Objective:To investigate the iodine nutritional status of pregnant women in Hangzhou City and analyze its influencing factors, in order to provide a basis for guiding pregnant women in Hangzhou City to supplement iodine scientifically.Methods:A stratified random sampling method was used to conduct a questionnaire survey on 1 400 pregnant women in Hangzhou City from March to October 2018. Random urine samples and household salt samples from pregnant women were collected, and the levels of urine iodine and salt iodine were measured using arsenic cerium catalytic spectrophotometry and direct titration, respectively. The iodine nutritional status of pregnant women with different basic characteristics and dietary levels were analyzed and compared (Kruskal-Wallis test), and the main influencing factors affecting the urinary iodine concentration level of pregnant women were identified (the ordinal multiple classification logistic regression analysis).Results:The median urinary iodine of pregnant women was 135.00 μg/L, and the qualified iodized salt consumption rate of pregnant women was 83.36% (1 167/1 400). In terms of basic characteristics, there were statistically significant differences in the distribution level of urine iodine among pregnant women with different pregnancy frequency, delivery frequency, and natural abortion frequency ( P < 0.05). In terms of diet, the frequency of consuming milk, yogurt, meat, and whether pregnant women consumed cabbage and cauliflower showed statistically significant differences in urinary iodine distribution levels ( P < 0.05). Ordinal multiple classification logistic regression analysis showed that the urine iodine levels of pregnant women who were pregnant twice were higher than those who were pregnant ≥3 times ( OR = 1.64, P = 0.003). Pregnant women who never or occasionally consumed yogurt had lower urine iodine levels than or equal to those who consumed 2 bottles of yogurt per day ( OR = 0.53, P = 0.044). Pregnant women who never or occasionally consumed meat and those who consumed meat once a week had higher urinary iodine levels than that who consumed meat ≥2 times per week ( OR = 1.40, 1.47, P < 0.05). Conclusions:The overall iodine nutrition of pregnant women in Hangzhou City is at an deficiency level. Pregnancy experience and dietary level are influencing factors on iodine nutrition of pregnant women. It is necessary to carry out in-depth health education for pregnant women, improve the dietary structure during pregnancy, and improve the abnormal iodine nutrition of pregnant women.

Objective:To analyze the changing trends of the epidemic characteristics of human brucellosis in Hangzhou City, and to provide a basis for further formulating prevention and control measures.Methods:The epidemic data of brucellosis in Hangzhou City from 2004 to 2021 were collected from the "China Disease Control and Prevention Information System" and the annual reports, compilations and summaries of prevention and control work of brucellosis in Hangzhou City, and the epidemiological characteristics and trends of brucellosis cases in Hangzhou City from 2004 to 2009, 2010 to 2015, and 2016 to 2021 were compared and analyzed.Results:A total of 186 cases of brucellosis were diagnosed in Hangzhou City from 2004 to 2021, with an average annual incidence rate of 0.151/100 000, ranging from 0.016/100 000 to 0.286/100 000. The incidence rate showed a stage-by-stage upward trend from 2004 to 2009, 2010 to 2015, and 2016 to 2021 ( Z = 3.15, P = 0.002). The age of onset of brucellosis cases was predominantly 18 - 60 years old, accounting for 78.49% (146/186). The male-to-female ratio was 2.10∶1.00 (126∶60). The occupational and non-occupational populations accounted for 62.90% (117/186) and 37.10% (69/186), respectively, with the proportion of non-occupational cases in the three stages being 28.57%, 23.29% and 51.76%, showing an increasing trend (χ 2trend = 9.85, P = 0.002). The regional distribution was dominated by Yuhang District, accounting for 55.91% (104/186), followed by Jianggan District (9.14%, 17/186) and Fuyang District (7.53%, 14/186). The number of brucellosis epidemic counties (cities, districts) increased from 6 to 9. The seasonal analysis showed that the proportion of cases from January to June decreased from 84.93% (23/28) from 2004 to 2009 to 54.12% (46/85) from 2016 to 2021. The proportion of infection from outside the province in the three stages was 0, 10.96% and 27.38%, respectively, showing an upward trend (χ 2trend = 18.16, P < 0.001), the main infected areas were Henan Province, Heilongjiang Province, and Inner Mongolia Autonomous Region. In clinical symptoms and signs, the incidence of muscle and joint pain and low back pain increased from 60.71% (17/28) and 10.71% (3/28) from 2004 to 2009, respectively, to 83.53% (71/85) and 25.88% (22/85) from 2016 to 2021, both showing an upward trend (χ 2trend = 9.92, 4.67, P = 0.002, 0.031). Conclusions:The incidence of human brucellosis in Hangzhou City is on the rise, and the number of cases of non-occupational population has increased significantly in recent years. The sheep breeding places have gradually become the high incidence areas of brucellosis in Hangzhou City. It is recommended to strengthen the promotion and education of knowledge on brucellosis prevention among the general public, and focus on actively monitoring human brucellosis in high-risk areas.

