Although the spread of disease on board Navy ships is not a novel concept, the medical department of the USS THEODORE ROOSEVELT recently experienced a significant outbreak of viral gastroenteritis while at sea. The impact on the crew and medical department is reviewed in this case report. The use of the Navy Disease Non-Battle Injury tracking system was validated. Furthermore, we proposed the placement of waterless, isopropyl alcohol-based, hand-cleaning systems in strategic locations throughout the ship, to help prevent and minimize the spread of future disease. Finally, more stringent recommendations regarding sick in quarters status and careful utilization of consumable resources are necessary components of an effective outbreak management strategy.
A shipboard microcosm provides a unique challenge for the logistical management and treatment of an outbreak of viral gastroenteritis. The media recently drew attention to several outbreaks of viral gastroenteritis on board commercial cruise ships.1 Naval vessels, however, are not exempt from such outbreaks. Historically, the close proximity of working and living spaces on board all seagoing vessels enhanced the propensity for diseases to spread from individual to individual. In the 185Os, during the Hamburg emigration, "three diseases in particular were rampant on ships: cholera, typhus, and smallpox."2
The crew of the USS THEODORE ROOSEVELT (CVN-71) recently experienced an outbreak of viral gastroenteritis while at sea. The medical department's effective and professional management of supplies, documentation, and prevention are reviewed, with the hope of presenting an organized framework of management and treatment that can be applied to future outbreaks.
The medical department aboard the USS THEODORE ROOSEVELT uses the Navy's Disease Non-Battle Injury System of diagnostic categorization. This system assigns codes to 18 general diagnostic categories to track the incidence of disease on the ship. For every patient examined on board the ship, the diagnosis is categorized with one of these 18 Joint Service (JS) codes. On a daily basis, the codes are tallied and compared against normal baseline values. A twofold increase from the baseline value indicates the possibility of an outbreak and requires additional investigation. Code JS3 refers to the "gastrointestinal infectious" category. On average, the medical department of the THEODORE ROOSEVELT notes six JS3 diagnoses per day. On December 12, 2002, while the ship was underway off the coast of Virginia, there was a noticeable increase in the number of cases in the JS3 category. Figure 1 clearly demonstrates the ensuing incidence curve. It is important to note the regularly scheduled return of the ship to home port on December 19, 2002.
Patients typically experienced 2 to 3 hours of nausea, followed by several bouts of nonbloody nonbilious emesis. Loose nonbloody diarrhea was associated with the emesis. These symptoms were soon followed by mid-grade fever and frequently incapacitating myalgias, arthralgias, abdominal cramping, malaise, anorexia, and apathy. The symptoms generally resolved within 24 hours.
The patients were initially examined by a triage corpsman, who recorded an entry set of vital signs and documented a chief complaint. If the patients complained of nausea, emesis, or diarrhea, they were sent immediately to the treatment room, where a designated provider obtained more history, completed a primary physical examination, and, if necessary, performed a set of orthostatic blood pressure measurements. This information was recorded on a preprinted form (Fig. 2). If the patients demonstrated signs of orthostasis, abaseline fever of >101.5°F, tachycardia of >110 beats/minute, or intractable vomiting, they were transferred to the ward for observation, intravenous fluid administration, and antiemetic/antidiarrheal therapy. If the patients had only mild symptoms, they were typically given oral antiemetic and antidiarrheal medication and placed on light duty status. Any patient with worsening abdominal pain, hematochezia, or hematemesis was evaluated by the General Surgeon. After administration of 2 L of lactated Ringer's solution, each patient was reevaluated and was discharged if stable or improving. If necessary, additional treatment was administered until the patients met the discharge criteria. Specifically, we looked for a temperature of
Although this outbreak placed a significant strain on the medical department personnel and medical supply system, the medical department of the THEODORE ROOSEVELT successfully treated and evaluated all patients, with no long-term morbidity and no deaths. In the 15 days from December 5, 2002 to December 19, 2002, 451 cases of viral gastroenteritis were diagnosed and treated. This was in addition to the 506 patients examined in regular medical department visits. In total,
The success of the medical department was not without effort or cost. The crew of 45 corpsmen and 9 providers often worked around the clock, in double shifts, to provide the necessary care. With 48% of the medical department also affected by this virus, an even greater burden was placed on the remaining personnel. Table I demonstrates the monetary cost of the significant amounts of supplies that were used. Even more notable was the fact that this single outbreak nearly exhausted the department's supply of promethazine (Phenergan, Wyeth Pharmaceuticals, Madison, NJ), prochlorperazine (Compazine, GlaxoSmithKline, Philadelphia, PA), and loperamide (Imodium, Janssen Pharmaceutica, Titusville, NJ). One-third of the ship's total intravenous fluid supply was used. Supply rationing was a critical aspect of the logistical management. For example, the department quickly realized that the 24-hour nature of the virus allowed patients to be discharged with prescriptions for two loperamide tablets, rather than the six tablets that were typically dispensed. Antiemetic drug administration was also closely regulated and appropriately rationed.
