ABSTRACT
Objective To analyze the spatial clustering of human schistosomiasis at the village level in key counties in Hubei Province, to provide scientific evidence for formulating strategies for human schistosomiasis prevention and control in the next stage. Methods Gong'an County and Jiangling County in Hubei Province were selected as representative counties for this study. A town or village was set up as a research unit. Schistosomiasis cases of a positive fecal examination in 2015 and cases with positive detection for schistosomiasis serological antibody titer equal or above 80 in 2016-2018 were selected as research subjects in these two counties. The Kulldorff circular scan statistic was used for the spatial clustering analysis of human schistosomiasis infection status in the population. Results There was spatial clustering of positive schistosomiasis cases of fecal examination, at the level of a town or village in both counties in 2015. There was spatial clustering of positive human serological antibody detection at the level of town or village from 2016-2018. Eighty-six endemic villages in five towns in the northeast of Gong'an County, along the Yangtze river,including Mahaokou Town, Zhakou Town, Yangjiachang Town, Jiazhuyuan Town and Douhuti Town, were the most prominent. There was no spatial clustering of positive results of human serological antibody detection at the town and village level in Jiangling County, in2017, while there was spatial clustering of human serological antibody detection in 2016 and 2018,respectively. Fifty-seven endemic villages in two towns (Puji Town and Xionghe Town) in the southwest of Jiangling County, along the Yangtze river,were the most prominent. Conclusion There were spatial clustering of human schistosomiasis epidemic at village level both in Gong'an County and Jiangling County, Hubei Province. Compared with the previous studies, there was a trend of shrink and decline of clustering areas. Therefore, the current situation of the epidemic has put forward higher requirements for the implementation of precise prevention and control in the progress of schistosomiasis elimination work in various epidemic areas.
ABSTRACT
Objective To analyze the antibody titer value of indirect haemagglutination test(IHA)in 135 confirmed acute schistosomiasis patients,so as to provide the evidence for improving the diagnosis and treatment of acute schistosomiasis. Meth-ods A total of 135 acute schistosomiasis inpatients were selected from 2001 to 2006. They all received the IHA antibody titer de-tection,and the correlation among the age,incubation period,and hospitalization days was calculated. Results The antibody titers of IHA were higher than 1:320 in all the cases. The percentages of 1:640,1:1280,1:2560,1:5120 and 1:10240 were 1.48%,28.15%,35.56%,20.00%,and 14.81%respectively. The mean age was(47.70 ± 14.58)years,average incuba-tion period was(38.03 ± 4.59)days and mean hospital stay time was(15.08 ± 3.79)days. The antibody titer value had no corre-lation with the age distribution(r=0.109,P>0.05). There was a negatively correlation between the antibody titer value and in-cubation period,(r=-0.558,P<0.01),there was a positive correlation between the antibody titer value and hospitalization time(r=0.791,P<0.01),and there were significant differences among different groups(F=17.07,64.53,both P<0.01). Conclusions The antibody titer of acute schistosomiasis cases detected by IHA is 1:640 and above. There is no correlation be-tween the antibody titer value and age,but the antibody titer value is higher,the incubation period is shorter and hospitalization time is longer.
ABSTRACT
Objective To evaluate the molluscicidal effect of suspension concentrate of niclosamide ethanolamine salt(SC-NE)against Oncomelania hupensis snails in laboratory and field. Methods The experiment of SCNE against the snails by using the immersing and spraying methods was performed in laboratory and field,with control groups of wettable powder of ni-closamide ethanolamine salt(WPN). Results In the laboratory,LC50(s) of SCNE for 24,48 h and 72 h by using the immersion method were 0.0926,0.0629 mg/L and 0.0549 mg/L,respectively. The mortality rates of snails for 24,48 h and 72 h by using the immersion method were all 100％ with the concentrations of 0.25 mg/L. The mortality rates of snails were all 100％ while spraying SCNE for 3 d in the laboratory with the concentrations of 0.25 g/m2. In Jiangling County,except 0.5 g/m3 SCNE immers-ing the snails for 24 h,the mortality rates of snails by using SCNE with the immersing method were all 100％. While the concen-tration of SCNE was 0.5 g/m3 or above,the mortality rates were all 100％after the use of it with the immersion method for 2 d in Gong'an County. In Jiangling County,the mortality rates of snails by using SCNE 0.5 g/m3 for 1 d,3 d,and 7 d with the spray-ing method were 87.5％,92.82％and 97.40％respectively. While the concentration of SCNE was 0.5 g/m3,the mortality rates were 85.94％,86.78％and 94.21％respectively after the use of it with the spraying method for 1 d,3 d,7 d in Gong'an Coun-ty,and the molluscicidal effect of SCNE(1.0 g/m2)was higher than that of WPN. Conclusion SCNE has a high molluscicidal effect in the laboratory and field,and it is a novel and simple formulation of niclosamide.
ABSTRACT
Objective To evaluate the effect of schistosomiasis control in Gongan County,Hubei Province by longitudinal ob-servations so as to provide the evidence for formulating the schistosomiasis control strategy in lake and marshland regions. Meth-ods The schistosomiasis epidemic data in Gongan County from 2000-2013 were collected by the retrospective research method, and analyzed about the changing tendency of human and cattle infection rates,and Oncomelania hupensis snail situation. Re-sults The tendency of schistosomiasis epidemic situation was descended from 2000 to 2013. The human infection rate declined from 12.62%in 2000 to 0.69%in 2013. The decline scope of human infection rate was 24.1%in the first stage,64.4%in the sec-ond stage,and 73.0%in the third stage. Eight acute schistosomiasis cases were reported in the first stage,15 cases in the second stage,and none in the third stage. The cattle infection rate declined from 6.50%in 2000 to 0.30%in 2013. The rise scope of cattle infection rate was 74.2%in the first stage,but the decline scope was 75.0%in the second stage and 87.6%in the third stage. All the cattle were disposal at the end of 2013. The infection rate of snails,area with infected snails,and average density of living snails in the first stage increased by 18.1%,46.0%and 7.6%,respectively. The 3 indexes above-mentioned in the second stage de-creased by 76.8%,97.8%and 37.9%,respectively. In the third stage,the infection rate of snails and area with infected snails de-creased by both 100%,but the average density of living snails increased by 2.7%. The infected snails were found from 2000 to 2011,but none in 2012 and 2013. The infection rate of snails and area with infected snails dropped yearly,the infection rate of snails declined from 0.0007% in 2000 to 0.0002% in 2011,and the area with infected snails declined from 267.8 hm2 in 2000 to 6.37 hm2 in 2011. Conclusions After the implementation of the integrated schistosomiasis prevention and control strategy with the emphasis on infectious source control,the human and cattle schistosome infection rates decline significantly. Hereafter,it is necessary to prevent the schistosomiasis epidemic outbreak or rebound.
ABSTRACT
Objective To understand the schistosomiasis endemic situation at a national surveillance site in Gong an Coun-ty Hubei Province. Methods According to The Scheme of Schistosomiasis Surveillance in China the schistosome infection rates of residents and cattle and the Oncomelaniahupensissnail status were investigated yearly in Zhangjiahu Village a nation-al surveillance site in Gong an County from 2004 to 2013. Results From 2004 to 2013 the human schistosome infection rates decreased from 10.66%to 0.58% and the cattle schistosome infection rates from 12.75%to 0. Meanwhile the snail areas and densities reduced and the schistosome infected snails were eliminated. Conclusion The schistosomiasis endemic situa-tion declined dramatically at the surveillance site and schistosomiasis is well-controlled.