Spatio-temporal distribution of emerging snail-infested sites in different environmental types in Yunnan Province / 中华地方病学杂志

Objective:To explore the spatial and temporal distribution patterns of emerging snail-infested sites in different environmental types in Yunnan Province.Methods:The data of snail-infested sites in Yunnan Province from 1950 to 2014 (from Yunnan Institute for Endemic Diseases Control and Prevention), were collected and sorted out, a spatial and temporal database on the distribution of emerging snail-infested sites were established, and the changes in the spatial and temporal distribution of emerging snail-infested sites in different environments types (ditches, tangerines, paddy fields, dry land, beaches and other environments) were studied by using spatial autocorrelation analysis and scanning statistics analysis.Results:From 1950 to 2014, the annual number of emerging snail-infested sites in Yunnan Province reached a peak (1 730) in 1955 and then showed a fluctuating downward trend. From 1993 to 2014, the number of emerging snail-infested sites remained below 100, and increased to 160 and 131, respectively, in 2004 and 2013. The longest mean duration of 43.85 years was recorded for the beaches environment for emerging snail-infested sites, followed by the paddy fields environment with a mean duration of 37.01 years, and the shortest mean duration of 20.44 years for the tangerines environment. Spatial autocorrelation analysis showed that there was a positive spatial correlation between the duration of emerging snail-infested sites of different environmental types (global Moran's I ranged from 0.43 to 0.64, P < 0.05). Scanning statistics analysis showed that emerging snail-infested sites of different environmental types had spatial and temporal aggregation ( P < 0.001), with 3- 6 clusters of statistically significant aggregation detected respectively. Conclusion:The emerging snail-infested sites in different environments types in Yunnan Province have spatial and temporal aggregation, and it is necessary to strengthen monitoring and prevention and control of the aggregation areas of different environment types to prevent further spread of the snail.

Spatial distribution characteristics of the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province in 2020 / 中国血吸虫病防治杂志

Objective To investigate the spatial distribution characteristics of the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody, and to examine the correlation between the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province in 2020, so as to provide insights into advanced schistosomiais control in the province. Methods The epidemiological data of schistosomiasis in Hunan Province in 2020 were collected, including number of permanent residents in survey villages, number of advanced schistosomiasis patients, number of residents receiving serological tests and number of residents seropositive for anti-Schistosoma antibody, and the prevalence advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody were descriptively analyzed. Village-based spatial distribution characteristics of prevalence advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody were identified in Hunan Province in 2020, and the correlation between the revalence advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody was examined using Spearman correlation analysis. Results The prevalence of advanced schistosomiasis was 0 to 2.72% and the seroprevalence of anti-Schistosoma antibody was 0 to 20.25% in 1 153 schistosomiasis-endemic villages in Hunan Province in 2020. Spatial clusters were identified in both the prevalence of advanced schistosomiasis (global Moran’s I = 0.416, P < 0.01) and the seroprevalence of anti-Schistosoma antibody (global Moran’s I = 0.711, P < 0.01) in Hunan Province. Local spatial autocorrelation analysis identified 98 schistosomiasis-endemic villages with high-high clusters of the prevalence of advanced schistosomiasis, 134 endemic villages with high-high clusters of the seroprevalence of anti-Schistosoma antibody and 36 endemic villages with high-high clusters of both the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province. In addition, spearman correlation analysis showed a positive correlation between the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody (rs = 0.235, P < 0.05). Conclusions There were spatial clusters of the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province in 2020, which were predominantly located in areas neighboring the Dongting Lake. These clusters should be given a high priority in the schistosomiasis control programs.

