through twice-weekly household visits. Poisson regression was used to determine if recent illness history was associated with incidence of diarrhea or acute lower respiratory infections (ALRI), accounting for exclusive breastfeeding. Recent diarrhea was associated with higher risk of incident diarrhea after the first 6 months of life (relative risk [RR] 1.10, 95% confidence interval [CI] 1.04, 1.16) and with higher risk of incident ALRI in the 3- to 5-month period (RR 1.23, 95% CI 1.03, 1.47). Fever was a consistent risk factor for both diarrhea and ALRI. Exclusive breastfeeding 0–6 months was protective against diarrhea (0–2 months: RR 0.39, 95% CI 0.32, 0.49; 3–5 months: RR 0.83, 95% CI 0.75, 0.93) and ALRI (3–5 months: RR 0.81, 95% CI 0.68, 0.98). Children with recent illness who were exclusively breastfed were half as likely as those not exclusively breastfed to experience diarrhea in the first 3 months of life. Recent illness was associated with greater risk of new illness, causing illnesses to cluster within children, indicating that specific illness-prevention programs may have benefits for preventing other childhood illnesses. The results also underscore the importance of exclusive breastfeeding in the first 6 months of life for disease prevention.

Measuring home environments across cultures: Invariance of the HOME scale across eight international sites from the MAL-ED study☆

The home environment provides the context for much of a childs early development. Examples of important aspects of the home environment include safety, cleanliness, and opportunities for cognitive stimulation. This study sought to examine the psychometric properties of an adapted form of the Home Observation for the Measurement of the Environment (HOME; Caldwell & Bradley, 1984, 2003) across the eight international sites of the MAL-ED project (Dhaka, Bangladesh; Vellore, India; Bhakatapur, Nepal; Naushahro Feroze, Pakistan; Fortaleza, Brazil; Loreto, Peru; Venda, South Africa; Haydom, Tanzania), to identify a factor structure that fit the data at all sites, and to derive a subset of items that could be used to examine home environmental characteristics across sites. A three-factor structure (i.e., Emotional and Verbal Responsivity; Clean and Safe Environment; Child Cleanliness) was identified, and partial measurement equivalence/invariance across sites was supported. Overall, these findings lend support for the use of portions of this abbreviated and adapted version of the HOME for use among heterogeneous, cross-cultural groups in low- and middle-income nations.

Approach temperament across cultures: Validity of the Infant Temperament Scale in MAL-ED

ABSTRACT Characteristics of temperament have been shown to predict aspects of personality and psychopathology. Approach temperament (i.e., sensitivity, reactivity, and behavioral disposition toward reward stimuli) may be a particularly salient predictor of developmental outcomes (e.g., Nigg, 2006; Shiner & Caspi, 2003). However, there is little research on approach temperament among children from low- and middle-income nations. This study examined the validity of an adapted version of the Infant Temperament Scale across eight international sites with a focus on approach temperament. Our sample included 1,933 infants from eight study sites in low- and middle-income nations: Bangladesh, Brazil, India, Nepal, Peru, Pakistan, South Africa, and Tanzania. The Infant Temperament Scale was translated and administered as a structured interview to caregivers at each site. Exploratory and confirmatory factor analyses were used to examine the factor structure of the scale, and multiple indicator multiple cause (MIMIC) modeling was used to examine invariance of scores across sites. The findings supported the validity of an approach temperament factor. Although the findings did not support the cross-cultural use of the entire Infant Temperament Scale among individuals from low- and middle-income nations in our sample, the supported approach temperament factor is a theoretically important subconstruct. Moreover, the inability to measure other aspects of temperament across cultures may have important implications for researchers interested in the nature of temperament. Implications and future directions are discussed.