Improving modelling for epidemic responses: reflections from members of the UK infectious disease modelling community on their experiences during the COVID-19 pandemic.

Background: The COVID-19 pandemic both relied and placed significant burdens on the experts involved from research and public health sectors. The sustained high pressure of a pandemic on responders, such as healthcare workers, can lead to lasting psychological impacts including acute stress disorder, post-traumatic stress disorder, burnout, and moral injury, which can impact individual wellbeing and productivity. Methods: As members of the infectious disease modelling community, we convened a reflective workshop to understand the professional and personal impacts of response work on our community and to propose recommendations for future epidemic responses. The attendees represented a range of career stages, institutions, and disciplines. This piece was collectively produced by those present at the session based on our collective experiences. Results: Key issues we identified at the workshop were lack of institutional support, insecure contracts, unequal credit and recognition, and mental health impacts. Our recommendations include rewarding impactful work, fostering academia-public health collaboration, decreasing dependence on key individuals by developing teams, increasing transparency in decision-making, and implementing sustainable work practices. Conclusions: Despite limitations in representation, this workshop provided valuable insights into the UK COVID-19 modelling experience and guidance for future public health crises. Recognising and addressing the issues highlighted is crucial, in our view, for ensuring the effectiveness of epidemic response work in the future.

Accumulation of Immunity in Heavy-Tailed Sexual Contact Networks Shapes Mpox Outbreak Sizes.

Many countries affected by the global outbreak of mpox in 2022 have observed a decline in cases. Our mathematical model accounting for heavy-tailed sexual partnership distributions suggests that mpox epidemics can hit the infection-derived herd immunity threshold and begin to decline, with <1% of sexually active men who have sex with men infected regardless of interventions or behavioral changes. We consistently found that many countries and US states experienced an epidemic peak, with cumulative cases of around 0.1% to 0.5% among men who have sex with men. The observed decline in cases may not necessarily be attributable to interventions or behavioral changes primarily.

Diversity of symptom phenotypes in SARS-CoV-2 community infections observed in multiple large datasets.

Variability in case severity and in the range of symptoms experienced has been apparent from the earliest months of the COVID-19 pandemic. From a clinical perspective, symptom variability might indicate various routes/mechanisms by which infection leads to disease, with different routes requiring potentially different treatment approaches. For public health and control of transmission, symptoms in community cases were the prompt upon which action such as PCR testing and isolation was taken. However, interpreting symptoms presents challenges, for instance, in balancing the sensitivity and specificity of individual symptoms with the need to maximise case finding, whilst managing demand for limited resources such as testing. For both clinical and transmission control reasons, we require an approach that allows for the possibility of distinct symptom phenotypes, rather than assuming variability along a single dimension. Here we address this problem by bringing together four large and diverse datasets deriving from routine testing, a population-representative household survey and participatory smartphone surveillance in the United Kingdom. Through the use of cutting-edge unsupervised classification techniques from statistics and machine learning, we characterise symptom phenotypes among symptomatic SARS-CoV-2 PCR-positive community cases. We first analyse each dataset in isolation and across age bands, before using methods that allow us to compare multiple datasets. While we observe separation due to the total number of symptoms experienced by cases, we also see a separation of symptoms into gastrointestinal, respiratory and other types, and different symptom co-occurrence patterns at the extremes of age. In this way, we are able to demonstrate the deep structure of symptoms of COVID-19 without usual biases due to study design. This is expected to have implications for the identification and management of community SARS-CoV-2 cases and could be further applied to symptom-based management of other diseases and syndromes.

HIV prevalence in transgender populations and cisgender men who have sex with men in sub-Saharan Africa 2010-2022: a meta-analysis.

