Epidemiology and control of pertussis outbreaks in a tertiary care center and the resource consumption associated with these outbreaks

Abstract

Objective: To describe the epidemiology and control of 2 separate outbreaks of pertussis at a large tertiary care center and the resource consumption associated with these outbreaks.

Design: Descriptive study.

Setting: The Mayo Clinic in Rochester, Minnesota, a tertiary care center catering to both referral patients and patients from the community.

Methods: We reviewed routine and enhanced surveillance data collected by infection prevention and control practitioners during the outbreaks. Pertussis was diagnosed either on the basis of a nasopharyngeal specimen positive for Bordetella pertussis by use of polymerase chain reaction (PCR) or on the basis of a compatible clinical syndrome along with an epidemiologic link to PCR-confirmed cases.

Results: Two pertussis outbreaks, the first community based and the second hospital based (ie, due to transmission among healthcare personnel), occurred during the period from October 2004 through October 2005. In the first outbreak from November 2004 through March 2005, there were 109 cases diagnosed; 105 (96%) of these cases were diagnosed on the basis of a nasopharyngeal specimen positive for B. pertussis by use of PCR. Adolescents 10-19 years of age were most affected (77 cases [71%]). Only 13 cases (12%) occurred among healthcare personnel; however, many healthcare personnel required postexposure prophylaxis. A second outbreak of 122 cases occurred during the period from July through October 2005; of these 122 cases, 96 (79%) were diagnosed on the basis of a nasopharyngeal specimen positive for B. pertussis by use of PCR, and 64 (52%) involved healthcare personnel. There were many instances of transmission among healthcare personnel and from patients to healthcare personnel, but no documented transmission from healthcare personnel to patients. The outbreaks were controlled by aggressive case finding, treatment of those infected, prophylaxis of all healthcare personnel and patients who had contact with both probable and confirmed cases, implementation of educational efforts, and compliance with respiratory etiquette. Vaccination of healthcare personnel against pertussis began in October 2005.

Conclusion: Pertussis remains a public health problem. Outbreaks in healthcare facilities consume the resources of those facilities in terms of personnel, testing, treatment of cases, and prophylaxis of those individuals who were in contact with those cases. Adult vaccination may reduce the disease burden.