The Potential Role of Synanthropic Rodents and Flies in the Transmission of Enterocytozoon bieneusi on a Dairy Cattle farm in China.

Enterocytozoon bieneusi causes microsporidiosis, a condition with complex epidemiology involving both direct and indirect transmission routes. To assess the potential role of synanthropic rodents and flies in the transmission of this pathogen, a total of 277 cattle fecal samples, 199 synanthropic rodents, and 50 batches of 20 flies were collected from a cattle farm. These samples were screened for the presence of E. bieneusi by PCR and sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. The positive rates of cattle, synanthropic rodents, and flies were 11.9% (33/277), 4.0% (8/199) and 12.0% (6/50), respectively. Nineteen genotypes were identified, including 11 known genotypes (BEB6, I, COS-I, EbpC, D, J, CHS5, CHG1 to CHG3 and CHG14) and eight novel genotypes (named CHC9 to CHC16). The dominant genotype detected in the present study, BEB6, was found in all three categories of hosts. Moreover, human pathogenic genotypes D and EbpC were also observed in both synanthropic rodents and flies. These results demonstrate that synanthropic rodents and flies may act as biological disseminator or mechanical vector in the transmission of microsporidiosis to humans. Efforts should be made to minimize threats from these commensal animals to public health.

First Molecular Evidence of Anaplasma phagocytophilum in Rodent Populations of Nanchang, China.

In this study, systematic surveillance of rodent populations in Nanchang of China and determination of Anaplasma phagocytophilum infection in rodents were performed. Between 2011 and 2015, 110,084 rodent snap traps were set in 4 counties and in the city center of Nanchang, China. Finally, 942 rodents were captured, with a relative density of 0.86%. The densities varied considerably by geographical area with Anyi being the most rodent-infested County. Frequently captured rodents were sewer rats (Rattus norvegicus), house mice (Mus musculus), and Rattus flavipectus. The Anaplasma genera were investigated by PCR in 19 live rodents trapped by welded cages in Anyi, 6 rodents were assessed as positive based on amplification of 16S rRNA. Sequence analysis revealed 3 variants of A. phagocytophilum in Nanchang. PCR analysis of the gltA (citrate synthase) gene found 1 sample that was positive for A. phagocytophilum infection. The sequence of A. phagocytophilum gltA gene formed a clade with and showed 99% identity to A. phagocytophilum that has been previously described in rodents from South-Eastern China. Taken together, our research indicated that commensal rodents are potential hosts for A. phagocytophilum and controlling the rodent population may facilitate subsequent prevention of human granulocytic anaplasmosis in Nanchang, China, in the future.

Predictors for abundance of Rattus tanezumi in households of commensal rodent plague foci / 中华流行病学杂志

Objective To explore the predictors on the abundance of Rattus (R.) tanezumi in households of commensal rodent plague foci.Methods Thirty natural villages that experienced previous plague cases in Lianghe county,Yunnan province,were selected followed by random selection of 20 households in each village through computer technique.Live traps were set in households to capture small mammals which were then identified to species in the field according to their morphological features.Data on potential factors for abundance of R.tanezumi were collected through questionnaires and field observation and were coded and computerized using EpiData software and further analyzed by hurdle regression model under R software.Results A total of 166 rodents (133 R.tanezumi and 33 Suucus murinus) were captured.Results from final multilevel hurdle regression model showed that the likelihood of R.tanezumi captures increased by 1.67-to 2.76-fold in households belonged to Dai ethnic families that stored foodstuff in metal pails,often raising dogs,and having adjacent houses.The number of R.tanezumi captures increased by 2.18-fold in the villages where over 80％ of the households would raise chickens.In the villages with communal latrine,the likelihood and the number of R.tanezumi capture increased 1.93-fold and 2.38-fold,respectively.While the likelihood of R.tanezumi captures would reduce by 45％-61％ in those households where there were cats and cattle being raised and maize grown in the village.The number of R.tanezumi captures would reduce by 63％ in the households where there were outside toilets.Conclusion The abundance of R.tanczumi seemed to be closely related to the ecological environment factors.Programs on plague control and prevention should relate to ecological factors that influencing the abundance of R.tanezumi.