Introduction: The Global AIDS Strategy 2021-2026 calls for equitable and equal access to HIV prevention and treatment programmes for all populations to reduce HIV incidence and end HIV/AIDS as a public health threat by 2030. Transgender populations (TGP), including transmen (TGM) and transwomen (TGW) are populations that have been marginalised and are at high risk of HIV infection in sub-Saharan Africa (SSA). Limited surveillance data on HIV among TGP are available in the region to guide programmatic responses and policymaking. Surveillance data on cisgender men who have sex with men (cis-MSM) are comparatively abundant and may be used to infer TGP HIV prevalence. Methods: Data from key population surveys conducted in SSA between 2010-2022 were identified from existing databases and survey reports. Studies that collected HIV prevalence on both TGP and cis-MSM populations were analysed in a random effect meta-analysis to estimate the ratio of cis-MSM:TGW HIV prevalence. Results: Eighteen studies were identified encompassing 8,052 TGW and 19,492 cis-MSM. TGW HIV prevalence ranged from 0-71.6% and cis-MSM HIV prevalence from 0.14-55.7%. HIV prevalence in TGW was 50% higher than in cis-MSM (prevalence ratio (PR) 1.50 95% CI 1.26-1.79). TGW HIV prevalence was highly correlated with year/province-matched cis-MSM HIV prevalence (R2 = 0.62), but poorly correlated with year/province-matched total population HIV prevalence (R2 = 0.1). Five TGM HIV prevalence estimates were identified ranging from 1-24%. Insufficient TGM data were available to estimate cis-MSM:TGM HIV prevalence ratios. Conclusion: Transgender women experience a significantly greater HIV burden than cis-MSM in SSA. Bio-behavioural surveys designed and powered to measure determinants of HIV infection, treatment coverage, and risk behaviours among transgender populations, distinct from cis-MSM, will improve understanding of HIV risk and vulnerabilities among TGP and support improved programmes.

Effectiveness of testing, contact tracing and isolation interventions among the general population on reducing transmission of SARS-CoV-2: a systematic review.

We conducted a systematic literature review of general population testing, contact tracing, case isolation and contact quarantine interventions to assess their effectiveness in reducing SARS-CoV-2 transmission, as implemented in real-world settings. We designed a broad search strategy and aimed to identify peer-reviewed studies of any design provided there was a quantitative measure of effectiveness on a transmission outcome. Studies that assessed the effect of testing or diagnosis on disease outcomes via treatment, but did not assess a transmission outcome, were not included. We focused on interventions implemented among the general population rather than in specific settings; these were from anywhere in the world and published any time after 1 January 2020 until the end of 2022. From 26 720 titles and abstracts, 1181 were reviewed as full text, and 25 met our inclusion criteria. These 25 studies included one randomized control trial (RCT) and the remaining 24 analysed empirical data and made some attempt to control for confounding. Studies included were categorized by the type of intervention: contact tracing (seven studies); specific testing strategies (12 studies); strategies for isolating cases/contacts (four studies); and 'test, trace, isolate' (TTI) as a part of a package of interventions (two studies). None of the 25 studies were rated at low risk of bias and many were rated as serious risk of bias, particularly due to the likely presence of uncontrolled confounding factors, which was a major challenge in assessing the independent effects of TTI in observational studies. These confounding factors are to be expected from observational studies during an on-going pandemic, when the emphasis was on reducing the epidemic burden rather than trial design. Findings from these 25 studies suggested an important public health role for testing followed by isolation, especially where mass and serial testing was used to reduce transmission. Some of the most compelling analyses came from examining fine-grained within-country data on contact tracing; while broader studies which compared behaviour between countries also often found TTI led to reduced transmission and mortality, this was not universal. There was limited evidence for the benefit of isolation of cases/contacts away from the home environment. One study, an RCT, showed that daily testing of contacts could be a viable strategy to replace lengthy quarantine of contacts. Based on the scarcity of robust empirical evidence, we were not able to draw any firm quantitative conclusions about the quantitative impact of TTI interventions in different epidemic contexts. While the majority of studies found that testing, tracing and isolation reduced transmission, evidence for the scale of this impact is only available for specific scenarios and hence is not necessarily generalizable. Our review therefore emphasizes the need to conduct robust experimental studies that help inform the likely quantitative impact of different TTI interventions on transmission and their optimal design. Work is needed to support such studies in the context of future emerging epidemics, along with assessments of the cost-effectiveness of TTI interventions, which was beyond the scope of this review but will be critical to decision-making. This article is part of the theme issue 'The effectiveness of non-pharmaceutical interventions on the COVID-19 pandemic: the evidence'.

The role of regular asymptomatic testing in reducing the impact of a COVID-19 wave.

