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Review of Bordetella pertussis polymerase chain reaction testing from 2007 through 2014 revealed a yearly spike in positivity rates during the summer throughout the United States. Paradoxically, the highest test volumes occurred outside of this time frame, which provides an opportunity for improved test utilization.

Propionibacterium acnes is an agent of shoulder infection, especially postsurgically (1, 2). The study by Butler-Wu et al. suggests a minimum culture incubation of 13 days for recovery of P. acnes from periprosthetic tissues and fluids (3). Methods for recovery of anaerobes vary, and parameters beyond duration of incubation may influence optimal P. acnes recovery. Butler-Wu et al. did not use anaerobic broth culture, and specimens were not transported under anaerobic conditions. We have routinely collected specimens for anaerobic culture into anaerobic tissue/fluid vials and have included an anaerobic thioglycolate broth incubated for 7 days in our anaerobic bacterial isolation strategy for tissue specimens. We had not been aware of any obvious limitation in isolation of P. acnes using this approach. In response to the findings by Butler-Wu et al., we examined whether 2-week culture incubation is needed for isolation of P. acnes when utilizing an anaerobic thioglycolate broth in conjunction with collection of specimens into anaerobic tissue/fluid vials.Our study was performed over ϳ6 months in 2011. Immediately following collection in the operating room, orthopedic fluids and tissues were placed into anaerobic fluid vials (20-ml serum stopper vials with 1.3 ml prereduced peptone yeast extract broth, 0.5 g/liter cysteine hydrochloride, and 1 mg/liter resazurin indicator) or tissue vials (sterile 30-ml screw-top vials filled with CO 2 ), respectively. Tissues were homogenized using a Seward Stomacher 80 Biomaster (Seward Inc., Port St. Lucie, FL) in 3 ml of brain heart infusion broth for 1 min. A 0.1-ml sample of tissue homogenate or fluid in anaerobic transport medium was inoculated onto CDC anaerobic sheep blood agar and placed in a CO 2 -flushed holding jar which, within 2 h, was set up with an AnaeroPack (Thermo Fisher Scientific, Lenexa, KS). After the jar was opened for plate examination, subsequent incubation was in a glove box at 37°C for 14 days. A 1-ml sample of fluid or homogenate was also inoculated into an anaerobically prereduced hemin-thioglycolate broth, which was closed and incubated at 37°C for 14 days. The broth was examined daily or until positive; cloudy broth was subcultured. The plate was examined Monday, Wednesday, and Friday for the first week and then on days 7 and 14 or until positive. Subjects with more than one specimen cultured on the same date (event) from a shoulder bone/joint source and with more than one specimen yielding P. acnes (1, 4) were analyzed.Fourteen subjects had more than one positive shoulder bone/joint culture for P. acnes. (One subject had two events, and another subject, who had blastomycosis of the joint from which P. acnes was isolated, was excluded, yielding 14 analyzed events.) The Butler-Wu study was similar in size, with 17 patient events involving more than one specimen culture positive for P. acnes (3). Among the 14 events in our study, there were 72 anaerobic plate and broth cultures performed (range, 3 to 13 per event); P. acnes grew on 28 plates (27 withi...

Whooping cough is traditionally ascribed to Bordetella pertussis; however, Bordetella parapertussis can cause a similar clinical syndrome. This study describes an outbreak of B. parapertussis in Southeastern Minnesota and the United States (US) in 2014. This was a retrospective analysis of Mayo Clinic and Mayo Medical Laboratories patients who tested positive for B. parapertussis from 2012 to 2014. The medical records of Mayo Clinic patients who tested positive in 2014 were reviewed for demographic information, presenting symptoms, disease course, and vaccination history. In Southeast Minnesota, 81% of the 31 patients who tested positive for B. parapertussis in 2014 were found to be positive from October through December. Their mean age was 5.9 years. Five reported “exposure to pertussis.” Two pairs of siblings were affected. Patients reported having had symptoms for an average of 2.6 weeks before nasopharyngeal specimen collection for B. parapertussis testing. Cough was the primary symptom reported. Forty percent reported posttussive vomiting, 40% coryza, 32% apnea/sleep disturbance, and 12% sore throat. All were current with pertussis vaccination. Based on the review of national data, an outbreak occurred nationally in the Northeast and Midwest US over the same time period. In 2014, there was an outbreak of B. parapertussis in Southeastern Minnesota and likely other parts of the US. The presenting illness was similar to that of B. pertussis. All patients were vaccinated against pertussis, suggesting that pertussis vaccination is ineffective against B. parapertussis.

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