Temporal-spatial analysis of bacillary dysentery in the Three Gorges Area of China, 2005-2016 / 中华流行病学杂志

Objective: To analyze the spatial and temporal distributions of bacillary dysentery in Chongqing, Yichang and Enshi (the Three Gorges Area) from 2005 to 2016, and provide evidence for the disease prevention and control. Methods: The incidence data of bacillary dysentery in the Three Gorges Area during this period were collected from National Notifiable Infectious Disease Reporting System. The spatial-temporal scan statistic was conducted with software SaTScan 9.4 and bacillary dysentery clusters were visualized with software ArcGIS 10.3. Results: A total of 126 196 cases were reported in the Three Gorges Area during 2005-2016, with an average incidence rate of 29.67/100 000. The overall incidence was in a downward trend, with an average annual decline rate of 4.74%. Cases occurred all the year round but with an obvious seasonal increase between May and October. Among the reported cases, 44.71% (56 421/126 196) were children under 5-year-old, the cases in children outside child care settings accounted for 41.93% (52 918/126 196) of the total. The incidence rates in districts of Yuzhong, Dadukou, Jiangbei, Shapingba, Jiulongpo, Nanan, Yubei, Chengkou of Chongqing and districts of Xiling and Wujiagang of Yichang city of Hubei province were high, ranging from 60.20/100 000 to 114.81/100 000. Spatial-temporal scan statistic for the spatial and temporal distributions of bacillary dysentery during this period revealed that the temporal distribution was during May-October, and there were 12 class Ⅰ clusters, 35 class Ⅱ clusters, and 9 clusters without statistical significance in counties with high incidence. All the class Ⅰ clusters were in urban area of Chongqing (Yuzhong, Dadukou, Jiangbei, Shapingba, Jiulongpo, Nanan, Beibei, Yubei, Banan) and surrounding counties, and the class Ⅱ clusters transformed from concentrated distribution to scattered distribution. Conclusions: Temporal and spatial cluster of bacillary dysentery incidence existed in the three gorges area during 2005-2016. It is necessary to strengthen the bacillary dysentery prevention and control in urban areas of Chongqing and Yichang.

Current situation and challenges on the implementation of prevention and control programs regarding the seasonal influenza, in China / 中华流行病学杂志

In China, the control and prevention programs on any disease has always been based on comprehensive strategies. Take influenza as an example, related contents would include: strengthening the surveillance, recommendation and promotion of vaccination, rational use of antiviral drugs, conducting outbreak investigation and control, and publicizing individual protective measures, etc. In terms of the response to challenges, specific proposals would include: adjustment of case reports, optimization of surveillance systems, reinforcement of vaccination recommendation by health care workers, improvement of access to vaccination, development of rapid diagnostic reagents, and rational use of antiviral drugs, etc.

Current situation and related policies on the implementation and promotion of influenza vaccination, in China / 中华流行病学杂志

Influenza can be prevented through annual appropriate vaccination against the virus concerned. In China, influenza vaccine is categorized as "Class Ⅱ" infectious diseases which the cost is paid out of the user's pockets. The annual coverage of influenza vaccination had been 2%-3%. The main reasons for the low coverage would include the following factors: lacking awareness on both the disease and vaccine, poor accessibility of vaccination service, and the cost of vaccination. To reduce the health and economic burden associated with influenza, comprehensive policies should be improved, targeting the coverage of seasonal influenza vaccination. These items would include: ① Different financing reimbursement schemes and mechanisms to improve the aspiration on vaccination and on the vaccine coverage in high-risk groups, as young children, elderly, people with underlying medical conditions; ② to ameliorate equality of vaccination services; ③ to improve knowledge of the health care workers (HCWs) and the public on influenza and related vaccines; ④ to improve clinical and preventive medical practice and vaccination among HCWs through revising clinical guidelines, pathway and consensus of experts; ⑤ to provide more convenient, accessible and normative vaccination service system; ⑥ to strengthen research and development as well as marketing on novel influenza vaccines; ⑦ to revise items regarding the contraindication for influenza vaccine on pregnancy women, stated in the Chinese Pharmacopoeia.