Immunological effect and influencing factors of HAART on HIV/AIDS with baseline CD4 below 350 cells/mm3 / 公共卫生与预防医学

Objective To analyze the immunological effect and its influencing factors of HAART on HIV/AIDS with a baseline CD4 of less than 350 cells/mm3 in Hubei Province during 2011-2020. Methods The treatment information of people living with HIV/AIDS (PLWH) was collected through China Disease Control and Prevention Information System, and the change of CD4 mean value was analyzed by Wilcoxon sign rank sum test. Chi square test and multivariate logistic regression were used to analyze the factors influencing the immunological effect. Results The mean value of CD4 cell count at baseline was (172.78±107.65) cells/mm3 before treatment and (398.85±206.71) cells/mm3 in the fifth year after treatment. Patients with baseline CD4<50 /mm3 had the largest increase in CD4 mean value after treatment (P<0.05). Multivariate logistic regression analysis showed that Age ≥35 years, heterosexual transmission, time interval from diagnosis to treatment≥1 month, baseline CD4<50 /mm3, treatment time 7-<18 months, and drug failure were the risk factors for the success of antiviral therapy(P<0.05). Conclusion The immunological effect of HIV/AIDS antiviral therapy in Hubei Province is affected by many factors. It is necessary to strengthen the implementation of early detection and early treatment strategy and promote treatment compliance education for patients aged ≥35 years.

Optimization of the medium and fermentation condition for the Penicillium aurantiocandidum Z12 strain with molluscicidal actions against Oncomelania hupensis / 中国血吸虫病防治杂志

Objective To optimize the culture and fermentation conditions of the Penicillium aurantiocandidum Z12 strain, a fungal strain with molluscicidal actions against Oncomelania hupensis, so as to provide the basis for the research and development of molluscicidal active substances from the P. aurantiocandidum Z12 strain and its fermentation broth and large-scale fermentation. Methods The carbon source, nitrogen source and mineral salts were identified in the optimal culture medium for the P. aurantiocandidum Z12 strain with a single-factor experiment to determine the best fermentation condition for the P. aurantiocandidum Z12 strain. Factors that significantly affected the growth of the P. aurantiocandidum Z12 strain were identified using the Plackett-Burman design, and the best range of each factor was determined using the steepest climb test. Response surface analyses of temperature, pH value, seeding amount and liquid-filling quantity were performed using the Box-Behnken design to create a regression model for fermentation of the P. aurantiocandidum Z12 strain to identify the optimal culture medium. Results Single-factor experiment preliminarily identified the best culture medium and conditions for the P. aurantiocandidum Z12 strain as follows: sucrose as the carbon source at approximately 20 g/L, tryptone as the nitrogen source at approximately 5 g/L, K2HPO4 as the mineral salt at approximately 5 g/L, initial pH at approximately 8, temperature at approximately 28 °C, seeding amount at approximately 6%, and liquid-filling quantity at approximately 50 mL/100 mL. Plackett-Burman design showed that factors that significantly affected the growth of the P. aurantiocandidum Z12 strain included temperature (t = −5.28, P < 0.05), seeding amount (t = 5.22, P < 0.05), pH (t = −4.30, P < 0.05) and liquid-filling quantity (t = −4.39, P < 0.05). Steepest climb test showed the highest mycelial growth at pH of 7.5, seeding amount of 8%, and liquid-filling quantity of 40 mL/100 mL, and this condition was selected as the central point of response surface analysis for the subsequent optimization of fermentation conditions. Response surface analyses using the Box-Behnken design showed that the optimal conditions for fermentation of the P. aurantiocandidum Z12 strain included sucrose at 15 g/L, tryptone at 5 g/L, K2HPO4 at 5 g/L, temperature at 28.2 °C, pH at 7.5, seeding amount at 10%, and liquid-filling quantity at 35.8 mL/100.0 mL, resulting in 0.132 g yield of the P. aurantiocandidum Z12 strain. Conclusion The optimal culture condition for the P. aurantiocandidum Z12 strain has been identified, and the optimized culture medium and fermentation condition may effectively improve the fermentation yield of the P. aurantiocandidum Z12 strain.

