Shared sanitation facilities and risk of respiratory virus transmission in resource-poor settings: A COVID-19 modeling case study.

Water supply and sanitation are essential household services frequently shared in resource-poor settings. Shared sanitation can increase the risk of enteric pathogen transmission due to suboptimal cleanliness of facilities used by large numbers of individuals. It also can potentially increase the risk of respiratory disease transmission. As sanitation is an essential need, shared sanitation facilities may act as important respiratory pathogen transmission venues even with strict control measures such as stay-at-home recommendations in place. This analysis explores how behavioral and infrastructural conditions surrounding shared sanitation may individually and interactively influence respiratory pathogen transmission. We developed an individual-based community transmission model using COVID-19 as a motivating example parameterized from empirical literature to explore how transmission in shared latrines interacts with transmission at the community level. We explored mitigation strategies, including infrastructural and behavioral interventions. Our review of empirical literature confirms that shared sanitation venues in resource-poor settings are relatively small with poor ventilation and high use patterns. In these contexts, shared sanitation facilities may act as strong drivers of respiratory disease transmission, especially in areas reliant on shared facilities. Decreasing dependence on shared latrines was most effective at attenuating sanitation-associated transmission. Improvements to latrine ventilation and handwashing behavior were also able to decrease transmission. The type and order of interventions are important in successfully attenuating disease risk, with infrastructural and engineering controls being most effective when administered first, followed by behavioral controls after successful attenuation of sufficient alternate transmission routes. Beyond COVID-19, our modeling framework can be extended to address water, sanitation, and hygiene measures targeted at a range of environmentally mediated infectious diseases.

Estimating the proportion of clinically suspected cholera cases that are true Vibrio cholerae infections: A systematic review and meta-analysis.

BACKGROUND: Cholera surveillance relies on clinical diagnosis of acute watery diarrhea. Suspected cholera case definitions have high sensitivity but low specificity, challenging our ability to characterize cholera burden and epidemiology. Our objective was to estimate the proportion of clinically suspected cholera that are true Vibrio cholerae infections and identify factors that explain variation in positivity. METHODS AND FINDINGS: We conducted a systematic review of studies that tested ≥10 suspected cholera cases for V. cholerae O1/O139 using culture, PCR, and/or a rapid diagnostic test. We searched PubMed, Embase, Scopus, and Google Scholar for studies that sampled at least one suspected case between January 1, 2000 and April 19, 2023, to reflect contemporary patterns in V. cholerae positivity. We estimated diagnostic test sensitivity and specificity using a latent class meta-analysis. We estimated V. cholerae positivity using a random-effects meta-analysis, adjusting for test performance. We included 119 studies from 30 countries. V. cholerae positivity was lower in studies with representative sampling and in studies that set minimum ages in suspected case definitions. After adjusting for test performance, on average, 52% (95% credible interval (CrI): 24%, 80%) of suspected cases represented true V. cholerae infections. After adjusting for test performance and study methodology, the odds of a suspected case having a true infection were 5.71 (odds ratio 95% CrI: 1.53, 15.43) times higher when surveillance was initiated in response to an outbreak than in non-outbreak settings. Variation across studies was high, and a limitation of our approach was that we were unable to explain all the heterogeneity with study-level attributes, including diagnostic test used, setting, and case definitions. CONCLUSIONS: In this study, we found that burden estimates based on suspected cases alone may overestimate the incidence of medically attended cholera by 2-fold. However, accounting for cases missed by traditional clinical surveillance is key to unbiased cholera burden estimates. Given the substantial variability in positivity between settings, extrapolations from suspected to confirmed cases, which is necessary to estimate cholera incidence rates without exhaustive testing, should be based on local data.

Trade-off Between Quarantine Length and Compliance to Optimize COVID-19 Control.

BACKGROUND: Guidance on COVID-19 quarantine duration is often based on the maximum observed incubation periods assuming perfect compliance. However, the impact of longer quarantines may be subject to diminishing returns; the largest benefits of quarantine occur over the first few days. Additionally, the financial and psychological burdens of quarantine may motivate increases in noncompliance behavior. METHODS: We use a deterministic transmission model to identify the optimal length of quarantine to minimize transmission. We modeled the relation between noncompliance behavior and disease risk using a time-varying function of leaving quarantine based on studies from the literature. RESULTS: The first few days in quarantine were more crucial to control the spread of COVID-19; even when compliance is high, a 10-day quarantine was as effective in lowering transmission as a 14-day quarantine; under certain noncompliance scenarios a 5-day quarantine may become nearly protective as 14-day quarantine. CONCLUSION: Data to characterize compliance dynamics will help select optimal quarantine strategies that balance the trade-offs between social forces governing behavior and transmission dynamics.

Enhanced cholera surveillance to improve vaccination campaign efficiency.

Systematic testing for Vibrio cholerae O1 is rare, which means that the world's limited supply of oral cholera vaccines (OCVs) may not be delivered to areas with the highest true cholera burden. Here we used a phenomenological model with subnational geographic targeting and fine-scale vaccine effects to model how expanding V. cholerae testing affected impact and cost-effectiveness for preventive vaccination campaigns across different bacteriological confirmation and vaccine targeting assumptions in 35 African countries. Systematic testing followed by OCV targeting based on confirmed cholera yielded higher efficiency and cost-effectiveness and slightly fewer averted cases than status quo scenarios targeting suspected cholera. Targeting vaccine to populations with an annual incidence rate greater than 10 per 10,000, the testing scenario averted 10.8 (95% prediction interval (PI) 9.4-12.6) cases per 1,000 fully vaccinated persons while the status quo scenario averted 6.9 (95% PI 6.0-7.8) cases per 1,000 fully vaccinated persons. In the testing scenario, testing costs increased by US$31 (95% PI 25-39) while vaccination costs reduced by US$248 (95% PI 176-326) per averted case compared to the status quo. Introduction of systematic testing into cholera surveillance could improve efficiency and reach of global OCV supply for preventive vaccination.

