Optimal human papillomavirus vaccination strategies in the context of vaccine supply constraints in 100 countries.

Background: Countries are recommended to immunise adolescent girls routinely with one or two doses of human papillomavirus (HPV) vaccines to eliminate cervical cancer as a public health problem. With most existing vaccine doses absorbed by countries (mostly high-income) with existing HPV vaccination programmes, limited supply has been left for new country introductions until 2022; many of those, low- and middle-income countries with higher mortality. Several vaccination strategies were considered by the Strategic Advisory Group of Experts on Immunization to allow more countries to introduce vaccination despite constrained supplies. Methods: We examined the impact of nine strategies for allocating limited vaccine doses to 100 pre-introduction countries from 2020 to 2030. Two algorithms were used to optimise the total number of cancer deaths that can be averted worldwide by a limited number of doses (knapsack and decreasing order of country-specific mortality rates), and an unoptimised algorithm (decreasing order of Human Development Index) were used. Findings: Routinely vaccinating 14-year-old girls with either one or two doses and switching to a routine 9-year-old programme when supply is no longer constrained could prevent the most cervical cancer deaths, regardless of allocation algorithm. The unoptimised allocation averts fewer deaths because it allocates first to higher-income countries, usually with lower cervical cancer mortality. Interpretation: To optimise the deaths averted through vaccination when supply is limited, it is important to prioritise high-burden countries and vaccinating older girls first. Funding: WHO, Bill & Melinda Gates Foundation.

Could prophylactic antivirals reduce dengue incidence in a high-prevalence endemic area?

Prophylactic drugs against dengue are currently under development. In this study, we explored how such prophylactic approaches might affect dengue cases in four communes of Nha Trang City, Vietnam. A community level dengue transmission survey indicated high levels of previous exposure to dengue (89.7%; 95% CI: 87.2,92.0). We fitted a spatially explicit model to an observed outbreak and simulated likely effectiveness of Case-Area Targeted Interventions (CATI) and One-Time Mass Distribution (OTMD) of drug and vector control strategies. Increasing radius and effectiveness and decreasing delay of CATI was most effective, with drugs being more effective in averting dengue cases than vector control. Using an OTMD approach early in the outbreak required the least number of treatments to avert a case, suggesting that OTMD strategies should be considered as pre-emptive rather than reactive strategies. These findings show that pre-emptive interventions can substantially reduce the burden of dengue outbreaks in endemic settings.

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.

Equity impact of HPV vaccination on lifetime projections of cervical cancer burden among cohorts in 84 countries by global, regional, and income levels, 2010-22: a modelling study.

Background: While human papillomavirus (HPV) vaccines have been available since 2006, the coverage has varied among countries. Our aim is to analyse the equity impact of HPV vaccination on the lifetime projections of cervical cancer burden among vaccinated cohorts of 2010-22 in 84 countries. Methods: We used WHO and UNICEF estimates of national immunisation coverage for HPV vaccination in 84 countries during 2010-22. We used PRIME (Papillomavirus Rapid Interface for Modelling and Economics) to estimate the lifetime health impact of HPV vaccination on cervical cancer burden in terms of deaths, cases, and disability-adjusted life years (DALYs) averted by vaccination in their respective countries. We generated concentration indices and curves to assess the equity impact of HPV vaccination across 84 countries. Findings: The health impact of HPV vaccination varied across the 84 countries and ranged from Switzerland to Tanzania at 2 to 34 deaths, 4 to 47 cases, and 40 to 735 DALYs averted per 1000 vaccinated adolescent girls over the lifetime of the vaccinated cohorts of 2010-22. The concentration index for the distribution of average coverage during 2010-22 among the 84 countries ranked by vaccine impact was 0.33 (95% CI: 0.27-0.40) and highlights the wide inequities in HPV vaccination coverage. Interpretation: Our findings suggested that countries with a relatively higher cervical cancer burden and thereby a relatively higher need for HPV vaccination had relatively lower coverage during 2010-22. Further, there were significant inequities in HPV vaccination coverage within the Americas, Europe, and Western Pacific regions, and in high- and low-income countries with a pro-advantaged and regressive distribution favouring countries with lower vaccine impact. Funding: Gavi, the Vaccine Alliance; Bill & Melinda Gates Foundation.

