Influenza viral infections can disrupt the lifestyles of college students. The symptoms, often involving fever, malaise, or cough, may force students to miss classes and social gatherings, interrupting their educational pursuits and those of the university community. The incidence of influenza has been reported to be higher among dormitory residents than among students in non-dormitory settings (Pons, Canter, & Dolin, 1980). To identify aspects of dormitory life that may increase the risk of self-reported influenza-like symptoms (ILS), this study surveyed dormitory residents at the University of Chicago near the conclusion of the 1999-2000 flu season. To the authors' knowledge, it is the first epidemiologic study of ILS conducted among college dormitory students in 20 years, and the first to explore a comprehensive cross-section within a dormitory environment.
Influenza viruses cause a seasonal respiratory illness that can spread rapidly from person to person throughout a community. Cough, fever, and sore throat are symptoms often associated with influenza, with illness typically lasting from one to two weeks in otherwise healthy individuals (Centers for Disease Control and Prevention [CDC], 2001). The mode of transmission is usually exposure to airborne respiratory secretions contaminated with the virus (Hayden & Palese, 2002). Influenza infection can be readily diagnosed and the disease well characterized, and symptoms, including fever, cough, and myalgia, have been found to correlate well with actual disease (Monto, Gravenstein, Elliot, Colopy, & Schweinle, 2000). Influenza also can be transmitted through an environmental-surface intermediate, as when an infected individual sheds the virus onto a surface and an uninfected, susceptible host later contacts the same surface and then self-inoculates the virus into his or her mucous membranes (Barker, Stevens, & Bloomfield, 2001). The most effective control against influenza is prevention of infection (Piedra, 1995). Increased knowledge about influenza transmission within college dormitories may aid in developing methods of preventing infection.
The authors designed and implemented a survey to study issues related to influenza. The survey questioned students about ILS symptoms and their college dormitory environment, a setting where factors such as roommates, room carpeting, and dining, laundry, and washroom environments could be evaluated. These variables were chosen because they represented sites where surface or air transmission was likely to occur. Gender and year in college also were assessed. To eliminate confounding variables, the survey asked students if they had received an influenza vaccine, an intervention known to reduce ILS risk (Piedra, 1995).
Prior to distribution of the survey, approval from the Institutional Review Board of the University of Chicago Hospitals was obtained, and the survey was pretested among a sample of students in the dorms surveyed. A questionnaire then was mailed to 1,704 dorm students, on February 26, 2000, and responses were collected in reply boxes at each dormitory through March 3, 2000. The seven-day reply period was near the end of a 10-week quarter that began January 4 and ended March 10. Surveying later in the quarter would have conflicted with final examinations, a factor likely to lower the response rate. Students were reminded to return the surveys through e-mails and flyers on dorm bulletin boards. Data were analyzed with SPSS 9.0 and Microsoft Excel 97. Two-sided p values were reported. Risks were expressed as proportions or percentages and risk ratios.
Influenza-like symptoms were defined as fever ([greater than or equal to]38[degrees]C for [greater than or equal to]48 hours) and at least two of the following symptoms lasting for at least two days: cough, myalgia (described as "aches and pains" on survey), sore throat, and...