120. Widespread Bordetella parapertussis Infections — Wisconsin, October 2011–May 2012
Session: Oral Abstract Session: Epidemiology of Respiratory Infections
Thursday, October 3, 2013: 10:30 AM
Room: The Moscone Center: 300
Background: During 2011–2012, statewide outbreaks of Bordetella pertussis and Bordetella parapertussis infections concurrently occurred in Wisconsin. We examined clinical and epidemiologic features of reported parapertussis and assessed effectiveness of azithromycin prophylaxis (AP) in preventing cough illness among patients’ household members (HHM).

Methods: A case was defined as an acute cough illness in a Wisconsin resident during October 1, 2011–May 31, 2012; confirmed pertussis and parapertussis cases had a polymerase chain reaction (PCR)-positive nasopharyngeal specimen for B. pertussis (IS481) and B. parapertussis (IS1001), respectively. Parapertussis patients were interviewed for patient and HHM information, including presence and duration of signs, symptoms, and antibiotic treatment. The primary HHM patient had the earliest cough onset date. Attack rates (ARs) of primary or coprimary (onsets ≤6 days after primary case onset) and secondary (onsets 7–28 days after primary case onset) cough onset among HHM AP recipients were compared with ARs among nonrecipients. Among County A residents, clinical features of pertussis and parapertussis were compared.

Results: Statewide, 2283 specimens were PCR-positive for B. pertussis (88%), B. parapertussis (11%), or both (1%); 218 illnesses met the parapertussis case criteria; 180 were followed until symptoms resolved. Parapertussis patient median age was 5.6 years (range: 1 mo–39 yrs). Parapertussis symptoms included paroxysmal cough (60%), whoop (15%), or posttussive vomiting (31%). Among 696 HHM, HHM who received ≥4 days of AP (n = 142) were less likely than HHM who did not receive prophylaxis (n = 554) to experience primary or coprimary (ARs: 1.4% vs. 40%; P <.001) or secondary (ARs: 0% vs. 14%; P<.001) cough illnesses. In County A, parapertussis patients (n = 23) were younger (mean age: 6 versus 13 years) and had median shorter cough duration than pertussis patients (14 vs. 28 days).

Conclusion: B. parapertussis infection results in significant pertussis-like symptoms. Empiric azithromycin treatment of patients suspected of having pertussis and contact AP appears to prevent parapertussis. PCR testing that differentiates between species is necessary to understand current B. parapertussis burden.

Michael Bartholomew, MD1,2, Ruth Koepke, MPH1,3, Roman Aydiko Ayele, MPH1,3, Diane Rodd, RN, BSN4, Joan Kuennen, RN, BSN4, Jean Rosekrans, RN, BSN4, David Warshauer, PhD5 and Jeffrey Davis, MD1, (1)Wisconsin Department of Health Services, Division of Public Health, Madison, WI, (2)Centers for Disease Control and Prevention, Atlanta, GA, (3)University of Wisconsin School of Medicine and Public Health, Madison, WI, (4)Wood County Health Department, Wisconsin Rapids, WI, (5)Wisconsin State Laboratory of Hygiene, Madison, WI

Disclosures:

M. Bartholomew, None

R. Koepke, Sanofi Pasteur: Research Contractor, Salary

R. Aydiko Ayele, Sanofi Pasteur: Research Contractor, Salary

D. Rodd, None

J. Kuennen, Wood County Health Department: Employee and Investigator, Salary

J. Rosekrans, None

D. Warshauer, None

J. Davis, Sanofi Pasteur: Grant Investigator, Research grant

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