Relationship between rodent population distribution and risks of major rodent-borne diseases in Nanchang.

Objective To investigate the rat density in different habitats and the prevalence of major rodent-borne diseases in Nanchang, and to assess the risks of occurrence of rodent-borne diseases. Methods The rodent species was measured using night traps, and data on major rodent-borne diseases were retrieved from the information reporting system for infectious diseases. Risk assessment was completed using the risk assessment matrix. Results From 2006 to 2008, the average density of rats was 1.03% in Nanchang. Rattus norvegicus was the predominant species, accounting for 52.55%, followed by Mus musculus and R. tanezumi, accounting for 18.88% and 17.35%, respectively. The highest rat density, 1.83%, was observed in natural villages of rural areas among the 3 habitats, followed by that in special sectors, 0.89%; and the lowest, 0.56%, was in residential lots. The average incidence of hemorrhagic fever with renal syndrome (HFRS) was 0.68/105 in Nanchang from 2006 to 2008, without human or rodent plague outbreaks in 3 consecutive years. As for the future risk, HFRS occurrence was highly likely in Nanchang, and plague occurrence was possible. Conclusion A scientific risk assessment system may help to predict the risk of disease occurrence.