Testing for infection with SARS-CoV-2 is an important intervention in reducing onwards transmission of COVID-19, particularly when combined with the isolation and contact-tracing of positive cases. Many countries with the capacity to do so have made use of lab-processed Polymerase Chain Reaction (PCR) testing targeted at individuals with symptoms and the contacts of confirmed cases. Alternatively, Lateral Flow Tests (LFTs) are able to deliver a result quickly, without lab-processing and at a relatively low cost. Their adoption can support regular mass asymptomatic testing, allowing earlier detection of infection and isolation of infectious individuals. In this paper we extend and apply the agent-based epidemic modelling framework Covasim to explore the impact of regular asymptomatic testing on the peak and total number of infections in an emerging COVID-19 wave. We explore testing with LFTs at different frequency levels within a population with high levels of immunity and with background symptomatic PCR testing, case isolation and contact tracing for testing. The effectiveness of regular asymptomatic testing was compared with 'lockdown' interventions seeking to reduce the number of non-household contacts across the whole population through measures such as mandating working from home and restrictions on gatherings. Since regular asymptomatic testing requires only those with a positive result to reduce contact, while lockdown measures require the whole population to reduce contact, any policy decision that seeks to trade off harms from infection against other harms will not automatically favour one over the other. Our results demonstrate that, where such a trade off is being made, at moderate rates of early exponential growth regular asymptomatic testing has the potential to achieve significant infection control without the wider harms associated with additional lockdown measures.

Heavy-tailed sexual contact networks and monkeypox epidemiology in the global outbreak, 2022.

The outbreak of monkeypox across non-endemic regions confirmed in May 2022 shows epidemiological features distinct from previously imported outbreaks, most notably its observed growth and predominance amongst men who have sex with men (MSM). We use a transmission model fitted to empirical sexual partnership data to show that the heavy-tailed sexual partnership distribution, in which a handful of individuals have disproportionately many partners, can explain the sustained growth of monkeypox among MSM despite the absence of such patterns previously. We suggest that the basic reproduction number (R0) for monkeypox over the MSM sexual network may be substantially above 1, which poses challenges to outbreak containment. Ensuring support and tailored messaging to facilitate prevention and early detection among MSM with high numbers of partners is warranted.

No increased HIV risk in general population near sex work sites: A nationally representative cross-sectional study in Zimbabwe.

OBJECTIVES: Sex work sites have been hypothesised to be at the root of the observed heterogeneity in HIV prevalence in sub-Saharan Africa. We determined if proximity to sex work sites is associated with HIV prevalence among the general population in Zimbabwe, a country with one of the highest HIV prevalence in the world. METHODS: In this cross-sectional study we use a unique combination of nationally representative geolocated individual-level data from 16,121 adults (age 15-49 years) from 400 sample locations and the locations of 55 sex work sites throughout Zimbabwe; covering an estimated 95% of all female sex workers (FSWs). We calculated the shortest distance by road from each survey sample location to the nearest sex work site, for all sites and by type of sex work site, and conducted univariate and multivariate multilevel logistic regressions to determine the association between distance to sex work sites and HIV seropositivity, controlling for age, sex, male circumcision status, number of lifetime sex partners, being a FSW client or being a stable partner of an FSW client. RESULTS: We found no significant association between HIV seroprevalence and proximity to the nearest sex work site among the general population in Zimbabwe, regardless of which type of site is closest (city site adjusted odds ratio [aOR] 1.010 [95% confidence interval {CI} 0.992-1.028]; economic growth point site aOR 0.982 [95% CI 0.962-1.002]; international site aOR 0.995 [95% CI 0.979-1.012]; seasonal site aOR 0.987 [95% CI 0.968-1.006] and transport site aOR 1.007 [95% CI 0.987-1.028]). Individual-level indicators of sex work were significantly associated with HIV seropositivity: being an FSW client (aOR 1.445 [95% CI 1.188-1.745]); nine or more partners versus having one to three lifetime partners (aOR 2.072 [95% CI 1.654-2.596]). CONCLUSIONS: Sex work sites do not seem to directly affect HIV prevalence among the general population in surrounding areas. Prevention and control interventions for HIV at these locations should primarily focus on sex workers and their clients, with special emphasis on including and retaining mobile sex workers and clients into services.

Engagement in HIV services over time among young women who sell sex in Zimbabwe.

