[Epidemic trend and control progress of soil-transmitted nematodiasis in Jiangsu Province].

Soil-transmitted nematodiasis was once widely prevalent in Jiangsu Province, which seriously threatened human health and hindered socioeconomic development. The control efforts over decades resulted in a remarkable decline in the prevalence of soil-transmitted nematode human infections in Jiangsu Province, with a reduction from 59.32% in 1989 to 0.12% in 2019, and the human prevalence remains at < 0.5% since 2013. Since 1987, an integrated strategy has been adopted for the control of soil-transmitted nematodiasis in Jiangsu Province; however, the core interventions varies at different stages, which mainly include deworming, water and sanitation service improvement, health education, and monitoring and assessment. The criteria of effective soil-transmitted nematodiasis control had been achieved in all epidemic counties (districts) of Jiangsu Province by 2019. Further actions to strengthen health education and monitoring and implement precision control measures are required to consolidate the achievements of soil-transmitted nematodiasis control and eliminate the harm of soil-transmitted nematodiasis to humans. This review summarizes the epidemiology, control progress and evolution of control strategy of soil-transmitted nematodiasis in Jiangsu Province.

[Establishment of a nucleic acid assay for detection of Echinococcus granulosus based on recombinase-aided isothermal amplification assay].

OBJECTIVE: To establish a nucleic acid assay for detection of Echinococcus granulosus based on recombinase-aided isothermal amplification (RAA) assay. METHODS: The 12S rRNA gene of E. granulosus was selected as the target gene, and the specific primers and fluorescent probes for RAA assay were designed, screened and synthesized to establish a fluorescent RAA assay for detection of E. granulosus. The sensitivity of the fluorescent RAA assay was evaluated using different copy numbers of target gene sequence-contained recombinant plasmids and various concentrations of E. granulosus genomic DNA as templates, and the specificity of the fluorescent RAA assay was evaluated using the genomic DNA from E. granulosus, E. multilocularis, Schistosoma japonicum, S. mansoni, Ancylostoma duodenale, Clonorchis sinensis, Taenia saginata, Spirometra mansoni and Taenia solium as templates. RESULTS: A fluorescent RAA assay was successfully established for detection of E. granulosus, which achieved specific amplification of E. granulosus genomic DNA within 20 min at 39 ℃. The lowest detection limit of the fluorescent RAA assay was 10 copies/µL of recombinant plasmids and 0.1 ng/µL E. granulosus genomic DNA, which exhibited a high sensitivity, and the fluorescent RAA assay was all negative for the genomic DNA from E. multilocularis, S. japonicum, S. mansoni, A. duodenale, C. sinensis, T. saginata, Spirometra mansoni and T. solium, which exhibited a high specificity. In addition, this fluorescent RAA assay successfully detected genomic DNA from E. granulosus cysts. CONCLUSIONS: A rapid, sensitive and specific fluorescent RAA assay is successfully established for nucleic acid detection of E. granulosus.

[Establishment and evaluation of a novel DNA detection method based on recombinase-aided isothermal amplification assay for Giardia lamblia].

OBJECTIVE: To establish a novel nucleic acid assay for detection of Giardia lamblia based on the recombinase-aided isothermal amplification (RAA) assay, and evaluate its sensitivity and specificity for detection of G. lamblia. METHODS: The specific primer sequences and florescent probes were designed and synthesized based on the G. lamblia ß-giardin gene as the target gene, and a fluorescent RAA assay was established. The recombinant plasmids at various copies (containing the ß-giardin gene target sequence) and the genomic DNA of G. lamblia at various concentrations were used as templates for the fluorescent RAA assay to assess the sensitivity, and the genomic DNA from G. lamblia, Schistosoma japonicum, Clonorchis sinensis, Cryptosporidium parvum, Ascaris lumbricoides, Salmonella and Shigella was used as templates to assess the specificity of the fluorescent RAA assay. RESULTS: A novel fluorescent RAA assay was successfully established for detection of G. lamblia, which allowed the rapid and specific amplification of the target gene fragments at 39 ℃ within 20 min. The sensitivities of the fluorescent RAA assay were 102 copies/µL and 1 pg/µL for detection of the recombinant plasmid and G. lamblia genomic DNA, respectively, and the fluorescent RAA assay was negative for detection of the genomic DNA from S. japonicum, C. sinensis, C. parvum, A. lumbricoides, Salmonella and Shigella, which showed a high specificity. CONCLUSIONS: A fluorescent RAA assay, which is simple, sensitive and specific, is successfully established for nucleic acid detection of G. lamblia.

[Investigation on the risk of of Anisakis infection among high - risk populations along the coastal areas of Jiangsu Province].

OBJECTIVE: To investigate the risk of Anisakis infections among high-risk populations along the coastal areas of Jiangsu Province, so as to develop the strategy for the prevention and control of anisakiasis in the province. METHODS: Three counties along the coastal areas of Jiangsu Province were selected as the study sites in 2018, including Rudong County in Nantong City, Haizhou District in Lianyungang City and Dongtai City in Yancheng City. The knowledge, attitude and practice (KAP) of anisakiasis prevention and control, and the prevalence of serum specific IgG antibody against Anisakis were investigated among high-risk populations among these three study sites, including fishermen, fish seller and people who liked eating fresh and live marine fish. Factors affecting the prevalence of the specific IgG antibody against Anisakis were identified using a multiple logistic regression model. In addition, Anisakis larvae infections were detected in fresh and live marine fish samples collected from local markets, and the prevalence and intensity of Anisakis infections were estimated. RESULTS: A total of 625 high-risk populations were investigated, including 349 men (55.8%). Only 13.0% of the subjects heard about anisakiasis, and a low awareness rate of anisakiasis prevention and control knowledge was seen among these three types of high-risk populations. There were 21.6% of the subjects eating raw or half-cooked marine fish, 5.8% eating undercooked marine fish, 3.2% presenting vomiting, nausea and diarrhea after eating marine fish, 5.1% developing systemic allergic symptoms, and 65.6% using the same chopping board for raw and cooked food. The sero-prevalence of the anti-Anisakis IgG antibody was 7.0% among the study subjects. Multiple logistic regression analysis identified education level [OR = 0.687, 95% CI (0.478, 0.987)] and development of systemic allergic symptoms [OR = 4.641, 95% CI(1.411, 15.268)]as factors affecting the positive anti-Anisakis IgG antibody among the study subjects. Among 494 fresh and live marine fish detected, the prevalence and intensity of Anisakis larvae infection was 64.0% and 8.1 larvae per fish, with high prevalence seen in Trichiurus haumela and Pneumatophorus japonicas. CONCLUSIONS: The awareness of anisakiasis prevention and control knowledge is low among the high-risk populations living along the coastal areas of Jiangsu Province, and there are high-risk behaviors, such as eating raw or half-cooked food, using the same chopping board for raw and cooked food. In addition, the prevalence of Anisakis infections is high in the marine fish in these areas. Therefore, the health education and health promotion for anisakiasis prevention and control should be intensified.