[Progress of schistosomiasis control in People's Republic of China in 2023].

To understand the progress of national schistosomiasis elimination program of China in 2023 and summarize the lessons and experiences, data on the endemic status of schistosomiasis and national schistosomiasis surveillance results in the People's Republic of China were collected and analyzed at a national level. By the end of 2023, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan and Hubei provinces were identified to achieve the criteria of transmission interruption in 2020, and Anhui, Jiangxi and Hunan provinces achieved the criteria of transmission interruption in 2023. A total of 451 counties (cites, districts) were found to be endemic for schistosomiasis in China in 2023, including 26 250 endemic villages covering 73 034 500 residents at risk of infections. Among the 451 endemic counties (cities, districts), 78.49% (354/451) achieved the criteria of schistosomiasis elimination and 21.51% (97/451) achieved the criteria of transmission interruption, respectively. In 2023, a total of 4 216 643 individuals received immunological tests, with 47 794 sero-positives identified, and a total of 184 216 individuals received parasitological examinations, with 4 egg-positives detected. A total of 27 768 cases with advanced schistosomiasis were documented in China by the end of 2023. In 2023, 539 548 bovines were raised in schistosomiasis-endemic areas of China, and 125 440 bovines received immunological tests, with 124 sero-positives detected, while no egg-positives were identified among the 133 508 bovines receiving parasitological examinations. In 2023, snail survey was performed at an area of 641 339.53 hm2 and 184 819.77 hm2 snail habitats were identified, including 51.53 hm2 emerging snail habitats and 642.25 hm2 reemerging snail habitats. In 2023, there were 20 198 schistosomiasis patients receiving praziquantel chemotherapy, and 598 183 person-time individuals and 283 954 herdtime bovines were given expanded chemotherapy. In 2023, snail control with chemical treatment was performed in 116 347.95 hm2 snail habitats, and the actual area of chemical treatment was 65 690.89 hm2, while environmental improvements were performed in snail habitats covering an area of 1 334.62 hm2. The national schistosomiasis surveillance results showed that the mean prevalence of Schistosoma japonicum infections were both zero among humans and bovines in 2023, and no S. japonicum infection was detected in snails. These data demonstrated that transmission interruption of schistosomiasis had been achieved across all endemic provinces in China in 2023, and the endemic status of schistosomiasis tended to be stable, while advanced cases were predominant among all schistosomiasis cases. However, the areas of snail habitats remained high and cattle re-raising was very common in some regions. Intensified schistosomiasis surveillance and forecast and snail control in high-risk areas are needed.

Desiccant Dusts, With and Without Bioactive Botanicals, Lethal to Rhipicephalus (Boophilus) microplus Canestrini (Ixodida: Ixodidae) in the Laboratory and on Cattle.

The exotic southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini) (Ixodida: Ixodidae), since its eradication from the United States in 1943, made a strong incursion into Texas, beginning 2016. The pest is arguably the most economically detrimental ectoparasite of cattle, Bos taurus L., worldwide. Current R. (B.) microplus control mostly relies on conventional synthetic acaricides to which the ixodid has been developing resistance. Our study demonstrates that commercially available desiccant dust products, with and without bioactive botanical additives, are strongly lethal, when applied dry, against larval R. (B.) microplus in the laboratory, and after being released on dust-treated cattle. Deadzone (renamed Celite 610, a diatomaceous earth product), Drione (silica gel + pyrethrins + piperonyl butoxide synergist), and EcoVia (silica gel + thyme oil), each prophylactically prevented larval R. (B.) microplus from attaching to and feeding on stanchioned calves. Desiccant dust-based products are less likely than conventional synthetic acaricides to decline in terms of efficacy as a result of ixodid resistance, and other desiccant dust advantages, including extended residual, flexibility in terms of application methods, environmental, animal, and human safety, and possible compatibility with organic, or 'green', production systems, are discussed. We anticipate that the desiccant dusts we evaluated, and others not included in this study (e.g., kaolin, perlite, and silica gel) will be effective when used with other control tactics in integrated pest management approaches for controlling R. (B.) microplus (and other ixodid species).

