BACKGROUND:
The morbidity and intensive investigation associated with nosocomial pertussis are under recognized.

OBJECTIVE:
To identify the source of pertussis infection in a 2 month-old NCU patient, and to prevent secondary transmission

METHOD:
All healthcare workers (HCWs) in the unit were queried about cough illness. Potentially exposed patients were assessed for symptoms of pertussis. Culture and polymerase chain reaction (PCR) testing for Bordetella pertussis were performed on symptomatic patients and HCWs by the hospital laboratory. IgG antibodies to B. pertussis were measured in HCW with at least 14 days of cough (Department of Public Health, State Laboratory Institute, Jamaica Plain, Massachusetts). Exposed patients and HCWs were offered azithromycin prophylaxis; eligible patients were given accelerated vaccination with DTaP.

RESULT:
Among 76 HCW workers, 4 NCU HCWs met the clinical case definition for pertussis. Serologic testing was positive in 3 HCWs; pertussis PCR and culture were negative. The primary case was a 36-year-old with a 3-week cough illness accompanied by paroxysms, whoop and post-tussive emesis. Duration of cough illness among the 4 HCWs prior to identification of the infant index case ranged from 11 to 25 days. Seventy-two infant patients were exposed to a symptomatic HCW. Azithromycin prophylaxis was offered to 72 patients and 72 HCWs. Pertussis immunization was initiated for hospitalized infants > 6 weeks of age. One additional case of pertussis, confirmed by PCR and culture, occurred in a resident physician who declined prophylaxis; she cared for the patient but had no contact with symptomatic HCWs. No additional infant cases were identified.

CONCLUSION:
HCWs may serve as the source of pertussis in nosocomial outbreaks that result in substantial morbidity and costs associated with the investigation. Pertussis should be an early consideration in HCWs with cough illness.

LEARNING OBJECTIVES:
Identify strategies to control a healthcare-associated pertussis outbreak.