Objective:To study the epidemiological and spatio-temporal distribution characteristics of hemorrhagic fever with renal syndrome (HFRS) in Hangzhou City, providing a scientific basis for prevention and control of HFRS.Methods:Data of HFRS cases reported in Hangzhou City from January 1, 2010 to December 31, 2022 were collected through the Infectious Disease Surveillance and Reporting Information System of China Disease Prevention and Control Information System. Descriptive epidemiological methods were used to analyze the prevalence and three-distribution characteristics of HFRS in Hangzhou City. Joinpoint regression was used to analyze the trend of HFRS incidence in Hangzhou City from 2010 to 2022. Global and local spatial autocorrelation were used to analyze the spatial distribution pattern of HFRS and the hotspots of incidence in Hangzhou City. And spatio-temporal scanning was used to analyze the spatio-temporal aggregation areas of HFRS in Hangzhou City.Results:From 2010 to 2022, a total of 224 HFRS cases were reported in Hangzhou City, with an average annual incidence of 0.18/100 000. The distribution of cases showed obvious seasonality, with peak incidence in spring (March to May) and autumn (September to November), accounting for 30.80% (69/224) and 26.34% (59/224), respectively. HFRS cases were reported in all districts (counties, cities) of the city, among which Xiaoshan District (66 cases, 29.46%), Chun'an County (41 cases, 18.30%) and Jiande City (25 cases, 11.16%) ranked the top three. The majority of the cases were individuals aged 31 to 60 (65.18%, 146/224), males (74.55%, 167/224), and farmers (46.43%, 104/224). Joinpoint regression analysis indicated that the overall incidence of HFRS in Hangzhou City was in downward trend from 2010 to 2022 [average annual percent change (AAPC) = - 5.01%, 95% confidence intervals ( CI): - 9.46% to - 0.34%, t = - 2.10, P = 0.036]. Global spatial autocorrelation analysis showed that there was a positive spatial correlation in the incidence of HFRS among various streets (townships) in Hangzhou City from 2011 to 2014, 2018, and 2020 (Moran's I > 0, Z > 1.96, P < 0.05). Local spatial autocorrelation analysis showed that from 2010 to 2022, the number of streets (towns) in hot areas (high-high) in Hangzhou City was 0, 2, 3, 3, 3, 3, 0, 0, 4, 0, 1, 0, and 1, respectively, and was relatively fixed in the southwest districts (counties, cities). Spatio-temporal scan analysis identified three clusters: Cluster I was from August 2011 to January 2015, centered on Fenkou Town in Chun'an County, involving 5 townships in Chun'an County; Cluster Ⅱ-1 was from August 2012 to March 2016, centered on Puyang Town in Xiaoshan District, involving 5 townships in Xiaoshan District; Cluster Ⅱ-2 was from June 2019 to June 2020, centered on Xiaya Town in Jiande City, not involving other streets (townships). Conclusions:From 2010 to 2022, the majority of HFRS cases in Hangzhou City are middle-aged male farmers. The overall trend of HFRS epidemic is decreasing, mainly concentrated in the southwest districts (counties, cities) of Hangzhou City. In the future, precise prevention and control measures should be implemented in key areas and among key populations.

