Incidence of Japanese encephalitis, visceral leishmaniasis and malaria before and after the Wenchuan earthquake, in China

The objective of this study was to investigate the incidence of insect-borne diseases from 2005 to 2011, before and after the 2008 Wenchuan earthquake in Longnan City, Gansu Province, China. The data include Japanese encephalitis, Kala-azar and malaria cases from 2005 to 2011 that occurred in Longnan City. We calculated the incidence rates and analyzed the epidemiological characteristics of the diseases before and after the Wenchuan earthquake. During 2005–2011, 212 Japanese encephalitis cases were reported in Longnan City, and the average incidence was 1.11/100,000. Compared with any year from 2005 to 2010 the incidence of Japanese encephalitis in Longnan City in 2011 was not significantly different (P ≥ 0.05). From 2005 to 2011, there were 719 Kala-azar cases in Longnan City, the annual incidence was 3.77/100,000, and the incidence in males was higher than females (P < 0.001). Compared with 2011, there was no significant difference in incidence of Kala-azar in 2009 or 2010 (P ≥ 0.05). There were seven total cases of malaria from 2005 to 2011, and the annual incidence was 0.07/100,000. Wudu District and Wen County were the main endemic areas of insect-borne diseases in Longnan City. The results showed that Japanese encephalitis and Kala-azar were common insect-borne infectious diseases in Longnan City, and that the incidence of insect-borne disease did not increase after the Wenchuan earthquake. It is possible that vector control measures implemented after the earthquake prevented an increase in such diseases.