Global impact and cost-effectiveness of one-dose versus two-dose human papillomavirus vaccination schedules: a comparative modelling analysis.

BACKGROUND: To eliminate cervical cancer as a public health problem, the World Health Organization had recommended routine vaccination of adolescent girls with two doses of the human papillomavirus (HPV) vaccine before sexual initiation. However, many countries have yet to implement HPV vaccination because of financial or logistical barriers to delivering two doses outside the infant immunisation programme. METHODS: Using three independent HPV transmission models, we estimated the long-term health benefits and cost-effectiveness of one-dose versus two-dose HPV vaccination, in 188 countries, under scenarios in which one dose of the vaccine gives either a shorter duration of full protection (20 or 30 years) or lifelong protection but lower vaccine efficacy (e.g. 80%) compared to two doses. We simulated routine vaccination with the 9-valent HPV vaccine in 10-year-old girls at 80% coverage for the years 2021-2120, with a 1-year catch-up campaign up to age 14 at 80% coverage in the first year of the programme. RESULTS: Over the years 2021-2120, one-dose vaccination at 80% coverage was projected to avert 115.2 million (range of medians: 85.1-130.4) and 146.8 million (114.1-161.6) cervical cancers assuming one dose of the vaccine confers 20 and 30 years of protection, respectively. Should one dose of the vaccine provide lifelong protection at 80% vaccine efficacy, 147.8 million (140.6-169.7) cervical cancer cases could be prevented. If protection wanes after 20 years, 65 to 889 additional girls would need to be vaccinated with the second dose to prevent one cervical cancer, depending on the epidemiological profiles of the country. Across all income groups, the threshold cost for the second dose was low: from 1.59 (0.14-3.82) USD in low-income countries to 44.83 (3.75-85.64) USD in high-income countries, assuming one dose confers 30-year protection. CONCLUSIONS: Results were consistent across the three independent models and suggest that one-dose vaccination has similar health benefits to a two-dose programme while simplifying vaccine delivery, reducing costs, and alleviating vaccine supply constraints. The second dose may become cost-effective if there is a shorter duration of protection from one dose, cheaper vaccine and vaccination delivery strategies, and high burden of cervical cancer.

Tuberculosis in older adults: challenges and best practices in the Western Pacific Region.

The Western Pacific has one of the fastest-growing older adult populations globally, and tuberculosis (TB) remains one of the foremost infectious causes of disease and death in the region. Older adults are at higher risk of TB due to immunosenescence, comorbidities, and increased institutionalisation. Atypical symptoms and reduced access to health services may delay care-seeking and TB diagnosis, while co-morbidity and increased risk of adverse drug reactions complicate TB treatment. Post-TB sequelae and socioeconomic challenges may decrease the quality of life after TB treatment completion. Despite their high disease burden and special challenges, there is a lack of regionally coordinated policies and guidelines to manage TB among older adults. Routine TB screening at aged-care facilities, age-friendly infrastructure and services, awareness of atypical TB features, integration of TB and non-communicable diseases services, and person-centred approaches to treatment support could improve TB management among older adults. Addressing these challenges and adopting the best practices identified should inform policy formulation and implementation. Funding: This project was funded by 1) the World Health Organization Regional Office for the Western Pacific, with financial contributions from the Government of the Republic of Korea through the Korean Disease Control and Prevention Agency and the Government of Japan through the Ministry of Health, Labour and Welfare, and 2) NUS Start-up Grant. The funders had no role in the paper design, collection, analysis, and interpretation of data and in writing of the paper.

What are the determinants of antiretroviral therapy adherence among stable people living with HIV? A cross-sectional study in Cambodia.

