Autochthonous dengue infections have not been reported in Ningbo, People’s Republic of China since 1929. In August–October 2004, an outbreak of dengue fever was confirmed in Xiaolin, Cixi, Ningbo. Of 83 cases reported, 68 were laboratory confirmed. Fifty-three percent (34 of 64) of the cases had IgM antibodies to dengue virus. Dengue virus serotype-1 was isolated from two cases. The outbreak was linked to a traveler who returned from Thailand. Phylogenetic analysis showed that the Ningbo isolate was closely associated to strains from Thailand. Prevalence of dengue-specific IgG in asymptomatic residents was significantly higher in the epidemic-stricken area than in a control area. High density of Aedes albopictus, which resulted from waterlogging caused by Typhoon Rananim and lifestyle of local residents, was responsible for rapid spread of the virus. Eradication of mosquito infestation might interrupt transmission. This outbreak underscores the importance of maintaining surveillance and control of potential vectors for the control of emerging infectious diseases.

Human immunodeficiency virus (HIV) testing is confirmed as a preventive strategy for HIV control. However, the testing rate and risk behaviors of HIV-negative men who have sex with men (MSM) remain unclear. We aimed to examine factors associated with HIV testing and high-risk behaviors among HIV-negative MSM. From July 2016 to June 2017, participants were recruited by snowball sampling from WeChat groups, bars, and other venues. HIV testing was performed to exclude HIV-positive MSM. Face-to-face questionnaires regarding HIV testing and high-risk behaviors were conducted; 988 MSM were included, and 57.1% of participants underwent HIV testing in the past year. The proportion of high-risk behaviors was 49.9%. Factors associated with HIV testing were bisexual orientation, substance use to adjust psychiatric disorders, and receiving acquired immune deficiency syndrome (AIDS) interventions. Being married, bisexual orientation, and receiving AIDS interventions were risk factors for high-risk sexual behaviors, while college or higher degree was a protective factor. We determined that HIV transmission factors are widespread, and the rate of HIV testing is relatively low. Attention should be given to marital status, using substances to adjust psychiatric disorders, or bisexual HIV-negative MSM, and AIDS interventions should be strengthened to promote HIV testing and reduce high-risk behaviors.

Objectives: To evaluate a community-based intervention that leveraged the non-communicable disease management system to increase seasonal influenza vaccination coverage among older adults in Ningbo, China. Methods: From October 2014 – March 2015, we piloted the following on one street in Ningbo, China: educating community healthcare workers (C-HCWs) about influenza and vaccination; requiring C-HCWs to recommend influenza vaccination to older adults during routine chronic disease follow-up; and opening 14 additional temporary vaccination clinics. We selected a non-intervention street for comparison pre- and post-intervention vaccine coverage. In April 2016, we interviewed a random sample of unvaccinated older adults on the intervention street to ask why they remained unvaccinated. Results: Pre-intervention influenza vaccine coverage among adults aged 60 years and older on both streets was 0.3%. Post-intervention, coverage among adults 60 years and older was 19% (1338/7013) on the intervention street and 0.4% (20/5500) on the non-intervention street (p<0.01). Among vaccinated older adults, 98% reported their main reason for vaccination was receiving a C-HCW's recommendation, 90% were vaccinated at temporary vaccination clinics, and 53% paid for vaccine (10 USD) out-of-pocket. Reasons for not getting vaccinated among 150 unvaccinated adults (response rate = 75%) included: good health (39%); not trusting C-HCWs' recommendations (24%); not knowing where to get vaccinated (17%); and not wanting to pay (9%). Conclusions: Recommending influenza vaccination within a non-communicable disease management system, combined with adding vaccination sites, increased vaccine coverage among older adults in Ningbo, China.

