Pertussis Outbreak Among Soldiers During Basic Training: The Need for Updated Protocols

Pertussis is a highly contagious, vaccine preventable upper respiratory disease. The incidence of the disease has been rising in the past few decades. During the winter of 2015, an upper respiratory outbreak occurred in one of Israel Defense Forces basic training bases in northern Israel. Following the detection of the first primary cases, a suspected outbreak investigation was initiated in conjunction with more rigorous clinical and laboratory testing efforts to include specific antibody enzyme-linked immunosorbent assay assays and polymerase chain reaction to diagnose pertussis. Initially, 1,596 soldiers were surveyed clinically using a questionnaire and physicians' interviews for upper respiratory disease symptoms. A total of 158 soldiers were further evaluated and 38.6% (61) of those were diagnosed as having pertussis (with laboratory evidence). Based on the protocol that we developed during the course of this outbreak, a postexposure prophylaxis was given to every soldier for whom there was a high level of suspicion for infection and met the inclusion criteria for the postexposure prophylaxis protocol. The effects of the postvaccination waning immunity among a vaccinated population were demonstrated, thus the need of maintaining a high index of suspicion of Brodetella pertussis as a causative agent during respiratory diseases outbreaks in young soldiers.