Application of the concentration ration and the circular distribution in the analysis of seasonality of infectious diseases.

[Objective] This study was conducted to gain insight into the characteristics of seasonal distribution of common infectious diseases in Shunyi district of Beijing,to provide scientific basis for the surveillance,prevention and control of the diseases.[Methods] The concentration ratio and the circular distribution were used for the analysis of seasonality of infection diseases.[Results] This study showed that occurrence of dysentery was obviously seasonal in Shunyi district of Beijing and the peak incidence from mid-May to late September.There was a certain seasonality in the prevalence of measles,rubella,hemorrhagic fever and the mumps,the peak incidence was from late January to late June,mid-March to early August,late December to early June next year,as well as mid-March to mid-October respectively and other infection diseases had poor seasonality in Shunyi district.[Conclusion] The different measures should be taken based on the characteristics of seasonal distribution of specific infectious diseases for the effective prevention and control of the diseases.