Landscape-epidemiological study on outbreak of infectious diseases after Wenchuan earthquake in An county.

Objective To study the situation of infectious disease outbreak with the characteristics of geographic distributions,susceptible populations before and after 5·12 Wenchuan earthquake in An county,Sihuan province,and to provide scientific evidences for disease control and prevention.Methods Thematic maps were made with epidemiological and social-economic information before and after earthquake using the techniques of geographic epidemiology and geographic information system(GIS).Results The incidence of communicable diseases higher than 200/100 000 person-years occurred in three townships,which were located in the central part of An county and stood alone respectively.The incidences between 150/100 000-200/100 000 person-years occurred in three towns which were located in the northwest and east parts of An county.The incidence was above 100/100 000 person-years in the townships without resettlement of the disaster victims.However,the incidence was more than 150/100 000 and less than 200/100 000 person-years in the townships where the resettlement number of the disaster victims was more than 10 000.The leading communicable disease changed from chickenpox before earthquake to the infectious diarrhea after earthquake.There were two peaks of communicable disease outbreak after earthquake.The distribution of high risk population was not changed comparing with that before earthquake.Conclusion The significant differences of the disease outbreak were due to the post-earthquake changes of environment and human behaviors.Geographic epidemiology could be useful in demonstrating post-disaster outbreak of infectious diseases intuitively and effectively.