Effect of integrated control intervention on soil-transmitted helminth infections in Jiangxi province in southeast China.

Soil transmitted helminths (STHs) burden was enormous in China several decades ago, however, rigorous control efforts have been successful with appreciable reduction in diseases burden. Here, we assessed provincial-level data derived from cross sectional surveys, executed in 1989, 2002 and 2014, on the prevalence of STHs among populations in Jiangxi province, China. This study, also, reported STHs integrated control intervention aimed at reducing STHs transmission and worm burden among population at county-level. The intervention strategies included mass drug administration (MDA), health education, improved water supply for drinking, improved sanitary facilities and environmental modification in Guixi municipality. The overall infection rate of STHs in Jiangxi province decreased from 77.7% (1989) to 6.3% (2014), while Ascaris lumbricoides, hookworm and Trichuris trichiura decreased from 71.1%, 17.6% and 17.0% (1989) to 0.9%, 4.7% and 1.0% (2014), respectively. STHs infection rates in female population were higher than male in the three surveys. Reduction in STHs prevalence was observed in all age groups, but the decline was less in higher age group. STHs prevalence in Guixi intervention region indicated remarkable reduction from 31.8% (2006) to 6.1% (2009) (χ2＝255.22, P＜0.01). A. lumbricoides, hookworm and T. trichiura infection rates decreased from 10.4%, 17.0% and 7.1% (2006) to 0.1%, 4.1% and 2.2%, respectively (2009) (X2A.l = 110.23, P<0.01; X2hk = 103.57, P < 0.01; X2T.t = 32.0, P < 0.01). A. lumbricoides infection rate declined the most of all STHs. Following control efforts with integrated control intervention strategies, STHs prevalence in Jiangxi province experienced remarkable trend in decline between 1989 and 2014. Consolidating control efforts with sustained integrated control strategies is, therefore, important to achieving STHs elimination in China.

[Survey of epidemic status of principal human parasites in Jiangxi Province in 2014].

OBJECTIVE: To understand and analyze the epidemic status of principal human parasites in Jiangxi Province, so as to provide the evidence for formulating The 13rd Five-Year Project of Parasites Control. METHODS: A survey was performed according to the scheme of The 3rd National Survey of Principal Human Parasites as well as the specific situation of Jiangxi Province. The survey of the soil-transmitted nematodes and intestinal protozoa were performed based on the ecological regions and stratified by economic and geographic situation. The survey of Clonorchis sinensis was performed along with the soil-transmitted nematodes in rural, and was performed by the sample method of random cluster in cities and towns. RESULTS: Totally 23 606 residents of 92 survey sites from 32 counties were surveyed, all of them were tested for the infection of soil-transmitted nematodes, in which 21,569 residents were tested for intestinal protozoa infection, and 1 486 children were tested for eggs of Enterobius vermicularis. Twenty kinds of intestinal parasites were found, with the total infection rate of 9.64%, and 4.296 millions of patients were reckoned in the whole Jiangxi Province. The infection rate of children of E. vermicularis was 13.73%. The infection rates of C. sinensis and intestinal protozoa were 0.58% and 1.42% respectively. The infection rate of Toxoplasma gondii was 7.50%. CONCLUSION: In Jiangxi Province, the infection rates of soil-transmitted nematodes are decreasing but the infection rate of C. sinensis is increasing in local areas, and the control work of parasites still should be strengthened.

[Studies on impact of Water Conservancy Project of Poyang Lake on schistosomiasis transmission I: impact of water level regulation schemes of project on Oncomelania hupensis snail habitats].