INTRODUCTION: Young female sex workers (FSW) are disproportionately vulnerable to HIV. Zimbabwe data show higher HIV incidence and lower engagement in services compared to older FSW. Utilizing data from a combination HIV prevention and treatment intervention, we describe engagement in the HIV services over time among FSW 18-24 years, compared to those ≥25 years of age. MATERIALS AND METHODS: Data were collected via respondent-driven sampling (RDS) surveys in 14 communities in 2013 and 2016, with >2500 FSW per survey. They included blood samples for HIV and viral load testing. As the intervention had no significant impact on HIV care cascade outcomes, data were aggregated across study arms. Analyses used RDS-II estimation. RESULTS: Mean age in 2013 and 2016 was 31 and 33 years, with 27% and 17% aged 18-24 years. Overall HIV prevalence was 59% at each timepoint, and 35% and 36% among younger FSW. From 2013 to 2016 there was an increase in young HIV-positive FSW knowing their status (38% vs 60%, OR = 2.51, p<0.01). Outcomes for all FSW improved significantly over time at all steps of the cascade, and the relative change over time was similar among older versus younger FSW for most cascade variables. DISCUSSION: Young FSW had improvements in care cascade outcomes, and proportionate improvements similar to older FSW, yet they remain less engaged in services overall. This implies that the dedicated FSW services in Zimbabwe are having a comparably positive impact across age groups, however more is likely required to address young FSW's unique vulnerabilities and needs.

Brief Report: Adolescent Girls Who Sell Sex in Zimbabwe: HIV Risk, Behaviours, and Service Engagement.

BACKGROUND: To reduce HIV incidence among adolescent girls who sell sex (AGSS) in Zimbabwe, we need to better understand how vulnerabilities intersect with HIV infection and how those living with HIV engage in care. METHODS: In 2017, we conducted social mapping in 4 locations in Zimbabwe and recruited girls aged 16-19 years who sell sex, using respondent-driven sampling or census sampling methods. Participants completed a questionnaire and provided finger prick blood samples for HIV antibody testing. RESULTS: Of 605 AGSS recruited, 74.4% considered themselves sex workers, 24.4% reported experiencing violence in the past year, 91.7% were not in school, and 83.8% had less than a complete secondary education. Prevalence of HIV increased steeply from 2.1% among those aged 16 years to 26.9% among those aged 19 years; overall, 20.2% of AGSS were HIV-positive. In the multivariate analysis, age, education, marital status, and violence from a client were associated with HIV. Among the 605 AGSS, 86.3% had ever tested for HIV, with 64.1% having tested in the past 6 months. Among AGSS living with HIV, half (50.8%) were aware of their status, among whom 83.9% reported taking antiretroviral therapy. CONCLUSION: The steep rise in HIV prevalence among those aged between 16 and 19 years suggests the window to engage with AGSS before HIV acquisition is short. To accelerate reductions in incidence among AGSS, intensified combination prevention strategies that address structural factors and tailor services to the needs of AGSS are required, particularly ensuring girls enroll and remain in school.

Challenges for modelling interventions for future pandemics.

Mathematical modelling and statistical inference provide a framework to evaluate different non-pharmaceutical and pharmaceutical interventions for the control of epidemics that has been widely used during the COVID-19 pandemic. In this paper, lessons learned from this and previous epidemics are used to highlight the challenges for future pandemic control. We consider the availability and use of data, as well as the need for correct parameterisation and calibration for different model frameworks. We discuss challenges that arise in describing and distinguishing between different interventions, within different modelling structures, and allowing both within and between host dynamics. We also highlight challenges in modelling the health economic and political aspects of interventions. Given the diversity of these challenges, a broad variety of interdisciplinary expertise is needed to address them, combining mathematical knowledge with biological and social insights, and including health economics and communication skills. Addressing these challenges for the future requires strong cross-disciplinary collaboration together with close communication between scientists and policy makers.

Experiences and challenges in sexual health service access among men who have sex with men in Kenya.

Men who have sex with men (MSM) in Kenya bear a heavy burden of HIV/STIs and are a priority population in the national HIV/AIDS response, yet remain criminalised and stigmatised within society. HIV pre-exposure prophylaxis (PrEP) offers an opportunity to significantly impact the HIV epidemic, as does the concept of U = U, whereby those who are living with HIV and on treatment are uninfectious when their viral load has been suppressed so as to be undetectable. However, the value of such innovations will not be realised without sufficient understanding of, and respect for, the sexual health service provision needs of MSM. This paper describes findings from 30 in-depth interviews with MSM living in Nairobi that explored engagement with sexual health service providers, barriers to access and perceived opportunities to improve service design and delivery. Findings indicate concern relating to the professionalism of some staff working within public hospitals as well as feelings that many sexual health services were not considered safe spaces for the discussion of MSM-specific sexual behaviour. Diverse views were expressed relating to comfort in public, community and private sexual health services as well as how these are and should be organised.

