Circular distribution analysis on seasonal characteristics of respiratory infectious diseases in Zhoushan
LI Ke-feng*，TONG Zhen-dong，LI Peng，CHEN Can，DAI Ya-xin，WANG Yu-chao，TANG An，CHEN Yan，YAN Jian-bo
*Zhoushan Center for Disease Control and Prevention，Zhejiang Provincial Key Laboratory of Health Risk Factors for Seafood，Zhoushan，Zhejiang 316021，China
Abstract：Objective To analyze the seasonal characteristics of respiratory infectious diseases in Zhoushan from 2015 to 2017，and to provide the basis for prevention and control of the diseases. Methods The surveillance data of measles，chickenpox，tuberculosis，mumps，influenza and influenza-like illness（ILI ）in Zhoushan from 2015 to 2017 were collected from the notifiable infectious disease reporting system. Circular distribution analysis was used to analyze the seasonal characteristics of the above diseases. Results The incidence of measles showed seasonal distribution with single peak，which was March 31st （January 31st-May 29th，r=0.583）in 2015，March 17th（January 26th-May 5th，r=0.556）in 2016 and April 10th （February 9th-June 9th，r=0.682）in 2017. The incidence of chickenpox，mumps，influenza and influenza-like illness（ILI） showed seasonal distribution with two peaks. The peaks of chickenpox were April 2nd（March 2nd-May 3rd，r=0.670）and December 20th（November 2nd-February 1st，r=0.221）. The peaks of mumps were April 7th（March 12th-May 3rd，r=0.745）and September 25th（September 6th-December 13th，r=0.138）. The peaks of influenza were August 13th（July 21st-September 5th，r=0.645）and December 19th （November 21st-January 6th，r=0.715）. The peaks of ILI were August 9th （Jun. 27th-Sep. 21th，r=0.217）and December 24th（November 20th-January 27th，r=0.610）. The seasonal distribution of tuberculosis was not obvious（r=0.078）. Conclusio From 2015 to 2017，measles，chickenpox，mumps and influenza in Zhoushan are prevalent mostly in winter and spring；while the seasonal characteristics of tuberculosis is not obvious.
