Before vaccine, pertussis requires a pound of cure

Before vaccine, pertussis requires a pound of cure

Follow-up spirals to scores of exposures

Petussis outbreaks among health care workers are of special concern because of the risk for transmission to vulnerable patients. Last year, the CDC detailed pertussis outbreaks among health care workers and patients that included hospital outbreaks in Pennsylvania and Oregon.¹ The outbreaks, which occurred before the availability of the new pertussis vaccine, are summarized below to underscore the disruptive nature of nosocomial pertussis outbreaks.

• Pennsylvania. In early September 2003, an infant aged 3 weeks was admitted to the pediatric unit at Hospital A for one day before being transferred to a referral hospital. The infant had cough, post-tussive vomiting, and fever for five days. Pertussis infection was considered unlikely in the differential diagnosis, the patient was not tested for pertussis, and droplet precautions were not observed by staff. However, secretions were obtained for culture from the infant at the referral hospital, and B. pertussis was isolated 16 days later. A pediatrician who cared for the infant at Hospital A had onset of a cough illness nine days after exposure. Even though he remained symptomatic, the pediatrician continued to treat patients without wearing a mask and was in contact with other health care workers, family members, and friends. Twenty-two days after his initial exposure, he tested positive for pertussis. Further investigation identified seven other pertussis cases in health care workers (a respiratory therapist, a radiograph technician, and five student nurses) who had been exposed to the infant at Hospital A. In addition, nine of their HCW contacts had cough illnesses lasting more than 14 days. Two children who had been examined by Pediatrician B tested positive for pertussis.

To prevent further transmission, hospital infection control personnel screened exposed employees for cough illness and treated all symptomatic health care workers with a five-day course of azithromycin (500 mg on Day 1 and 250 mg on Days 2-5), and these workers were excluded from work for five days. A total of 307 close contacts of the symptomatic workers, including other health care workers, household members, patients, residents of an institution for mentally impaired persons, and residents of a dormitory for student nurses, received prophylaxis with a five-day course of azithromycin.

• Oregon. In late September 2003, Physician C treated an infant aged 2 months with PCR-confirmed pertussis in the pediatric ICU. Physician C, who wore a mask while providing care to the infant, had been exposed to a colleague who had prolonged cough illness since mid-September. The colleague was subsequently found to have elevated IgG anti-pertussis toxin antibody levels consistent with recent pertussis infection. Approximately two weeks after treating the infant, Physician C had onset of a cough illness; two weeks later, the physician’s NP secretions tested positive for B. pertussis DNA by PCR. Physician C was treated with a five-day course of azithromycin (500 mg on Day 1 and 250 mg on Days 2-5) and was excluded from work for five days. The hospital infection control program identified 129 close contacts of Physician C, including 22 pediatric ICU patients, 78 employees, and 29 medical students and physicians. One exposed patient had severe cough illness and tested positive for B. pertussis DNA by PCR, and three employees had pertussis-like illness. The patient with confirmed pertussis and three symptomatic contacts were treated with a five-day course of azithromycin; the remaining 125 contacts accepted prophylaxis.

Reference

1. Centers for Disease Control and Prevention. Outbreaks of pertussis associated with hospitals — Kentucky, Pennsylvania, and Oregon, 2003. MMWR 2005; 54(03):67-71.