Prevalence Of Human Cystic Echinococcosis Research Articles

A regressive analysis of the main environmental risk factors of human echinococcosis in 370 counties in China.

Echinococcosis is a natural focal, highly prevalent disease in China. Factors influencing the spread of echinococcosis are not only related to personal exposure but also closely related to the environment itself. The purpose of this study was to explore the influence of environmental factors on the prevalence of human echinococcosis and to provide a reference for prevention and control of echinococcosis in the future. Data were collected from 370 endemic counties in China in 2018. By downloading Modis, DEM and other remote-sensing images in 2018. Data on environmental factors, i.e., elevation, land surface temperature (LST) and normalized difference vegetation index (NDVI) were collected. Rank correlation analysis was conducted between each environmental factor and the prevalence of echinococcosis at the county level. Negative binomial regression was used to analyze the impact of environmental factors on the prevalence of human echinococcosis at the county level. According to rank correlation analysis, the prevalence of human echinococcosis in each county was positively correlated with elevation, negatively correlated with LST, and negatively correlated with NDVI in May, June and July. Negative binomial regression showed that the prevalence of human echinococcosis was negatively correlated with annual LST and summer NDVI, and positively correlated with average elevation and dog infection rate. The prevalence of human cystic echinococcosis was inversely correlated with the annual average LST, and positively correlated with both the average elevation and the prevalence rate of domestic animals. The prevalence of human alveolar echinococcosis was positively correlated with both NDVI in autumn and average elevation, and negatively correlated with NDVI in winter. The prevalence of echinococcosis in the population is affected by environmental factors. Environmental risk assessment and prediction can be conducted in order to rationally allocate health resources and improve both prevention and control efficiency of echinococcosis.

The Diagnosis, Treatment, Surveillance and Control of Cystic Echinococcosis in the Province of Rio Negro: The “One-Health” Model

Cystic Echinococcosis (CE) is an endemo-epidemic disease in the Rio Negro Province, República Argentina. Due to the number of cases, the length of hospital stays after surgery and its associated mortality, it is a serious public health problem that generates high costs for the health system. Oriented towards its control, primary prevention activities have been carried out since 1980, based on the deworming of dogs and the vaccination of lambs; secondary prevention has consisted in the actively search for cases through serological or ultrasonographic screening; and tertiary prevention has been based on timely treatment, either by surgery or by medical treatment with albendazole. All these prevention activities have been carried out under the concept and strategies of the “One Health” model, through both inter-institutional and interdisciplinary work, as well as with the support, commitment and critical participation of the community. As a result, an important drop has been observed in the prevalence of CE in humans and in its lethality (0.5% in 1997–2020, no deaths in the last two years); moreover, an important decrease has been observed in costs to the health system, due to the reduction of hospitalizations and the number of surgeries.

Prevalence of human cystic echinococcosis in the towns of \xd1orquinco and Ramos Mexia in Rio Negro Province, Argentina, and direct risk factors for infection

BackgroundCystic 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.MethodsTo 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.ResultsAbdominal 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).ConclusionsOur 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.Graphical

The Prevalence of Human Cystic Echinococcosis in Campania Region: Result of a Regional Screening Project

Abstract Cystic echinococcosis is a world-wide parasitic infection mainly caused by Echinococcus granulosus (E. granulosus). The purpose of our study was to assess the current status of human Cystic Echinococcosis (CE) epidemiology in Campania region. In view of the severity of this human disease, the early diagnosis of the presence of the cyst/s avoid surgery practice and allow the admission of drug therapy. In this regard the project has offered farmers, their families, and farm workers the possibility of CE serological and clinical diagnosis. The study was conducted between 2014 and 2018 in 650 farms, located in four provinces of Campania region (Salerno, Avellino, Caserta and Benevento). Seroprevalence was evaluated through EnzymeLinked Immunosorbent Assay (ELISA), Indirect Hemagglutination Test (IHA) and Western Blot (WB). A seroprevalence of 0.4% was documented, in particular 0,3 % in Salerno and 0,1 % in Avellino. Out of a total of 4 positive subjects, 3 were male, all were recorded in over 40 years’ age group, located in sheep farms (0,6%). Liver cyst, as CE3a stage, was identified in one subject from Salerno province. This is the first study on human hydatidosis in Campania region so could have a huge impact to define the strategies and monitoring activities for spread reduction of human CE. Keywords Campania; Cystic echinococcosis; Echinococcus granulosus; Epidemiology; Italy; Ultrasound