BACKGROUND: Understanding context-specific determinants of antiretroviral therapy (ART) adherence is crucial for developing tailored interventions for improving health outcomes and achieving the UNAIDS' third 95% target. This cross-sectional study explores factors associated with ART adherence among stable people living with HIV on ART in Cambodia. METHODS: We used baseline survey data from a quasi-experimental study conducted in 2021. The participants were recruited from 20 ART clinics in nine provinces for face-to-face interviews. A structured questionnaire collected information on sociodemographic characteristics, ART adherence, perceived ART self-efficacy, mental health, quality of life, stigma, and discrimination. We conducted bivariate and multiple logistic regression analyses to identify factors associated with ART adherence. RESULTS: Out of the 4101 participants, 86.5% reported adhering to ART in the past two months. The adjusted odds of ART adherence were significantly higher among participants in older age groups than those aged 15-29, participants with elevated cholesterol than those without it, participants who exhibited strong self-efficacy in health responsibility to maintain life than those with poor self-efficacy in health responsibility, participants who scored < 3 on the stigma and discrimination scale than those who scored ≥ 3, participants who scored ≥ 42 on the mental component of the quality-of-life scale than those who scored < 42. The adjusted odds of ART adherence were significantly lower in participants who earned > 301 USD per month than those who earned ≤ 100 USD per month. CONCLUSION: The ART adherence rate among stable people living with HIV in this study was comparable to that of the general people living with HIV in Cambodia. The results suggest the need for innovative interventions to further reduce stigma and discrimination and strategies to improve the self-efficacy and mental health of people living with HIV to improve ART adherence.

Application of the network scale-up method to estimate the sizes of key populations for HIV in Singapore using online surveys.

INTRODUCTION: Singapore lacks robust data on the sizes of the key populations that are most at risk for HIV. Using the network scale-up method for hidden or hard-to-reach populations, we estimate the sizes of five key populations-male clients of female sex workers (MCFSW), men who have sex with men (MSM), female sex workers (FSW), people who inject drugs (PWID) and transgender people-and profile the ages and ethnicities of respondents with the high-risk contacts they report knowing. METHODS: We conducted a cross-sectional online survey between March and May 2019 (n = 2802) using a network scale-up instrument previously developed for Singapore. Participants were recruited using an existing panel and online advertising, and the sample reweighted by age, sex, ethnicity and education attained to represent the general adult population. We built a Bayesian hierarchical model to estimate the sizes of the five key populations for HIV in Singapore. RESULTS: After adjustment, the sizes of the at-risk populations are estimated to be: 76,800 (95% credible interval [CI]: 64,200-91,800) MCFSW; 139,000 (95% CI: 120,000-160,000) MSM; 8030 (95% CI: 3980-16,200) FSW; 3470 (95% CI: 1540-7830) PWID and 18,000 (95% CI: 14,000-23,200) transgender people. Generally, men reported knowing more people in all the high-risk groups; older people reported knowing more MCFSW, FSW and transgender people; and younger people reported knowing more MSM. There was a bimodal effect of age on those who reported knowing more PWIDs: people in their 20s and 60s reported more contacts. CONCLUSIONS: This study demonstrates that a size estimation study of hidden populations is quickly and efficiently scalable through using online surveys in a socially conservative society, like Singapore, where key populations are stigmatized or criminalized. The approach may be suitable in other countries where stigma is prevalent and where barriers to surveillance and data collection are numerous.

Where are the missing people affected by tuberculosis? A programme review of patient-pathway and cascade of care to optimise tuberculosis case-finding, treatment and prevention in Cambodia.

