An outbreak of influenza in a residential drug-rehabilitation community

✍ Scribed by Antonio Boschini; Benedetta Longo; Francesca Caselli; Marco Begnini; Cesare De Maria; Filippo Ansaldi; Paolo Durando; Giancarlo Icardi; Giovanni Rezza

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 121 KB
• Volume: 78
• Category: Article
• ISSN: 0146-6615
• DOI: 10.1002/jmv.20684

✦ Synopsis

Abstract

Influenza outbreaks can be difficult to control in confined settings where high‐risk individuals are concentrated. Following the occurrence of a large number of cases of influenza‐like illness in a rehabilitation community for drug users, between February and March 2004, surveillance activities were implemented. Attack rates of influenza‐like illness were calculated, and risk factors for the development of disease and complications were evaluated through the use of relative risks (RR) with 95% confidence intervals (CI). Nasal‐pharyngeal samples were collected for virological studies. Of 1,310 persons who were living in the community, 209 were diagnosed with influenza‐like illness: the attack rate (15.9% overall) was higher for HIV‐infected persons (RR: 1.77, 95% CI: 1.32–2.37), older individuals, and dormitory residents. HIV‐infected participants were also more likely to develop complications compared with HIV‐uninfected persons diagnosed with influenza‐like illness (RR: 5.13, 95% CI: 2.52–10.20). The outbreak was attributable to Christchurch‐like influenza A strains. Vaccination was ineffective because of the mismatch between wild and vaccine strains. J. Med. Virol. 78:1218–1222, 2006. © 2006 Wiley‐Liss, Inc.