Using a household-structured branching process to analyse contact tracing in the SARS-CoV-2 pandemic.

We explore strategies of contact tracing, case isolation and quarantine of exposed contacts to control the SARS-CoV-2 epidemic using a branching process model with household structure. This structure reflects higher transmission risks among household members than among non-household members. We explore strategic implementation choices that make use of household structure, and investigate strategies including two-step tracing, backwards tracing, smartphone tracing and tracing upon symptom report rather than test results. The primary model outcome is the effect of contact tracing, in combination with different levels of physical distancing, on the growth rate of the epidemic. Furthermore, we investigate epidemic extinction times to indicate the time period over which interventions must be sustained. We consider effects of non-uptake of isolation/quarantine, non-adherence, and declining recall of contacts over time. Our results find that, compared to self-isolation of cases without contact tracing, a contact tracing strategy designed to take advantage of household structure allows for some relaxation of physical distancing measures but cannot completely control the epidemic absent of other measures. Even assuming no imported cases and sustainment of moderate physical distancing, testing and tracing efforts, the time to bring the epidemic to extinction could be in the order of months to years. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.

Challenges in control of COVID-19: short doubling time and long delay to effect of interventions.

Early assessments of the growth rate of COVID-19 were subject to significant uncertainty, as expected with limited data and difficulties in case ascertainment, but as cases were recorded in multiple countries, more robust inferences could be made. Using multiple countries, data streams and methods, we estimated that, when unconstrained, European COVID-19 confirmed cases doubled on average every 3 days (range 2.2-4.3 days) and Italian hospital and intensive care unit admissions every 2-3 days; values that are significantly lower than the 5-7 days dominating the early published literature. Furthermore, we showed that the impact of physical distancing interventions was typically not seen until at least 9 days after implementation, during which time confirmed cases could grow eightfold. We argue that such temporal patterns are more critical than precise estimates of the time-insensitive basic reproduction number R0 for initiating interventions, and that the combination of fast growth and long detection delays explains the struggle in countries' outbreak response better than large values of R0 alone. One year on from first reporting these results, reproduction numbers continue to dominate the media and public discourse, but robust estimates of unconstrained growth remain essential for planning worst-case scenarios, and detection delays are still key in informing the relaxation and re-implementation of interventions. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.

HIV burden and correlates of infection among transfeminine people and cisgender men who have sex with men in Nairobi, Kenya: an observational study.

BACKGROUND: Transgender people are disproportionately affected by HIV and other sexually transmitted infections (STIs) worldwide, and culturally competent prevention and treatment services are often unavailable or inaccessible. Despite recent improvements in national HIV responses for many key populations in east Africa, evidence of effective responses informed by transgender sexual health needs is sparse. We aimed to assess gender identity among men and transgender people who have sex with men in Kenya, and to explore its associations with sexual health-related outcomes, risk behaviours, and uptake of HIV prevention and care interventions. METHODS: We did a cross-sectional study in Nairobi, Kenya, and recruited adult cisgender men and transfeminine people who reported having sex with men, through respondent-driven sampling. Inclusion criteria were possession of a valid study coupon, being aged 18 years or older, having male sex assignment at birth or male gender identification currently, living within 50 km of Nairobi, and having had consensual anal or oral sexual activity with a man in the previous 12 months. Seed participants were identified by three community organisations that provide targeted health-care services to gay, bisexual, or other men who have sex with men (MSM) communities in Nairobi. We assessed gender identity, sociodemographics, sexual behaviour, and HIV prevention and care uptake, by self-completed survey. Participants were tested for HIV, syphilis, and rectal and urethral gonorrhoea and chlamydia. We compared prevalence of sexual health outcomes, risk behaviour, and HIV prevention and care service uptake among transfeminine and cisgender participants, using multivariable robust Poisson regression models, with gender identity as the independent variable. FINDINGS: Between May 4 and Dec 8, 2017, we enrolled 618 participants. Six participants did not answer the questions on sex assigned at birth and gender identity and so were excluded from the analyses. 522 (sample-weighted percentage 86%) of 612 participants were classified as cisgender men, 70 (11%) as transfeminine, and three (<1%) as transmasculine. 17 participants (2%) did not identify as male, female, or transgender. Compared with cisgender men, transfeminine people were more likely to be HIV-positive (28 [41%] of 70 transfeminine vs 151 [25%] of 521 cisgender men; p=0·0009) and to report current symptoms consistent with a rectal STI (eight [16%] of 67 vs 38 [7%] of 518; p=0·014). Transfeminine people reported higher numbers of recent male sexual partners (22 [27%] of 70 transfeminine people reported four or more male sexual partners in the past 3 months vs 112 [13%] of 522 cisgender men; p=0·042) and were more likely to report condomless anal intercourse with men (43 [62%] of 70 vs 208 [39%] of 522; p=0·0009) and receptive anal intercourse (54 [76%] of 70 vs 252 [46%] of 522; p<0·0001) in the past 3 months, and transactional sex with men (42 [57%] of 69 vs 240 [42%] of 518; p=0·023) and experience of sexual assault (16 [23%] of 69 vs 65 [11%] of 520; p=0·019) in the past 12 months. Use of pre-exposure prophylaxis and post-exposure prophylaxis was low in both groups. INTERPRETATION: Transfeminine people who have sex with men have a higher burden of HIV and associated risk behaviours compared with cisgender MSM in the same context, yet their uptake of prevention and care services is poor. Policies should acknowledge the specific needs of transfeminine people as distinct from cisgender MSM, and support health-care providers to address these needs. FUNDING: Evidence for HIV Prevention in Southern Africa (EHPSA), UK Aid.