BACKGROUND: Cambodia has achieved great success in tuberculosis (TB) control in the past decade. Nevertheless, people with TB are missed by the health systems at different stages of the care pathway. This programme review corroborated the care-seeking behaviours of people with TB and TB services availability and estimated the number of people completing each step of the TB disease and TB preventive treatment (TPT) care cascade. METHODS: Patient pathways and the care cascades for TB disease and TPT were constructed using data from the latest national TB prevalence survey, routine surveillance and programme, the global TB database and published studies. We also randomly selected TB survivors in the 2019 cohort to assess recurrence-free survival 1-year post-treatment. TPT care cascade was constructed for people living with HIV (PLHIV) and household contacts (children <5 years and all ages) of persons with bacteriologically-confirmed TB in 2019 and 2020. RESULTS: Nationally, 54% of those who exhibited TB symptoms sought initial care in the private sector. Overall, 93% and 58% of people with presumptive TB did not access a facility with TB diagnostic and treatment services, respectively, at the first point of care-seeking. Approximately 56% (95% CI 52% to 57%) of the 47 000 (95% CI 31 000 to 68 000) estimated TB cases in 2019 achieved recurrence-free survival. Among the estimated PLHIV in Cambodia, <30% completed TPT. Among children <5 years, 53% (95% CI 29% to 65%) (2019) and 67% (95% CI 36% to 80%) (2020) of those eligible for TPT completed the regimen successfully. In 2019 and 2020, 23% (95% CI 22% to 25%) and 54% (95% CI 50% to 58%) of the estimated household contacts (all ages) eligible for TPT completed the regimen successfully. CONCLUSION: There are significant gaps in care-seeking, coverage and access to TB services and TPT in Cambodia. Action plans to improve TB response have been co-developed with local stakeholders to address the gaps throughout the care cascades.

Impact of including boys in the national school-based human papillomavirus vaccination programme in Singapore: A modelling-based cost-effectiveness analysis.

Globally, gender-neutral Human Papillomavirus (HPV) vaccination programmes are gaining traction. Although cervical cancer remains the most prevalent, other HPV-related cancers are increasingly recognised as important, especially among men who have sex with men. We assessed if including adolescent boys in Singapore's school-based HPV vaccination programme is cost-effective from the healthcare perspective. We adapted a World Health Organization-supported model, Papillomavirus Rapid Interface for Modelling and Economics, and modelled the cost and quality-adjusted life years (QALY) associated with vaccinating 13-year-olds with the HPV vaccine. Cancer incidence and mortality rates were obtained from local sources and adjusted based on the expected direct and indirect vaccine protection for various population subgroups at an 80 % vaccine coverage. Moving to a gender-neutral vaccination programme with a bivalent or nonavalent vaccine could avert 30 (95 % uncertainty interval [UI]: 20-44) and 34 (95 % UI: 24-49) HPV-related cancers per birth cohort, respectively. At a 3 % discount rate, a gender-neutral vaccination programme is not cost-effective. However, with a 1.5 % discount rate, which puts more value on long-term health gains from vaccination, moving to a gender-neutral vaccination programme with the bivalent vaccine is likely cost-effective, with an incremental cost-effectiveness ratio of SGD$19 007 (95 % UI: 10 164-30 633) per QALY gained. The findings suggest the need to engage experts to examine, in detail, the cost-effectiveness of gender-neutral vaccination programmes in Singapore. Issues of drug licensing, feasibility, gender equity, global vaccine supplies, and the global trend towards disease elimination/eradication should also be considered. This model provides a simplified method for resource-strapped countries to gain a preliminary estimate of the cost-effectiveness of a gender-neutral HPV vaccination programme before investing resources for further research.

Potential benefit of extended dose schedules of human papillomavirus vaccination in the context of scarce resources and COVID-19 disruptions in low-income and middle-income countries: a mathematical modelling analysis.