Farmers' perception on the control of gastrointestinal parasites in organic and conventional sheep production in Sweden.

A questionnaire was sent to sheep owners in Sweden to get information about anthelmintic drug use. The survey also investigated how respondents experienced problems with gastrointestinal nematode infections (GIN) focusing on Haemonchus contortus. The response rate was 31% and included both conventional and organic farms. The use of anthelmintics was low (45%), among which a majority (76%) drenched ewes on a single occasion, mostly with ivermectin (59%) followed by albendazole (19%). Other drugs were used rarely, however, unawareness of GIN risk was high (19%), especially among respondents with few animals. Anthelmintic dose calculations were done after visual appraisal by 63% and 22% calibrated the equipment before drug delivery, which is worrying since underdosing is a risk factor for the development of anthelmintic resistance. Like with anthelmintics, the perceived risk for GIN increased with herd size both by conventional and organic farmers. Faecal examination for the presence of GIN was done by 65% of the respondents and, among their sheep, H. contortus was or had been diagnosed in 41% of the herds. Irrespective of new stock had been imported from other countries or not, common problems were reported by 5% and 7% of the organic and conventional producers, respectively. Land use and grazing management strategies differed more in relation to herd size than by production form, with a majority (47%) having their sheep grazed in several paddocks, or at least the lambs were moved when separated from the ewes at weaning (25%). In contrast set stocked grazing was mainly reported on smaller farms. Co-grazing with cattle and horses were also frequently reported irrespective of production form, but with cattle to a somewhat greater degree on larger organic farms. Wild cervids, especially roe deer, were frequently observed on sheep pastures (87%). The veterinary involvement was higher on organic (65%) than on conventional farms (53%), and only 5% considered advice unimportant. Still, some conventional and organic producers treated sheeps routinely without a prior diagnosis, against the national regulations. 46% of the respondents drenched new and replacement stock. In conclusion, although some differences were observed between conventional and organic producers, the divergences were mainly due to herd size categories. Furthermore, despite a high veterinary involvement, we identified factors which can contribute to anthelmintic use, such as poor quarantine procedures, and deworming routines that can contribute to anthelmintic resistance in H. contortus.

[Potential impact of water transfer project from Yangtze River to Huaihe River on snail spread and schistosomiasis transmission].

OBJECTIVE: To investigate the possibility of spread of snails and transmission of schistosomiasis japonica due to the construction of water transfer project from Yangtze River to Huaihe River. METHODS: In order to understand the current endemic situation of schistosomiasis in the project area, the distribution of snails was surveyed by routine methods, level of anti-schistosome antibody in human sera was detected by indirect haemagglutination test (IHA), and the prevalence of schistosomiasis in cattle was detected by egg hatching method. The snail survival and reproduction were observed in Chaohu Lake area(experimental area) and a control area for one year. RESULTS: Snail density was high in two starting points, from where the water in Yangtze River will be directed to Huaihe River. In counties of Wuwei and Hexian, through which the project will be built, the positive rate of anti-schistosome antibody in residents was 22.11% (168/760) and 18.59% (37/199), schistosomiasis prevalence in cattle was 2.42% (9/371) and 0.2% (2/997), respectively. Schistosomiasis was also endemic in Juchao District of Chaohu City. Snails respectively from grassland and hilly area were collected and put in Chaohu Lake for breed and newborn snails were found one year later. During the egg-laying season, the survival rate of snails from grassland in 2 experiment areas and a control area was 11.3%-16.7%, 3.0%-20.8% and 4.7%-14.7% respectively (chi2 = 0.093, 0.760, P > 0.05; chi2 = 0.647, 0, P > 0.05), and that of snails from hilly area was 24.1%-44.4%, 37.8%-67.3% and 86.3%-93.1% respectively (chi2 = 9.575, 5.302, P < 0.05; chi2 = 56.863, 36.218, P < 0.05). There was no significant difference between the experimental area and the control area on the number of eggs in the ovaries of the same type female snails. CONCLUSION: The one-year observation reveals that the construction of the project might result in spread of snails and transmission of schistosomiasis japonica in the relevant areas.