"They have their own people": Emotional connections, community belonging, and Chinese gay, bisexual and other men who have sex with men (GBMSM) college students' needs for sexual health support.

Gay, bisexual and other men who have sex with men (GBMSM) college students in China have unique sexual health challenges, including a higher risk of HIV infection, stigma and discrimination against LGBTQ (lesbian, gay, bisexual, transgender, and queer) population, and limited access to LGBTQ-affirmative sexual health support. Nonetheless, previous research or policymaking has rarely addressed the students' needs for sexual health support from their perspectives. This study aims to explore GBMSM college students' perceptions and attitudes to current sexual health resources, the challenges they encounter, and their expectations to acquiring LGBTQ-affirmative sexual health information and services. The exploration was carried out through field visits and in-depth interviews with 26 GBMSM college students and eight relevant stakeholders in five cities in China. Qualitative thematic analysis was applied to the interview transcripts and fieldwork memos. Four themes emerged around the preference and needs of GBMSM students in dealing with their sexual health challenges: the association between tackling sexual health challenges and entering LGBTQ communities, the roles of emotional attachment in shaping the preference for HIV-related care and support, the desired modes of acquiring sexual health support, and the current unmet service needs. We discovered that the information-and-care-seeking behaviors of GBMSM college students are highly influenced by and connected to their participation in online and in-person LGBTQ communities. Due to the overall stigmatizing sociocultural environment of LGBTQ in China, GBMSM college students tend to rely on LGBTQ communities, seeking trust and a sense of belongingness for tackling their sexual health challenges. Conventional school-based sexual health educational programs, which often apply top-down, stigma-and-fear-based, and non-LGBTQ-inclusive teaching strategies, rarely help GBMSM college students to solve sexual health problems in real life. GBMSM college students are eager to have LGBTQ-affirmative "health managers" who can understand their emotional experiences and interpersonal contexts and assist them with sexual health issues. However, such support is generally perceived as limited by the students. Our study highlights these unmet needs of the GBMSM students and emphasizes the importance of developing future LGBTQ-affirmative sexual health programs among Chinese GBMSM college students and young GBMSM in general.

Silica nanoparticles induce unfolded protein reaction mediated apoptosis in spermatocyte cells.

With increasing air pollution, silica nanoparticles (SiNPs), as a main inorganic member of PM2.5, have gained increasing attention to its reproductive toxicity. Most existing studies focused on the acute exposure, while data regarding the chronic effect of SiNPs on reproduction is limited. Therefore, this study was designed to evaluate the chronic toxicity of SiNPs on spermatocyte cells. The cells were continuously exposed to SiNPs for 1, 10, 20 and 30 generations at dose of 5 µg/ml SiNPs for 24 h per generation after attachment. The results showed that with the increasing generations of the exposure, SiNPs decreased the viability of spermatocyte cells, induced apoptosis and increased the level of reactive oxygen species in spermatocyte cells. Moreover, SiNPs increased the protein expression of GRP-78, p-PERK, IRE1α, ATF6 and Cleaved caspase-3 in spermatocyte cells, suggesting that SiNPs improved unfolded protein response (UPR) and apoptosis. The present results indicated that the long-term and low-dose exposure to SiNPs could induce apoptosis by triggering ROS-mediated UPR in spermatocyte cells.

The association between work related factors and breastfeeding practices among Chinese working mothers: a mixed-method approach.

Background: Breastfeeding rates remain low in China and some mothers stop breastfeeding shortly after returning to work. Our study aimed to investigate the association between breastfeeding practices of working mothers and their employment status (formal versus informal) and occupational fields (agriculture related, industry related, and business and white collar). We also identified key work-related factors that influence breastfeeding practices in Chinese working mothers. Methods: This is a mixed-method research consisted of two components. We conducted a cross-sectional study of 10,408 breastfeeding mothers with children under 12 months old from 12 regions in China from July 2017 to January 2018. Multiple logistic regression was used to calculate adjusted odds ratios (AdjORs) and 95% confidence intervals (CIs) for breastfeeding practices. For the qualitative component, semi-structured interviews were conducted with 84 breastfeeding mothers in the study areas from July to December 2017, Content analysis was used for the qualitative component. Results: Agriculture related occupations were positively associated with early initiation of breastfeeding (AdjOR 1.32, 95% CI 1.15, 1.51), current breastfeeding (AdjOR 1.76, 95% CI 1.41, 2.20), ever breastfed (AdjOR 1.69, 95% CI 1.09, 2.62), exclusive breastfeeding (AdjOR 1.30, 95% CI: 1.04, 1.62), and predominant breastfeeding (AdjOR 1.72, 95% CI 1.44, 2.05). Business and white collar occupations were positively associated with early initiation (AdjOR1.38, 95% CI 1.23, 1.56) and ever breastfed (AdjOR 1.64, 95% CI 1.12, 2.39), and inversely associated with predominant breastfeeding (AdjOR 0.81, 95% CI 0.68, 0.95). For industry related and business and white collar occupations, informal employment was negatively related to current breastfeeding. In qualitative analysis, four main themes were developed to identify key work-related factors that influence breastfeeding practices: 1) employment benefits; 2) commute time; 3) workplace environment; 4) labor intensity. Mothers who experienced difficulties in one or more of the above would choose to lower breastfeeding frequency or stop breastfeeding. Conclusions: Having flexible work schedules and proximity of workplace to home can assist continuance of breastfeeding. Policies promoting supportive breastfeeding environment at work ought to be implemented. Additionally, informally employed mothers require more attention due to limited legal protection.