Giardiasis is the third most commonly notified disease in New Zealand, and the most frequently notified water-borne disease. Nearly 2,000 cases are reported yearly, an incidence rate of about 50 per 100,000 population; the infection is most common in young children.
Dr. M Ekramul Hoque and colleagues from the University of Auckland, New Zealand, did a case-control study in 1998 to identify modifiable risk factors for Giardia infection in Auckland.
183 patients with stool-positive Giardia spp referred to community laboratories were compared with 336 age-matched controls identified randomly from the Auckland telephone directory. Exposure information for the previous 3 weeks was obtained retrospectively by telephone.
Housewives and nursing mothers were more than twice as likely to be infected than other groups; nappy changing was associated with a four-fold increased risk of infection after controlling for other confounders.
|Children wearing nappies could be an important source of Giardia infection
in the community.|
The investigators conclude that children wearing nappies could be an important source of Giardia infection in the community.
Dr M Ekramul Hoque comments: "Washing hands with soap and water after every nappy change as well as after using the toilet and before handling food could reduce person-to-person transmission of this ubiquitous protozoan parasite. Safe and rapid disposal of soiled nappies is also important.
"More than half of those infected remain asymptomatic and these rates of infection are unknown. Improved surveillance and further research into the transmission of this organism, especially in developed countries, focusing on transmission within households and in childcare centres will assist in identifying potentially effective preventive interventions, not only for giardiasis but for other diarrheal diseases".