Correspondence

Echinococcosis — An Emerging Disease in Farmers

N Engl J Med 2000; 343:738-739September 7, 2000

Article

To the Editor:

Two echinococcus species — Echinococcus multilocularis and E. granulosus — are known to exist in central Europe and to cause alveolar and cystic echinococcosis, respectively, in humans. We report a high prevalence of antibodies against these organisms in farmers.

We tested 152 swine farmers (82 men and 70 women; mean age, 42 years [range, 22 to 70]) and 50 subjects who had not been exposed to farm animals (22 men and 28 women; mean age, 41 years [range, 19 to 60]) for serum antibodies against a variety of viral, bacterial, and parasitic zoonotic agents. Anamnestic data and information on risk factors were obtained with use of a detailed questionnaire. All the subjects lived in the Austrian province of Styria. The serologic results were analyzed in relation to the responses to the questionnaires. The results of a similar study involving 137 veterinarians from Styria have been published.1

Ten of the 152 farmers (6.6 percent) had serum antibodies against echinococcus antigens, as determined by enzyme-linked immunosorbent assay and Western blot analysis, as compared with none of the 50 unexposed subjects and none of the 137 veterinarians.1 Follow-up abdominal ultrasonographic and computed tomographic examinations of the seropositive farmers revealed liver cysts in 3 of them (2.0 percent of the overall group of 152 farmers) (Figure 1Figure 1Ultrasonogram Showing Multiple Echinococcus Cysts in the Liver of a Swine Farmer.). According to the results of clinical, imaging, and serologic studies, these three farmers (all women) had clinically inapparent infections. Thus, the rate of infection in farmers was 50 times the rate in the general Austrian population (in which it is 0.04 percent).2

The routes of transmission of echinococcus eggs to humans are still not clear, but dogs (27 percent of the farmers studied were dog owners) and cats (88 percent were cat owners) are potential final hosts. Pigs, cattle, and other herbivores or omnivores are potential intermediate hosts.

We suggest that a serologic or ultrasonographic screening program be established for the detection of echinococcal infection in swine farmers.

Armin Deutz, D.V.M.
Department of Veterinary Affairs, A-8010 Graz, Austria

Klemens Fuchs, Ph.D.
Joanneum Research, A-8010 Graz, Austria

Herbert Auer, Ph.D.
University of Vienna Medical School, A-1095 Vienna, Austria

Norbert Nowotny, Ph.D.
University of Veterinary Sciences, A-1210 Vienna, Austria

2 References

1. 1

   Nowotny N, Deutz A, Fuchs K, et al. Prevalence of swine influenza and other viral, bacterial, and parasitic zoonoses in veterinarians. J Infect Dis 1997;176:1414-1415
   CrossRef | Web of Science | Medline

2. 2

   Auer H. Zur Epidemiologie der Echinokokkosen in Österreich. In: Janata O, Reisinger E, eds. Infektiologie: Aktuelle Aspekte. Jahrbuch 1999. Vienna, Austria: Österreichische Verlagsgesellschaft,1999;