Determinants and Impact of Giardia Infection in the First 2 Years of Life in the MAL-ED Birth Cohort

Abstract

SummaryIn a multisite birth-cohort study, Giardia spp were detected by enzyme immunoassay at least once in two-thirds of the children. Early persistent infection with Giardia, independent of diarrhea, was associated with deficits in both weight and length at 2 years of age.

The Intersection of Immune Responses, Microbiota, and Pathogenesis in Giardiasis

“…Nevertheless, Giardia was found to be the 4 th most common pathogen found in stools of children younger than 1 year of age and the second most common pathogen among children between 1 and 2 years of age [16]. In the latest report from the Interactions of Malnutrition and Enteric Infections: Consequences for Child Health and Development Project (MAL-ED) project, Giardia detection was associated with reduced height and weight measurements by children of age 2 [17], though stunting and wasting were reported to be somewhat variable between infection studies [18]. …”

“…Yet in the past several years, it has become apparent that Giardia infections that occur early in childhood (earlier than age 2) are associated with reduced height and weight attainment [17, 115], with a critical window of preventing infection between birth and 6 months of life having the greatest impact on growth faltering [115]. This window may be critical due to the establishment and shaping of the composition of intestinal microbiota that provide essential amino acids and vitamins used for growth [116].…”

The Burden of Enteropathy and “Subclinical” Infections

“…Despite these reductions, “subclinical” pathogen detection in stools continues to be common in many impoverished settings and has been associated with poor outcomes. 8,9,52 …”

“…Recognized examples of non-intestinal outcomes associated with enteric infections include associations of toxoplasmosis with birth defects and congenital brain damage (“TORCH” syndrome) 4 and of Campylobacter infections with Guillain-Barré Syndrome. 5 However, as research studies include detection of wider arrays of bacterial, viral, and parasitic pathogens and longer term follow-up, potential effects of enteric infections and enteropathy on vaccine responses, 6,7 child growth, 8,9 cognitive development, 10,11 and even later life obesity, diabetes, and metabolic syndrome are increasingly being recognized. 12–15 Here, we review the evolving challenges to defining EE and enteric infections, current evidence for the magnitude and determinants of its burden, new assessment tools, and relevant interventions.…”

Giardiasis Epidemiology

“…Giardia infections can be detected repetitively in over 40% of children suggesting that persistent infections are common and associated with a damage of the intestinal permeability, which-independently of diarrhea-can lead to stunted growth. In fact, according to the results from the MAL-ED birth cohort study, the persistence of Giardia before 6 months of age was associated with a −0.29 (95% CI, −0.53 to −0.05) deicit in weight-for-age z score and −0.29 (95% CI, −0.64 to 0.07) deicit in length-for-age z score at 2 years [44].…”