Online socializing among men who have sex with men and transgender people in Nairobi and Johannesburg and implications for public health-related research and health promotion: an analysis of qualitative and respondent-driven sampling survey data.

INTRODUCTION: There is little published literature about gay, bisexual and other men who have sex with men and transgender individuals (MSM and TG)'s use of social media in sub-Saharan Africa, despite repressive social and/or criminalizing contexts that limit access to physical HIV prevention. We sought to describe MSM and TG's online socializing in Nairobi and Johannesburg, identifying the characteristics of those socializing online and those not, in order to inform the development of research and health promotion in online environments. METHODS: Respondent-driven sampling surveys were conducted in 2017 in Nairobi (n = 618) and Johannesburg (n = 301) with those reporting current male gender identity or male sex assigned at birth and sex with a man in the last 12 months. Online socializing patterns, sociodemographic, sexual behaviour and HIV-testing data were collected. We examined associations between social media use and sociodemographic characteristics and sexual behaviours among all, and only those HIV-uninfected, using logistic regression. Analyses were RDS-II weighted. Thirty qualitative interviews were conducted with MSM and TG in each city, which examined the broader context of and motivations for social media use. RESULTS: Most MSM and TG had used social media to socialize with MSM in the last month (60% Johannesburg, 71% Nairobi), mostly using generic platforms (e.g. Facebook), but also gay-specific (e.g. Grindr). HIV-uninfected MSM and TG reporting riskier recent sexual behaviours had raised odds of social media use in Nairobi, including receptive anal intercourse (adjusted OR = 2.15, p = 0.006), buying (aOR = 2.24, p = 0.015) and selling sex with men (aOR = 2.17, p = 0.004). Evidence for these associations was weaker in Johannesburg, though socializing online was associated with condomless anal intercourse (aOR = 3.67, p = 0.003) and active syphilis (aOR = 13.50, p = 0.016). Qualitative findings indicated that while online socializing can limit risk of harm inherent in face-to-face interactions, novel challenges were introduced, including context collapse and a fear of blackmail. CONCLUSIONS: Most MSM and TG in these cities socialize online regularly. Users reported HIV acquisition risk behaviours, yet this space is not fully utilized for sexual health promotion and research engagement. Effective, safe and acceptable means of using online channels to engage with MSM/TG that account for MSM and TG's strategies and concerns for managing online security should now be explored, as complements or alternatives to existing outreach.

Public target interventions to reduce the inappropriate use of medicines or medical procedures: a systematic review.

