Giardia intestinalis is unlikely to be a major cause of the poor growth ofrural gambian infants

Parasite-specific plasma immunoglobulins have been used to indicate the pre sence of Giardia intestinalis infection in 60 infants living in a rural are a of The Gambia. Infants were studied longitudinally between 2 and 8 mo of age, The median age for first exposure to G. intestinalis was between 3 and 4 mo, and by 8 mo all but 3 infants (95%) showed a positive titer on at le ast one occasion. Raised Giardia-specific IgM titers were associated with r educed weight gain in the 2 wk preceding a positive titer, but catch-up gro wth occurred in the following 2 wk. IgM antibody titers were also positivel y associated with intestinal permeability (lactulose/mannitol ratio), urina ry lactose excretion, plasma concentrations of alpha(1)-antichymotrypsin an d total IgM, IgA and IgG immunoglobulins. However, infant growth over the w hole 6-mo period (i.e., between 2 and 8 mo of age) was not related to mean Giardia-specific antibody titers, nor the time of first exposure to the par asite. The data suggest that giardiasis in these very young breast-fed chil dren occurs as a mild, acute disease, and its presence could not explain th e marked, long-term growth faltering observed in many of the subjects.