Objective To develop a bionic animal skin and evaluate its detective effect of Schistosoma japonicum cercariae so as to provide a new technique for the monitoring of the schistosome susceptibility water body.Methods A bionic animal skin was made with pigskin and the experiments were carried out for evaluating its detective effects of S.japonicum cercariae in labo-ratory and simulate fields,and at the same time,the sentinel mouse method was used as the control.Results In the laborato-ry,the cercariae were found in 10-,30-,60-cercaria subgroups in the bionic animal skin group after 1 and 2 hours,but the cer-cariae were found only in the 60-cercaria subgroup in the sentinel mouse group.In the simulate fields,in the water body with 5 schistosome-infected Oncomelania hupensis snails,the cercariae were found in 2 bionic animal skin devices(2/4)and 3 bionic animal skin devices(3/4)after 2 hours and 4 hours respectively,and in the water body with 10 schistosome-infected O.hupensis snails,the cercariae were found in 4 bionic animal skin devices(4/4)and 3 bionic animal skin devices(3/4)after 2 hours and 4 hours respectively in the bionic animal skin group.In the the sentinel mouse group,in the above-mentioned water bodies(with 5 or 10 schistosome-infected O.hupensis snails),the cercariae were found in 2 sentinel mice(2/4)and 1 sentinel mice(1/4)af-ter 2 hours and 4 hours respectively;and the cercariae were found in 2 sentinel mice(2/4)and 3 sentinel mice(3/4)after 2 hours and 4 hours respectively.Conclusion The bionic animal skin device can be used to detect the S.japonicum cercariae, and its sensibility and efficiency are superior to the traditional sentinel mouse method.

Objective To understand the present situation of the chronic schistosomiasis patients'knowledge,attitude and practice on schistosomiasis control in Nanchang City. Methods The knowledge,attitude and values on schistosomiasis control of 523 chronic schistosomiasis patients in Nanchang County,Jinxian County and Xinjian District in the Poyang Lake District were investigated with questionnaires. And the accuracy rates of the knowledge,attitude and practice among the patient groups of different counties,genders,age groups,occupations and educational levels were analyzed. Results The accuracy rates of the knowledge,attitude and practice of patients on schistosomiasis control were 95.76%,82.80%,and 81.73% in Nanchang County;91.37%,93.32%,and 76.48%in Jinxian County;88.25%,67.56%,and 49.40%in Xinjian District. In the accuracy rates of knowledge,attitude and practice,the differences among the three counties (districts) were statistically significant (χ2=57.511-301.378,all P<0.05). Conclusions The accuracy rates of chronic schistosomiasis patients'attitude and prac-tice on schistosomiasis control in Nanchang City remain low. Therefore,the intensity of attitude and practice intervention should be strengthened in the Poyang Lake District in order to enhance the self-protection awareness of the patients.

Objective:To understand the epidemic characteristics of malaria in Nanchang, and provide a basis for timely adjustment of prevention and control strategies and measures after elimination of malaria in Nanchang.Methods:By retrospective analysis, the malaria case information and epidemiological case questionnaire reported in Nanchang from 2016 to 2020 were collected from the "China Disease Control and Prevention Information System Infectious Disease Report Information Management System" and "Parasitic DiseasePrevention and Control Information Special Report System". General situation of the cases, three distributions (time, region and population distributions) and the source of infection were described and statistically analyzed.Results:A total of 69 malaria cases were reported in Nanchang from 2016 to 2020, including 39 cases of falciparum malaria, 19 cases of vivax malaria, 9 cases of ovale malaria, 1 case of quartan malaria and 1 case of mixed infection. The onset time of 69 malaria cases was not seasonal, and cases were reported every month; they were distributed in 8 districts (counties) of Nanchang, with Jinxian County was most, accounting for 36.2% (25/69); the sex ratio of men and women was 22 ∶ 1 (66 ∶ 3), and the age of the cases was mainly 20 - < 60 years old, accounting for 97.1% (67 cases); the occupation distribution was dominated by workers, accounting for 26.1% (18/69). The 69 malaria cases were all imported cases from abroad, of which 67 cases were imported from Africa, accounting for 97.1%.Conclusions:There is no report of local malaria case in Nanchang from 2016 to 2020, all cases are imported from abroad. In the future, the control and prevention of imported personnel from abroad should be strengthened.

