Serological evidence of human cystic echinococcosis and associated risk factors among general population in Mazandaran Province, northern Iran

Epidemiological characteristics of human cystic echinococcosis in Khuzestan province (Iran), 2011-2021: a retrospective analytical study

Hydatid cyst (HC) disease is endemic in many Mediterranean countries. The most polluted areas of Iran include the Alborz and Zagros Mountain ranges, where animal husbandry is common. This study investigated the epidemiological dimensions of HC in patients admitted to hospitals in Khuzestan province from 2011 to 2021. Of all 183 patients identified, 113 (61.7%) were female with the mean age of 37.7 ± 17, men with the mean age of 36.7 ± 19. Also, we found that housewives made up 49.2% of our HC patients. 65% of the patients in this study lived in urban areas, and 42% had a history of contact with dogs. The liver was reported to be the most HC-affected organ. The most clinical symptoms were abdominal pain and hepatomegaly. 59% of the patients had only one cyst. This study found that surgery and radiology were the most common treatment and diagnostic methods. There were significant relationships between: gender and occupation (p < 0.001); location with dog contact, duration of dog contact (p < 0.001); ways of washing raw vegetables (p < 0.01), and type of treatment (p < 0.05); occupation and dog contact (p < 0.001); with the involvement of the liver being greater in patients who used only water to wash vegetables (p < 0.01). The key to successful disease management is early diagnosis. How to intervene and treat HC necessitates the identification of the stages of the cyst, which is dependent on imaging techniques. The prevalence of human hydatidosis has been overlooked as the most important disease that health policymakers should consider. Furthermore, training programs are required to better understand the disease's symptoms and identify sources of infection.

Status of human cystic echinococcosis based on hospital records in Mazandaran Province: A first registry-based evidence

Background

Human cystic echinococcosis, as an emerging neglected parasitic disease, is caused by tapeworms of the genus Echinococcus spp. Because of the medical and economic importance, this study aims to review the epidemiology and clinical features of hydatidosis in patients admitted to medical and surgical wards in three referral teaching hospitals over 15 years in Mazandaran Province, northern Iran.

Methods

Data were collected from hospital records that were accessible via the hospital information system (HIS) between 2005 and 2019 (15 years).The demographic information (age, sex, living area, and occupation), dog contact, number of the cysts, types of organs involved, and history of disease recurrence were assessed.

Results

One hundred twenty-one patients with human cystic echinococcosis (CE) were involved in the study, from whom 58 patients (47.93%) were male and 63 (52.07%) were female. The majority of patients were rural residents (64.46%) and also housewife (28.10%). Based on the results, only about 16.53% of the patients had history of close contacts with dogs. The liver was the organ involved in the most cases of CE. There were statistically significant differences between residence, occupation, history of close contacts with dogs, type of organs involved, number of cysts and history of disease recurrence (P < 0.05).

Conclusions

Our data provides valuable registry-based information about CE in an endemic region. The data highlights that most patients lived in rural areas and were housewives. Additionally, they had a low rate of disease recurrence but a high rate of close contact with dogs. Moreover, further monitoring on registry-based program and strengthening the HIS in the provincial hospitals in the studied area are required.

Molecular genotyping of Echinococcus granulosus sensu stricto from human Echinococcal cysts in Hatay, Türkiye

Cystic echinococcosis (CE) is one of the zoonotic infections in human, an important global health problem. It was aimed to determine the molecular characterization and phylogenetic analysis of isolates obtained from patients diagnosed with CE in Hatay province, according to the cox1 gene region. A total of 31 patients, 14 males and 17 females, with a mean age of 35.19 (±14.28) years were included in the study. 35 cyst materials obtained from patients were studied. DNA isolation was performed from the samples with protoscoleces determined in the cyst fluid. One-way DNA sequencing was performed with the Sanger Sequencing Protocol through the obtained PCR products. In the study, 35 hydatid cysts of human origin were examined and protoscoleces was detected in 11 (31.43%) of them. Twenty of the patients had liver involvement, seven had lung involvement, and four had both liver and lung involvement. All the samples with protoscoleces detected were observed of PCR product with a size of approximately 446 bp. When the sequence results of the isolates were evaluated within themselves, it was seen that there were three different sequences with 99% similarity to each other. As a result, of the phylogenetic analysis, it was determined that the isolates were identified in the Echinococcus granulosus sensu stricto (E. granulosus s. s.) (G1-G3) complex. This study is thought to contribute to the epidemiology, parasite control, effective diagnosis and treatment techniques, eradication, vaccine and drug development studies of E. granulosus s. s in Türkiye.

