An Outbreak of Rubella aboard a Ship of the German Navy

Abstract

Background: During May and June 1996, an outbreak of rubella occurred offshore aboard a ship of the German Navy. The outbreak spread among 330 crew members over a period of 9 weeks, ending 2 days after the ship's return. This is the first detailed epidemiological investigation of a rubella outbreak on a ship, describing temporal progression, clinical manifestations, immunization status and seroprevalence of the population exposed. Patients and Methods: Outbreak investigation using a questionnaire, health records and rubella serology (hemagglutination inhibition (HI) test and EIA). Results: Of the 330 crew members 298 (90%) participated in the investigation. The outbreak was continuous without a peak and ended abruptly after the ship's return. It resulted in 20 cases, 11 of which were clinically symptomatic. A total of 35 (12%) crew members were susceptible to rubella prior to the outbreak, resulting in an attack rate of 57%. The highest risk for infection was linked to accommodation aboard the ratings deck ( 2 -test, p = 0.004) with most favorable conditions of transmission. Only 9% of the participating crew were able to provide complete proof of their immunization status. The positive predictive value of a past history of rubella for the presence of antibodies against rubella was 59%. Conclusion: The transmission of rubella that we describe aboard a ship was facilitated by the unusually close proximity of the crew and their insufficient immunity.

A Systematic Review for Vaccine-Preventable Diseases on Ships: Evidence for Cross-Border Transmission and for Pre-Employment Immunization Need

“…It should be noted that the two highest attack rates (4% and 6%) were derived from sero-surveys after confirmed rubella outbreaks, which included asymptomatic cases (approx. 50% of cases in both studies); the highest attack (6%) was for a rubella outbreak on a Navy ship where no control measures were documented and the outbreak only ended after the ship’s return [3]. The mumps outbreak had a crew attack rate of 4%, and a crew attack rate of 2.4% was calculated from the data available for the measles outbreak in 2014 [31].…”

“…For the 2014 measles outbreak on a cruise ship, as of 10 March 2014, there were 29 laboratory confirmed cases, 80% ( n = 23) of the cases were crew [3,31]. Twenty-three of the 968 crew (2.4%) and six of approximately 3352 passengers (0.2%) became infected with measles over a three-week period.…”

“…Half of the outbreaks involving crew (7/14, 50%) documented the vaccination history or susceptibility rate of crew members and all found insufficient vaccination and/or documentation (Table 1). In all three rubella outbreaks, a substantial proportion of crew were found to have negative or no documentation of rubella vaccination or immunity (75%, 81%, and 96%, respectively) [3,34]. In the measles 2014 outbreak, 85% of all crew and 21/24 cases (87.5%) had a negative or unknown vaccination history [28].…”

“…Ships are long acknowledged as semi-closed and densely populated environments with close living and sleeping quarters, and shared water, ventilation and sewage systems [1,2,3]. Such environments are accountable to a constant flux of people from over the world and conducive for the spread of communicable diseases.…”

Outbreak of Rubella Among Cadets in an Academy

“…Jirous and Machula [13], have reported increasing incidence of rubella in the Czech Army. Ziebold et al [14], have reported an outbreak of rubella aboard a German ship having 12% susceptible sailors prior to the outbreak. The short review indicates that among militaries of different countries susceptibility varies, so does the vaccination policy.…”