Objective:To study the impact of "Five Water Governance" policy on iodine in drinking water of residents in the external environment in Hangzhou City, and to provide scientific basis for iodine supplementation in accordance with local conditions.Methods:In May 2017, in the process of implementing the "Five Water Governance" program in Hangzhou City, water samples were collected in 13 districts (counties and cities) with towns as units according to different water supply methods. The "Method for Iodine Detection in Iodine-deficient and High-iodine Areas" recommended by the National Iodine Deficiency Disorders Reference Laboratory was adopted for water iodine detection. According to the water source (tap water, well water, spring water) and geographical location (urban area, suburb area, rural area), the distribution of water iodine was analyzed.Results:A total of 722 water samples were tested in the city, the median water iodine was 1.1 μg/L, ranged from 0.3 to 105.0 μg/L, the median water iodine of all districts (counties, cities) was < 10 μg/L. There were 182 townships in the city, with 94 townships providing centralized water supply, 3 townships decentralized water supply, and 85 townships mixed water supply. The median water iodine levels in tap water, well water, and spring water were 1.3, 0.9, and 1.6 μg/L, respectively, and the median iodine levels in urban, suburban, and rural water were 3.6, 1.2, and 1.0 μg/L, respectively.Conclusions:The iodine content in the drinking water of residents in the external environment of Hangzhou City is relatively low, and it still belongs to iodine deficiency areas. The strategy of salt iodization for prevention and treatment of iodine deficiency disorders should be continued while the measures of "Five Water Governance" are carried out.

Objective: To investigate the epidemiological characteristics of malaria in Hangzhou City from 2004 to 2021, so as to provide the evidence for formulating the post-elimination control strategy for malaria in Hangzhou City. Methods: The epidemic situation of malaria in Hangzhou City from 2004 to 2021 were collected from the National Information System for Disease Control and Prevention in China, and the temporal, spatial and human distributions of malaria cases and the source of malaria infections were analyzed in Hangzhou City during the pre-elimination stage (2004 to 2009), the elimination stage (2010 to 2015) and the post-elimination stage (2016 to 2021). Results: Totally 602 malaria cases were reported in Hangzhou City from 2004 to 2021,and the annual mean incidence of malaria was 0.22/105, 0.20/105 and 0.18/105 during the pre-elimination, elimination and post-elimination stages, appearing a tendency towards a decline. Men accounted for 63.96%, 85.07% and 93.75% of all malaria cases and there were 67.86%, 82.84% and 80.00% of cases at ages of 18 to 50 years during the pre-elimination, elimination and post-elimination stages, both appearing a tendency towards a decline (χ2trend=56.748, P<0.001; χ2trend=39.971, P<0.001). The predominant occupation of malaria cases shifted from farmers or migrant workers to multiple occupations, and the proportion of commercial servants increased from 4.87% during the pre-elimination stage to 24.38% during the post-elimination stage (χ2trend=73.308, P<0.001). The proportion of Plasmodium vivax malaria cases reduced from 96.43% during the pre-elimination stage to 7.50% during the post-elimination stage, and the proportion of P. falciparum malaria cases increased from 3.57% to 71.25%, while P. ovale, P. malariae and mixed infections were identified since 2010. There was a significant season-specific incidence of P. vivax malaria during the pre-elimination stage, and the period between May and October was an epidemic season; however, there was no season-specific incidence of P. vivax malaria during the elimination and post-elimination stages. The regional distribution of malaria cases presented a tendency towards a shift from suburb and rural areas to urban areas (χ2trend=74.229, P<0.001). No local cases were detected in Hangzhou City since 2010, and 94.22% of malaria cases were overseas imported cases after malaria elimination, including 90.61% from Africa. Conclusions oung and middle-aged men were high-risk populations for malaria in Hangzhou City from 2004 to 2021, and overseas commercial servants gradually became the predominant source of malaria infections, with malaria parasite species tending to be diverse. Improving the management of overseas imported cases and timely identification and treatment of cases are major interventions to consolidate malaria elimination achievements in Hangzhou City.