OBJECTIVE: To investigate the impact of the Water Conservancy Project of Poyang Lake after operation on Oncomelania hupensis snail habitats in 10 counties (cities or districts) around Poyang Lake. METHODS: The data of the distribution, numbers, areas, elevation and slope, etc. of snail infested marshlands on upstream of the project site in Poyang Lake were investigated and collected. Accordingly, the status of the submerged and flooding areas of the marshlands were analyzed and calculated respectively in the case that the project ran by different water regulation schemes at 14, 13, 12 m and 11 m levels. RESULTS: In accordance with the regulation and storage preset programs at 14, 13, 12 and 11 m water levels, the number and its areas of submerged marshlands, from downstream to upstream in Poyang Lake, in turn decreased. Under the condition of the regulation at the 14 m water level, the numbers of completely submerged and partially submerged marshlands as well as the submerged areas were accounted for 32.9%, 51.4% and 60.3% of the whole marshlands, respectively. At the 13 m water level regulation, they were 9.8%, 46.8% and 1.9% respectively. At the 11 m level, only part of 4 marshlands were flooded, which were accounted for only 0.5% of the total number of marshlands and 0.2% of whole areas of the marshlands. CONCLUSIONS: The Water Conservancy Project of Poyang Lake may create a condition for eliminating snails through water flooding. If implementing regulation at the 14 m level for two or three consecutive years, 60.3% of snail habits could realize the snail-free objective. However, if implementing the 11 m or 10 m water level regulation, there will be little impact on areas of snail habitats and the snail distribution in the Poyang Lake region from the point of view of "marshlands flooding". The impacts on marshlands in different counties might differ due to the location and elevation.

[The changes of hydrological regime in Poyang Lake after runs of Three Gorges Project and its impact on prevalence of schistosomiasis in the lake region].

OBJECTIVE: To clarify new features of hydrological regime in the Poyang Lake after runs of the Three Gorges Project and its impact on the prevalence of schistosomiasis in this region. METHODS: It is collected information of Three Gorges Project, average daily water level from 2002 to 2012 at Duchang hydrological station in Poyang Lake and the data of prevalence and control of schistosomiasis in 12 endemic counties along the lake. It was analyzed the trends of prevalence of schistosomiasis under the changed condition of hydrologic situation. RESULTS: Effects of impoundment of Three Gorges reservoir running on water level of Poyang Lake are mainly shown in: Water levels of the lake are suppressed throughout the year which was characterized by high water level in flood season dropped, lower water level appeared in the spring, water withdrew earlier and quicker in the fall and to an even lower level in dry season. After impoundment of Three Gorges Project, infection rate of Schistosomajaponica in human and in bovine decreased by 92.65% and 76.37% respectively in endemic areas around the lake. The density of Oncomelania snails decreased by 94.21%. Prevalent of schistosomiasis in this region showed a significant downward trend. CONCLUSIONS: After runs of the Three Gorges Project, regularized changes hydrologic conditions has taken place in Poyang Lake which is characterized by lower water level and thus might lead to lower density of Oncomelania snails on marshlands and reducing of prevalence of schistosomiasis. Significant strengthening of schistosomiasis control efforts might also contributed to the stable and low level of prevalence of schistosomiasis in the region.

[Prevalence and control of schistosomiasis in Jiangxi Province during 2002-2012].

OBJECTIVE: To analyze the status of prevalence and control of schistosomiasis in Jiangxi Province from 2002 to 2012. METHODS: Endemic status and control effectiveness during the period from 2002 to 2012 was analyzed by using a combination of field survey, data collection and retrospective investigation. RESULTS: From 2002 to 2012, schistosomiasis control made significant achievements in Jiangxi Province. The number of counties which have reached the criteria of transmission interruption of schistosomiasis increased from 19 in 2002 to 22 in 2012. The number of patients with schistosome infection decreased from 128 331 in 2002 to 73 102 in 2012. The positive rate of serological test and fecal examination in residents decreased from 12.2% and 4.2% in 2002 to 5.2% and 0.4% in 2012, respectively. Acute infection reduced from 146 cases in 2002 to 3 cases in 2012, but advanced cases increased by 42.4%. The positive rate of fecal examination in cattle reduced from 4.7% in 2002 to 1.3% in 2012. The density of living snails and infected snails significantly decreased to 0.083 5/0.1 a? and 0.000 037/0.1 m2 in 2012, respectively. However, the snail-ridden areas slightly increased. Jiangxi Province reached the criteria of endemic control for schistosomiasis in 2008. During 2002-2012, control activities were intensified. Examination and chemotherapy for human increased by 65.2% and 65.5%, while 23.4% and 251.1% for cattle. Mean while, area with snail control activities increased by 617.8%. An integrated strategy of infection source control was implemented in the Province. CONCLUSION: During 2002 to 2012, endemic index of schistosomiasis in Jiangxi showed a steady decline after 2005. Currently, schistosomiasis prevalence shows a low level. The endemic indicators of infection in human and livestock as well as Oncomelania snails have been kept stable at low level.