BACKGROUND: The WHO Strategic Advisory Group of Experts recommended that an extended interval of 3-5 years between the two doses of the human papillomavirus (HPV) vaccine could be considered to alleviate vaccine supply shortages. However, three concerns have limited the introduction of extended schedules: girls could be infected between the two doses, the vaccination coverage for the second dose could be lower at ages 13-14 years than at ages 9-10 years, and identifying girls vaccinated with a first dose to give them the second dose could be difficult. Using mathematical modelling, we examined the potential effect of these concerns on the population-level impact and efficiency of extended dose HPV vaccination schedules. METHODS: We used HPV-ADVISE, an individual-based, transmission-dynamic model of multitype HPV infection and disease, calibrated to country-specific data for four low-income and middle-income countries (India, Viet Nam, Uganda, and Nigeria). For the extended dose scenarios, we varied the vaccination coverage of the second dose among girls previously vaccinated, the one-dose vaccine efficacy, and the one-dose vaccine duration of protection. We also examined a strategy in which girls aged 14 years were vaccinated irrespective of their previous vaccination status. We used a scenario of girls-only two-dose vaccination at age 9 years (vaccine=9 valent, vaccine-type efficacy=100%, duration of protection=lifetime, and coverage=80%) as our comparator. We estimated two outcomes: the relative reduction in the age-standardised cervical cancer incidence (population-level impact) and the number of cervical cancers averted per 100 000 doses (efficiency). FINDINGS: Our model projected substantial reductions in cervical cancer incidence over 100 years with the two-dose schedule (79-86% depending on the country), compared with no vaccination. Projections for the 5-year extended schedule, in which the second dose is given only to girls previously vaccinated at age 9 years, were similar to the current two-dose schedule, unless vaccination coverage of the second dose is very low (reductions in cervical cancer incidence of 71-78% assuming 30% coverage at age 14 years among girls vaccinated at age 9 years). However, when the dose at age 14 years is given to girls irrespective of vaccination status and assuming high vaccination coverage, the model projected a substantially greater reduction in cervical cancer incidence compared with the current two-dose schedule (reductions in cervical cancer incidence of 86-93% assuming 70% coverage at age 14 years, irrespective of vaccination status). Efficiency of the extended schedule was greater than the two-dose schedule, even with a drop in vaccination coverage. INTERPRETATION: The three concerns are unlikely to have a substantial effect on the population-level impact of extended dose schedules. Hence, extended dose schedules will likely provide similar cervical cancer reductions as two-dose schedules, while reducing the number of doses required in the short-term, providing a more efficient use of scarce resources, and offering a 5-year time window to reassess the necessity of the second dose. FUNDING: WHO, Canadian Institute of Health Research Foundation, Fonds de recherche du Québec-Santé, Digital Research Alliance of Canada, and Bill & Melinda Gates Foundation.

Now or later: Health impacts of delaying single-dose HPV vaccine implementation in a high-burden setting.

We aimed to quantify the health impact of immediate introduction of a single-dose human papillomavirus (HPV) vaccination program in a high-burden setting, as waiting until forthcoming trials are completed to implement single-dose HPV vaccination may result in health losses, particularly for cohorts who would age-out of vaccination eligibility. Two mathematical models fitted to a high-burden setting projected cervical cancer incidence rates associated with (a) immediate implementation of one-dose HPV vaccination vs (b) waiting 5 years for evidence from randomized trials to determine if one- or two-doses should be implemented. We conducted analyses assuming a single dose was either noninferior or inferior to two doses. The models projected that immediate implementation of a noninferior single-dose vaccine led to a 7.2% to 9.6% increase in cancers averted between 2021 to 2120, compared to waiting 5 years. Health benefits remained greater with immediate implementation despite an inferior single-dose efficacy (80%), but revaccination of one-dose recipients became more important assuming vaccine waning. Under most circumstances, immediate vaccination avoided health losses for those aging out of vaccine eligibility, leading to greater health benefits than waiting for more information in 5 years.

Changes in social contacts in England during the COVID-19 pandemic between March 2020 and March 2021 as measured by the CoMix survey: A repeated cross-sectional study.