False negatives of screening in large-scale population / 上海预防医学

ObjectiveTo explore the changing trend of negative predictive value and number of false negatives in screening tests under the condition of low infection rate of infectious diseases. MethodsAssuming that the population is 20 million， to calculate the negative predictive value， numbers of true negatives and false negatives of the combination of different sensitivity （75.0%， 80.0%， 85.0%， 90.0%， 95.0%， 99.0%） and specificity （90.0%， 95.0%， 99.0%， 99.9%） when the disease infection rate of the population is 0.10%， 1.0% and 5.0% respectively. ResultsWhen the population infection rate is 0.1%， with the screening test sensitivity ≥75.0% and specificity ≥90.0%， the number of true negatives in 20 million people is about 17.98‒19.96 million. When the sensitivity is 75.0%， the negative predictive value is 99.972%‒99.975%， and the number of false negatives is 5 000； When the sensitivity increases to 99.0%， the negative predictive value is 99.999%， and the number of false negatives decreases to 200. When the population infection rate is 1.0%， a screening test with sensitivity ≥75.0% and specificity ≥90.0% can detect about 17.82‒19.78 million true negatives in 20 million population. When the sensitivity is 75.0%， the negative predictive value is 99.720%‒99.748%， and the number of false negatives is 50 000； When the sensitivity increases to 99.0%， the negative predictive value increases to 99.990%， and the number of false negatives decreases to 2 000. When the population infection rate is 5.0%， with sensitivity ≥75.0% and specificity ≥90.0%， the number of true negatives in 20 million people is about 17.10‒18.98 million； when the sensitivity is 75.0%， the negative predictive value is 98.559%‒98.700%， and the number of false negatives can reach 250 000； When the sensitivity is 99.0%， the negative predictive value increases to 99.942%‒99.947%， and the number of false negatives decreases to 10 000. The lower the infection rate of the population， the fewer false negatives will appear in the screening. ConclusionThe number of false negatives in large-scale screenings increases exponentially with the increase of infection rate. Screenings should be carried out as early as possible in a pandemic of infectious diseases， so as to control the spread of the pandemic as soon as possible.

False positives of screening in large-scale population with low infection rate of an infectious diseasea： a modeling analysis / 上海预防医学

ObjectiveTo explore the positive predictive value （PPV） and false positive （FP） number of screening test in mass testing when the prevalence of infection is low. MethodsAssuming a population of 20 million with the prevalence of disease infection ranging from 0.1% to 5.0%， PPV， true positive （TP） and FP numbers were calculated under different scenarios of combination of sensitivity （99.0%， 99.5%， and 100.0%） with specificity （97.0%， 97.5%， 98.0%， 98.5%， 99.0%， 99.5%， and 99.9%）. ResultsFor low infection prevalence （≤5.0%）， specificity has a greater impact on PPV than sensitivity； with the decrease of infection prevalence， the increase in PPV elevates when the specificity increases. When the infection prevalence is >1.0%， the closer the specificity is to 99.9%， the closer the PPV is to 100.0%. However， when the infection prevalence is <1.0%， the maximum PPV is only about 90.0%. When the infection rate is 0.1%， a screening test with more than 99.0% sensitivity could detect about 20 thousand TP cases in a population of 20 million. Additionally， the FP and PPV are estimated to be 599 thousand and 3.2% if the specificity is 97.0%， and 20 thousand and 50.0% if the specificity is 99.9%. When the infection rate is 1.0%， a screening test with ≥99.0% sensitivity and ≥97.0% specificity could detect about 0.198‒0.200 million TP cases； and the number of FP decreases from 594 thousand to 20 thousand when the specificity increases from 97.0% to 99.9%. When the infection rate is 5.0%， a screening test with ≥99.0% sensitivity and ≥97.0% specificity could detect about 0.99‒1.00 million TP cases； and the number of FP decreases from 570 thousand to 19 thousand when the specificity increases from 97.0% to 99.9%. When the infection prevalence is ≤5.0% in a total population of 20 million， there are about 20，000 FP cases even if the sensitivity and specificity reach the maximum values of 100.0% and 99.9%， respectively. ConclusionWhen the population is large and the infection prevalence is low， in addition to improving the specificity of the screening test in mass testing， the problem of a large number of false positives cannot be ignored.