Cystic Echinococcosis in Humans in Turkey

Although cystic echinococcosis (CE) is quite prevalent in Turkey, it is extremely neglected due to being usually asymptomatic for years and frequently not to be reported although it is obligatory. Most of the data on the prevalence of CE in humans in Turkey are based on hospital records, reported cases and the studies based on serological methods and they do not reflect the truth. The fact that detecting no cysts in most of the seropositive cases limits the value of researches based on serological tests. The most valuable epidemiologic data on CE are obtained by mass screening surveys with the use of portable ultrasonography (US) and it took the place of serological tests, especially in the last 20 years. Two of 190 cases older than 20 years were found to be positive for CE in a village of Konya city at the first study that US was performed in Turkey. At the first research performed on preliminary school children in Manisa Province; of the 630 students examined by US, serology and chest X-ray, 2 (0.3%) were diagnosed as CE by US. Only US was used at the second study, and hydatid cysts were observed in 3 (0.5%) of the 575 students in two villages; these data suggested that the use of US alone was more easy, fast and beneficial in the field studies. In the third research, 6093 students from 37 different schools of Manisa Province were selected as a representative sample, and 9 (0.2%) children (two previously operated) were found to be positive for CE by US. The only response to the invitation to use this model in different regions of Turkey was from Elazig Province and of the 2500 students selected, six cases (one previously operated) were detected, and the prevalence was found to be 0.2% in Elazig Province. During the same years, of the 102 cases sharing the same living space with 40 patients operated due to CE, 13 (12.7%) were radiologically diagnosed as CE in Van, while CE was diagnosed in 1 (0.5%) of the 209 cases in an area dealing with animal husbandry in Aydın. At the fourth research in Manisa, 4275 students from university were examined by US, while 2034 of these were also serologically tested by ELISA and Western Blot (WB). The efficacy of WB as a screening test in CE was investigated for the first time in the world; six new and three operated cases were detected, and the prevalence was 0.2%. During the research in the rural areas of Bulgaria, Romania and Turkey, of the 8618 cases living in six cities (Ankara, Aksaray, Balikesir, Bitlis, Edirne, Sanliurfa) of Turkey, 53 (0.6%) abdominal CE cases were detected by US and one of every 163 cases in Turkey was found to be infected with CE. This ratio shows that CE is one of the most important public health problems in Turkey. Control of CE is possible with "One Health" concept. An effective control program and changes in valid laws are needed in Turkey. In this review, the value of different diagnostic procedures have also been discussed.

Geographical Environment Factors and Risk Mapping of Human Cystic Echinococcosis in Western China.

The study aimed to reveal the risk factors and predict the prevalence of human cystic echinococcosis (CE) in Western China. To do this, we analyzed county-wide data relating to the prevalence of human CE in seven provinces of Western China, along with associated human, natural geographical environmental data. We then used spatial analysis and multiple regression analysis to investigate the correlation between the prevalence of human CE and associated environmental factors and to create a risk map of the disease in the seven provinces. Our analysis showed that grassland area ratio and Tibetan population ratio were independent variables positively correlated with the prevalence of human CE and that gross domestic product (GDP) and land surface temperature (LST; Spring) were negative independent variables. We also created a predictive risk map of human CE that revealed that the high-risk areas were mainly located in the south of Qinghai, the Northwest of Sichuan and most of the Tibet Autonomous Region. Knowledge of the spatial distribution and risk factors associated with human CE could help to prevent and control echinococcosis in China.

Prevalence of echinococcosis in humans, livestock and dogs in northern Italy

Abstract The presence of Echinococcus sp. cysts was investigated in 822 sheep, 123 goats and 112,521 cattle from Lombardy region, North Italy. Faecal samples from 40 sheepdogs were also analyzed, with 9 samples containing taeniid eggs (22.5 %), 8 samples being coproantigen-positive (20 %), and one dog from a northern province (Lecco) positively confirmed by PCR. Cystic Echinococcosis (CE) was detected in 0.36 % of sheep and in 0.29 % of cattle in 2004. No goat resulted to be infected. Data from CE patients treated in Lombardy were collected by inspecting hospital discharge records. In 2004, 156 CE-related admissions (62 % male and 38 % female) were reported in Lombardy. Total hospital stay was 1,372 days (1,286 for inpatients, 86 for outpatients). Most patients (72.4 %) were residents in Lombardy and 1.9 % were from Piedmont; the remaining patients were from central and southern Italy. According to acquired data CE resulted hypoendemic in animals in Lombardy. Prevalence rates in humans were higher than expected in this region, usually considered as non-endemic. Assessment of the prevalence of CE in humans remains a difficult, costly, time-consuming and labourintensive task. The present study suggests establishing a National Registry of Cystic Echinococcosis with the aim to highlight regional risk factors and to benefit from its matching both clinical and epidemiological data.