Prevalence of human cystic echinococcosis in the towns of Ñorquinco and Ramos Mexia in Rio Negro Province, Argentina, and direct risk factors for infection

Background

Cystic echinococcosis (CE) is a parasitic zoonosis caused by infection with the larval stage of Echinococcus granulosus (s.l.). This study investigated the prevalence and potential risk factors associated with human CE in the towns and rural areas of Ñorquinco and Ramos Mexia, Rio Negro province, Argentina.

Methods

To detect abdominal CE cysts, we screened 892 volunteers by ultrasound and investigated potential risk factors for CE using a standardized questionnaire. Prevalence ratio (PR) with 95% confidence intervals (CI) was used to measure the association between CE and the factors investigated, applying bivariate and multivariate analyses.

Results

Abdominal CE was detected in 42/892 screened volunteers (4.7%, 95% CI 3.2–6.1), only two of whom were under 15 years of age. Thirteen (30.9%) CE cases had 25 cysts in active stages (CE1, CE2, CE3a, according to the WHO Informal Working Group on Echinococcosis [WHO-IWGE] classification). The most relevant risk factors identified in the bivariate analysis included: living in rural areas (P = 0.003), age > 40 years (P = 0.000), always drinking water from natural sources (P = 0.007), residing in rural areas during the first 5 years of life (P = 0.000) and having lived more than 20 years at the current address (P = 0.013). In the multivariate final model, the statistically significant risk factors were: frequently touching dogs (P = 0.012), residing in rural areas during the first 5 years of life (P = 0.004), smoking (P = 0.000), age > 60 years (P = 0.002) and living in rural areas (P = 0.017).

Conclusions

Our results point toward infection with CE being acquired since childhood and with constant exposure throughout life, especially in rural areas with a general environmental contamination.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04753-y.

Designing a Recombinant Multi-Epitope Antigen of Echinococcus granulosus to Diagnose Human Cystic Echinococcosis

BACKGROUND

Cystic echinococcosis can cause severe disease and probable death in humans. Epitopes of its antigens play a key role in the sensitivity and specificity of immunodiagnostic tests.

METHODS

Epitope prediction software programs predict the most antigenic linear B-cell epitopes of AgB (8 kD), Ag5, and Ag95. Six such epitopes were predicted and connected by "Gly-Ser" linker and synthesized. The purity of the concentrated recombinant multi-epitope protein was assessed by 15% SDS-PAGE. Overall, 186 serum samples were collected from the Loghman Hakim Hospital and different laboratories, Tehran, Iran, from July 2016 to February 2017. Patients infected with hepatic hydatid cysts, patients infected by other parasites and viruses, and healthy individuals were used to detect the anti-CE IgG using recombinant multi-epitope protein.

RESULTS

Forty-one samples out of 43 cases of hydatidosis were diagnosed correctly as positive, and two were negative. In addition, six negative cases of healthy individual group were diagnosed as positive and negative with rMEP-ELISA and the commercial kit, respectively. Therefore, these six samples were considered as false positive using our method. In addition, a diagnostic sensitivity of 95.3% (95% CI, 84.19% to 99.43%) and a specificity of 95.0% (95% CI, 89.43% to 98.14%) were obtained using optimum cutoff value (0.20). The sensitivity and specificity of the commercial kit was 100%.

CONCLUSION

Our findings showed high diagnostic accuracy of the ELISA test using the developed recombinant protein, which encourages the use of this recombinant multi-epitope protein for rapid serological diagnosis of hydatidosis.

Epidemiology of echinococcosis in Iran: a systematic review and meta-analysis

BACKGROUND

Echinococcosis is a zoonotic disease caused by the larval stages of taeniid cestodes of the genus Echinococcus. The two major types of infection in humans are cystic echinococcosis (CE) or hydatidosis and alveolar echinococcosis (AE). It is endemic in some parts of the world, such as the Middle East, with Iran being a part of it. This systematic review and meta-analysis were conducted to determine the prevalence of CE and AE echinococcosis and their epidemiological and clinical aspects in Iran.

