Giardia duodenalis infection in humans can cause a variety of clinical symp
toms. The relation between clinical symptomatology and the Giardia isolate
genotype was studied in 18 Dutch patients infected with G. duodenalis who v
isited their general practitioner. Contrary to earlier studies, a 100% corr
elation between severity of diarrhoeal complaints and genotype: was found:
assemblage A isolates were solely detected in patients with intermittent di
arrhoeal complaints, while assemblage B isolates were present in patients w
ith persistent diarrhoeal complaints. These results are significant because
they show for the first time that genetically linked features of G. duoden
alis are major determinants in the severity of infection in human giardiasi
s. (C) 2001 Australian Society for Parasitology Inc. Published by Elsevier
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