Pertussis outbreak among patients and healthcare workers in a provincial dialysis facility in Japan

Background Sixteen pertussis cases in haemodialysis patients and healthcare workers were detected in a 25-bed outpatient haemodialysis facility in Japan between October 2013 and April 2014. Aim To describe an outbreak of pertussis among patients and healthcare workers, and to identify risk factors for pertussis infection. Methods Sputum cultures, loop-mediated isothermal amplification assays performed on nasopharyngeal swabs to detect respiratory pathogens including Bordetella pertussis, and serum anti-pertussis toxin immunoglobulin G measurements were performed for all haemodialysis patients and healthcare workers. A retrospective case–control study was performed to identify the risk factors for pertussis infection in the clinic. Findings Only six of the 16 pertussis patients (37.5%) had respiratory symptoms. Recent exposure to an unmasked individual with a cough was associated with pertussis infection (odds ratio 6.25, P<0.05). The outbreak was terminated successfully after enforcing the use of surgical masks among both patients and healthcare workers. Conclusion This report demonstrates the risk of pertussis transmission in a haemodialysis facility, and underscores the importance of wearing surgical masks to control a pertussis outbreak.