METHODS

Electronic databases, including MEDLINE (via PubMed), SCOPUS, Web of Science, SID and Mag Iran (two Persian scientific search engines) were searched from 1 January 1990 to 8 August 2017. The prevalence of CE and AE echinococcosis was estimated using the random effects meta-analysis. Heterogeneity was evaluated by subgroup analysis. Data were analyzed by STATA version 12.

RESULTS

Of the 2051 records identified in the mentioned electronic databases, Seventy-eight articles met our eligibility criteria, with a total of 214124individuals. The meta-analysis was performed on only 37 out of 78 included studies. The pooled prevalence of CE and AE in Iran was 5% [95% confidence interval )CI(: 3-6%] and 2% [95% CI: 0-5%], respectively. Subgroup meta-analysis revealed that the prevalence of CE was significantly higher in North [9%, 95% CI: 4-18%] and West of Iran [6%, 95% CI: 3-11%], patients younger than 40 years of age [7%, 95% CI: 4-12%], villagers and nomads [6%, 95% CI: 2-12%], and studies that used the combination of serological, clinical, and imaging diagnostic methods [7%, 95% CI: 5-9%]. There were no significant differences between the prevalence of CE among low and high-quality studies. Housewives were the most affected group by hydatidosis (n=24/77, 31%), followed by illiterate people (n=11/77, 14%) and farmers (n= 9/77, 12%). Liver [55%, 95% CI: 46-65%] and lung [28%, 95% CI, 22-35%] were the most common sites of cyst formation.

CONCLUSIONS

Given to the importance of echinococcosis on human health and domestic animals industry, it is necessary to implement monitoring and control measures in this regard.

The pattern of cystic echinococcosis in children in an endemic area in Morocco

Cystic echinococcosis is a parasitic infection of major public health concern. The infection is generally acquired during childhood and the disease incubation period can last many years. The occurrence and characteristics of the disease in children were not well studied. The present study aimed to explore the pattern and features of cystic echinococcosis in children in rural and urban environments in Morocco. A total of 338 children diagnosed and treated for cystic echinococcosis were investigated. The trend of the infection, risk and exposure factors and the distribution of the anatomic locations of cysts were studied. A non-uniform decrease in proportions of infected children was found. Children from rural environs had significantly higher infection rates than children from urban environs (p < 0.001). Males were significantly more infected than females. Children aged 7-11 years were the most affected. For cysts locations, single organ involvement was found in 94.4% of the children versus 5.6% with multi-organ localization. Despite control program, active transmission of echinococcosis still occurred in children and remains a major public health problem. The infection in younger population may have some features that need to be considered in the prevention and control programs in endemic areas.

Seroprevalence of Hydatidosis in People Referring to Reference Laboratory of Gorgan, Golestan Province, Northern Iran 2017

BACKGROUND

Hydatidosis is a neglected global zoonotic disease, caused by larval stage of the cestode Echinococcus granulosus in human and animal. Because of high economic and medical importance of the disease, this study was performed to find the seroprevalence of human hydatidosis in Gorgan City, Golestan Province, northern Iran.

METHODS

In this cross-sectional study, blood samples were collected from people referring to Reference laboratory of Golestan University of Medical sciences in 2017. A relevant questionnaire was completed for demographic data for each person. Echinococcus IgG antibody was investigated by ELISA using native antigen B. The data were analyzed using SPSS software applying logistic regression.

RESULTS

Overall, 612 blood samples were collected. Cut-off was considered 0.29. Sixteen cases (2.6%) were seropositive for hydatidosis. The seroprevalence of hydatidosis was 2.3% and 4.7% among males and females, respectively. There was no statistically significant correlation between the hydatidosis and investigated variables such as sex, age, tribes, residence, education, etc.

CONCLUSION

The prevalence of human hydatidosis shows approximately the same range as other regions of Iran. Although due to the neighboring the Mazandaran Province reported as the highest seroprevalence of hydatidosis, we expected more rate of seropositivity.