ABSTRACT
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.
ABSTRACT
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.
