Joinpoint regression model analysis on epidemiological trends of hand, foot and mouth disease in Guangdong, 2008–2017

ObjectiveTo analyze the change in the epidemiological trends of hand, foot and mouth disease (HFMD)in Guangdong province.

MethodsThe incidence data of HFMD in Guangdong during 2008–2017 were collected from National Notifiable Infectious Disease Reporting Information System, and population data in Guangdong during this period were collected from Guangdong Statistical Yearbook. The epidemiological trends of HFMD were analyzed by using Joinpoint regression model.

ResultsThe incidence trend of HFMD began to change in 2012. From 2008 to 2012, the incidence rate of HFMD increased sharply (β₁＝72.552, P＝0.001), and from 2012 to 2017, the incidence increased with slight fluctuation, the difference had no significance (β₂＝6.647, P＝0.588). The incidence change trend was not parallel between males and females, the change extent in males exceeded that in females. The incidence increase sharply from January to May and peaked in May, then it began to decline, the monthly annual percent change (APC) was 138.33%(P＝0.002). From May to December, the incidence of HFMD declined slightly, the monthly APC was –19.19% (P＝0.002). Two joinpoints were detected among the trend change of the monthly incidence rate of HFMD in 2008、2013 and 2017 years respectively and only one joinpoint was found in the other years. The age specific incidence was characterized by high level in age group from 0– to 2– years (Age group APC＝17.32%, P＝0.001), decrease rapidly from age group 2– years to 15–19 years (APC＝−44.81%, P＝0.000), and keeping at very low level from age group 15–19 years to ≥85 years (APC＝−2.66%, P＝0.148).

ConclusionThe annual incidence of HFMD in Guangdong first showed a rapid increase and then slight increase with fluctuation during 2008–2017. The trend change of annual incidence rate was significantly different between male and female. Two models were found in the trend change of monthly incidence rate and there were significant seasonal variations. Very most of the HFMD case were among young children, so they were the key object for prevention and control. Prevention and control measures should be more targeted.