Human hydatid disease: evaluation of an ELISA for diagnosis, population screening and monitoring of control programmes

Epidemiology and clinical features of cystic hydatidosis in Western Sicily: A ten-year review

AIM: To assess retrospectively the epidemiological and clinical aspects of cystic echinococcosis (CE) and to evaluate follow-up and response to treatment in patients affected by CE.

METHODS: From January 2000 to December 2010, all patients affected by CE at the Infectious Diseases Units of the University of Catania and of Basilotta Hospital in Nicosia-Enna, were enrolled as participants in the study. Epidemiological, clinical and laboratory data were collected for each patient. Diagnosis of CE was performed using clinical imaging and laboratory parameters. Response to treatment was categorized as follows: “cure” as the disappearance or complete calcification of cyst/s; “improvement” as a reduction in the diameter and/or number of existing cysts; and “impairment” as an increase in the diameter and/or number of existing cyst/s and the onset of relapses (i.e., the onset of new cyst/s and an increase in the diameter of previously existing cyst/s and/or complications. Immunoglobulin E (IgE) titers and eosinophil percentages were evaluated at diagnosis, at six months after the initiation of treatment and again in the case of relapse. Hyper-eosinophilia was defined as an eosinophil percentage of ≥ 6%.

RESULTS: Thirty-two patients were diagnosed with CE in our Unit during the research period, with a male-female ratio of 2:1. At the time of diagnosis, 40% of patients presented a single CE cyst. Sixty percent showed multi-organ involvement. The liver-lung localization ratio was 2:1. Patients below the age of 50 at diagnosis were more likely to have multiple cysts (73.7% vs 35.5%, P < 0.05). Regarding treatment, 30 patients were treated medically and 16 surgically. Fourteen patients were treated both medically and surgically. Relapses were seen to be less frequent in patients treated with albendazole before and after surgery. Complete cure or an improvement was achieved in 23 patients. Impairment was observed in one patient. Two patients showed no improvement. Relapses were more frequent in those patients treated before 2005. At diagnosis, 71% of patients were positive for specific CE IgE, and 56.3% showed an eosinophil percentage of ≥ 6%. Patients who were diagnosed with hyper-eosinophilia developed complications more frequently than the other patients, but did not suffer relapses.

CONCLUSION: On the basis of our results, we propose cystic echinococcosis screening for family members of patients, appropriate pre- and post-surgery treatment and the assessment of anti-echinococcus IgE titer or eosinophil percentage as a therapy response marker in settings with limited resources.

Advances in liver echinococcosis: diagnosis and treatment

Echinococcosis or hydatid cyst disease is a zoonosis caused by the larval cestode Echinococcus granulosus. It consists of a parasitic tapeworm disease affecting mainly liver. Nevertheless, the disease might well spread to more unusual sites such as lungs and brain. The definitive diagnosis of liver echinococcosis requires a combination of imaging, serologic, and immunologic studies. Despite the fact that a number of scolecoidal agents have been developed against liver hydatid disease, the cornerstone of the definitive treatment remains surgery. Both the classic surgical techniques and the recently developed minimally invasive and laparoscopic methods target the eradication of the disease by simultaneously avoiding perioperative spillage and dissemination or recurrence of echinococcosis. The present article constitutes a review of the biology of the parasite as well as the epidemiology, diagnosis, and therapeutic options of the liver hydatid disease.

Prevalence of cystic echinococcosis among Muslim and Jewish populations in southern Israel

Following a review of records at the Soroka University Medical Center (SUMC) showing a recent increase in the annual incidence of hydatidosis among the Bedouin population of southern Israel, a seroepidemiological survey was conducted. A total of 1439 blood samples were collected from Bedouins and Jews living in the Negev area in southern Israel. An enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G, indirect haemagglutination (IHA) and immunoelectrophoresis (IEP) were used to detect anti-Echinococcus granulosus antibodies. The seroprevalence in the Bedouin group was 0.68% (7/1026), including two children under the age of 10. Among Jews, a seroprevalence of 0.5% was recorded in patients over 60 years of age only. A high rate of infection was shown in goats and sheep slaughtered in abattoirs in Bedouin localities. The results indicate that echinococcosis is a common disease in the Muslim communities of southern Israel.

A review of some simple immunoassays in the serodiagnosis of cystic hydatid disease

Laboratory diagnosis of cystic hydatid disease (CHD) in the field or rural health centres catering to the needs of rural populations, especially in the developing countries, is faced with many difficulties. This paper reviews the need for simple and rapid immunoassays for the diagnosis of hydatid disease in such conditions. Simple and rapid immunoassays such as Dot-enzyme-linked immunosorbent assay (ELISA), hydatid antigen dot immunobinding assay (HA-DIA) and Co-agglutination (Co-A) which have the potential for wider use in the field or poorly equipped laboratories for serodiagnosis of hydatid disease are discussed.

"Congealed waterlilly" sign: a new sonographic sign of liver hydatid cyst

The ultrasonographic (US) appearance of hydatid liver disease is well established, but solid cysts have long defied US characterization. We present 23 solid cysts and describe a new feature called the "Congealed waterlilly" sign. As the physical characteristics of the hydatid fluid change from watery to a viscid gel, it becomes echogenic. The intact folds of the germinal layer trapped within the viscid matrix give rise to the appearance of curvilinear structures which no longer move with changing patient posture. Similar findings have been observed in eight medically treated patients. We observed progression from an initial simple cyst to a "floating waterlilly" through to a "congealed waterlilly" in treated patients. The final appearance was indistinguishable from the untreated solid cysts. The congealed waterlilly sign is reliable and strongly suggestive of hydatid cysts.