Objective:To learn about the knowledge and practice of iodine deficiency disorders (IDD) prevention and control among main caregivers of pregnant women in trimester and its related influencing factors, so as to provide a scientific basis for effectively improving the iodine nutrition level of pregnant women.Methods:In April 2020, using the stratified sampling method, 2 districts and counties were selected in the urban, suburban and rural areas of Hangzhou City, respectively, and 5 maternal and child health care institutions were selected as the survey sites in each district and county according to the five directions of East, West, South, North and Middle. A face-to-face questionnaire investigation was used to investigate the knowledge and practice of IDD prevention and control among main caregivers of pregnant women.Results:Totally 601 caregivers of pregnant women were investigated. Among them, 68.9% (414/601) knew that eating iodized salt was the best way to prevent IDD. However, 15.0% (90/601) thought that eating seafood was the best way to prevent IDD. And 41.9% (252/601) caregivers of pregnant women would actively purchase iodine-rich food for cooking, and 63.6% (382/601) would choose iodized salt. There were statistically significant differences in the knowledge and practice of IDD prevention and control among caregivers of pregnant women in urban, suburban and rural areas ( P < 0.05). And 50.3% (87/173) male caregivers would actively purchase iodine-rich food for cooking, which was higher than that of female caregivers [38.6% (165/428)], the difference was statistically significant (χ 2 = 6.97, P = 0.008). There was a statistically significant difference between the caregivers of pregnant women of different ages in actively purchasing iodine-rich food for cooking (χ 2 = 12.61, P = 0.013). And there were statistically significant differences between the caregivers of pregnant women with different educational levels in actively purchasing iodine-rich food for cooking and choosing iodized salt (χ 2 = 29.34, 39.42, P < 0.001). Conclusions:The awareness of knowledge about IDD prevention and control and the formation of prevention and control behavior among caregivers of pregnant women in Hangzhou City are poor. Active education of caregivers of pregnant women should be strengthened to promote maternal and infant health.

Objective:To investigate the situation of salt sales and education on prevention and treatment of iodine deficiency disorders in salt sales outlets in Hangzhou after the reform of salt industry system, and provide a basis for promotion of scientific iodine supplementation for the public.Methods:In 2020, 4 townships (towns, streets) were selected from 13 districts (counties, cities) of Hangzhou by stratified sampling method. Each township (town, street) delimited 5 survey areas according to the directions of east, west, south, north and middle, and a salt sales place was selected as the survey site in each investigation area. A face-to-face questionnaire was used to investigate the sales of salt in sales outlets and the publicity and education of iodine deficiency disorders prevention and treatment.Results:A total of 238 edible salt sales outlets were effectively investigated, including 113 urban outlets, 78 suburban outlets, and 47 rural outlets; 55.9% (133/238) of the outlets sold non-iodized salt. A total of 68 072 bags of small packaged salt were sold every month, the overall sales of iodized salt was significantly higher than that of non-iodized salt ( Z = - 2.865, P < 0.05), and the sales of iodized salt in urban and suburban sales outlets were higher than that of non-iodized salt ( Z = - 2.313, - 2.237, P < 0.05). The sales of salt in urban and suburban sales outlets were the highest with the price of 2-5 yuan of salt, accounting for 78.6% (33 562/42 705) and 82.3% (13 970/16 979), respectively; in rural sales outlets, with the price of 1-2 yuan of salt was the highest, accounting for 72.8% (6 110/8 388). Among the 238 salt sales outlets, 29.4% (70/238) of the outlets had set up a prevention and treatment of iodine deficiency disorders sign, and 39.9% (95/238) of the outlets salt sales staff known "recommended salt for pregnant women", 31.1% (74/238) of the outlets whose salt sales staff had actively informed salt buyers about the prevention and treatment of iodine deficiency disorders. The total monthly sales of salt and the sales of iodized salt at outlets where the prevention and treatment of iodine deficiency disorders signs were set up and the salt sales staff were aware of the "recommended salt for pregnant women" were higher than outlets where no signs were set up and the sales staff were not aware ( Z = - 3.733, - 3.722, - 2.109, - 2.324, P < 0.05). Conclusions:After the reform of salt industry system, the iodized salt supply of salt sales outlets in Hangzhou is sufficient. With the increase of non-iodized salt supply channels, we should strengthen the active publicity and education on prevention and treatment of iodine deficiency disorders in the sales section.

