ABSTRACT
Objective:To investigate the epidemic characteristics and current situation of animal plague in Zhejiang Province, in order to provide data support for prevention and control of the plague in the whole province.Methods:A retrospective study was carried out to collect surveillance data of animal plague in Zhejiang Province from 2006 to 2020 from the "Pubonic Plague Control Management Information System". Descriptive epidemiological methods were used to analyze the density of domestic and wild rodents, the distribution of rodent species and flea species, and the serological and pathogenic test results of host animals.Results:From 2006 to 2020, the annual average density of domestic rodent in Zhejiang Province was 3.99%, which was lower than that in 2006, 2007, 2008, 2009, 2019 and 2020. The annual average density of wild rodents was 4.52%, which was lower than that in 2013, 2016, 2017, 2018, 2019 and 2020. From 2006 to 2020, a total of 173 432 rodents were captured, belonging to 3 orders, 5 families, 12 genera and 17 species; in the composition of rodent species, Rattus norvegicus was the most, accounting for 32.15% (55 765/173 432). A total of 107 736 rodents were examined, the number of flea-infected rodent was 3 885, and the flea-infested rate was 3.61%; the total number of flea collected was 9 039 and the total flea index was 0.083 9. A total of 172 235 serological samples were tested at various monitoring sites in Zhejiang Province, and 10 positive samples were detected, there were 7 copies of Apodemus agrarianus, 2 copies of Smelly Shrew and 1 copy of Rattus norvegicus, with titers ranging from 1 ∶ 40 - 1 ∶ 320; a total of 163 618 copies of rodent liver and spleen organs were cultured, and no Yersinia pestis was isolated. Conclusions:Positive host animals have been detected in Zhejiang Province for many years. It is necessary to further standardize plague surveillance and make emergency preparations to prevent relapse and import of the epidemics.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012.</p><p><b>METHODS</b>Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed.</p><p><b>RESULTS</b>The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area.</p><p><b>CONCLUSION</b>This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.</p>