[Effect of schistosomiasis control in Yangxin County, Hubei Province, 2004-2015].

OBJECTIVE: To evaluate the effect of schistosomiasis control and prevention in Yangxin County from 2004 to 2015, so as to provide the evidence for improving the work of schistosomiasis transmission interrupted and elimination in the future. METHODS: According to the endemic types and endemic regularity of schistosomiasis in Yangxin County, the comprehensive control strategies were adopted, and the programs related to sanitation, water conservancy, forestry, and agriculture were implemented continuously. The schistosomiasis control effects in this county from 2004 to 2015 were analyzed and compared. RESULTS: After the implementation of the schistosomiasis comprehensive control strategies in Yangxin County, the calculated number of patients reduced from 22 240 in 2004 to 1 471 in 2015, the infection rate of residents reduced from 8.57% in 2004 to 0.16% in 2015, the number of patients with acute schistosome infection reduced from 64 in 2004 to 0, and no cases of acute schistosomiasis found since 2009. The infection rate of cattle decreased from 8.87% in 2004 to 0. The area with Oncomelania hupensis snails and the area of susceptible zone reduced from 3 446.21 hm2 and 1 111.59 hm2 in 2004 to 2 285.75 hm2 and 41.28 hm2 in 2015 respectively, and the schistosome-infection rate of snails reduced from 0.76% in 2004 to 0. CONCLUSIONS: Since the comprehensive control strategy implemented from 2004, the endemic situation of schistosomiasis in Yangxin County has decreased significantly. However, the harness force of the Fu River as well as the control of infection source of livestock still should be strengthened to consolidate the control achievement.

[Study on interventions based on urban - rural integration system construction to consolidate achievements of schistosomiasis control in hilly schistosomiasis endemic areas].

OBJECTIVE: To explore the effectiveness of comprehensive schistosomiasis control interventions based on urban-rural integration system construction to carry out the schistosomiasis control in hilly schistosomiasis endemic areas, so as to offer a new mode to consolidate the achievements of schistosomiasis control in the new situation. METHODS: Shouan Town and Changqiu Township in Pujiang County in hilly schistosomiasis endemic regions were selected as demonstration areas. The comprehensive schistosomiasis control interventions based on urban-rural integration system construction were implemented, including the land consolidation, centralized residence and so on. The effectiveness the interventions was evaluated. RESULTS: In Shouan Town and Changqiu Township, the transformed environments with Oncomelania hupensis snail habitats were 1 330.61 hm2 and 1 456.84 hm2, the areas with snails decreased from 94.31 hm2 and 83.00 hm2 in 2000 to both 0 in 2015, the positive rates of serological tests for schistosomiasis decreased from 11.8% and 7.53% in 2000 to 1.01% and 1.86% in 2015, and the positive rates of parasitological tests decreased from 0.18% and 0.15% in 2000 to both 0 in 2015 respectively. The numbers of cattle decreased from 358 and 368 in 2000 to 4 and 6 in 2015 respectively. In 2000, the schistosome infection rates of cattle were 3.63% and 6.51% in Shouan Town and Changqiu Township respectively, and from 2004, no infected cattle were found. CONCLUSIONS: The comprehensive schistosomiasis control interventions based on urban-rural integration system construction can decrease the schistosome infection rate and area with snails effectively, providing a new mode for schistosomiasis elimination.

[Role of new strategy in transmission control of schistosomiasis in Poyang Lake region].

