Intense Focus of Alveolar Echinococcosis, South Kyrgyzstan.

Human alveolar echinococcosis (AE) is a highly pathogenic zoonotic parasitic disease caused by Echinococcus multilocularis. An ultrasound study in southern Kyrgyzstan during 2012 revealed a prevalence of 4.2% probable or confirmed AE and an additional 2.2% possible AE, representing an emerging situation. The risk for probable or confirmed AE was significantly higher in dog owners.

Dog ownership, dog behaviour and transmission of Echinococcus spp. in the Alay Valley, southern Kyrgyzstan.

Echinococcosis is a re-emerging zoonotic disease in Kyrgyzstan, and the incidence of human infection has increased substantially since the collapse of the Soviet Union in 1991. Domestic dogs are hosts of Echinococcus spp. and play an important role in the transmission of these parasites. The demography, ecology and behaviour of dogs are therefore relevant in studying Echinococcus spp. transmission. Dog demographics, roles of dogs, dog movements and faecal environmental contamination were assessed in four rural communities in the Alay Valley, southern Kyrgyzstan. Arecoline purge data revealed for the first time that E. granulosus, E. canadensis and E. multilocularis were present in domestic dogs in the Alay Valley. Surveys revealed that many households had dogs and that dogs played various roles in the communities, as pets, guard dogs or sheep dogs. Almost all dogs were free to roam, and GPS data revealed that many moved outside their communities, thus being able to scavenge offal and consume rodents. Faecal environmental contamination was high, presenting a significant infection risk to the local communities.

Human alveolar echinococcosis in Kyrgyzstan.

Human echinococcosis is a reportable disease in Kyrgyzstan. Between 1995 and 2011, human alveolar echinococcosis increased from <3 cases per year to >60 cases per year. The origins of this epidemic, which started in 2004, may be linked to the socioeconomic changes that followed the dissolution of the former Soviet Union.

Transmission ecosystems of Echinococcus multilocularis in China and Central Asia.

From continental to regional scales, the zoonosis alveolar echinococcosis (AE) (caused by Echinococcus multilocularis) forms discrete patches of endemicity within which transmission hotspots of much larger prevalence may occur. Since the late 80s, a number of hotspots have been identified in continental Asia, mostly in China, wherein the ecology of intermediate host communities has been described. This is the case in south Gansu, at the eastern border of the Tibetan plateau, in south Ningxia, in the western Tian Shan of Xinjiang, and in the Alay valley of south Kyrgyzstan. Here we present a comparative natural history and characteristics of transmission ecosystems or ecoscapes. On this basis, regional types of transmission and their ecological characteristics have been proposed in a general framework. Combining climatic, land cover and intermediate host species distribution data, we identified and mapped 4 spatially distinct types of transmission ecosystems typified by the presence of one of the following small mammal 'flagship' species: Ellobius tancrei, Ochotona curzoniae, Lasiopodomys brandtii or Eospalax fontanierii. Each transmission ecosystem had its own characteristics which can serve as a reference for further in-depth research in the transmission ecology of E. multilocularis. This approach may be used at fine spatial scales to characterize other poorly known transmission systems of the large Eurasian endemic zone, and help in consideration of surveillance systems and interventions.

Toxoplasma gondii infection in Kyrgyzstan: seroprevalence, risk factor analysis, and estimate of congenital and AIDS-related toxoplasmosis.

BACKGROUND: HIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan. METHODOLOGY/PRINCIPAL FINDINGS: We screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG) against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8-7.8) (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9-6.5), and 19.0% (95%CI: 16.5-21.7) (adjusted 16.4%, 95% CI 14.1-19.3), respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked meat, as well as cat ownership, had no significant influence on the risk for seropositivity. CONCLUSIONS: We present a first seroprevalence analysis for human T. gondii infection in the Kyrgyz Republic. Based on these data we estimate that 173 (95% CI 136-216) Kyrgyz children will be born annually to mothers who seroconverted to toxoplasmosis during pregnancy. In addition, between 350 and 1,000 HIV-infected persons are currently estimated to be seropositive for toxoplasmosis. Taken together, this suggests a substantial impact of congenital and AIDS-related symptomatic toxoplasmosis on morbidity and mortality in Kyrgyzstan.

