To determine potential, long-term deficits associated with early childhood diarrhea and parasitic infections, we studied the physical fitness (by the Harvard Step Test) and cognitive function (by standardized tests noted below) of 26 children who had complete surveillance for diarrhea in their first 2 years of life and who had continued surveillance until 6-9 years of age in a poor urban community (favela) in Fortaleza in northeast Brazil. Early childhood diarrhea at 0-2 years of age correlated with reduced fitness by the Harvard Step Test at 6-9 years of age (P = 0.03) even after controlling for anthropometric and muscle area effects, anemia, intestinal helminths, Giardia infections, respiratory illnesses, and socioeconomic variables. Early childhood cryptosporidial infections (6 with diarrhea and 3 without diarrhea) were also associated with reduced fitness at 6-9 year of age, even when controlling for current nutritional status. Early diarrhea did not correlate with activity scores (P = 0.697), and early diarrhea remained significantly correlated with fitness scores (P = 0.035) after controlling for activity scores. Early diarrhea burdens also correlated in pilot studies with impaired cognitive function using a McCarthy Draw-A-Design (P = 0.01; P = 0.017 when controlling for early helminth infections), Wechsler Intelligence Scale for Children coding tasks (P = 0.031), and backward digit span tests (P = 0.045). These findings document for the first time a potentially substantial impact of early childhood diarrhea and cryptosporidial infections on subsequent functional status. If confirmed, these findings have major implications for calculations of global disability adjusted life years and for the importance and potential cost effectiveness of targeted interventions for early childhood diarrhea.
1 May 2002 in The American Journal of Tropical Medicine and Hygiene
Diarrhea is well recognized as a leading cause of childhood mortality and morbidity in developing countries; however, possible long-term cognitive deficits from heavy diarrhea burdens in early childhood remain poorly defined. To assess the potential long-term impact of early childhood diarrhea (in the first 2 years of life) on cognitive function in later childhood, we studied the cognitive function of a cohort of children in an urban Brazilian shantytown with a high incidence of early childhood diarrhea. Forty-six children (age range, 6-10 years) with complete diarrhea surveillance during their first 2 years of life were given a battery of five cognitive tests. Test of Non-Verbal Intelligence-III (TONI) scores were inversely correlated with early childhood diarrhea (P = .01), even when controlling for maternal education, duration of breast-feeding, and early childhood helminthiasis (Ascaris or Trichuris). Furthermore, Wechsler Intelligence Scale for Children (WISC-III) Coding Tasks and WISC-III Digit Span (reverse and total) scores were also significantly lower in the 17 children with a history of early childhood persistent diarrhea (PD; P < .05), even when controlling for helminths and maternal education. No correlations were seen between diarrhea rates and Wide Range Assessment of Memory and Learning subtests or WISC-III Mazes. This report (with larger numbers of participants and new tests) confirms and substantially extends previous pilot studies, showing that long-term cognitive deficits are associated with early childhood diarrhea. These findings have important implications for the importance of interventions that may reduce early childhood diarrheal illnesses or their consequences.
Critical to the design and assessment of interventions for enteropathy and its developmental consequences in children living in impoverished conditions are non-invasive biomarkers that can detect intestinal damage and predict its effects on growth and development. We therefore assessed fecal, urinary and systemic biomarkers of enteropathy and growth predictors in 375 6–26 month-old children with varying degrees of malnutrition (stunting or wasting) in Northeast Brazil. 301 of these children returned for followup anthropometry after 2-6m. Biomarkers that correlated with stunting included plasma IgA anti-LPS and anti-FliC, zonulin (if >12m old), and intestinal FABP (I-FABP, suggesting prior barrier disruption); and with citrulline, tryptophan and with lower serum amyloid A (SAA) (suggesting impaired defenses). In contrast, subsequent growth was predicted in those with higher fecal MPO or A1AT and also by higher L/M, plasma LPS, I-FABP and SAA (showing intestinal barrier disruption and inflammation). Better growth was predicted in girls with higher plasma citrulline and in boys with higher plasma tryptophan. Interactions were also seen with fecal MPO and neopterin in predicting subsequent growth impairment. Biomarkers clustered into markers of 1) functional intestinal barrier disruption and translocation, 2) structural intestinal barrier disruption and inflammation and 3) systemic inflammation. Principle components pathway analyses also showed that L/M with %L, I-FABP and MPO associate with impaired growth, while also (like MPO) associating with a systemic inflammation cluster of kynurenine, LBP, sCD14, SAA and K/T. Systemic evidence of LPS translocation associated with stunting, while markers of barrier disruption or repair (A1AT and Reg1 with low zonulin) associated with fecal MPO and neopterin. We conclude that key noninvasive biomarkers of intestinal barrier disruption, LPS translocation and of intestinal and systemic inflammation can help elucidate how we recognize, understand, and assess effective interventions for enteropathy and its growth and developmental consequences in children in impoverished settings.
Persistent diarrhea (PD; duration >/=14 days) is a growing part of the global burden of diarrheal diseases. A 45-month prospective cohort study (with illness, nutritional, and microbiologic surveillance) was conducted in a shantytown in northeastern Brazil, to elucidate the epidemiology, nutritional impact, and causes of PD in early childhood (0-3 years of age). A nested case-control design was used to examine children's diarrhea burden and nutritional status before and after a first PD illness. PD illnesses accounted for 8% of episodes and 34% of days of diarrhea. First PD illnesses were preceded by a doubling of acute diarrhea burdens, were followed by further 2.6-3.5-fold increased diarrhea burdens for 18 months, and were associated with acute weight shortfalls. Exclusively breast-fed children had 8-fold lower diarrhea rates than did weaned children. PD-associated etiologic agents included Cryptosporidium, Giardia, enteric adenoviruses, and enterotoxigenic Escherichia coli. PD signals growth shortfalls and increased diarrhea burdens; children with PD merit extended support, and the illness warrants further study to elucidate its prevention, treatment, and impact.