OBJECTIVE: To evaluate the role of new strategy in the transmission control of schistosomiasis in Poyang Lake region. METHODS: The information and epidemic data of schistosomiasis control were collected and analyzed in Poyang Lake region from 2005 to 2016. RESULTS: After eleven years of carrying out the new strategy, thirteen counties achieved the objective of transmission control in Poyang Lake region. In 2016, the number of schistosomiasis cases and human infection rate were 10 301 and 0.03%, decreased by 89.64% and 99.45% compared with those in 2005, respectively. The number of cattle and schistosome -infected cattle were 68 152 and 5, decreased by 50.84% and 99.83% compared with those in 2005, respectively. The average density of Oncomelania hupensis snails was decreased by 61.52%. No schistosome-infected snails were found since 2014. CONCLUSIONS: The new strategy accurately locates the key points and targets of schistosomiasis transmission chain, which has controlled the human and animal's fecal eggs from polluting grassland, and cut off the transmission chain, reduced both the infection rates of human and animal and the re-infection risk, and promoted to achieve the target of schistosomiasis transmission control in Poyang Lake region.

[Surveillance on schistosomiasis after its transmission interruption in Baoying County, Jiangsu Province].

OBJECTIVE: To understand the endemic situation of schistosomiasis after its transmission interruption in Baoying County, so as to provide the evidence for adjusting the prevention and control strategy. METHODS: The data of schistosomiasis surveillance in Baoying County from 1988 to 2015 were collected and retrospectively analyzed. RESULTS: The schistosomiasis surveillance has been established since it was interrupted in Baoying County in 1987. The total surveyed area with Oncomelania hupensis snails was 21 269.95 hm2, but no living snails were found. The number of schistosomiasis examinations of residents was 163 196 person-times, and 270 person-times were positive in serum test, 26 person-times were positive in stool test. No positive cases were found since 1997. The number of schistosomiasis tests of livestock was 2 180 cattle-times but no infection was found. CONCLUSIONS: No schistosome infected snails or livestock are founded in Baoying County for last 28 years, and no patients are founded for last 11 years. The effect of schistosomiasis control is steady.

[Study on the strategy of interrupting schistosomiasis transmission in a hilly new endemic area of Taoyuan County].

OBJECTIVE: To develop a strategy for interrupting the transmission of schistosomiasis japonica in a hilly new endemic area. METHODS: Since 1996, chemotherapy with praziquantel (adult 40 mg/kg, child 50 mg/kg, cattle 30 mg/kg, once a year) on human beings in Taoyuan County who had ever contacted with infectious water and cattle which were herded in endemic situation was the major intervention, with focal control of Oncomelania snails in susceptible areas as supplementary one. RESULTS: The positive rate of stool examination for schistosomiasis in human and cattle reduced from 5.69% and 6.76% in 1996 to 0.04% and 0 in 2005 respectively. The positive rate of indirect hemagglutination test (IHA) in human dropped from 7.45% in 1996 to 1.61% in 2004. Though living snails were still found in most habitats, the density of infected snails decreased from 0.0036/0.11m2 in 1997 to 0 in 2005 and no infected snails were found since 2000. CONCLUSION: Due to less movement of human and cattle populations and the hilly area relatively isolated, chemotherapy combined with focal mollusciciding have been highly effective in eliminating the infection sources and interrupting transmission of schistosomiasis.

[Effect of integrated measures on schistosomiasis transmission--interruption in hilly areas].

OBJECTIVE: To evaluate the effect of control integrative measures which persist in snail eradication and chemotherapy on schistosomiasis transmission-interruption in hilly areas. METHODS: The data of integrated control and endemic situation of schistosomiasis from 2004 to 2014 were collected, and the control effect of integrated measures was evaluated. RESULTS: From 2004 to 2014, both the Oncomelania hupensis snail area and density of living snails of Jurong City were reduced from 43.13 hm2 and 1.48 snails/0.1 m2 to 0; the residents' seropositive rate declined continuously; the residents' and students' awareness rates on schistosomiasis control were increased from 88.43% and 82.04% to 92.56% and 95.74% respectively; the snail area was significantly negatively correlated with the coverage rate of snail control (r = -0.864, P < 0.05). CONCLUSIONS: In the hilly areas, the schistosomiasis control integrated measures which persist in snail eradication and chemotherapy could control the endemic situation rapidly and steadily, accelerating to achieve the goal of schistosomiasis transmission-interruption.