Objective To evaluate the safety and immunogenicity of one booster dose of inactivated hepatitis A vaccine in young adults.Methods The subjects were selected from participants in the clinical trial of immunogenicity of inactivated and attenuated live hepatitis A vaccine in young adults.Eligible subjects were those who had received one dose of inactivated or attenuated hepatitis A vaccine,could be contacted and were sero-negative before primary vaccination.All qualified subjects were immunized with one booster dose of inactivated hepatitis A vaccine.The blood samples were collected before booster dose vaccination and 28 days after the immunization.Anti-HAV antibody titer ≥20 mIU/ml was considered to be sero-protected against hepatitis A virus.Results The GMCs in the inactivated HAV vaccine group and attenuated live vaccine group before booster dose vaccination were 70.80 mIU/ml and 50.12 mIU/ml,respectively,and the sero-protection rates were 94.7％ and 65.0％,respectively.After the vaccination of the booster dose,the sero-protection rates in both groups were 100.0％,and the GMCs were 2 816.09 mIU/ml and 2 654.55 mIU/ml,respectively.Conclusion The GMCs and sero-protection rates of anti-HAV antibody in young adults declined after three years of the primary vaccination.However,the higher GMC and sero-protection rate were observed in the inactivated vaccine group than in the attenuated live vaccine group.Significant increases of GMC levels were observed in both groups after one booster dose vaccination.

Objective:To analyze the monitoring situation of iodized salt in Nanchang City after implementation of the new iodized salt standard, in order to provide a basis for formulating prevention and control strategy to iodine deficiency disorders.Methods:From 2013 to 2015, according to "Jiangxi Province Surveillance Pilot Scheme of Iodine Deficiency Disorders (2012)", 9 counties (districts) were selected for surveillance of iodized salt, every county (district) was divided into 5 sampling areas according to the east, west, south, north, and middle positions, and 1 township (street) was selected from each area, 4 administrative villages (neighborhood committees) were selected from each township (street), and 15 samples of household salt were sampled from each administrative village (neighborhood committee). From 2016 to 2018, according to "National Surveillance Pilot Scheme of Iodine Deficiency Disorders (2016)", some counties (districts) were divided into 5 sampling areas according to the east, west, south, north, and middle positions, and 1 township (street) was selected from each area, 1 elementary school was selected from each township (street), 40 non-boarding students aged 8 to 10 (aged balanced, half male and female) were selected from each elementary school, and salt samples from students' homes were collected and in each township (street) salt samples were collected from 20 pregnant women's homes. The remaining counties (districts) were sampled in accordance with "Jiangxi Province Surveillance Pilot Scheme of Iodine Deficiency Disorders (2012)". The iodine content of salt samples was detected, and the coverage rate, qualified rate and consumption rate of qualified iodized salt were calculated.Results:From 2013 to 2018, the coverage rate of iodized salt, the qualified rate of iodized salt and the consumption rate of qualified iodized salt were 99.52% (16 122/16 200), 95.83% (15 449/16 122) and 95.36% (15 449/16 200), respectively, and the median salt iodine was 23.50 mg/kg; the coverage rate of iodized salt in 2018 was the lowest [98.63% (2 663/2 700)], and the difference was statistically significant between different years (χ 2 = 97.856, P < 0.05); the qualified rate of iodized salt and the consumption rate of qualified iodized salt were both the lowest in 2016, which were 93.93% (2 509/2 671) and 92.93% (2 509/2 700) , respectively. There were significant differences in the qualified rate of iodized salt and the consumption rate of qualified iodized salt between different years (χ 2 = 65.090, 81.053, P < 0.05); the non-iodized salt rate in 2018 was the highest [1.37% (37/2 700)], and the difference was statistically significant between different years (χ 2 = 97.856, P < 0.05). From 2013 to 2018, the range of salt iodine content was 0.00 - 64.67 mg/kg. The coverage rate of iodized salt in Qingyunpu District and Nanchang County was both 100% (1 800/1 800), in Donghu District was the lowest [98.06% (1 765/1 800)]. There was significant difference in coverage rate of iodized salt among different counties (districts, χ 2 = 131.247, P < 0.05). The qualified rate of iodized salt in Qingyunpu District was the highest [99.11% (1 784/1 800) ], and in Xihu District was the lowest [93.16% (1 674/1 797)]. There was significant difference in qualified rate of iodized salt among different counties (districts, χ 2 = 127.257, P < 0.05). The consumption rate of qualified iodized salt in Qingyunpu District was the highest [99.11% (1 784/1 800) ], and in Xihu District was the lowest [93.00% (1 674/1 800)]. There were significant differences in the consumption rate of qualified iodized salt among different counties (districts, χ 2 = 123.784, P < 0.05). Conclusion:The coverage rate of iodized salt and the consumption rate of qualified iodized salt in Nanchang City from 2013 to 2018 are generally stable, meeting the requirements of iodized salt index in iodine deficiency disorders elimination standard.

