Experience with directly observed prophylaxis using erythromycin in military trainees exposed to pertussis

Pertussis, once a serious respiratory disease in children, has recently been identified as a common cause of chronic cough in adults. Military personnel are known to be vulnerable to this disease. After a training barracks exposure to pertussis, routine arrangements for contact prophylaxis with erythromycin failed. This experience is reported here as well as that of our subsequent aggressive attempts using directly observed prophylaxis (DOP) with standard erythromycin regimens. No secondary cases occurred. However, many contacts (35%) could not finish a 14-day course despite DOP, mostly because of nausea (85%) or diarrhea (72%). Seventeen (18%) soldiers missed classes because of erythromycin side effects; five required emergency department visits or hospital admission for the same. Sixteen (17%) soldiers were switched to azithromycin because of side effects; all were able to complete a 14-day course without symptoms. High adherence rates with erythromycin administration using DOP are attainable but may trigger unacceptable toxicities; alternative prophylactic regimens should be considered for active duty personnel.