Zoonotic transmission of giardiasis: a case control study.

A case control study of locally acquired giardiasis was carried out in a district in East Anglia. Thirty-three primary cases were matched for age and sex with 112 controls selected from Family Health Service Authority registers. An association was shown between giardiasis and contact with farm animals (odds ratio 4.77; confidence interval 1.31-17.38) and pets (odds ratio 14.55; confidence interval 4.18-50.62).