Objective To investigate the biological characteristics of the praziquantel-resistant isolate of Schistosoma japoni-cum in mice,so as to explore the pathogenicity to definitive hosts and transmission intensity of the praziquantel-resistant isolate of S. japonicum. Methods Mice were infected with the cercariae released from two praziquantel-resistant isolates and two pra-ziquantel-susceptible isolates of S. japonicum. The mouse-Oncomelania hupensis snail-mouse cycle was established and main- tained in the laboratory. The prepatent period of parasite eggs,egg production,egg distribution in mice,parasite susceptibility to mice and egg size were investigated in each parasite isolate. Results The prepatent period of parasite eggs,egg counts in mouse feces,adult worms recovered from each mouse,egg counts in mouse tissues,egg counts in the mouse liver,and egg counts in intestine tissues were 36.1 d and 36.8 d ( t=0.907, P=0.372 ) , 14.6 / 100 mg and 21.2 / 100 mg (t=2.946, P=0.007),20.5 and 25.1 worms per mouse(t=2.128, P=0.042),31303 and 38594 per paired adult worm(t=2.185, P=0.04),14810 and 19715 per paired adult worm(t=2.934, P=0.007),and 16493 and 18879 per paired adult worm(t=1.044, P=0.309)in the mice infected with Jiangsu praziquantel-susceptible and-resistant isolates of S. japonicum, respectively,and there were no significant differences between Jiangsu praziquantel-susceptible and-resistant isolates of S. ja-ponicum in the length of paired adult worms(t=0.328, P=0.744),female adult worms(t=0.386, P=0.701)or male adult worms(t=0.332, P=0.741). The prepatent period of parasite eggs,egg counts in mouse feces,adult worms recovered from each mouse,egg counts in mouse tissues,egg counts in the mouse liver,and egg counts in intestine tissues were 35.5 d and 35.6 d(t=0.169, P=0.867),13.3/100 mg and 18.9/100 mg(t=3.622, P=0.001),17.6 and 25.1 worms per mouse(t=3.153, P=0.004),30932 and 53903 per paired adult worm(t=3.865, P=0.001),12307 and 26363 per paired adult worm (t=4.388, P<0.01),and 18625 and 27541 per paired adult worm(t=2.679, P=0.012)in the mice infected with Hunan praziquantel-susceptible and-resistant isolates of S. japonicum,respectively,and there were no significant differences between Hunan praziquantel - susceptible and - resistant isolates of S. japonicum in the length of paired adult worms (t=0.853, P=0.397),female adult worms(t=0.573, P=0.569)or male adult worms(t=0.742, P=0.461). Conclusions The praziquantel-resistant isolate of S. japonicum has a higher parasite egg production and more eggs deposited in the mouse liver than drug-susceptible isolate,suggesting that the praziquantel-resistant isolate of S. japonicum exhibits a greater pathogenicity to definitive hosts. In addition,more parasite eggs are detected in the feces of mice infected with the praziquantel-resistant isolate of S. japonicum relative to the drug-susceptible isolate,indicating that the praziquantel-resistant isolate of S. japonicum exhibits a greater transmissibility than the drug-susceptible isolate.

Objective To investigate the difference of biological characteristics between the praziquantel-resistant and-sus-ceptible isolates of Schistosoma japonicum in intermediate host Oncomelania hupensis snails. Methods Mice were infected with cercariae of praziquantel-resistant and-susceptible isolates of S. japonicum,and the parasite eggs were collected 37 days post-in-fection to hatch miracidium. Then,the snails were infected with the miracidium of each parasite isolate. The snail infection,sur-vival rate of infected snails,prepatent period of cercariae,and the total number of cercariae shed from each infected snail were observed and compared between the praziquantel-resistant and-susceptible isolates of S. japonicum. Results If each snail was exposed to a single miracidium,there were significant differences between the praziquantel-resistant and-susceptible Jiangsu isolates in the snail infection(8.99％vs. 19.74％;χ2=3.948,P=0.047)and the number of cercaria released from a single snail (1460.2 vs. 1039.3;t=2.507,P=0.02),and there were significant differences between the praziquantel-susceptible and-re-sistant Hunan isolates in the snail infection(10.00％vs. 21.52％;χ2=3.980,P=0.046)and the number of cercaria released from a single snail(1319.4 vs. 1003.5;t=2.566,P=0.017). However,there were no significant differences between the pra-ziquantel-resistant and-susceptible isolates of S. japonicum in the prepatent period of cercariae and the survival rate of infected snails(P>0.05). Conclusion The praziquantel-resistant isolate of S. japonicum has a higher susceptibility to O. hupensis but less cercaria released from each infected snail than the susceptible isolate.