Spatial prediction of the risk of exposure to Echinococcus spp. among schoolchildren and dogs in Ningxia Hui Autonomous Region, People's Republic of China

Opisthorchis viverrini and Strongyloides stercoralis mono- and co-infections: Bayesian geostatistical analysis in an endemic area, Thailand

Parasitic infections caused by Opisthorchis viverrini and Strongyloides stercoralis remain a major public health threat in the Greater Mekong Sub-region. An understanding of climate and other environmental influences on the geographical distribution and emergence of parasitic diseases is a crucial step to guide targeted control and prevention programs. A parasitological survey was conducted from 2008 to 2013 and included 12,554 individuals (age between 20 and 60 years) from 142 villages in five districts in Khon Kaen Province, Thailand. Geographical information systems, remote sensing technologies and a Bayesian geostatistical framework were used to develop models for O. viverrini and S. stercoralis mono- and co-infections in areas where both parasites are known to co-occur. The results indicate that male sex, increased age, altitude, precipitation, and land surface temperature have influenced the infection rate and geographical distribution of mono- and co-infections of O. viverrini and S. stercoralis in this area. Males were 6.69 times (95% CrI: 5.26-8.58) more likely to have O. viverrini - S. stercoralis co-infection. We observed that O. viverrini and S. stercoralis mono-infections display distinct spatial pattern, while co-infection is predicted in the center and southeast of the study area. The observed spatial clustering of O. viverrini and S. stercoralis provides valuable information for the spatial targeting of prevention interventions in this area.

Prevalence of human alveolar echinococcosis in China: a systematic review and meta-analysis

Background

Human alveolar echinococcosis (HAE), caused by the larvae of Echinococcus multilocularis, is a severe parasitic disease that is a major public health concern. New HAE cases in China account for 91% of the global HAE burden every year. Although there are a few studies and systematic reviews (SRs) on the prevalence of HAE in China, trends in the prevalence have not been estimated. This study aims to describe the overall variation in the trend of HAE prevalence in China, and provide evidence for preventive measures in the future.

Methods

Thirty-five eligible studies were retrieved from PubMed, Web of Science, EMBASE, CNKI, Wanfang Data, and VIP, and included in the SR and meta-analysis. An adjusted Agency for Healthcare Research and Quality checklist was used to evaluate study quality. The arcsine transformation was used to adjust the individual reported prevalence, and the pooled HAE prevalence was calculated. Heterogeneity was evaluated using the chi-square test and I² statistic. Forest plots were generated for the meta-analysis, and publication bias of the studies was assessed using the Egger’s test and funnel plots. We conducted subgroup analyses, sensitivity analyses, and meta-regression analyses to analyze the source of heterogeneity and factors potentially influencing the prevalence of HAE.

Results

The meta-analysis indicated that the pooled HAE prevalence in China was 0.96% (95% CI: 0.71 to 1.25%). Factors potentially influencing HAE prevalence were female sex (OR = 1.60, 95% CI: 1.35 to 1.91, P<0.01), being ≥30 years old (OR = 4.72, 95% CI: 2.29 to 9.75, P<0.01), and being farmers and/or herdsmen (OR = 2.54, 95% CI: 1.60 to 4.02, P<0.01). The results of the meta-regression analysis (R² = 38.11%, P < 0.01) indicated that HAE prevalence is on a downward trend.

Conclusions

HAE prevalence has decreased over time and maintained low levels after 2005 in China. This decline was influenced by the utilization of One Health strategies as intervention measures. Therefore, these One Health strategies should be used as references to formulate future programs for HAE control. More high-quality epidemiological investigations and surveillance programs should be conducted in order to improve HAE control in the future.

Identification of potential 'hot spots' of cystic echinococcosis transmission in the province of Río Negro, Argentina

Cystic echinococcosis (CE) is a parasitic zoonosis caused by Echinococcus granulosus. The control program of CE of Rio Negro province, Argentina, involves annual surveillance using ultrasound (US) screening in school children, and five-year cross-sectional surveys to detect livestock farms with parasitized dogs by coproELISA with confirmation tests (Western Blot or PCR). Control program is based on deworming of dogs with praziquantel and the aim is to identify areas at risk of Cystic echinococcosis transmission to humans, using all available data sources. The information was spatially distributed in 13 program areas and, at a smaller geographical scale, in 80 Primary Health Care Centers. CoproELISA surveys involved three randomized sampling periods (2003-05, 2009-10, 2017-18), with 1790 canine fecal samples. The US surveys were conducted in 2003-08, 2009-16 and 2017-18 in 34,515 children. Heat maps were created at the smallest geographic scale with QGIS 3.4.6. For the consecutive sampling periods, prevalence of positive canine fecal samples from livestock farms were 14.7, 12.1 and 7.8%, respectively, and children prevalence was 0.4, 0.2 and 0.1%, respectively. The study has been developed on a scale according to which the temporal-spatial distribution of CE allows to adjust control strategies in those areas of potential transmission of the zoonosis to humans.