Evaluation and analysis of the effectiveness of syphilis prevention and control in Hubei in 2011-2020 / 公共卫生与预防医学

Objective To evaluate the implementation and effectiveness of syphilis prevention and control in Hubei Province from 2011 to 2020, to summarize the experience and practice, to analyze the existing problems and causes, and to study and put forward policy and strategy suggestions, so as to provide reference for formulating the national “14th five-year plan” and carrying out the next step of prevention and control work. Methods The National STD Prevention and Control Management Information System, STD Prevention and Control New Media Health Service Platform, National AIDS Comprehensive Prevention Information System, and National Management Information System for the Prevention of AIDS, Syphilis, and Mother-to-Child Transmission of Hepatitis B were used to analyze and evaluate the completion of main prevention and control indicators in Hubei Province. Results Among the 16 evaluation indexes, 10 indexes including the effectiveness of syphilis promotion and training for various groups of people, the proportion of pregnant women undergoing syphilis testing in the monitoring and testing work, and the effectiveness of syphilis prevention and treatment, all met the requirements of the plan. In addition, some of the 5 indexes failed to meet the requirements of the plan. Conclusion Hubei Province has fairly fulfilled the work requirements of the Plan. It is still necessary to strengthen the syphilis prevention and control to ensure the urban pregnant women infected with syphilis and their infants to receive standardized STD diagnosis and treatment services, and the drug users in the drug maintenance treatment clinic to receive free syphilis testing, and to provide referral services for the syphilis antibody positive patients at AIDS voluntary counseling and testing points.

Prevalence of informing of HIV infection status during medical care seeking and influential factors among people living with HIV/AIDS / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the prevalence of informing doctors of the HIV infection status during medical care seeking and influential factors among people living with HIV/AIDS.</p><p><b>METHODS</b>The study was conducted among people living with HIV/AIDS in 7 provinces in China, including those receiving HIV test, HIV counsel and HIV infection treatment. The data were analyzed with software SAS 9.2. Chi-square test was used to compare the informing rates in patients with different characteristics. Univariate and multivariate logistic regression analyses were conducted to identify the influential factors.</p><p><b>RESULTS</b>Of the 2 432 HIV/AIDS patients, 49.7% (716/1 442) didn't inform the doctors of their HIV infection status actively. The non-active informing rate was 51.9% (559/1 077) in males, 62.9% (212/337) in age group 18-30 years old, 58.1% (555/955) in those with a educational level >primary school, 65.7% (241/367) in those working in private/joint companies or the self employed and 62.5% (197/315) in those living in small cities. The non active informing rate was highest in those infected through sexual contact (66.3%, 275/415). Multivariate logical regression analysis indicated that those infected through illegal blood donation would like to inform of the HIV infection status actively (OR=0.083, 95% CI: 0.049-0.141) , but those working in private/joint companies or the self employed would like not to inform of the HIV infection status actively (OR=1.531, 95% CI: 1.017-2.304).</p><p><b>CONCLUSION</b>The non active informing rate of HIV infection status was high in people living with HIV/AIDS. It is necessary to conduct the targeted health education to encourage people living with HIV/AIDS to inform of their HIV infection status actively.</p>

Recent HIV infection among men who have sex with men in Hubei, 2010-2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the HIV infection status among MSM in Hubei province and provide scientific evidence for the development of intervention strategy.</p><p><b>METHODS</b>A total of 11 438 samples were collected from MSM in sentinel surveillance during 2010-2013 to detect HIV-1 antibody. BED-CEIA was used to identify the recent HIV infection, and the recent HIV infection rate among the MSM was estimated. The age, group and area specific recent infection rate and condom use rate were analyzed.</p><p><b>RESULTS</b>The annual HIV positive rates among MSM were 3.34% , 3.74% , 2.96% and 3.15% respectively and the annual recent infection rates were 2.31% , 1.91% , 1.53% and 1.71% respectively during 2010-2013. The HIV positive rate in age group ≤ 30 years was lower than that in age group >30 years, but the recent HIV incidence rate was higher in age group ≤ 30 years than in age group >30 years. The detection rate of recent HIV infection varied with sample source, the highest detection rate was among the samples form work group/CDC and public bathroom (3.54% and 3.49%, respectively). The recent HIV i nfection rate in Wuhan was highest (5.73%). The proportion of MSM using condoms in each homosexual behavior during past six months was 38.91% . Multiple logistic regression analysis indicated that the factors related to recent HIV infection included sample source (OR = 0.344-0.713), area (OR = 3.581-9.577) and condom usage (OR = 6.686).</p><p><b>CONCLUSION</b>The HIV-1 infection rate in MSM was at a high level in Hubei, especially in some areas. The condom use rate was low, it is necessary to strengthen the prevention and control of HIV infection in MSM.</p>