[Impact of implementation of Three Gorges Project on schistosomiasis endemic situation and control in Nanjing City].

OBJECTIVE: To understand the changes of hydrological regime in the Yangtze River and schistosomiasis endemic situation in Nanjing City after the implementation of Three Gorges Project. METHODS: The data of hydrological regime of the Yangtze River, schistosomiasis epidemic situation, and Oncomelania hupensis snail status were collected and analyzed in Nanjing City from 2002 to 2012. RESULTS: After the implementation of the Three Gorges Project in 2003, the water level of the Yangtze River slightly rose from January to April, the average water levels in May and August both reduced compared with those in 2002, and the time of water withdrawal was moved up. The water level of the Yangtze River slightly reduced from November to December. The endemic situation of schistosomiasis showed a decline tendency in the areas along the Yangtze River in Nanjing City. In 2012, the rates of human and bovine infected with Schistosoma japonicum both reduced by 100% as compared with those in 2002, and the snail area, infected snail area and snail density were reduced by 48.45%, 100% and 95.76% respectively as compared with those in 2002. CONCLUSION: After the implementation of the Three Gorges Project, the schistosomiasis endemic situation shows a decline tendency in the areas along the Yangtze River in Nanjing City, but the long-term monitoring still need to be carried out.

[Analysis of epidemic situation and control strategy of schistosomiasis in Jiu- jiang City from 2008 to 2014].

OBJECTIVE: To understand the epidemic situation of schistosomiasis in Jiujiang City, so as to provide the evidence for formulating further control strategy. METHODS: The data of schistosomiasis control were collected in Jiujiang City from 2008 to 2014. and the indicators including the annual schistosome infections of human and cattle, acute schistosome infection, outbreak of schistosomiasis endemic, schistosome infected Oncomelania hupensis snails were analyzed statistically. RESULTS: Compared with 2008, in 2014, the infection rates of schistosomiasis declined by 98.40% and 92.54% in human and cattle respectively. The area of schistosome infected snails decreased from 103.24 hm² to zero. The occurrence rate of frames with snails and density of living snails declined from 14.86% and 0.334 5/0.1 m² to 6.89% and 0.126 5/0.1 m², respectively. The acute schistosomiasis infection cases occurred except 2011 and 2014. CONCLUSION: The control strategy emphasizing on infection sources control is effective in Jiujiang City, but the risk of schistosomiasis still exists, and the risk control and schistosomiasis control strategy should be strengthened.

Elimination of schistosomiasis japonica from formerly endemic areas in mountainous regions of southern China using a praziquantel regimen.

Schistosomiasis japonica is a major public health problem in China. Domestic animals play a major role in the transmission of Schistosoma japonicum to humans. To better understand the epidemiology of schistosomiasis japonica in domestic animals in the mountainous areas of China, we performed a 5-year longitudinal study of schistosomiasis in cattle and horses in Yunnan Province from 2009 to 2013. We also performed a concurrent drug-based intervention study in three settlement groups in Yunnan Province aimed at developing an effective means of controlling transmission in this region. The prevalence of infection in cattle fluctuated between 1.67% and 3.05% from 2009 to 2011, and monthly treatments of schistosome-positive animals reduced the prevalence to 0% (P<0.05) from 2012 to 2013. Prior to the intervention, we found that schistosomiasis was prevalent from May to October, with the highest prevalence observed in June (10.00%). We surveyed for environmental schistosome contamination, and 94.29% of the miracidia found were from cattle. Our study showed that it is possible to eliminate schistosomiasis in domestic animals in the mountainous regions of China by monthly treating cattle and horses from schistosome-positive households from May to October.

[Measures and effectiveness of comprehensive schistosomiasis control along Xinglong River in Qianjiang City].

