In February 2009, a cluster of rubella cases was recognized in Austria occurring between calendar weeks 3 and 7, 2009 after a long period of low rubella virus activity. A nationwide 2-dose measles, mumps, and rubella vaccination program had been introduced in 1994 to prevent this childhood illness.
An epidemiologic investigation was conducted to describe the cluster by time, place, and person. A confirmed outbreak case was defined as a febrile person (1) with generalized rash, which was laboratory confirmed or epidemiologically linked to a laboratory confirmed case and (2) who became ill after October 1, 2008 in the 2 affected provinces. A probable outbreak case was defined as any person meeting the clinical criteria of rubella and meeting the criterion 2 of a confirmed outbreak case. All cases were telephone interviewed on demographics and vaccination status.
A total of 355 outbreak cases (including 247 confirmed cases) occurred in 2 neighboring Austrian provinces from mid-October 2008 until the end of June 2009, peaking in mid-March. The 2 most-affected age groups were 15 to 19 (44.4%) and 20 to 24 year olds (32.4%). The vaccination status was available for 230 cases; 10% of cases had received 1 measles, mumps, and rubella vaccine dose. No case had received 2 doses. Of the 146 female cases, one laboratory-confirmed rubella infection in a pregnant 18-year-old native Austrian resulted in elective abortion.
These findings underline the waning epidemiologic role of children in maintaining the circulation of rubella virus and indicate that additional vaccination activities targeting >15 year olds are needed to achieve the 2010 WHO target for rubella elimination in the European Region.
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From the *Austrian Agency for Health and Food Safety (AGES), Vienna, Austria; †National Reference Center, Institute of Virology, Medical University Vienna, Vienna, Austria; ‡Institute of Hygiene, Microbiology and Environmental Medicine, Medical University Graz, Graz, Austria; §Steiermaerkische Gebietskrankenkasse (Styrian Sickness Fund), Graz, Austria; ¶Public Health Authority Styria, Graz, Austria; and ∥Public Health Authority Burgenland, Eisenstadt, Austria.
Accepted for publication November 20, 2009.
Reprints: Sabine Kasper, MPH, RD, Österreichische Agentur für Gesundheit und Ernährungssicherheit GmbH, Institut für medizinische Mikrobiologie und Hygiene Wien, Kompetenzzentrum Infektionsepidemiologie, Währingerstraße 25a, Vienna, Austria A-1090. E-mail: firstname.lastname@example.org.
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