1755. Adult Rubella: A Retrospective Analysis of 45 Cases
Session: Poster Abstract Session: Viral Infections; Pathogenesis and Epidemiology
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Background: The rubella epidemic in Japan has escalated since 2012. Clinical manifestations of pediatric rubella are well known, but those of adults have not been fully described. This study was a comprehensive analysis of adult rubella from 2011 to 2013 in Japan. 

Methods: This was a descriptive, retrospective review of all medical records of adult patients with suspected rubella seen from April 2011 to March 2013. Serological confirmation criteria included either strong positivity for rubella-specific IgM in one sample, weak positivity for IgM plus a low titer of IgG in one sample, or a ≥4× increase of IgG titer in acute and convalescent samples. Criteria for clinical confirmation included weakly positive or negative IgM in an initial, single serum sample in the setting of classic manifestations. Without serological data, if two or more clinicians diagnosed rubella, the case was classified as possible rubella.

Results: There were 45 patients who met the inclusion criteria. Of these, 31 were classified as "serologically confirmed" and 14 were "clinically possible." Mean age was 30.5 (range, 18-60) years, and the sex distribution was 37 males and 8 females. Signs included rash (100%), swollen lymph nodes (93.3%), and fever >37.9C° (57.8%). Overall, 38/39 (97.4%) had reddish eyes and 4 were hospitalized for severe constitutional symptoms. Involved lymph nodes included posterior cervical (28, 62.2%), pre/post-auricular (20, 44.4%), and suboccipital (11, 24.4%). In some, the exanthem was not mild, was partially confluent, and did not fade within a few days. False positivity for measles-specific IgM was demonstrated in 11/37 (29.7%).

Conclusion: High-grade fever, reddish eyes, and prolonged, confluent rash were distinctive features observed. Adult rubella shares clinical characteristics with measles. False positivity for measles IgM can occur acutely in rubella; therefore, clinicians should be careful to differentiate rubella from measles when adults present with fever and rash.

Junwa Kunimatsu, MD1, Eriko Kanehisa, MD1, Kei Yamamoto, MD2, Satoshi Kutsuna, MD2, Riri Watanabe, MD1, Yasuyuki Kato, MD, MPH3, Atsuto Yoshizawa, MD1 and Norio Ohmagari3, (1)Department of Internal Medicine, National Center for Global Health and Medicine Hospital, Tokyo, Japan, (2)Diseases Control and Prevention Center, National Center for Global Health and Medicine Hospital, Shinjuku-ku, Tokyo, Japan, (3)Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan


J. Kunimatsu, None

E. Kanehisa, None

K. Yamamoto, None

S. Kutsuna, None

R. Watanabe, None

Y. Kato, None

A. Yoshizawa, None

N. Ohmagari, None

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