Surveillance of Oncomelania hupensis distribution and water levels in Gaoyou sections of the eastern route project of the South-to-North Water Diversion Project following operation of the project / 中国血吸虫病防治杂志

Objective To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project. Methods The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019. Results A total area of 235.42 hm2 were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project. Conclusion Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by “land in winter and water in summer” has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

[Analysis of endemic status of schistosomiasis in Gaoyou City from 1970 to 2009].

OBJECTIVE: To explore the changing rule of schistosomiasis endemic situation in Gaoyou City, so as to provide the evidences for schistosomiasis control in lake and marshland regions. METHODS: The endemic data of schistosomiasis of Gaoyou City from 1970 to 2009 were collected to analyze the endemic patterns of schistosomiasis in different control stages comprehensively. RESULTS: In the first years of infection control stage (1970-1975), transmission control stage (1976-1994) and transmission interruption stage (1995-2009), the prevalence rates of schistosomiasis were 4.20%, 0.80% and 0 in human and 3.00%, 0.51% and 0 in cattle respectively. In 1984, the positive rate of crowd stool tests fell to 0.04%, which was reduced by 99.05% compared with that in 1970. From 1970 to 1980, the positive rates of stool tests of people and livestock were positively correlated significantly (r = 0.67, P < 0.05). After 1985, no local infection patients or cattle were found. No schistosome infected Oncomelania hupensis snails were found from 1970 to 2009. CONCLUSIONS: The comprehensive control measures have been insisted in Gaoyou City in different prevention and control stages. Although the snail situation is undulate, the prevalence of schistosomiasis steadily declines and the interruption of transmission has achieved.

[Study on schistosomiasis control measures in mobile boat fishermen. III. Construction and application of regional joint mechanism for schistosomiasis examination and treatment in boatmen].

OBJECTIVE: To construct the regional joint mechanism for schistosomiasis examination and treatment and the examination protocol among mobile boatmen, so as to provide effective measures for control of mobile infectious sources of schistosomiasis in the Yangtze River basin. METHODS: According to the characteristics of the cargo frequent mobility of ships with fixed anchor points, the health, maritime and transport sections were jointly cooperated to set up sites for schistosomiasis examination and treatment in ship locks, wharfs and harbors. The infection of schistosomiasis was detected by means of rapid immunological screening and stool examination, and the regional joint mechanism was constructed. The sero-positives were traced for further parasitological examinations and treatment by using the regional joint network for schistosomiasis examination and treatment. The schistosome infections in boatmen were analyzed and compared between different examination and treatment sites and among different navigation coverage. RESULTS: A total of 16 sites for examination and treatment of schistosomiasis, including 5 fixed sites and 11 mobile sites, were set up in 12 townships of 6 districts (counties) of Yangzhou City. During a period between June and August, the examination of schistosomiasis was conducted in 40 sites, and of the 1 225 boatmen from 967 boats detected, 19 cases were sero-positive, with a positive rate of 1.55%. Among the 14 sero-positives examined, no stool positive patients were found. Among the 1 225 boatmen detected, 820 were from fixed sites and 405 from mobile sites, and 4 and 15 cases were found, respectively, with positive rates of 0.49% and 3.70%, respectively, and the sero-positive rate was higher in mobile sites and that in fixed sites. A total of 898 boatmen from the Yangtze River basin and 305 from the local inland rivers were examined, and 3 and 16 sero-positive cases were detected, respectively, with positive rates of 0.33% and 5.25%, respectively, and the sero-positive rate was significantly higher in the boatmen from the local inland rivers than that from the Yangtze River basin. CONCLUSION: Regional joint mechanism is an effective strategy for examination and treatment of schistosomiasis among mobile boatmen, which provides a new approach to control mobile infectious sources of schistosomiasis in the Yangtze River basin.