No abstract

Universities are faced with decisions on how to resume campus activities while mitigating SARS-CoV-2 risk. To provide guidance for these decisions, we developed an agent-based network model of SARS-CoV-2 transmission to assess the potential impact of strategies to reduce outbreaks. The model incorporates important features related to risk at the University of California San Diego. We found that structural interventions for housing (singles only) and instructional changes (from in-person to hybrid with class size caps) can substantially reduce R0, but masking and social distancing are required to reduce this to at or below 1. Within a risk mitigation scenario, increased frequency of asymptomatic testing from monthly to twice weekly has minimal impact on average outbreak size (1.1-1.9), but substantially reduces the maximum outbreak size and cumulative number of cases. We conclude that an interdependent approach incorporating risk mitigation, viral detection, and public health intervention is required to mitigate risk.

Background Cluster randomized trials have been utilized to evaluate the effectiveness of human immunodeficiency virus (HIV) prevention strategies on reducing incidence. Design of such studies must take into account possible correlation of outcomes within randomized units. Purpose To discuss power and sample size considerations for cluster randomized trials of combination HIV prevention, using an HIV prevention study in Botswana as an illustration. Methods We introduce a new agent-based model to simulate the community-level impact of a combination prevention strategy and investigate how correlation structure within a community affects the coefficient of variation–an essential parameter in designing a cluster randomized trial. Results We construct collections of sexual networks and then propagate HIV on them to simulate the disease epidemic. Increasing level of sexual mixing between intervention and standard of care communities reduces the difference in cumulative incidence in the two sets of communities. Fifteen clusters per arm and 500 incidence cohort members per community provides 95% power to detect the projected difference in cumulative HIV incidence between standard of care and intervention communities (3.93% and 2.34%) at the end of the third study year, using a coefficient of variation 0.25. Although available formulas for calculating sample size for cluster randomized trials can be derived by assuming an exchangeable correlation structure within clusters, we show that deviations from this assumption do not generally affect the validity of such formulas. Limitations We construct sexual networks based on data from Likoma Island, Malawi and base disease progression on longitudinal estimates from an incidence cohort in Botswana and in Durban as well as a household survey in Mochudi, Botswana. Network data from Botswana and larger sample sizes to estimate rates of disease progression would be useful in assessing the robustness of our model results. Conclusions Epidemic modeling plays a critical role in planning and evaluating interventions for prevention. Simulation studies allow us to take into consideration available information on sexual network characteristics, such as mixing within and between communities as well as coverage levels for different prevention modalities in the combination prevention package.

IMPORTANCE The management of noncommunicable diseases in humanitarian crises has been slow to progress from episodic care. Understanding disease burden and access to care among crisisaffected populations can inform more comprehensive management. OBJECTIVE To estimate the prevalence of hypertension and diabetes with biological measures and to evaluate access to care among Syrian refugees in northern Jordan. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study was undertaken from March 25 to April 26, 2019, in the districts of Ramtha and Mafraq, Jordan. Seventy clusters of 15 households were randomly sampled, and chain referral was used to sample Syrian households, representative of 59 617 Syrian refugees. Adults were screened and interviewed about their access to care. Data analysis was performed from May to September 2019. EXPOSURES Primary care delivered through a humanitarian organization since 2012. MAIN OUTCOMES AND MEASURES The main outcomes were self-reported prevalence of hypertension and diabetes among adults aged 18 years or older and biologically based prevalence among adults aged 30 years or older. The secondary outcome was access to care during the past month among adults aged 18 years or older with a diagnosis of hypertension or diabetes. RESULTS In 1022 randomly sampled households, 2798 adults aged 18 years or older, including 275 with self-reported diagnoses (mean [SD] age, 56.5 [13.2] years; 174 women [63.3%]), and 915 adults aged 30 years or older (608 women [66.5%]; mean [SD] age, 46.0 [12.8] years) were screened for diabetes and hypertension. Among adults aged 18 years or older, the self-reported prevalence was 17.2% (95% CI, 15.9%-18.6%) for hypertension, 9.8% (95% CI, 8.6%-11.1%) for diabetes, and 7.3% (95% CI, 6.3%-8.5%) for both conditions. Among adults aged 30 years or older, the biologically based prevalence was 39.5% (95% CI, 36.4%-42.6%) for hypertension, 19.3% (95% CI, 16.7%-22.1%) for diabetes, and 13.5% (95% CI, 11.4%-15.9%) for both conditions. Adjusted for age and sex, prevalence for all conditions increased with age, and women had a higher prevalence of diabetes than men (adjusted prevalence ratio, 1.3%; 95% CI, 1.0%-1.7%), although the difference was not significant. Complications (57.4%; 95% CI, 51.5%-63.1%) and obese or overweight status (82.8%; 95% CI, 79.7%-85.5%) were highly prevalent. Among adults aged 30 years or older with known diagnoses, 94.1% (95% CI, 90.9%-96.2%) currently took medication. Among adults aged 18 years or older with known diagnoses, 26.8% (95% CI, 21.3%-33.1%) missed a medication dose in the past week, and 49.1% (95% CI, 43.3%-54.9%) sought care in the last month. CONCLUSIONS AND RELEVANCE During this protracted crisis, obtaining care for noncommunicable diseases was feasible, as demonstrated by biologically based prevalence that was (continued)