Use of an online survey during an outbreak of clostridium perfringens in a retirement community - Arizona, 2012

Context: An outbreak of gastrointestinal (GI) illness among retirement community residents was reported to the Maricopa County Department of Public Health. Online surveys can be useful for rapid investigation of disease outbreaks, especially when local health departments lack time and resources to perform telephone interviews. Online survey utility among older populations, which may lack computer access or literacy, has not been defined. Objective: To investigate and implement prevention measures for a GI outbreak and assess the utility of an online survey among retirement community residents. Design: A retrospective cohort investigation was conducted using an online survey distributed through the retirement community e-mail listserv; a follow-up telephone survey was conducted to assess computer literacy and Internet access. A case was defined as any GI illness occurring among residents during March 1-14, 2012. Setting: A barbecue in a retirement community of 3000 residents. Participants: Retirement community residents. Intervention: Residents were directed to discard leftover food and seek health care for symptoms. A telephone survey was conducted to assess the utility of online surveys in this population. Main outcome measures: Computer literacy and Internet access of retirement community residents. Results: Of 1000 residents on the listserv, 370 (37%) completed the online survey (mean age, 69.7 years; 60.6% women); 66 residents (17.8%) reported a GI illness after the barbecue, 63 (95.5%) reported diarrhea, and 5 (7.6%) reported vomiting. Leftover beef from an attendee's refrigerator grew Clostridium perfringens. Of 552 residents contacted by telephone, 113 completed the telephone survey (mean age, 71.3 years; 63.3% women), 101 (89.4%) reported the ability to send e-mail, 82 (81.2%) checked e-mail daily, and 28 (27.7%) checked e-mail on a handheld device. The attack rate was 17.8% for online versus 2.7% for telephone respondents (P < .001). Conclusions: This outbreak demonstrated the utility of an online survey to rapidly collect information and implement prevention measures among an older demographic.