Epidemic trend of measles in Shandong Province, China, 1963–2005

Abstract

Although measles is a vaccine-preventable infectious disease and the measles vaccine is safe and effective, it still poses a serious threat to the health of children and susceptible populations in China every year. This study aimed to investigate the epidemiological characteristics of measles in Shandong Province, China, including its spatial distribution pattern, in order to have a precise prediction of measles epidemics for better public health strategic planning and resource allocation. Longitudinal data study. This study was based on the surveillance data set of measles from all 17 regions (cities) in Shandong Province between 1963 and 2005. Geographical Information Systems and piecewise exponential smoothing of logarithmic transformed data were applied with consideration of the spatial and temporal features of the data. The parameters of epidemic peaks were estimated by filtering off the drifting long-term trends. Measles presented in almost all regions in Shandong Province with different spatial distribution over the 43-year study period. The incidence of measles was very high in the pre-vaccination period, with an average incidence of 617.61/100,000 population in 1963. With the implementation of vaccination, the average incidence of measles decreased to 3.63/100,000 population in 2005, the periodicity died out and the trend remained at a stable low level. Outbreaks have been reported recently. This study identified the effects of different strategies on the incidence of measles observed in Shandong, China, and will provide valuable information to assist local and national public health policy making. There are still some challenges to improve vaccination coverage and efficacy in order to eliminate measles in China. Strengthening surveillance will be essential in the framework of the anticipated global elimination campaign for measles.