BACKGROUND: During the Coronavirus Disease 2019 (COVID-19) pandemic, the United Kingdom government imposed public health policies in England to reduce social contacts in hopes of curbing virus transmission. We conducted a repeated cross-sectional study to measure contact patterns weekly from March 2020 to March 2021 to estimate the impact of these policies, covering 3 national lockdowns interspersed by periods of less restrictive policies. METHODS AND FINDINGS: The repeated cross-sectional survey data were collected using online surveys of representative samples of the UK population by age and gender. Survey participants were recruited by the online market research company Ipsos MORI through internet-based banner and social media ads and email campaigns. The participant data used for this analysis are restricted to those who reported living in England. We calculated the mean daily contacts reported using a (clustered) bootstrap and fitted a censored negative binomial model to estimate age-stratified contact matrices and estimate proportional changes to the basic reproduction number under controlled conditions using the change in contacts as a scaling factor. To put the findings in perspective, we discuss contact rates recorded throughout the year in terms of previously recorded rates from the POLYMOD study social contact study. The survey recorded 101,350 observations from 19,914 participants who reported 466,710 contacts over 53 weeks. We observed changes in social contact patterns in England over time and by participants' age, personal risk factors, and perception of risk. The mean reported contacts for adults 18 to 59 years old ranged between 2.39 (95% confidence interval [CI] 2.20 to 2.60) contacts and 4.93 (95% CI 4.65 to 5.19) contacts during the study period. The mean contacts for school-age children (5 to 17 years old) ranged from 3.07 (95% CI 2.89 to 3.27) to 15.11 (95% CI 13.87 to 16.41). This demonstrates a sustained decrease in social contacts compared to a mean of 11.08 (95% CI 10.54 to 11.57) contacts per participant in all age groups combined as measured by the POLYMOD social contact study in 2005 to 2006. Contacts measured during periods of lockdowns were lower than in periods of eased social restrictions. The use of face coverings outside the home has remained high since the government mandated use in some settings in July 2020. The main limitations of this analysis are the potential for selection bias, as participants are recruited through internet-based campaigns, and recall bias, in which participants may under- or overreport the number of contacts they have made. CONCLUSIONS: In this study, we observed that recorded contacts reduced dramatically compared to prepandemic levels (as measured in the POLYMOD study), with changes in reported contacts correlated with government interventions throughout the pandemic. Despite easing of restrictions in the summer of 2020, the mean number of reported contacts only returned to about half of that observed prepandemic at its highest recorded level. The CoMix survey provides a unique repeated cross-sectional data set for a full year in England, from the first day of the first lockdown, for use in statistical analyses and mathematical modelling of COVID-19 and other diseases.

Prevalence and Determinants of Vaginal Infection With Human Papillomavirus Among Female University Students in Vietnam.

BACKGROUND/AIM: Cervical cancer is the second most common malignancy among women in Vietnam, but the country is yet to introduce a national human papillomavirus (HPV) vaccine programme targeted at adolescents. We determined HPV prevalence and HPV vaccine knowledge among female university students in Vietnam. PATIENTS AND METHODS: We surveyed and screened 1,491 female university students in Hanoi, Hue, and Ho Chi Minh City for their sexual behaviours, HPV knowledge and low- and high-risk HPV infection. RESULTS: The prevalence of any HPV infection and any high-risk HPV infection were 4.2% (95%CI=3.3%-5.4%) and 3.4% (95%CI=2.5%-4.4%), respectively. Being sexually active [adjusted prevalence ratio (aPR): 6.22; 95%CI=3.4-11.37] and having ever been pregnant (aPR: 4.82; 95%CI=1.93-12.04) were positively associated with high-risk HPV infection. Whilst 60% of participants had heard of HPV vaccine, only 4.6% had received the vaccine. CONCLUSION: The low HPV prevalence found in university students in Vietnam indicates that they can benefit from HPV vaccination, along with a well-designed HPV health promotion programme.

A global assessment of the impact of school closure in reducing COVID-19 spread.