A multiplex PCR for the simultaneous detection and genotyping of the Echinococcus granulosus complex.

Echinococcus granulosus is characterized by high intra-specific variability (genotypes G1-G10) and according to the new molecular phylogeny of the genus Echinococcus, the E. granulosus complex has been divided into E. granulosus sensu stricto (G1-G3), E. equinus (G4), E. ortleppi (G5), and E. canadensis (G6-G10). The molecular characterization of E. granulosus isolates is fundamental to understand the spatio-temporal epidemiology of this complex in many endemic areas with the simultaneous occurrence of different Echinococcus species and genotypes. To simplify the genotyping of the E. granulosus complex we developed a single-tube multiplex PCR (mPCR) allowing three levels of discrimination: (i) Echinococcus genus, (ii) E. granulosus complex in common, and (iii) the specific genotype within the E. granulosus complex. The methodology was established with known DNA samples of the different strains/genotypes, confirmed on 42 already genotyped samples (Spain: 22 and Bulgaria: 20) and then successfully applied on 153 unknown samples (Tunisia: 114, Algeria: 26 and Argentina: 13). The sensitivity threshold of the mPCR was found to be 5 ng Echinoccoccus DNA in a mixture of up to 1 µg of foreign DNA and the specificity was 100% when template DNA from closely related members of the genus Taenia was used. Additionally to DNA samples, the mPCR can be carried out directly on boiled hydatid fluid or on alkaline-lysed frozen or fixed protoscoleces, thus avoiding classical DNA extractions. However, when using Echinococcus eggs obtained from fecal samples of infected dogs, the sensitivity of the mPCR was low (<40%). Thus, except for copro analysis, the mPCR described here has a high potential for a worldwide application in large-scale molecular epidemiological studies on the Echinococcus genus.

Echinococcosis, toxocarosis and toxoplasmosis screening in a rural community in eastern Kazakhstan.

OBJECTIVE: To determine the extent of carnivore-transmitted parasitic zoonoses in a community in eastern Kazakhstan, a region where cystic echinococcosis (CE) re-emerged in recent years. METHODS: Cross sectional ultrasound study of 3126 human subjects to determine the extent of human cystic and alveolar echinococcosis (AE). Blood samples were taken from each subject and analysed for antibodies against Echinococcus, Toxocara and Toxoplasma spp. Each subject was questioned about possible risk factors that might be associated with zoonotic transmission. Analysis employed a mixed modelling approach based on the results of the ultrasound study, the serological results and the results of the questionnaire. Bayesian techniques were employed to estimate diagnostic performance. A helminthological study of the local dog population was also undertaken. RESULTS: A total of 23 subjects tested positive for CE on ultrasound and a further three individuals had strong serological evidence of infection. Another 24 reported treatment for CE. Ultrasound lesions or treatment for CE were associated with poverty. No ultrasound evidence of AE was found, but one individual had strong serological evidence of exposure to Echinococcus multilocularis. Toxoplasma seropositivity (16%; 504 individuals) increased with age. Household level Toxoplasma-seropositivity was associated with unsafe drinking water. Toxocara seropositivity (11%; 349 individuals) was more frequent in children and in individuals who disposed of dog faeces on the vegetable garden. A purgation study of dogs indicated that 13% of dogs in the community were infected with Echinococcus granulosus, 5% with E. multilocularis and 2% with Toxocara canis respectively. CONCLUSIONS: There is significant transmission of E. granulosus to humans in this community. Transmission may be associated with poverty. There is little evidence of E. multilocularis transmission to humans, despite the presence in the parasite in the domestic dog population. Toxoplasma is actively transmitted and there is evidence for transmission by the water supply. Children are at highest risk of exposure to Toxocara.