Study on the relationship of thallium exposure and outcomes of births / 中华流行病学杂志

Objective: To investigate the relationship of thallium exposure and outcomes of births. Methods: A total of 3 236 mothers who had visited in Ma'anshan Maternal and Child Health-Care Hospital between May 2013 and September 2014 were included in this study and their thallium concentrations measured from samples of maternal and umbilical cord blood by inductively coupled plasma mass spectrometry. The results were correlated and evaluated with birth outcomes of the infants, using the multiple linear regression method. Results: The median (P(25)-P(75)) of thallium levels in first trimester, second trimester and umbilical cord blood were 61.7 (50.8-77.0), 60.3 (50.8-75.2) and 38.5 (33.6-44.1) ng/L, respectively. After adjustment for potential confounders, the thallium levels showed an inversely significant association with birth head circumference (unstandardized β coefficient=-0.41, 95%CI: -0.76- -0.06) in the first trimester blood, and associated with reduced birth length (unstandardized β coefficient=-0.65, 95%CI: -1.25- -0.05) in umbilical cord blood. However, there appeared no significantly associations with birth weight, length and head circumference (P>0.05) in second trimester. On stratification by sex, in girls but not in boys, the thallium levels were adversely associated with birth head circumference (unstandardized β coefficient=-0.53, 95%CI: -1.05--0.01) in the first trimester and were associated with decreased birth weight (unstandardized β coefficient=-277.08, 95%CI: -485.13- -69.03) and length (unstandardized β coefficient=-1.39, 95%CI: -2.26- -0.53) in umbilical cord blood thallium. Conclusions: Thallium exposure appeared a gender difference in newborn birth outcomes. In the first trimester, it was negatively associated with the birth head circumference, in the umbilical cord blood, and reduced birth weight and length in girls.

Strategy for prevention and control of imported infectious disease / 中华流行病学杂志

The process of globalization increases the risk of global transmission of infectious diseases, resulting in pressure for country's prevention and control of imported infectious disease. Based on the risk assessment of disease importation and local transmission, a strategy that conducting importation prevention and routine prevention and control before the importation of disease and taking emergency control measures after the importation of disease was developed. In addition, it is important to take part in global infectious disease response action, aid the countries with outbreak or epidemic to actively decrease the risk of disease importation.

Technical guidelines for seasonal influenza vaccination in China, 2018-2019 / 中华流行病学杂志

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications. Currently, China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. In most parts of China, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients need to pay for it. To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC), Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" , based on most recent existing scientific evidences. The main updates include: epidemiology and disease burden of influenza, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, and, IIV3 and IIV4 vaccines'major immune responses, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The recommendations include: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥1 licensed, recommended, and appropriate products. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to pregnant during the influenza season. Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in previous influenza season, 1 dose is recommended. People ≥ 9 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for CDC members who are working on influenza control and prevention, PoVs members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and members of maternity and child care institutions at all levels.

Surveillance data on notifiable infectious diseases among students aged 6-22 years in China, 2011-2016 / 中华流行病学杂志

Objective: To analyze the epidemiological characteristics of notifiable infectious diseases among Chinese students from 2011 to 2016 and to provide reference for the effective prevention and control programs on infectious disease among students. Methods: Both morbidity and mortality of notifiable infectious diseases among Chinese students aged 6-22 years from 2011 to 2016 were analyzed, with main characteristics of the disease described. Results: During 2011 to 2016, morbidities of Categories A, B and C infectious diseases among the Chinese students aged 6-22 years showed a decreasing trend, from 248.24/100 000 in 2012 to 158.57/100 000 in 2016. Mortality rates of Category A, B and C infectious diseases had also decreased from 0.12/100 000 in 2011 to 0.07/100 000 in 2016. The average morbidity of the top four diseases from Category A and B infectious diseases appeared as: tuberculosis (16.24/100 000), scarlet fever (9.39/100 000), hepatitis B (7.69/100 000) and bacillary and amebic dysentery (7.15/100 000). The average rates of mortality on the top four diseases appeared as: rabies (0.044 8/100 000), HIV/AIDS (0.027 7/100 000), tuberculosis (0.008 0/100 000) and Japanese encephalitis (0.005 9/100 000). The average rates of morbidity on the top four diseases appeared as: mumps (75.81/100 000), hand-foot-mouth disease (28.55/100 000), other infectious diarrhea (22.41/100 000) and influenza (15.67/100 000) in the Category C. Reported death cases were from hand-foot-mouth disease (11 cases), influenza (9 cases), mumps (1 case) and rubella (1 case). The prevalence rates varied among different student populations, with higher HIV/AIDS, hepatitis B and tuberculosis rates among college and senior high school students, while higher mumps, influenza and hand-foot-mouth disease rates among primary school and junior high school students. Conclusions: Both morbidity and mortality of notifiable infectious diseases among Chinese students aged 6-22 years had decreased significantly in 2011-2016. However, the major infectious diseases had become new challenges among students. HIV/AIDS had become a key infectious disease among college students and the relatively high prevalence of tuberculosis was seen in college and high school students.

Relationship between white spot syndrome virus [WSSV] loads and characterizations of water quality in Litopenaeus vannamei culture ponds during the tropical storm

An in-situ experiment was conducted to investigate the effect of tropical storm on the white spot syndrome virus [WSSV] loads in Litopenaeus vannamei rearing ponds. White spot syndrome virus loads, heterotrophic bacteria, Vibrio and water quality [including temperature, dissolved oxygen [DO], salinity, pH, NH4-N, and NO2-N] were continually monitored through one tropical storm. The WSSV loads decreased when tropical storm made landfall, and substantially increased when typhoon passed. The variation of WSSV loads was correlated with DO, temperature, heterotrophic bacteria count, and ammonia-N concentrations. These results suggested that maintaining high level DO and promoting heterotrophic bacteria growth in the shrimp ponds might prevent the diseases' outbreak after the landfall of tropical storm