Height, Zinc and Soil-Transmitted Helminth Infections in Schoolchildren: A Study in Cuba and Cambodia

Abstract

Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children, plasma zinc was associated with height for age (aB-0.033, p = 0.029), but STH infection was not. Only in Cambodia, STH infection showed an association with zinc concentration (aB-0.233, p = 0.051). Factors influencing child growth differ between populations and may depend on prevalences of STH species and zinc deficiency. Further research is needed to elucidate these relationships and their underlying mechanisms.

Intestinal parasites: Associations with intestinal and systemic inflammation

“…For instance, Sanchez et al,34 found no association between STH and IL‐10 in a study in Honduran children. Also, de Gier et al35, did not find differences in acute phase protein or CRP in Cuban or Cambodian children between infected and non‐infected children with STH. Our results confirm the lack of association between systemic inflammatory markers and intestinal parasitic infection.…”

“…33 For instance, Sanchez et al, 34 found no association between STH and IL-10 in a study in Honduran children. Also, de Gier et al 35 To our knowledge, this is the first study to evaluate the relation-…”

“…The literature addressing the effect of STH and intestinal protozoa parasites on stool leukocytes is scarce. However, one study reported no association between hookworm infection and intestinal inflammation measured as faecal calprotectin concentrations 35. The results indicate that intestinal parasites might have the ability to evade systemic inflammatory reactions, but they fail to do so in the gut.…”

“…For instance, A. lumbricoides penetrates through the gut and migrates to the bloodstream causing tissue injury that might trigger an immune response in the gut. 48 In contrast, the association of E. coli with faecal leucocytes is unexpected, as E. coli is considered a "non- 35 The results indicate that intestinal parasites might have the ability to evade systemic inflammatory reactions, but they fail to do so in the gut.…”

Assessing zinc in humans

“…Hair has the advantage of being easily collected and is stable indefinitely if stored appropriately. Included studies collected hair samples ranging from 0.2 to 2g, from the nape of the neck, adjacent to scalp (4, 6), or from 1.5 cm from scalp at the nape or occipital region (5). Hair samples were washed in deionised water, dried and acid digested prior to analysis by either atomic absorption spectrometry (AAS) (4,5) or inductively couple plasma mass spectrometry (ICPMS) (6).…”