OBJECTIVE: To evaluate the effect of comprehensive control of schistosomiasis along the Xinglong River in Qianjiang City, so as to provide the evidence for improving schistosomiasis control. METHODS: The comprehensive control measures including infection source control and Oncomelania hupensis snail eradication were surveyed along the Xinglong River in Qianjiang City. RESULTS: The prevalence of schistosomiasis was under control, that was the human and cattle infection rates decreased by 53.77% and 100% respectively, the snail area decreased by 26.9%, the mean density of living snails decreased by 25.5%, and no infected snails was found. CONCLUSIONS: The comprehensive control measures along the Xinglong River are effective, and the management and surveillance of snail environments still should be strengthened.

Human interferon alpha fails to inhibit the development of Babesia bigemina and Anaplasma marginale infections in cattle.

Studies were undertaken to determine whether human interferon alpha (HuIFN-alpha) administered orally could inhibit the development of clinical disease caused by the intraerythrocytic protozoan Babesia bigemina and the intraerythrocytic rickettsia Anaplasma marginale in cattle. HuIFN-alpha did not inhibit intraerythrocytic multiplication of either of the two parasites, suggesting that there is no role for HuIFN-alpha administered orally in the control of these pathogens.

Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France.

Four freshwater pulmonate species (Lymnaea ovata, L. stagnalis, Physa acuta, Planorbis leucostoma) were living in several watercress beds known for their relationships with human cases of fasciolosis, whereas L. truncatula was never found. The aims of these studies were to determine the prevalence of natural infections with Fasciola hepatica in snails and to verify if these species might ensure the full larval development of this trematode (with cercarial shedding) when they were experimentally subjected to F. hepatica only, or to co-infections with an other trematode species. Investigations were so carried out in six snail populations living in watercress beds (including three for P. acuta) and in four others originating from three brooks or a pond (as controls). Snails naturally infected with F. hepatica were found in two watercress beds inhabited by L. ovata (prevalence of infection: 1.4%) and P. leucostoma (0.1%), respectively. The L. ovata from the watercress bed could be infected at a higher size than those from the control population and the prevalence of this infection was greater in the bed population. Similar findings were noted for L. stagnalis. Despite single or dual infections, the results obtained with the four populations of P. acuta were unsuccessful. In contrast, the co-infections of young P. leucostoma with Paramphistomum daubneyi and F. hepatica resulted in the shedding of some F. hepatica cercariae. According to the authors, the occurrence of fasciolosis in these watercress beds would be the consequence of frequent natural encounters between parasite and snails (L. ovata, L. stagnalis), or of co-infections with P. daubneyi and F. hepatica (P. leucostoma). In watercress beds only colonized by P. acuta, a lymnaeid species would have ensured the larval development of F. hepatica but it would have been eliminated by P. acuta, as this last species was known to be invasive and could colonize open drainage ditches on siliceous soil.

Neospora caninum infections in Australia and New Zealand.

OBJECTIVE: To review the current state of knowledge of Neospora caninum infections with particular reference to Australia and New Zealand. PROCEDURE: Several databases were searched electronically including Medline, Current Contents, Vet CD using several key words (Neospora caninum, neosporosis, abortion, cattle, dogs) and authors names. References in original articles were also traced and use made of the author's own original research in the field. CONCLUSION: N caninum is recognised worldwide and is also widespread, in particular in dairy cattle, in Australia and New Zealand. It has been reported in both countries retrospectively (in dogs) from the early 1970s. Abortion storms in dairy herds appear to be the most common feature. Recent reports indicate that the dog is the definitive host, in which the sexual cycle is completed. Further studies are however required to establish important aspects of the epidemiology, such as mode of transmission. In the absence of an effective vaccine, the most effective control strategy is selective culling of infected animals and the prevention of access of dogs to expelled placentas and foetuses and, possibly, to raw beef.

Determination of residues of pyrethroid and organophosphorous ectoparasiticides in foods of animal origin.

