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

Abstract

Summaryobjective 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.

Seroprevalence of toxoplasmosis, toxocariasis and cysticercosis in a rural settlement, São Paulo State, Brazil

“…[27][28][29][30] Infection with one agent could also be associated with an increased risk of infection with the other. 26,27 In our study, 14.4% of individuals showed concomitant Toxocara spp./T. gondii infection.…”

“…Low socioeconomic status is an additional factor contributing to T. gondii infection in Brazilian communities and worldwide. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]27 There was also a significant increase in infections in females compared to males. This may be a result of women remaining near or inside the house, close to domestic animals, and becoming predisposed to T. gondii infection.…”

Association between covariates and disease occurrence in the presence of diagnostic error

“…For example a population study of human cystic echinococcosis, a highly pathogenic parasitic disease caused by Echinococus granulosus, in Kazakhstan reported an estimated prevalence of 0 . 011 [28]. As part of the study the population was tested with an ELISA using cyst fluid antigens isolated from E. granulosus.…”

A Mechanistic Individual-Based Two-Host Interaction Model for the Transmission of a Parasitic Disease

“…The disease has a worldwide distribution and its prevalence in humans and animals changes between different regions. The highest prevalence of the parasite in humans is found in rural areas where people are in close contact with livestock, as for example a prevalence of about 9% in the Central Peruvian Andes [15], 3.8% in Qinghai (China) [29] and 2% in Southern Kazakhstan [25]. The transmission dynamics of the parasite modelled here can be described as parasites in the host, but not the parasite densities.…”