Prolonged school closure has been adopted worldwide to control COVID-19. Indeed, UN Educational, Scientific and Cultural Organization figures show that two-thirds of an academic year was lost on average worldwide due to COVID-19 school closures. Such pre-emptive implementation was predicated on the premise that school children are a core group for COVID-19 transmission. Using surveillance data from the Chinese cities of Shenzhen and Anqing together, we inferred that compared with the elderly aged 60 and over, children aged 18 and under and adults aged 19-59 were 75% and 32% less susceptible to infection, respectively. Using transmission models parametrized with synthetic contact matrices for 177 jurisdictions around the world, we showed that the lower susceptibility of school children substantially limited the effectiveness of school closure in reducing COVID-19 transmissibility. Our results, together with recent findings that clinical severity of COVID-19 in children is lower, suggest that school closure may not be ideal as a sustained, primary intervention for controlling COVID-19. This article is part of the theme issue 'Data science approach to infectious disease surveillance'.

Prevalence and risk factors for human papillomavirus infection among female sex workers in Hanoi and Ho Chi Minh City, Viet Nam: a cross-sectional study.

Objective: Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infections and cervical cancer due to their high number of sexual partners. The objectives of this study were to determine the prevalence of HPV and identify risk factors for high-risk HPV infection among FSWs in Hanoi and Ho Chi Minh City (HCMC), Viet Nam. Methods: A cross-sectional study was conducted in Hanoi and HCMC between December 2017 and May 2018. We surveyed and screened 699 FSWs aged 318 years for HPV infection and abnormal cytology. A multivariable modified Cox regression model was used to determine risk factors for high-risk HPV infection. Results: The overall prevalence of any HPV, high-risk HPV and HPV-16/18 infection in the 699 FSWs was 26.3%, 17.6% and 4.0%, respectively, and were similar in both cities. Multiple infections were identified in 127 participants (69.0%). HPV-52 was the most prevalent (7%), followed by HPV-58 (6%). Abnormal cytology was detected in 91 participants (13.0%). FSWs who are divorced (adjusted prevalence ratio [aPR]: 1.96, 95% confidence interval [CI]: 1.01-3.81), widowed (aPR: 3.26, 95% CI: 1.49-7.12) or living alone (aPR: 1.85, 95% CI: 1.01-3.39) were associated with a higher prevalence of high-risk HPV infection. Discussion: Almost one in five FSWs in Viet Nam are infected with high-risk HPV. This highlights the importance of prevention strategies such as HPV vaccination and screening in this high-risk group.

Epidemiology of Extended-Spectrum Beta-Lactamase and Carbapenemase-Producing Enterobacterales in the Greater Mekong Subregion: A Systematic-Review and Meta-Analysis of Risk Factors Associated With Extended-Spectrum Beta-Lactamase and Carbapenemase Isolation.

Background: Despite the rapid spread of extended-spectrum beta-lactamase (ESBL) producing-Enterobacterales (ESBL-E) and carbapenemase-producing Enterobacterales (CPE), little is known about the extent of their prevalence in the Greater Mekong Subregion (GMS). In this systematic review, we aimed to determine the epidemiology of ESBL-E and CPE in clinically significant Enterobacterales: Escherichia coli and Klebsiella pneumoniae from the GMS (comprising of Cambodia, Laos, Myanmar, Thailand, Vietnam and Yunnan province and Guangxi Zhuang region of China). Methods: Following a list of search terms adapted to subject headings, we systematically searched databases: Medline, EMBASE, Scopus and Web of Science for articles published on and before October 20th, 2020. The search string consisted of the bacterial names, methods involved in detecting drug-resistance phenotype and genotype, GMS countries, and ESBL and carbapenemase detection as the outcomes. Meta-analyses of the association between the isolation of ESBL from human clinical and non-clinical specimens were performed using the "METAN" function in STATA 14. Results: One hundred and thirty-nine studies were included from a total of 1,513 identified studies. Despite the heterogeneity in study methods, analyzing the prevalence proportions on log-linear model scale for ESBL producing-E. coli showed a trend that increased by 13.2% (95%CI: 6.1-20.2) in clinical blood specimens, 8.1% (95%CI: 1.7-14.4) in all clinical specimens and 17.7% (95%CI: 4.9-30.4) increase in carriage specimens. Under the log-linear model assumption, no significant trend over time was found for ESBL producing K. pneumoniae and ESBL-E specimens. CPE was reported in clinical studies and carriage studies past 2010, however a trend could not be determined because of the small dataset. Twelve studies were included in the meta-analysis of risk factors associated with isolation of ESBL. Recent antibiotic exposure was the most studied variable and showed a significant positive association with ESBL-E isolation (pooled OR: 2.9, 95%CI: 2.3-3.8) followed by chronic kidney disease (pooled OR: 4.7, 95%CI: 1.8-11.9), and other co-morbidities (pooled OR: 1.6, 95%CI: 1.2-2.9). Conclusion: Data from GMS is heterogeneous with significant data-gaps, especially in community settings from Laos, Myanmar, Cambodia and Yunnan and Guangxi provinces of China. Collaborative work standardizing the methodology of studies will aid in better monitoring, surveillance and evaluation of interventions across the GMS.

