An Integrated Surveillance in Zhejiang Province: Ecological and Pathogen Survey of Vectors and Reservoir Hosts in 2024

Jinna WangMingyu LuoQinmei LiuTianqi LiZhou GuanZhenyu GongJimin Sun^*Jianmin Jiang^*

• Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China

In this study, an integrated surveillance framework was employed to simultaneously quantify the 11 population densities of key vectors and reservoir hosts and screen them for associated pathogens 12 across Zhejiang Province, China. Methods: The light trap method, larval pipette method, fly trap 13 method, sticky trap method, trap-night method, tick-picking method, dragging method, visual 14 inspection method, and chigger mite picking method were used for the ecological surveillance of 15 mosquitoes, flies, cockroaches, rodents, ticks, bedbugs, and chigger mites. Rodent samples were 16 screened for Dabie Bandavirus, Hantavirus, Leptospira interrogans, Rickettsia typhi, and Orientia 17 tsutsugamushi. Mosquito samples were tested for dengue, yellow fever, Japanese encephalitis, West 18 Nile, Zika, and chikungunya viruses. The descriptive statistics were used for analysis. Results: In 19 2024, the mosquito density in Zhejiang Province was 16.03 mosquitoes per trap-night, with Culex 20 tritaeniorhynchus (59.05%) and Culex pipiens pallens (31.37%) being the dominant species. 21 Livestock sheds harbored the greatest mosquito densities, averaging 81.07 mosquitoes per trap-night. 22 The average BI was 12.97. The rodent density was 0.34 rodents per 100 trap-nights, and the 23 dominant species was Rattus norvegicus. The fly density was 3.06 flies per trap, with Sarcophagidae 24 species being dominant. The cockroach density was 0.44 cockroaches per trap, with Blattella 25 germanica comprising 97.13% of the total catch. The tick densities were 0.51 ticks per animal and 26 0.35 ticks per flag per 100 m. No bedbugs were detected. The chigger mite infestation rate was 27 71.11%. Regarding rodent-borne pathogens, the positivity rates for Hantavirus, L. interrogans, and O. 28 tsutsugamushi were 2.42%, 10.46%, and 0.16%, respectively. No Dabie Bandavirus or R. typhi were 29 recorded. All 27,402 mosquitoes tested negative for the target pathogens. Conclusions: This 30 integrated surveillance established baseline metrics for important vectors and reservoir hosts, 31 furnishing evidence-based support for the ongoing management and prevention of vector-borne 32 diseases.