Background Mycoplasma genitalium (MG) causes a sexually transmitted infection (STI) with a rising rate of antimicrobial resistance. Currently, guidelines do not recommend screening asymptomatic men who have sex with men (MSM). We developed a mathematical model of MG transmission to examine the impact of various screening strategies on the incidence and prevalence of MG among MSM attending a sexual health clinic. Methods A compartmental mathematical model of MG transmission among MSM was constructed and calibrated using data from the Melbourne Sexual Health center, where resistance-guided therapy provides high treatment effectiveness (92–95%). The model stratified men by symptom status, sexual risk behaviours and whether or not they had MG with macrolide resistance. We simulated the impact on endemic steady-state MG prevalence and incidence of the following screening scenarios, namely screening: 1) no MSM; 2) only symptomatic MSM (the current recommendation); 3) all symptomatic and high-risk asymptomatic MSM; and 4) all MSM. Our base case analysis assumed a treatment effectiveness of 92–95% using resistance-guided therapy. We also examined the impact of treatment effectiveness (i.e. the proportion of detected MG that were cured) and screening coverage (i.e. testing rate) on MG prevalence. Findings The model predicts that the overall endemic MG prevalence is 9.1% (95% CI: 7.9–10.0) in the current situation where screening is only offered to symptomatic MSM (base-case). This would increase to 11·4% (95% confidence intervals (CI): 10.2–13.7) if no MSM are offered screening, but would decrease to 7.3% (95% CI: 5.7–8.4) if all symptomatic and high-risk asymptomatic MSM were offered screening and 6.4% (95% CI: 4.7–7·7) if all MSM were offered screening. Increasing coverage of MSM screening strategies shows a similar effect on decreasing endemic MG incidence. When evaluating the simultaneous impact of treatment effectiveness and screening coverage, we found that offering screening to more MSM may reduce the overall prevalence but leads to a higher proportion of macrolide-resistant MG, particularly when using treatment regimens with lower effectiveness. Interpretation Based on the available treatment options, offering screening for MG to other MSM (beyond the currently recommended group of symptomatic MSM) could slightly reduce the prevalence and incidence of MG. However, further increasing screening coverage must be weighed against the impact of lower treatment effectiveness (i.e. when not using resistance-guided therapy), increasing the selection of macrolide resistance, and other negative consequences related to AMR and management (e.g. unnecessary psychological morbidity from infections that do not need treatment).

The prevalence and incidence of human immunodeficiency virus type 1 (HIV-1) among men who have sex with men (MSM) are on the rise throughout China. With a large population of MSM, Jiangsu Province is facing an escalating HIV-1 epidemic.The aim of this study was to explore the phylogenetic and temporal dynamics of HIV-1 CRF01_AE and CRF07_BC among antiretroviral therapy (ART)-naïve MSM recently infected with HIV-1 in Jiangsu Province.We recruited MSM in Jiangsu Province (Suzhou, Wuxi, Nantong, Taizhou and Yancheng) 2012 to 2015. We collected information on demographics and sexual behaviors and a blood sample for HIV genome RNA extraction, RT-PCR amplification, and DNA sequencing. Multiple alignments were made using Gene Cutter, with the selected reference sequences of various subtypes/recombinants from the Los Alamos HIV-1 database. Phylogenetic and Bayesian evolutionary analysis was performed by MEGA version 6.0, Fasttree v2.1.7. and BEAST v1.6.2. Categorical variables were analyzed using χ2 test (or Fisher exact test where necessary). χ2 test with trend was used to assess the evolution of HIV-1 subtype distribution over time. All data were analyzed using SPSS20.0 software package (IBM Company, New York, NY).HIV-1 phylogenetic analysis revealed a broad viral diversity including CRF01_AE (60.06%), CRF07_BC (22.29%), subtype B (5.88%), CRF67_01B (5.26%), CRF68_01B (2.79%), CRF55_01B (1.55%), CRF59_01B (0.93%), and CRF08_BC (0.62%). Two unique recombination forms (URFs) (0.62%) were also detected. Four epidemic clusters and 1 major cluster in CRF01_AE and CRF07_BC were identified. The introduction of CRF01_AE strain (2001) was earlier than CRF07_BC strain (2004) into MSM resided in Jiangsu based on the time of the most recent common ancestor.Our study demonstrated HIV-1 subtype diversity among ART-naïve MSM recently infected with HIV-1 in Jiangsu. We first depicted the spatiotemporal dynamics, traced the dates of origin for the HIV-1 CRF01_AE/07_BC strains and made inference for the effective population size among newly infected ART-naïve MSM in Jiangsu from 2012 to 2015. A real-time surveillance of HIV-1 viral diversity and phylodynamics of epidemic cluster would be of great value to the monitoring of the epidemic and control of transmission, improvement of antiretroviral therapy strategies, and design of vaccines.