Economic Evaluation of Community Tuberculosis Active Case-Finding Approaches in Cambodia: A Quasi-Experimental Study.

This study aimed to estimate the costs and incremental cost-effectiveness of two community-based tuberculosis (TB) active case-finding (ACF) strategies in Cambodia. We also assessed the number needed to screen and test to find one TB case. Program and national TB notification data from a quasi-experimental study of a cohort of people with TB in 12 intervention operational districts (ODs) and 12 control ODs between November 2018 and December 2019 were analyzed. Two ACF interventions (ACF seed-and-recruit (ACF SAR) model and one-off roving (one-off) ACF) were implemented concurrently. The matched control sites included PCF only. We estimated costs using the program and published data in Cambodia. The primary outcome was disability-adjusted life years (DALY) averted over 14 months. We considered the gross domestic product per capita of Cambodia in 2018 as the cost-effectiveness threshold. ACF SAR needed to test 7.7 people with presumptive TB to identify one all-forms TB, while one-off ACF needed to test 22.4. The costs to diagnose one all-forms TB were USD 458 (ACF SAR) and USD 191 (one-off ACF). The incremental cost per DALY averted was USD 257 for ACF SAR and USD 204 for one-off ACF. Community-based ACF interventions that targeted key populations for TB in Cambodia were highly cost-effective.

Anal human papillomavirus prevalence and risk factors among men who have sex with men in Vietnam.

OBJECTIVES: Men who have sex with men (MSM) are at risk of human papillomavirus (HPV)-related cancers, while published data are scarce. This study determined HPV prevalence and risk factors in MSM in Vietnam to inform HPV prevention strategies in this key population. METHODS: A cross-sectional study of 799 MSM aged 16-50 years was conducted in Vietnam in 2017-2018. Information was collected on risk behaviours, and knowledge of HPV and anal cancer; rectal swabs were taken to detect anal HPV infection. An in-house polymerase chain reaction and Genoflow HPV array test kit were used for HPV detection and genotyping. RESULTS: The median age of the study participants was 25 years (range 18-52). Overall prevalence of any HPV and HPV16/18 infection was 32.3% and 11.0%, respectively. A higher prevalence of high-risk HPV infection to all 14 types tested was found in Ho Chi Minh City (30.9%) than in Hanoi (18.4%). High-risk HPV infection was associated with inconsistent condom use and history of engaging in sex under the influence of drugs (adjusted odds ratio (aOR), 2.27; 95% CI, 1.48-10.67), as well as having multiple sexual partners (aOR, 1.01; 95% CI, 1.00-1.02). CONCLUSIONS: High-risk anal HPV infections in Vietnamese MSM were significantly associated with risky sexual behaviours. A targeted HPV vaccination strategy would have substantial benefit for MSM in Vietnam.