Analytical methods were introduced for the determination of residues of ectoparasiticides containing pyrethroid and organophosphate active ingredients in foods. Milk and edible tissues of cows treated with three experimental ectoparasiticides (containing cypermethrin + diazinon, deltamethrin + diazinon and alphamethrin + diazinon, respectively) were assayed for the presence of active ingredient residues. Synthetic pyrethroid residues were not detected in any of the samples processed. Diazinon residues could only be detected in milk samples taken on the first day after treatment (0.005-0.025 mg/kg) and in liver and fat tissue samples taken on the day of slaughtering (0.12 and 0.01 mg/kg, respectively). Permethrin and propetamphos residues were determined in the skin, meat and liver of chickens kept on 'Blotic-B' treated litter and in eggs collected at different times after the treatment of layer houses. Permethrin residues could not be detected in any of the samples (< 0.01 mg/kg). Meat and fat tissues of chickens slaughtered on the day after treatment contained small amounts of propetamphos (0.003 and 0.02 mg/kg, respectively). In the case of chickens kept on the treated litter and slaughtered after one week, active ingredient was not detected in meat, but 0.006 mg/kg propetamphos was present in the fat. The residue content of other samples (liver, egg) was below the detection limit of the applied method at all sampling times. From the food toxicological point of view these pesticide combinations can be used safely if the recommended withdrawal period is observed between ectoparasiticide administration and slaughter.

[Survey of endemic situations in schistosomiasis transmission controlled or interrupted regions in Anhui Province].

OBJECTIVE: To understand the variation rules of schistosomiasis endemic situation before and after schistosomiasis transmission controlled or interrupted, so as to provide the evidence for the consolidation of control achievements. METHODS: In Anhui Province, 3 counties reaching the criteria of schistosomiasis transmission controlled or interrupted were selected and their historical endemic data were collected and analyzed statistically from 10 years before the schistosomiasis transmission controlled to 2008. RESULTS: In Tianchang City, the Oncomelania hupensis snail area was 3.54 hm2 in a part of the lake marshland in the year reaching the criteria of transmission controlled (1998), and no snails were found in the year of transmission interrupted (2008). No stool-test-positive resident was detected except there were 58 acute schistosomiasis cases in 1993, and the sero-test-positive rate of local residents remained at low levels (0-1.55%). In Taihu County, the snail area was 0.84 hm2 accounting for 0.06% of its historical accumulative snail areas in the year of transmission controlled (1971) , and no snails were found three years before the transmission interrupted (1983). However, the schistosomiasis endemic rebounded 12 years later (1995), there was an outbreak of acute schistosome infections (73 cases), and the snail area increased again to 133.7 hm2 accounting for 2.91% of historical accumulative snail areas. After that, the snail area kept on rising and the infection rates of residents and bovine remained higher than 1%. In Guangde County, the snail area was 32.4 hm2 accounting for 1.90% of its historical accumulative snail areas in the year of transmission controlled (1995). After that, the snail area increased progressively, and the schistosomiasis endemic rebounded and there were acute schistosome infections 5 years later. The Spearman tests showed that the sero-test-positive rate (Tianchang City) and the stool-test-positive rates of residents and bovine (Taihu County) had positive correlations with the snail areas (r = 0.582, 0.401, 0.596, all P < 0.05). CONCLUSION: The snail status is a key for the consolidation of schistosomiasis transmission controlled and interrupted. Therefore, a valid surveillance system of snail situation should be established as quickly as possible.

[Strategy and effect of schistosomiasis emergency control after earthquake in Lushan County].

OBJECTIVE: To evaluate the effects of measures on the schistosomiasis control after the earth quake in Lushan County, so as to provide the experiences for post-disaster schistosomiasis control. METHODS: The measures taken in schistosomiasis control after the earth quake were reviewed in Lushan County in 2013, and the epidemic situation of schistosomiasis was investigated and the results were analyzed. RESULTS: The schistosomiasis control in floating population and the control of Oncomelania hupensis snails were enhanced, and no schistosome infections were found in both human and livestock. No infected snails and infested water were found. CONCLUSION: The measures of schistosomiasis control after the disaster are effective in Lushan County, and the goal to prevent major plague after the earth quake is achieved.