The medical department found that development of the form in Figure 2 facilitated appropriate documentation of each patient's care. Furthermore, its standardized approach optimized the treatment of individual patients while minimizing the potential for a missed diagnosis, such as appendicitis. The stepwise patient flow path from the triage desk to discharge also minimized potential patient morbidities with a systematic treatment algorithm.
As important as the effect on the medical department was the effect on the ship's overall level of functioning. Fortunately, the 24-hour nature of this virus facilitated the rapid return of personnel to their duties. However, a documented 158 sailor-days worth of work were lost to sick in quarters (SIQ) status during the stated time period. Obviously, the comparatively small number of lost work days was attributable to the efficient treatment and return to work of the majority of affected sailors. Typically, only patients ill enough to require treatment on the ward were placed on SIQ status. These numbers do not reflect the additional lost work time secondary to the ill sailors' inefficiency or individual departments' decisions to release sailors from their duties because of illness. Some divisions were reduced to 50% of their staff for brief periods of time. It was only through the hard work and perseverance of the sailors that the ship was able to maintain its high level of functioning.
Navy Environmental and Preventative Medicine Unit 2 recommended 48 hours of SIQ status for all affected sailors during this specific gastroenteritis outbreak. Although this would have provided additional isolation of the affected sailors from the healthy sailors, with the potential to limit the spread of disease, the workforce reduction could have had staggering effects on the ship's mission. However, a review of Figure 1 demonstrates a gradual increase in incidence until day 12, when a significant spike occurred. It is possible that stricter isolation of patients in the preceding 11 days might have prevented the day 12 spike.
From the epidemiological standpoint, the logistics of shipboard life impose unique challenges for the management of this type of infectious outbreak. It had been
The medical department quickly realized the critical importance of personal hygiene for the prevention of disease spread. This information was passed to all crew members through several routes, including the ship's daily newspaper and closedcircuit television system. Several recent studies'1"5 demonstrated the effectiveness of waterless, isopropyl alcohol-based hand cleansers in the prevention of disease spread within a hospital setting. "During routine patient care handrubbing with an alcohol based solution is significantly more efficient in reducing hand contamination than handwashing with antiseptic soap."5 Because of the logistical difficulties of handwashing before meals for the thousands of sailors who move through the mess decks on a daily basis, the medical department is currently evaluating the placement of these waterless hand-cleaning systems in strategic locations around the mess decks and in the bathrooms.
In conclusion, the experience of the THEODORE ROOSEVELT with this outbreak of viral gastroenteritis provided learning points that may be applicable to other seagoing vessels. It clearly validated the use of the Navy's Disease NonBattle Injury tracking system to warn of and track disease categories. Impending outbreaks can be identified early and hopefully managed aggressively from the onset. Vigilance with medical and crew hygiene practices must be continuously pursued. The widespread use of waterless, isopropyl alcohol-based, hand-cleaning systems placed in strategic locations should receive further consideration. Despite an initial effect on the ship's workforce, stricter adherence to the 48-hour SIQ recommendation of Navy Environmental and Preventative Medicine Unit 2 might limit future outbreaks. Only a formal prospective study could clearly demonstrate the benefit of this intervention. Finally, it was learned that highquality effective care could be provided to large numbers of patients while limited amounts of consumable resources were considered.
1. Charatan F: Viral gastroenteritis sickens hundreds on cruise ships. BMJ 2002; 325: 1192.
2. Bowen CG (editor): Emigration from Hamburg. Available at http://blacklake.biz/ meck/hambrg.htm; accessed March 1, 2003.
3. Hugonnet S, Perneger TV, Pittet D: Alcohol-based handrub improves compliance with hand hygiene in intensive care units. Arch Intern Med 2002; 162: 1037-43.
4. Guilhermetti M, Hernandes SE, Fukushigue Y, Garcia LB, Cardoso CL: Effectiveness of hand-cleansing agents for removing methicillin-resistant Staphylococcus aureus from contaminated hands. Infect Control Hosp Epidemiol 2001; 22: 105-8.
5. Girou E, Loyeau S, Legrand P, Oppein F, Brun-Buisson C: Efficacy of handrubbing with alcohol based solution versus standard handwashing with antiseptic soap: randomized clinical trial. BMJ 2002; 325: 362.
Guarantor: LCDR David R. Whittaker, MC USNR
Contributors: LCDR David R. Whittaker, MC USNR; LT James E. Callan, MC USNR; LT Jerome T. Campbell MSC USN; CAPT Michael D. McCarten, MC USN
Medical Department, USS THEODORE ROOSEVELT, FPO AE 09599-2871.
This manuscript was received for review in March 2003. The revised manuscript was accepted for publication in September 2003.
Copyright Association of Military Surgeons of the United States Sep 2004
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