Molecular Identification and Genetic Characterization of Public Health Threatening Ticks — Chongming Island, China, 2021–2022

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC? Although ticks and tick-borne diseases are prevalent throughout China, there remains a knowledge gap regarding their biology and potential risk of distribution to human and animal populations on Chongming Island. The island, being China’s third largest and a crucial component in the ecological preservation of the Yangtze Delta region, has yet to be comprehensively studied in this context. WHAT IS ADDED BY THIS REPORT? In this study, employing molecular methodologies, a significant prevalence of Haemaphysalis (H.) longicornis and H. flava ticks — widely recognized for their high pathogenicity — is reported from Chongming Island. Additionally, the identification of two previously unreported species on the island, namely, H. doenitzi and H. japonica, expands our understanding of both the range and evolution of tick species. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE? The populations of humans and animals in nearly all 18 towns on Chongming Island are potentially at risk for transmission of tick-borne infectious agents. As a result, there is a pressing necessity for public health alerts, proactive tick surveillance, and effective screening of suspected clinical cases of tick-borne diseases within the Chongming population.