[Water exposure modes and times of different populations in mountainous schistosomiasis endemic areas near Qionghai lake].

Objective: To investigate water exposure modes and times of different populations in mountainous schistosomiasis endemic areas and to inform about the control strategies.

Methods: All 1054 residents from populations around Qionghai Lake were randomly sampled according to occupation for a retrospective questionnaire survey in November 2001. Each individual was interviewed for his/her mode, frequency, and duration of water exposure occurring between April and October 2001.

Results: The average exposure times and intensity were higher in farmers (median: 16 - 18 min/day and 2.41 - 2.5, respectively) who grow rice, tobacco, and vegetables than others (median: 3.74 - 7.39 min/day and 0.81 - 1.52, respectively); exposure frequency was found highest in farmers (median: 2.04 times/day) in all occupations; schoolchildren had low exposure frequency and times, but very high exposure intensity (median 2.34). Between April and June it is an agriculturally busy season, that is also a peak season of water exposure of adults. Schoolchildren's water exposure peaks on July and August, mainly due to playing water and swimming. Exposure times and intensities were higher in females than in males.

Conclusion: Water exposure modes, times, and intensities of different populations were different in mountainous schistosomiasis endemic areas of Xichang. Between April and June should be the peak infection season of adults who are engaging in agricultural activities, while July to August should be the peak infection season for schoolchildren with non-agricultural activities.