Implementation of a Web-Based Symptom Checker to Manage the Quarantine of the USS Theodore Roosevelt Crew Following a Shipboard Outbreak of SARS-CoV-2

Fenequito, R. L.; Houskamp, D.; Siu, V.; Rorie, J.; Bhatt, N.; Kuang, M.; Luartes, B.; Shell, D.; Reeder, J.; Rainey, K.; Olson, N.

Introduction: In late March 2020, the USS Theodore Roosevelt (TR), a nuclear-powered aircraft carrier, pulled into port in the US territory of Guam to assess the severity of a developing outbreak of COVID-19 aboard the ship. A small staff contingent of 60 personnel from US Naval Hospital (USNH) Guam was tasked with the medical care of 4,079 sailors who were placed in single room quarantine amongst 11 hotels across the island of Guam. With the assistance of the Defense Digital Service, the USNH Guam staff implemented a web-based symptom checker, which allowed for monitoring of developing COVID symptoms, and selective testing of symptomatic individuals. Materials and Methods: Sailors from the TR were placed in quarantine or isolation cohorts upon debarking the ship. Sailors not positive for COVID-19 were quarantined amongst 11 hotels on Guam. Sailors positive for COVID-19 were isolated aboard Naval Base Guam (NBG). A retrospective cohort analysis and subgroup analyses were performed on symptom data obtained from sailors in quarantine. The sailors recorded their symptoms and temperature in a web-based symptom checker that assigned a symptom severity score (SSS). Sailors with a SSS >50 were evaluated by a medical provider and re-tested. Data were collected from 4 April 2020 to 1 May 2020. Sailors required two negative tests to exit quarantine and re-embark the ship. The time course, and most common cluster of symptoms associated with a positive COVID-19 PCR test were determined retrospectively after data collection. Results: The web-based symptom checker was successful in establishing daily positive contact and symptom monitoring of susceptible individuals in quarantine. 4,079 sailors in quarantine maintained positive contact with medical staff via the symptom checker, with at least 81% of the sailors recording their symptoms on a daily basis. Individuals with high symptom scores were quickly identified and underwent further evaluation and repeat COVID-19 testing. A cohort of 331 sailors tested positive for COVID-19 while in quarantine and recorded symptoms in the symptom checker before and after a positive COVID-19 test. In this cohort, the most frequent symptoms reported prior to a positive test were headache, anosmia, followed by cough. The symptom of anosmia was reported more frequently in sailors positive for COVID-19, compared to a cohort of matched controls. A small medical staff was able to monitor developing symptoms in a large quarantined population, while efficiently allocating resources, preserving personal protective equipment (PPE), and maintaining isolation and social distancing protocols. Conclusions and Relevance: The application provided a tool for broad health surveillance over a large population while maintaining strict quarantine and social distancing protocols. Highly symptomatic sailors were quickly identified, triaged, and transferred to a higher level of care if indicated. The symptom checker and predictive model generated from the data can be utilized by military and civilian public health officials to triage large populations and make rapid decisions on isolation measures, resource allocation, selective testing.