Problems associated with prophylactic use of erythromycin in 1566 staff to prevent hospital infection during the outbreak of pertussis

Background and objective: Pertussis developed in Kagawa University Medical School and University Hospital in May 2007. To control the outbreak and prevent the infection of hospital inpatients, the Infection Control Team (ICT) carried out the prophylactic administration of erythromycin (EM) to hospital staff (1566 staff) who might be exposed to Bordetella pertussis. Methods: An oral dose of 1000 mg/day EM was given for 10 days. To assess compliance and estimate the frequency of adverse effect, the ICT conducted a questionnaire survey. Results and discussion: Of 942 respondents (response rate: 60·2%), 264 (28·0%) experienced some form of EM adverse effects, of which the most commonly reported involved digestive organ symptoms, e.g. diarrhoea (15·6%), stomachache (7·5%), nausea (3·6%), epigastric distress (2·1%) and abdominal distention (1·8%). More importantly, 246 participants (26·1%) stopped taking the EM before completing 10 days because of perceived adverse effects. Conclusion: These results indicate that EM appears to cause adverse effects more frequently than reported in the package insert in Japan. The prophylactic use of EM for pertussis infection is recognized in the guideline of the Centers for Disease Control and Prevention. However, this study suggests that attention should be paid to EM non-compliance during a pertussis outbreak, which could extend the duration of the outbreak and increase the number of affected patients.