Page 114 - JSOM Fall 2025

FIGURE 2 Echinococcosis demographic characteristics, 2000–2024.

Source: Veterans Health Administration, 2025.

feeling of pressure can manifest. Hydatid cysts in the lungs may in 88% of cases that employed an open surgical technique
2
present with chronic cough, chest pain, and shortness of breath. (n=48). 3
2
Intact hydatid cysts—their inner contents walled off behind an
immunosuppressive partition—often do not elicit an immune TABLE 1 Hydatid Cyst Prevalence by Anatomic Site
response. Eosinophilia, a classic laboratory indicator of para- Location Prevalence
sitic infection, has been reported as occurring in 39% of cases. Liver 3,5 75%
3
Besides the liver and lungs, hydatid cysts have been discovered Lungs 2 15%
in the heart, bones (sacrum, spine, pelvis, femur, tibia, humerus, Heart 0.02%–2%
5
skull, and ribs), the orbit, the mediastinum, kidneys, central ner- Bone 5 0.5%–4%
vous system, and the spleen. Site prevalence and symptomology 5
5
for these various sites are shown in Tables 1 and 2. Orbit <1%
Mediastinum 5 <0.1%
Kidney 5 up to 3%
Diagnosis Central nervous system 5 1%–3%
A definitive diagnosis for hydatid disease begins with clini- Spleen 5 2%
cal imaging. Ultrasonography of hepatic hydatid cysts is 90% Peritoneum (ruptured liver cyst) 1%–16%
10
sensitive. Ruptured hydatid cyst should be foremost in the
4
differential diagnosis of patients with a history of blunt-force
trauma and immediate anaphylaxis. The immune response to Prevention
the sudden presence of millions of antigenic protoscolices in Effective prevention of hydatid disease, as with most infectious
the peritoneum (or elsewhere) typically results in an anaphy- diseases, follows a multimodal approach. Dog deworming, re-
lactic shock state. Differential diagnoses for suspected hy- striction of the ingestion of slaughterhouse offal by dogs, and
4
datid disease in various anatomic locations is given in Table 3. the education of people living in endemic areas can greatly
reduce prevalence. A much more draconian measure—the
2
Treatment culling of all sheep and dogs—resulted in eradication of the
disease in Iceland. The 6th edition of the Parasitic Diseases
4
The WHO lists four treatment options for hydatid cysts: (1) textbook recommends the following drugs for the deworming
percutaneous treatment using the PAIR (puncture, aspiration, of dogs: niclosamide, arecoline hydrobromide, and praziquan-
injection, re-aspiration) technique; (2) surgical removal; (3) an- tel. The WHO recommends canine deworming with prazi-
4
thelminthic drug therapy; (4) “watch and wait.” Tables 4 and 5 quantel four times per year. 2
2
elucidate both the staging of cysts and therapeutic protocols for
cysts at different stages of development. The WHO states that the infection is asymptomatic in livestock
and dogs, an aspect of the disease that lends difficulty to its detec-
2
In a 2018 Romanian study, surgical excision was achieved using tion among the natural host species. Sufficiently-equipped and
the Lagrot operation (cystectomy with partial pericystectomy) motivated healthcare practitioners can attempt examination of
112 | JSOM Volume 25, Edition 3 / Fall 2025