Human cystic echinococcosis in two Mongolian communities in Hobukesar (China) and Bulgan (Mongolia)

In order to investigate the prevalence of human cystic echinococcosis (CE) in traditional Mongolian communities in western Mongolia and Xinjiang (northwest China), studies were carried out between 1995 and 2000, on two ethnically identical populations in Hobukesar (China) and Bulgan (Mongolia). The prevalence of human hepatic CE in the two communities was significantly different. In Hobukesar, human CE prevalence by ultrasound was 2.7% (49/1844), while in Bulgan it was 0.2% (4/1609) (P<0.001). Dog surveys showed that coproantigen-positive rates or dog necropsy positives were similar in both communities (35.0% in Hobukesar and 35.7% in Bulgan). Comparing possible risk factors, there appeared to be some significant differences between the two communities, which might contribute to the observed difference in CE prevalence. These included: the proportion of herdsman or farmers recorded; the proportions of dog ownership and livestock ownership; and the proportion of families practising home slaughter. The presence of a Russian dog-dosing programme up to the mid-1980s may explain the lower prevalence of human CE in the Bulgan population; no similar programme operated in the China-administered Hobukesar community.

A canine purgation study and risk factor analysis for echinococcosis in a high endemic region of the Tibetan plateau

The Tibetan plateau of western China has been shown to have a very high prevalence of human cystic echinococcosis (CE) caused by Echinococcus granulosus and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. A purgation study of 371 dogs in Shiqu County, Sichuan Province during 2002–2003 resulted in an E. multilocularis prevalence of 12% and an E. granulosus prevalence of 8%. These crude prevalences were then adjusted, based on the known sensitivity of arecoline purgation for the detection of E. granulosus and a suggested sensitivity for the detection of E. multilocularis. In addition, it was assumed that some immature parasites of either species could be misidentified morphologically and wrongly assigned. This resulted in credible true prevalence intervals of between 13–33% for E. multilocularis and 8–19% for E. granulosus. Prevalences of other intestinal helminthes found on purgation were: Taenia spp. 31%, Dipylidium caninum 1%, and ascarids 8%. Risk factors associated with the acquisition of canine echinococcosis were evaluated based on responses to a questionnaire administered to dog owners. Male dogs were more likely to be infected with Echinococcus spp. than female dogs ( P < 0.05) and dogs allowed to roam were more likely to be infected with E. multilocularis ( P < 0.05).

Cystic echinococcosis in semi-nomadic pastoral communities in north-west China

In order to determine the prevalence of human cystic echinococcosis (CE) in semi-nomadic traditional pastoralist groups in north-west China, 2 large community studies were undertaken in Altai and Tacheng Prefectures in 1990/91 and 1995/96, respectively. The Kekergash community (Altai) comprised mainly ethnic Kazakhs, whereas the Narenhebuke community (Tacheng) comprised mainly Mongolians. Populations were screened for CE by abdominal ultrasound scan (US) and serological tests. The total prevalence of confirmed human CE was higher in Narenhebuke (2·7%, 49/1844) than in Kekergash (0·9%, 17/1861; P < 0·01). Within each community there was no significant difference of CE prevalence between the Kazakh and Mongolian groups, although Han Chinese exhibited twice the rate of CE (4·9%) in Narenhebuke compared to the dominant Mongolian population. For each community, human CE prevalence increased with age and there was a greater risk associated with the practice of home slaughter of livestock. Dogs were screened for Echinococcus granulosus infection and re-infection levels using a highly specific coproantigen test. The proportion of dogs with positive coproantigen tests was significantly higher in Narenhebuke (36·0%, 50/139) compared to Kekergash (17·8%, 16/90). In Narenhebuke the re-infection levels of dogs, as determined by coproantigen positivity, were higher in the winter quarters (49·4%, 39/79) compared to the summer quarters (18·3%, 11/60; P < 0·01). Furthermore, coproantigen re-test positivity was 25% at 3 months and 29·2% at 7 months. Highest dog coproantigen positivity was obtained over the winter period.

