title: [Analysis of seasonal variability of vivax malaria by circular distribution method in Jiangsu Province from 1961 to 2010].
abstract: OBJECTIVE
  To study the law of seasonal variability of vivax malaria in Jiangsu Province from 1961 to 2010, so as to provide the reference for improving malaria control.
  
  
  METHODS
  The data of vivax malaria incidence from the epidemic reporting system of Jiangsu Province were collected and analyzed to understand the month morbidity, peak prevalence time and mean durations, and the peak incidence durations every 10 years with the circular distribution method.
  
  
  RESULTS
  Vivax malaria appeared obvious seasonal variability (P < 0.01) with different peak time (P < 0.01). The average peak time occurred on August 9th. The morbidity duration was shortest (75 d) in 1963 and longest (123 d) in 2010 with a mean duration of 93 days, and the peak duration extended 146 days in 10 years from 2001-2010 compared with that from 1960-1970.
  
  
  CONCLUSIONS
  The incidence of vivax malaria presents obvious seasonal peak in Jiangsu Province and its peak concentrates in mid-July to early August, and in nearly 10 years, the days of peak incidence of vivax malaria extended.
authors.affiliation: Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China.
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Wang
authors.forename: Hua-Yun
authors.initials: HY
authors.lastname: Zhou
authors.forename: Jun
authors.initials: J
authors.lastname: Cao
authors.forename: Yao-Bao
authors.initials: YB
authors.lastname: Liu
mesh_terms: D002681:China / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D016780:Malaria, Vivax / Q000453:epidemiology*; D015995:Prevalence; D012621:Seasons