BACKGROUND: An epidemic of health disorders can be triggered by a collective manifestation of inappropriate behaviors, usually systematically fueled by non-medical factors at the individual and/or societal levels. This study aimed to (1) landscape and assess the evidence on interventions that reduce inappropriate demand of medical resources (medicines or procedures) by triggering behavioral change among healthcare consumers, (2) map out intervention components that have been tried and tested, and (3) identify the "active ingredients" of behavior change interventions that were proven to be effective in containing epidemics of inappropriate use of medical resources. METHODS: For this systematic review, we searched MEDLINE, EMBASE, the Cochrane Library, and PsychINFO from the databases' inceptions to May 2019, without language restrictions, for behavioral intervention studies. Interventions had to be empirically evaluated with a control group that demonstrated whether the effects of the campaign extended beyond trends occurring in the absence of the intervention. Outcomes of interest were reductions in inappropriate or non-essential use of medicines and/or medical procedures for clinical conditions that do not require them. Two reviewers independently screened titles, abstracts, and full text for inclusion and extracted data on study characteristics (e.g., study design), intervention development, implementation strategies, and effect size. Data extraction sheets were based on the checklist from the Cochrane Handbook for Systematic Reviews. RESULTS: Forty-three studies were included. The behavior change technique taxonomy v1 (BCTTv1), which contains 93 behavioral change techniques (BCTs), was used to characterize components of the interventions reported in the included studies. Of the 93 BCTs, 15 (16%) were identified within the descriptions of the selected studies targeting healthcare consumers. Interventions consisting of education messages, recommended behavior alternatives, and a supporting environment that incentivizes or encourages the adoption of a new behavior were more likely to be successful. CONCLUSIONS: There is a continued tendency in research reporting that mainly stresses the effectiveness of interventions rather than the process of identifying and developing key components and the parameters within which they operate. Reporting "negative results" is likely as critical as reporting "active ingredients" and positive findings for implementation science. This review calls for a standardized approach to report intervention studies. TRIAL REGISTRATION: PROSPERO registration number CRD42019139537.

Decisions to use antibiotics for upper respiratory tract infections across China: a large-scale cross-sectional survey among university students.

OBJECTIVES: To investigate the decision-making process of Chinese university students with respect to antibiotic use for upper respiratory tract infections (URTIs). DESIGN: A cross-sectional questionnaire study. SETTING: The participants recruited from six universities across all Chinese regions from September to November 2015. PARTICIPANTS: A total of 2834 university students sampled across six Chinese regions who self-reported experiencing symptoms of URTI within the past month completed the survey. OUTCOME MEASURES: The prevalence of decisions for treatment and antibiotic use for URTIs as well as knowledge about antibiotic use were measured by a self-administrated questionnaire. Using regular and multinomial logistic regression a nd adapted health belief model, we identified and measured a number of variables as potential risk factors for antibiotic misuse behaviours in order to explain and predict people's treatment decisions and antibiotic use including knowledge, perceptions, access to antibiotics and cues to action. RESULTS: Of the 2834 university students who self-diagnosed a URTI, 947 (33.4%) self-reported having taken antibiotics; among them, 462 (48.8%) used non-prescription antibiotics, which came principally from left-over prescriptions (29.0%) and over-the-counter purchases at retail pharmacies (67.3%). One in four who sought care pressured their doctors for antibiotics; all received them. Those who perceived greater severity of the disease, had access to antibiotics, perceived benefits of using antibiotics (for the common cold: adjusted OR (aOR)=2.55, 95% CI 1.93 to 3.38 or as anti-inflammatory drugs: aOR=1.35, 95% CI 1.12 to 1.63), and were cued to action (eg, seeing presence of fever: aOR=2.05, 95% CI 1.62 to 2.60 or self-diagnosing their current infection as severe: aOR=1.86, 95% CI 1.41 to 2.45), keeping antibiotics at home (aOR=2.27, 95% CI 1.83 to 2.81) and access to over-the-counter antibiotics (aOR=2.00, 95% CI 1.63 to 2.45), were more likely to misuse antibiotics. CONCLUSIONS: Misconceptions of antibiotic efficacy and easy access to antibiotics-with or without a prescription-were associated with antibiotic misuse among Chinese university students, which calls for context-appropriate multifaceted interventions in order to effectively reduce antibiotic misuse.

Using statistics and mathematical modelling to understand infectious disease outbreaks: COVID-19 as an example.

During an infectious disease outbreak, biases in the data and complexities of the underlying dynamics pose significant challenges in mathematically modelling the outbreak and designing policy. Motivated by the ongoing response to COVID-19, we provide a toolkit of statistical and mathematical models beyond the simple SIR-type differential equation models for analysing the early stages of an outbreak and assessing interventions. In particular, we focus on parameter estimation in the presence of known biases in the data, and the effect of non-pharmaceutical interventions in enclosed subpopulations, such as households and care homes. We illustrate these methods by applying them to the COVID-19 pandemic.