Domestic Pets as Risk Factors for Alveolar Hydatid Disease in Austria

Abstract

To identify the risk of pet ownership (i.e., cats and dogs) for alveolar echinococcosis caused by Echinococcus multilocularis, the habits and activities of 21 patients (histologic confirmation or positive serology with corresponding evidence on an ultrasonogram, radiograph, or computed tomography scan) in Austria during the period 1967-1997 were compared with the habits and activities of 84 controls matched by sex, age, and residence. Cat ownership (odds ratio (OR) = 6.47, 95% confidence interval (CI) 1.54-27.29) and hunting (OR = 7.83, 95% CI 1.16-52.77) were independent risk factors associated with alveolar hydatid disease. The study is not in agreement with the hypothesis that eating mushrooms or certain wild berries which grow near the ground are the main risk factors for acquiring this disease. No other behavior patterns or activities studied were identified as risk factors.

An epidemiologic survey of human alveolar echinococcosis in southwestern Germany. Römerstein Study Group.

“…5,31 Recently, a case-control study with 21 AE patients from Austria identified cat ownership and hunting in forests as independent risk factors, while agricultural activity was not identified as high-risk. 4 In our study, none of the factors mentioned was found to be significantly correlated with seroreactors or cases. It has to be noted, however, that the retrospective studies mentioned were based on confirmed AE cases, while in our study the risk was largely evaluated with seroreactors.…”

“…Contaminated foodstuffs from the environment eaten uncooked and infected dogs and cats carrying the tapeworm eggs in their fur are suspected to be important sources of infection. 4 In parts of Europe, AE seems to be an occupational hazard for farmers, 5,6 who may be at risk by handling contaminated soil or by inhaling dust containing eggs during farming activities. The primary location of the parasite in humans is the liver, although metastases may form elsewhere in later stages of the disease.…”

Risk factors for Echinococcus granulosus infection: a case-control study.

“…In the Alaskan study, 7 the risk of disease was associated with dog ownership and residence in a dwelling constructed directly over the tundra. The Austrian study found no association between dog ownership and a higher risk of disease, 8 possibly because dogs enjoy greater freedom of movement in Alaska than they do in Austria and the likelihood of Austrian dogs ingesting carrion is therefore lower. Nevertheless, cat ownership was significantly associated with E. multilocularis infection, a variable not considered in the Alaskan study.…”

“…7,8 These studies analyzed 19 and 23 cases of alveolar echinococcosis caused by the larval phase of E. multilocularis that occurred in Alaska and Austria, respectively. In the Alaskan study, 7 the risk of disease was associated with dog ownership and residence in a dwelling constructed directly over the tundra.…”

“…Only two case-control studies had previously been published, 7,8 although both concentrated exclusively on alveolar hydatidosis, which is caused by E. multilocularis and whose clinical presentation and pattern of distribution are different from those of cystic hydatid disease. Furthermore, we sought to identify behavior patterns associated with higher risk of infection, with the aim of suggesting disease-prevention guidelines based on implementation of public health programs.…”