Objective:To understand the iodine deficiency disorders (IDD) knowledge, attitude and practice (KAP) among population in and near salts marketing areas of Hangzhou urban areas, so as to provide the evidence for making effective health education and health promotion models.Methods:A face to face KAP questionnaire investigation was conducted in 5 salts marketing survey points of 5 urban areas according to the north, south, east, west and center locations in 2018. The survey included basic information, awareness of the harm of iodine deficiency disorders (IDD), ways to acquire knowledge of IDD prevention and control, knowledge of IDD prevention, and attitudes towards iodized salt and iodine-free salt. The survey results were analyzed.Results:Totally 991 people completed the investigation; and 80.8% (801/991) of the population surveyed knew that iodine deficiency will cause endemic goiter, and 41.7% (413/991) of them knew that IDD could lead to varying degrees of mental impairment; 62.1% (615/991) obtained IDD prevention knowledge from TV, radio, Internet and newspaper; 76.8% (761/991) knew that IDD can be prevented by taking iodized salt. However, 8.9% (88/991) thought eating seafood was the best way to prevent IDD; 50.9% (504/991) thought iodized salt may not cause excessive iodine intake, but 56.5% (560/991) considered that there was a correlation between iodized salt and thyroid nodules. 56.2% (557/991) believed that the supply of iodized salt should be opened.Conclusions:The population in and near salts marketing areas of Hangzhou urban areas remains relatively lack of knowledge on IDD and salt iodization. The routes people obtaining IDD knowledge are very limited and the health education should be highlighted.

Objective To investigate the effects of administrative region changes on prevention and control of fluorosis,in order to provide a scientific basis for evaluation and improvement of prevention and control measures.Methods An investigation was conducted in all drinking water-born endemic fluorosis areas in Hangzhou in 2017,to evaluate the status quo of water-improving defluoridation projects,measure the water fluoride content with "the Standard Detection Methods for Domestic Drinking Water" (GB/T 5750.7-2006),detect the dental fluorosis with Dean method and the urinary fluoride content by fluoride selective electrode method in children aged 8 to 12 years old.Results The historical endemic fluorosis areas in Hangzhou now involved 38 natural villages of 22 administrativevillages in 8 townships of 5 counties (cities and districts).All villages had completed water-improving projects which were running well as the fluoride contents of drinking water were less than 1.00 mg/L.The detection rate of dental fluorosis was 1.13％ (9/795) among children aged 8-12 years.A total of 198 urine samples were tested,the urinary fluoride content varied from 0.12 to 2.90 mg/L,and the geometric mean was 0.77 mg/L.Conclusion Administrative region changes do not influence the effect of water-improving defluoridation projects,but management and monitoring of the water-improving projects still should be strengthened.

Objective To establish a normal reference range of thyroid-related indicators of early pregnant women in Hangzhou,and investigate the prevalence of thyroid disease among them after the implementation of a new standard of salt iodine content, in order to provide reference for monitoring of thyroid disease in pregnant women.Methods A total of 582 women in early pregnancy(0 - 13 weeks of gestation) in Hangzhou were selected via the stratified random sampling method as the subjects of the study and for detection of serology thyroid function. The levels of serum thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroid peroxidase antibody(TPOAb) and thyroglobulin antibody (TgAb) were measured by chemiluminescence method. According to the standard American Academy of Clinical Biochemistry (NACB), 359 women in early pregnancy were strictly screened to establish the normal reference value of TSH, FT4, and the reference range using the 95% confidence interval (95%CI). At the same time, the newly establish reference interval was used to evaluate the thyroid function of 582 early pregnant women. Results The reference interval of TSH in early pregnant women of Hangzhou was 0.048 -3.354 mU/L.The reference interval of FT4was(13.023 ± 3.316) pmol/L, and the tenth percentile of FT4was 11.030 pmol/L. Eighty-four persons' thyroid function was abnormal in 582 and the rate of abnormal was 14.4% (84/582), in which the rates of abnormal in clinical hypothyroidism, subclinical hypothyroidism, subclinical hyperthyroidism and hypothyroxinemia were 0.2% (1/582), 3.4% (20/582), 1.9% (11/582) and 8.9% (52/582), respectively. The case with clinical hyperthyroidism was not detected. The positive rate of TPOAb and TgAb were 10.8% (63/582) and 11.7%(68/582). The abnormal rate of hypothyroxinemia and the positive rate of TPOAb in early pregnant women in the city(11.4%,13.5%)were significantly higher than that in the rural areas(6.3%,8.1%,χ2=4.708,4.309, P < 0.05). Conclusions The normal reference value of thyroid hormones in early pregnant women in Hangzhou is established, and it is found that the incidence of thyroid disease is higher in pregnant women in Hangzhou after the implementation of the new standard of salt iodine content, therefore, it is imperative to carry out monitoring (or screening)of thyroid function in early pregnant women.