Background: HIV testing and early linkage to care are critical for reducing the risk of HIV transmission. HIV self-testing (HIVST) is a useful tool for increasing HIV testing frequency.This study aimed to investigate HIVST rates among men who have sex with men (MSM), the characteristics of MSM who had HIVST, and factors associated with HIVST uptake among MSM in Ningbo, China. Methods: A cross-sectional study was conducted from April to October 2019 in Ningbo,China. Participants were aged at least 18 years and having had sexual contact with men in the past year. Proportions were used for categorical variables. Adjusted Odds Ratio (AOR) and 95% Confidence Interval (CI) for characteristics associated with HIVST uptake was processed by multivariable logistic regression models. Results: Among a sample of 699 MSM recruited, 38.2% had reported previous use of an HIV self-test kit. A greater proportion of HIVST users had a higher frequency of HIV testing (≥ 2 times: 70.0% versus 41.2%, p < 0.001) in the past 1 year. The odds of older age (30–39 years: AOR = 0.49, CI 0.32–0.76; more than 40 years: AOR = 0.07, CI 0.04–0.14, compared to 18–29 years), bisexual (AOR = 0.49, CI 0.29–0.84) were lower among HIVST users,and were higher among MSM who were higher education level (high school: AOR = 2.82, CI 1.70–4.69, compared to middle school or less), gay apps use (AOR = 1.86, CI 1.13–3.05), multiple male sex partners (AOR = 1.90, CI 1.29–2.80), frequency of male–male sexual contact ≥ 1 times per week (AOR = 1.86, CI 1.30–2.66), syphilis infection (AOR = 5.48, CI 2.53–11.88). Conclusions: Further HIVST education should be strengthened for school-aged children and teenagers, and free HIVST kits may be provided to high-risk MSM through gay apps and CBO to achieve the increased HIV testing frequency.

Evaluate safety and immunization coverage of a new kind of recombinant Hepatitis B vaccine (HepB) in Ningbo city, China. Two groups were carried out in 2 of 11 randomly selected countries in Ningbo in 2009. All of the infants born from July 1 to December 31, 2009 were enrolled as subjects and received 3 doses of HepB at 0, 1, 6 month. Control group (N = 3452) received current HepB derived from Saccharomyces Cerevisiae Yeast (HepB made by recombinant DNA techniques in Saccharomyces Cerevisiae Yeast, HepB-SCY; 5 μg/0.5 ml per dose) and experimental group (N = 5104) received the new kind of HepB derived from Hansenula polymorpha Yeast (HepB made by recombinant DNA techniques in Hansenula polymorpha Yeast, HepB-HPY; 10 μg/0.5 ml per dose). 3-dose and timely birth dose (TBD) coverage were available and compared between 2 groups. Standard structured questionnaires were applied to record information from parents and hospitals for selecting determinants of coverage. The data were analyzed using stepwise multiple logistic regression models. After each dose, HepB-related adverse events (AEs) and recta-temperature were recorded for 7 days. 3-dose coverage in control group (89.98%) was higher than that in experimental group (χ2 = 575.1173, P < 0.0001). TBD coverage in control and experimental group were 98.41% and 98.53%, respectively. No statistically significant difference in TBD coverage was found between 2 groups (χ2 = 0.0623, P = 0.8029). A total of 9 local AEs were reported, 4 for control group and 5 for experimental group. The percentages of subjects reporting AEs were similar across the 2 vaccination groups. No serious or immediate reactions were found in this study. From logistic models, receiving 10 μg vaccine (odds ratio [OR]:0.38; 95% confidence interval [95%CI]: 0.34–0.44) and mother migrating from other cities (OR: 0.45; 95%CI: 0.42–0.47) were the determinants for non-acceptance of 3 doses of HepB; infants born from low grade hospitals and native mothers contributed to administrate the TBD.

Summary: Novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is pandemic. However, data concerning the epidemiological features, viral shedding, and antibody dynamics between asymptomatic SARS-CoV-2 carriers and COVID-19 patients remain controversial. We enrolled 193 subjects infected with SARS-CoV-2 in Ningbo and Zhoushan, Zhejiang, China from January 21 to March 6, 2020. All subjects were followed up to monitor the dynamics of immunoglobulin M (IgM) and IgG against SARS-CoV-2. Of those, 31 were asymptomatic carriers, 149 were symptomatic patients, and 14 were presymptomatic patients. Compared to symptomatic patients, asymptomatic carriers were younger and had higher levels of white blood cell and lymphocyte, lower levels of C-reactive protein and viral load, and shorter viral shedding duration. Conversion of IgM from positive to negative was shorter in asymptomatic carriers than in COVID-19 patients ( P =0.030). The proportion of those persistently seropositive for IgG was higher in COVID-19 patients than in asymptomatic carriers ( P =0.037). Viral load was higher in symptomatic than presymptomatic patients. Viral shedding was longer in presymptomatic patients than in asymptomatic carriers. Conclusively, asymptomatic carriers have a higher antiviral immunity to clear SARS-CoV-2 than do symptomatic patients and this antiviral immunity is not contributable to humoral immunity.