ObjectivesNegative estimates can be produced when statistical modelling techniques are applied to estimate morbidity and mortality attributable to influenza. Based on the prior knowledge that influenza viruses are hazardous pathogens and have adverse health outcomes of respiratory and circulatory disease (R&C), we developed an improved model incorporating Bayes’ theorem to estimate the disease burden of influenza in Shanghai, China, from 2010 to 2017.DesignA modelling study using aggregated data from administrative systems on weekly R&C mortality and hospitalisation, influenza surveillance and meteorological data. We constrained the regression coefficients for influenza activity to be positive by truncating the prior distributions at zero.SettingShanghai, China.ParticipantsPeople registered with R&C deaths (450 298) and hospitalisations (2621 787, from 1 July 2013), and with influenza-like illness (ILI) outpatient visits (342 149) between 4 January 2010 and 31 December 2017.Primary outcome measuresInfluenza-associated disease burden (mortality, hospitalisation and outpatient visit rates) and clinical severity (outpatient–mortality, outpatient–hospitalisation and hospitalisation–mortality risks).ResultsInfluenza was associated with an annual average of 15.49 (95% credibility interval (CrI) 9.06–22.06) excess R&C deaths, 100.65 (95% CrI 48.79–156.78) excess R&C hospitalisations and 914.95 (95% CrI 798.51–1023.66) excess ILI outpatient visits per 100 000 population in Shanghai. 97.23% and 80.24% excess R&C deaths and hospitalisations occurred in people aged ≥65 years. More than half of excess morbidity and mortality were associated with influenza A(H3N2) virus, and its severities were 1.65-fold to 3.54-fold and 1.47-fold to 2.16-fold higher than that for influenza A(H1N1) and B viruses, respectively.ConclusionsThe proposed Bayesian approach with reasonable prior information improved estimates of influenza-associated disease burden. Influenza A(H3N2) virus was generally associated with higher morbidity and mortality, and was relatively more severe compared with influenza A(H1N1) and B viruses. Targeted influenza prevention and control strategies for the elderly in Shanghai may substantially reduce the disease burden.

Background Elimination of HIV is a public health priority in China, but there has been reports of an upsurge in HIV among young people. A nationwide cross-sectional survey was conducted to assess the awareness of HIV knowledge, attitudes towards homosexuality and practice of sexual behaviours among Chinese aged 15–24 years. Methods: The face-to-face survey was conducted from June to August 2017, collecting data on sociodemographic characteristics, HIV-related knowledge, attitudes towards homosexuality and practice of sexual behaviours among Chinese senior high school and university students. A generalised linear model (GLM) was used to assess the different levels of HIV knowledge between groups, and identify the key contributors to HIV knowledge scores. Results: The survey was completed by 73.6% (1355/1840) of the students approached. The overall level of HIV-related knowledge was low (58.9%, 10.6/18); 48.0% (650/1355) supported same-sex marriage; and 6.9% (93/1355) self-identified as homosexual or bisexual. The major factors associated with higher scores [mean ± standard deviation (s.d.)] in HIV knowledge among students included: having received school-based HIV education (11.47 ± 3.51 vs 9.02 ± 4.14, P < 0.05); support for same-sex marriage (11.69 ± 3.33 vs 9.49 ± 4.29, P < 0.05) and older age (11.61 ± 2.78 vs 9.87 ± 4.17, P < 0.05). Compared with females, males were significantly more likely (all P < 0.05) to report masturbation (60.7% vs 7.6%), pornography experiences (77.4% vs 35.3%), sexual encounters (24.6% vs 12.3%), casual sex (37.0% vs 18.1%) and sex under the influence of alcohol (29.5% vs 12.8%). Conclusions: There is is still much room for improvement in terms of HIV/AIDS prevention and health education for Chinese young people, and more comprehensive and diverse models of education for HIV prevention are urgently needed.