Disease Surveillance Methods Used in the 8-Site MAL-ED Cohort Study

Abstract

Describing the early life associations between infectious disease episodes and growth, cognitive development, and vaccine response in the first 2 years of life is one of the primary goals of the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study. To collect high-resolution data during a critical early period of development, field staff visit each study participant at their house twice weekly from birth to 2 years of age to collect daily reported illness and treatment data from caregivers. Detailed infectious disease histories will not only allow us to relate the overall burden of infectious disease with the primary outcomes of the study, but will also allow us to describe the ages at which infectious diseases have the greatest effect on child health. In addition, twice-weekly visits allow for sample collection when diarrhea episodes are identified. This article describes the methods used to collect illness and treatment history data and discusses the a priori definitions of diarrhea and acute lower respiratory illness episodes.

Use of antibiotics in children younger than two years in eight countries: a prospective cohort study

“…Children were referred to locally available care, generally a local clinic, when ill 38 . Fieldworkers asked the mother (or other caregiver) to report all oral or injected antibiotics given to their child on each day since the previous visit and to show the medication packaging to confirm the antibiotic and class.…”

“…Non-bloody diarrhoea was defined as mother’s reports of three or more loose stools in 24 hours. Bloody diarrhoea was defined as mother’s report of at least one loose stool with visible blood 38 . Respiratory illness was defined as cough or shortness of breath.…”

“…Respiratory illness was defined as cough or shortness of breath. Acute lower respiratory tract illness was defined as cough or shortness of breath with a rapid respiratory rate determined by fieldworkers (defined by the average of two measurements per day that were: > 60 breaths per minute when the child was < 2 months old; > 50 breaths per minute at age 2 months to 1 year; and > 40 breaths per minute at age ≥ 1 year) 38 . If antibiotics were taken during any day of the illness episode, the episode was classified as treated with antibiotics.…”

A Comparison of Diarrheal Severity Scores in the MAL‐ED Multisite Community‐Based Cohort Study

“…Fieldworkers were trained to use the World Health Organization (WHO-IMCI) dehydration scale (19) and they in turn trained caregivers to recognize dehydration (20). …”

Cost-effectiveness of norovirus vaccination in children in Peru

“…For children 0-5, 6–11, and 12–24 months of age, the incidence was 2.4, 6.6 and 7.0 cases per 100 child-months, respectively. We also performed the analysis using recent data collected from an ongoing rural jungle diarrhea surveillance site in the Amazon Basin [15–17]. With these estimates, children aged 0–5 months, 6–11 months, 12–17 months, 18–24 months, 25–35 months, 36–47 months, and 48–59 months, experienced an incidence of 3.6, 15.8, 15.1, 8.6, 7.9, 6.8, and 5.5 cases per 100 child-months, respectively.…”