Field diagnosis of Echinococcus granulosus infection among intermediate and definitive hosts in an endemic focus of human cystic echinococcosis

Human, canine and ovine echinococcosis prevalence was determined in a highland community located in the central Peruvian Andes during 1997 and 1998. Human echinococcosis was determined using portable ultrasonography, chest X-ray examination, and an enzyme-linked immunoelectrotransfer blot (EITB) assay. Canine echinococcosis was determined using microscopy stool examinations and a coproantigen detection enzyme-immunoassay (EIA) for Echinococcus granulosus. Ovine echinococcosis was determined by an EITB assay for sheep echinococcosis and necropsy examination of viscera from domestic slaughtered animals. An abdominal ultrasound, a chest X-ray examination and an EITB for echinococcosis were performed on 214 subjects (45% of the village population). The frequency of presumptive liver/abdominal, lung and liver-lung hydatid cysts was 5·1% ( 11 214 ), 3·7% ( 8 214 ) and 0·5% ( 1 214 ), respectively. The overall prevalence of human cystic echinococcosis was 9·3% ( 20 214 ). The frequency of canine echinococcosis was 46% ( 23 50 ) and 32% ( 16 50 ) by the coproantigen EIA test and arecoline purging, respectively. The frequency of sheep echinococcosis was 65% ( 22 34 ) by the EITB and 38% ( 13 34 ) by necropsy. We demonstrated a high prevalence of human and animal echinococcosis in this Peruvian village. In remote areas where echinococcosis is endemic, both the coproantigen EIA and arecoline purging may be used for the study of canine echinococcosis; the EITB is useful in establishing the diagnosis of echinococcosis in sheep prior to necropsy.

An extensive ultrasound and serologic study to investigate the prevalence of human cystic echinococcosis in northern Libya.

A prevalence study of abdominal cystic echinococcosis (CE) was undertaken in the northwest, north-central, and northeast regions of Libya. A total of 36 villages along the coast were included, in which 20,220 people were screened by portable ultrasound. Three hundred thirty-nine (1.7%) were diagnosed with CE. There was no significant difference between CE prevalence rates in the three regions of Libya (mean = 1.6%); however, intervillage rates were variable, ranging from 0% to 4.5%. The prevalence of CE increased significantly with age (P < 0.0001) and females were significantly more affected (2%) than males (1.3%) (P < 0.0001). Cases of CE were distributed among 3.2% of housewives, 2.6% of farmers, 2.3% of male civil servants, 1.3% of female students, and 1.1% of male students. Housewives (P < 0.0001) and students (P < 0.0001) were significantly more at risk for CE. A statistically significant proportion (62% [210 of 339]) of CE cases kept dogs (P < 0.0001). Of the ultrasound-positive CE cases 69% (233 of 339) were antibody seropositive by ELISA using Echinococcus granulosus hydatid cyst fluid antigen B. Blood samples (n = 10,096) collected onto filter papers were taken randomly from ultrasound-negative people who entered the study, of which 11.2% were found to be seropositive. Seropositivity increased with age (P < 0.0001), with females exhibiting higher seroprevalence than males for all age groups (P < 0.0001). Seroprevalence was distributed occupationally among 17.3% of female students, 11.2% of male students, 8.3% of housewives, 7.3% of farmers, and 6.4% of male civil servants. Housewives and students were more likely to be seropositive (P < 0.0001). Forty-seven percent (526) of the seroreactors kept dogs. All liver hydatid cysts detected by ultrasound during community screening were classified according to morphology and size into six types. Type I (17.5% of all cases) were small univesicular cysts less than 50 mm in diameter with no laminations or daughter cysts. Type II (34%) were univesicular cysts with only laminations. Type IIIa (8.5%) were univesicular cysts with the appearance of laminations and daughter cysts. Type IIIb (13%) were univesicular with laminations and less prominent daughter cysts. Type IV (5.6%) presented as a solid mass. Type V were degenerated calcified or partially calcified cysts (13.2%). Type VI presented as multiple cysts (8% of all cases). The CE cases that exhibited Types II, IIIa, IIIb, IV or VI cysts showed the highest seropositivity (86%, 96%, 95%, 100%, and 96%, respectively), while Types I and V were the least seroreactive (38% and 22%, respectively). Cases of CE occurred in 311 families, with 93% having only one member as a CE case while 7% of the families had two or more cases. However, 25% of the ultrasound-negative persons belonging to families with an index CE case were seropositive for antibodies to Echinococcus. These results confirm the importance of human CE in Libya. They also confirm the usefulness of ultrasound combined with serology as a mass screening approach for CE in north African communities.