RESUMO
The present study aimed to investigate the interactions between serum zinc and Giardia lamblia infection. This infection was diagnosed by direct stool microscopy for Giardia parasites and by detection of Giardia coproantigen in the stool by ELISA. ELISA was found relatively more sensitive than direct stool microscopy as it detected 31 positive cases compared with 27 by direct methods from 112 tested stool samples. It had a sensitivity of 91.2% and a specificity of 100%. Serum zinc level was estimated and compared in 3 groups, 30 children each, aged 1 to 13 years: Children positive for Giardia infection with or without diarrhea [group 1], children with diarrhea due to non-parasitic causes [group 2] and healthy controls [group 3]. Mean values of serum zinc level detected in group 1 [54 mug%] and in group 2 [46.6 mug%] were highly significantly lower [p <0.001] than that detected in healthy controls [92 mug%]. This serum zinc deficiency showed insignificant difference in relation to the degree of intensity of G. lamblia infection [p >0.05]. No significant difference was detected between serum zinc levels of G. lamblia infected children with or without diarrhea. Also, Giardia infected children without diarrhea had a highly significant lower concentration of serum zinc in comparison with the healthy control group [p <0.001]. It was concluded that acute diarrhea and giardiasis may lead to zinc depletion and infants recovering from these infections may benefit from zinc supplementation