Notional Spread of Cholera in Haiti Following a Natural Disaster: Considerations for Military and Disaster Relief Personnel.

INTRODUCTION: Cholera remains a significant public health threat for many countries, and the severity largely varies by the population and local conditions that drive disease spread, especially in endemic areas prone to natural disasters and flooding. Epidemiological models can provide useful information to military planners for understanding disease spread within populations and the effectiveness of response options for preventing the transmission among deployed and stationed personnel. This study demonstrates the use of epidemiological modeling to understand the dynamics of cholera transmission to inform emergency planning and military preparedness in areas with highly communicable diseases. MATERIALS AND METHODS: Areas with higher probability for a potential cholera outbreak in Haiti followed by a natural disaster were identified. The hotspots were then used to seed an extended compartmental model, EpiGrid, to simulate notional spread scenarios of cholera originating in three distinct areas in Haiti. Disease parameters were derived from the 2010 cholera outbreak in Haiti, and disease spread was simulated over a 12-week period under uncontrolled and controlled spread. RESULTS: For each model location, scenarios of mitigated (intervention with 30% transmission reduction via international aid) and unmitigated (without intervention) are simulated. The results depict the geographical spread and estimate the cumulative cholera infection for each notional scenario over the course of 3 months. Disease transmission differs considerably across origin site with an outbreak originating in the department of Nippes spanning the largest geographic area and resulting in the largest number of cumulative cases after 12 weeks under unmitigated (79,518 cases) and mitigated (35,667 cases) spread scenarios. CONCLUSIONS: We modeled the notional re-emergence and spread of cholera following the August 2021 earthquake in Haiti while in the midst of the global COVID-19 pandemic. This information can help guide military and emergency response decision-making during an infectious disease outbreak and considerations for protecting military personnel in the midst of a humanitarian response. Military planners should consider the use of epidemiological models to assess the health risk posed to deployed and stationed personnel in high-risk areas.

A Universal Travel Risk Assessment Questionnaire: Travel Assessment During COVID-19 Pandemic and Endemicity.

INTRODUCTION: Throughout the Coronavirus Disease 2019 (COVID-19) pandemic, military commanders have been challenged with providing appropriate travel guidance for their military and civilian personnel and dependents. This guidance, where promulgated, lacks uniformity. Travel aids and computer applications similarly differ and are not updated as often as jurisdictional travel health guidance is changed. Given the ever-evolving Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants with differing degrees of infectivity, COVID-19 travel guidance will remain relevant for military travelers during the transition from pandemic to endemic phases and for the foreseeable future. MATERIALS AND METHODS: We reviewed all germane travel guidance promulgated by the U.S, Department of Defense; the U.S. Centers for Disease Control and Prevention; and other federal, state, and international agencies. From these materials, we identified and delineated applicable universal components for COVID-19 travel risk and created a universal Travel Risk Assessment Questionnaire (TRAQ). RESULTS: We present a universal TRAQ that identifies and allows for a graded most-appropriate response to known travel risk assessment factors including travel restrictions, travel mode, travel time, travel party size, trip duration, COVID-19 incidence rate at travel destination, lodging, planned activities, personal interaction level, vaccination coverage at destination, travel location, traveler's vaccination status, previous COVID-19 infection, mask wear compliance, mask type, and work environment, along with additional considerations and post-travel COVID-19 questions. We provide examples of the use of this questionnaire that describe low, medium, and high risk to the traveler for contracting COVID-19. CONCLUSION: Our TRAQ provides an easy-to-use format that can enable military, business, or personal travelers to more completely assess their likelihood of COVID-19 exposure and help them to reduce their potential for contracting COVID-19 during travel and subsequently transmitting it to others upon return. It should help commanders and traveling personnel to better assess COVID-19 travel risks through application of known travel risk factors.

Operational Considerations in Global Health Modeling.

Epidemiological modeling and simulation can contribute cooperatively across multifaceted areas of biosurveillance systems. These efforts can be used to support real-time decision-making during public health emergencies and response operations. Robust epidemiological modeling and simulation tools are crucial to informing risk assessment, risk management, and other biosurveillance processes. The Defense Threat Reduction Agency (DTRA) has sponsored the development of numerous modeling and decision support tools to address questions of operational relevance in response to emerging epidemics and pandemics. These tools were used during the ongoing COVID-19 pandemic and the Ebola outbreaks in West Africa and the Democratic Republic of the Congo. This perspective discusses examples of the considerations DTRA has made when employing epidemiological modeling to inform on public health crises and highlights some of the key lessons learned. Future considerations for researchers developing epidemiological modeling tools to support biosurveillance and public health operations are recommended.

Coronavirus Disease 2019 on the Heels of Ebola Virus Disease in West Africa.

This study utilized modeling and simulation to examine the effectiveness of current and potential future COVID-19 response interventions in the West African countries of Guinea, Liberia, and Sierra Leone. A comparison between simulations can highlight which interventions could have an effect on the pandemic in these countries. An extended compartmental model was used to run simulations incorporating multiple vaccination strategies and non-pharmaceutical interventions (NPIs). In addition to the customary categories of susceptible, exposed, infected, and recovered (SEIR) compartments, this COVID-19 model incorporated early and late disease states, isolation, treatment, and death. Lessons learned from the 2014-2016 Ebola virus disease outbreak-especially the optimization of each country's resource allocation-were incorporated in the presented models. For each country, models were calibrated to an estimated number of infections based on actual reported cases and deaths. Simulations were run to test the potential future effects of vaccination and NPIs. Multiple levels of vaccination were considered, based on announced vaccine allocation plans and notional scenarios. Increased vaccination combined with NPI mitigation strategies resulted in thousands of fewer COVID-19 infections in each country. This study demonstrates the importance of increased vaccinations. The levels of vaccination in this study would require substantial increases in vaccination supplies obtained through national purchases or international aid. While this study does not aim to develop a model that predicts the future, it can provide useful information for decision-makers in low- and middle-income nations. Such information can be used to prioritize and optimize limited available resources for targeted interventions that will have the greatest impact on COVID-19 pandemic response.