Disease/Syndrome |
Echinococcosis |
Category |
Infection, Occupational |
Acute/Chronic |
Chronic |
Synonyms |
Alveolar hydatid disease; Unilocular echinicoccosis; Cystic hydatid disease; Echinococcus granulosus infection; Hydatidosis |
Biomedical References |
Search PubMed |
Comments |
The dog tapeworm, Echinococcus granulosus, causes cystic hydatid disease. Cysts take years to develop reaching diameters of 1-15 cm or more. Cysts are common in the liver and lungs. The differential diagnoses include cancer, amebic abscesses, congenital cysts, and tuberculosis. The disease is most common in grazing areas of the world. Domestic dogs are hosts, and sheep are the intermediate hosts. Other intermediate hosts include cattle, goats, pigs, horses, moose, and caribou. Dogs are infected by eating infected sheep viscera. Human infections usually occur in childhood after direct contact with the feces of infected dogs or indirectly through contaminated flies, fomites, food, or water. [CCDM, p. 183-7] Cysts are usually found in the liver. Bile obstruction may occur and cause jaundice. Rupture of a cyst, depending upon its location, may cause fever, urticaria, abdominal pain, cough, chest pain, and hemoptysis. [Merck Manual, p. 1561-2] E. granulosa forms cysts in the liver 50% to 70% of the time, in the lung 20% to 30% of the time, and in other organs 10% of the time. Cysts can reach a size of 5-10 cm within one year. Cyst rupture can cause severe allergic reactions including anaphylaxis. Serology assays are available from the CDC to confirm past exposure when suspicious cysts are found by MRI, CT, or ultrasound. [PPID, p. 3290-2] |
Latency/Incubation |
12 months to many years |
Diagnostic |
Sonography, MRI, and CT; The immunoblot test is accurate for liver cyst (91% sensitive/95% specific); Biopsy; [Current Consult, p. 350; CDC website] Serology is helpful when positive; [ID, p. 2397] |
ICD-9 Code |
122.4 |
Effective Antimicrobics |
Yes |
Scope |
Worldwide, mostly in northern latitudes |
Reference Link |
CDC - Echinococcosis |
Image |
MedlinePlus Medical Encyclopedia: Liver echinococcus - CT scan |
Related Information in Haz-Map |
Symptoms/Findings |
Symptoms/Findings associated with this disease:
|
Job Tasks |
High risk job tasks associated with this disease:
|
|
|