The Epidemiology of Operation Stress during Continuing Promise 2011: A Humanitarian Response and Disaster Relief Mission aboard a US Navy Hospital Ship.

Introduction Operational stress describes individual behavior in response to the occupational demands and tempo of a mission. The stress response of military personnel involved in combat and peace-keeping missions has been well-described. The spectrum of effect on medical professionals and support staff providing humanitarian assistance, however, is less well delineated. Research to date concentrates mainly on shore-based humanitarian missions. Problem The goal of the current study was to document the pattern of operational stress, describe factors responsible for it, and the extent to which these factors impact job performance in military and civilian participants of Continuing Promise 2011 (CP11), a ship-based humanitarian medical mission. METHODS: This was a retrospective study of Disease Non-Battle Injury (DNBI) data from the medical sick-call clinic and from weekly self-report questionnaires for approximately 900 US military and civilian mission participants aboard the USNS COMFORT (T-AH 20). The incidence rates and job performance impact of reported Operational Stress/Mental Health (OS/MH) issues and predictors (age, rank, occupation, service branch) of OS/MH issues (depression, anxiety) were analyzed over a 22-week deployment period. RESULTS: Incidence rates of OS/MH complaints from the sick-call clinic were 3.7% (4.5/1,000 persons) and 12.0% (53/1,000 persons) from the self-report questionnaire. The rate of operational stress increased as the mission progressed and fluctuated during the mission according to ship movement. Approximately 57% of the responders reported no impact on job performance. Younger individuals (enlisted ranks E4-6, officer ranks O1-3), especially Air Force service members, those who had spent only one day off ship, and those who were members of specific directorates, reported the highest rates of operational stress. CONCLUSION: The overall incidence of OS/MH complaints was low in participants of CP11 but was under-estimated by clinic-based reporting. The OS/MH complaints increased as the mission progressed, were more prevalent in certain groups, and appeared to be related to ship's movement. These findings document the pattern of operational stress in a ship-based medical humanitarian mission and confirm unique ship-based stressors. This information may be used by planners of similar missions to develop mitigation strategies for known stressors and by preventive medicine, behavioral health specialists, and mission leaders to develop sensitive surveillance tools to better detect and manage operational stress while on mission. Scouten WT , Mehalick ML , Yoder E , McCoy A , Brannock T , Riddle MS . The epidemiology of operation stress during Continuing Promise 2011: a humanitarian response and disaster relief mission aboard a US Navy hospital ship. Prehosp Disaster Med. 2017;32(4):393-402.

Incidence, Etiology and Risk Factors for Travelers' Diarrhea during a Hospital Ship-Based Military Humanitarian Mission: Continuing Promise 2011.

Travelers' diarrhea (TD) is the most common ailment affecting travelers, including deployed U.S. military. Continuing Promise 2011 was a 5-month humanitarian assistance/disaster response (HA/DR) military and non-governmental organization training mission aboard the hospital ship USNS Comfort, which deployed to Central and South America and the Caribbean between April and September 2011. Enhanced TD surveillance was undertaken during this mission for public health purposes. Passive surveillance (clinic visits), active surveillance (self-reported questionnaires), and stool samples were collected weekly from shipboard personnel. Descriptive statistics and multivariate-logistic regression methods were used to estimate disease burden and risk factor identification. Two polymerase chain reaction methods on frozen stool were used for microbiological identification. TD was the primary complaint for all clinic visits (20%) and the leading cause of lost duties days due to bed rest confinement (62%), though underreported, as the active self-reported incidence was 3.5 times higher than the passive clinic-reported incidence. Vomiting (p = 0.002), feeling lightheaded or weak (p = 0.005), and being a food handler (p = 0.017) were associated with increased odds of lost duty days. Thirty-eight percent of self-reported cases reported some amount of performance impact. Based on the epidemiological curve, country of exercise and liberty appeared to be temporally associated with increased risk. From the weekly self-reported questionnaire risk factor analysis, eating off ship in the prior week was strongly associated (adjusted odds ratio [OR] 2.4, p<0.001). Consumption of seafood increased risk (aOR 1.7, p = 0.03), though consumption of ice appeared protective (aOR 0.3, p = 0.01). Etiology was bacterial (48%), with enterotoxigenic Escherichia coli as the predominant pathogen (35%). Norovirus was identified as a sole pathogen in 12%, though found as a copathogen in an additional 6%. Despite employment of current and targeted preventive interventions, ship-board HA/DR missions may experience a significant risk for TD among deployed US military personnel and potentially impact mission success.

Incidence and risk factors for disease and non-battle injury aboard the hospital ship USNS COMFORT during a Humanitarian Assistance and Disaster Response Mission, Continuing Promise 2011.

BACKGROUND: Disease and non-battle injury (DNBI) are a leading cause of morbidity in deployments and can compromise operational mission performance. No study to date has examined DNBI incidence and impact aboard humanitarian aid/disaster response (HADR) mission ships. METHODS: From April to September 2011, US military and civilian personnel participated in Continuing Promise 2011, a HADR training mission aboard USNS COMFORT (T-AH 20). Health surveillance was conducted for the purpose of assessing DNBI trends and improving force health protection during the deployment through passive surveillance, collection of DNBI data among those seeking care at the ship's clinic, and actively through use of an anonymous weekly, self-report questionnaire. Categorical and total DNBI incidence rates were calculated per 100 person-weeks and incidence rate ratios (IRR) were calculated utilizing a negative binomial model to assess potential risk factors. RESULTS: The leading syndrome-specific cause of weekly visits to the ship's clinic was gastrointestinal (GI) followed by dermatologic and respiratory conditions (2.22, 1.97, and 1.46 cases per 100 person-weeks, respectively). The top three categorical DNBI were similarly represented by the questionnaire, with respiratory conditions having the highest reported rate followed by dermatologic and GI (11.79, 8.71, and 7.38 cases per 100 person-weeks, respectively). GI had the highest morbidity measures accounting for 61.9 % of lost work days and 27.3 % of reported moderate/severe impact to mission performance. Several factors were also associated with increased DNBI rates including personnel ages 26-36 (IRR = 1.23), officers (IRR = 1.23), days-off-ship (IRR = 1.09), and affiliation with nursing services (IRR = 1.48), naval mobile construction battalion (IRR = 3.17), and security (IRR = 1.71). CONCLUSIONS: DNBI can significantly impact mission performance on HADR missions, and establishing baseline rates and identifying risk factors can help improve force health protection in future HADR missions.