Trial Outcomes & Findings for Vanderbilt Pertussis Exposure Study: PEP in Vaccinated Healthcare Workers Following Pertussis Exposure (NCT NCT00469274)

NCT ID: NCT00469274

Last Updated: 2013-01-29

Results Overview

Defined as a positive nasopharyngeal culture or PCR for B. pertussis at any time point, a two-fold rise in the anti-PT IgG titer between acute and convalescent sera, or a single acute or convalescent anti-PT IgG titer of ≥94 EU. Post hoc, a modified definition was devised because of concern that the serologic criteria used in the primary definition might actually represent acquisition of pertussis infection prior to the intervention. The modified definition of pertussis excluded an acute anti-PT IgG titer of ≥94 EU and an acute nasopharyngeal swab that was positive for B. pertussis by PCR.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 1102 participants
• Primary outcome timeframe: In the 21 days following exposure identification
• Results posted on: 2013-01-29

Participant Flow

Between May 2007 and October 2009, all HCWs working at a 206-bed, tertiary care pediatric acute care hospital were recruited for enrollment. Inclusion criteria were age 18 - 64 years; self-report of direct patient contact; planning to work at least one year from enrollment; and willing to cooperate with surveillance.

Subjects were excluded from randomization if they had a previous pertussis exposure within the past 4 weeks; fever, cough, sore throat, or rhinorrhea; received PEP outside of the study; had been vaccinated with Tdap <7 days prior to the exposure; or were recognized as exposed ≥5 days after identification of the infected patient.

Participant milestones

Measure	No PEP Enrolled subjects involved in a pertussis exposure who received no antibiotic post-exposure prophylaxis as per standard recommendations (i.e. azithromycin 500mg x 1 day followed by 250mg Q day for on days 2-5 or trimethoprm sulfamethoxasole DS BID for 14 days)	Antibiotic PEP Enrolled subjects involved in a pertussis exposure who received post-exposure prophylaxis as per standard recommendations (i.e. azithromycin 500mg x 1 day followed by 250mg Q day for on days 2-5 or trimethoprm sulfamethoxasole DS BID for 14 days)
Overall Study STARTED	44	42
Overall Study COMPLETED	44	42
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Vanderbilt Pertussis Exposure Study: PEP in Vaccinated Healthcare Workers Following Pertussis Exposure

Baseline characteristics by cohort

Measure	No PEP n=44 Participants Enrolled subjects involved in a pertussis exposure who received no antibiotic post-exposure prophylaxis as per standard recommendations (i.e. azithromycin 500mg x 1 day followed by 250mg Q day for on days 2-5 or trimethoprm sulfamethoxasole DS BID for 14 days)	Antibiotic PEP n=42 Participants Enrolled subjects involved in a pertussis exposure who received post-exposure prophylaxis as per standard recommendations (i.e. azithromycin 500mg x 1 day followed by 250mg Q day for on days 2-5 or trimethoprm sulfamethoxasole DS BID for 14 days)	Total n=86 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	44 Participants n=5 Participants	42 Participants n=7 Participants	86 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age Continuous	32 years STANDARD_DEVIATION 2 • n=5 Participants	27 years STANDARD_DEVIATION 2 • n=7 Participants	29 years STANDARD_DEVIATION 2 • n=5 Participants
Sex: Female, Male Female	26 Participants n=5 Participants	29 Participants n=7 Participants	55 Participants n=5 Participants
Sex: Female, Male Male	18 Participants n=5 Participants	13 Participants n=7 Participants	31 Participants n=5 Participants
Region of Enrollment United States	44 participants n=5 Participants	42 participants n=7 Participants	86 participants n=5 Participants

PRIMARY outcome

Timeframe: In the 21 days following exposure identification

Defined as a positive nasopharyngeal culture or PCR for B. pertussis at any time point, a two-fold rise in the anti-PT IgG titer between acute and convalescent sera, or a single acute or convalescent anti-PT IgG titer of ≥94 EU. Post hoc, a modified definition was devised because of concern that the serologic criteria used in the primary definition might actually represent acquisition of pertussis infection prior to the intervention. The modified definition of pertussis excluded an acute anti-PT IgG titer of ≥94 EU and an acute nasopharyngeal swab that was positive for B. pertussis by PCR.

Outcome measures

Measure	No PEP n=44 Participants Enrolled subjects involved in a pertussis exposure who received no antibiotic post-exposure prophylaxis as per standard recommendations (i.e. azithromycin 500mg x 1 day followed by 250mg Q day for on days 2-5 or trimethoprm sulfamethoxasole DS BID for 14 days)	Antibiotic PEP n=42 Participants Enrolled subjects involved in a pertussis exposure who received post-exposure prophylaxis as per standard recommendations (i.e. azithromycin 500mg x 1 day followed by 250mg Q day for on days 2-5 or trimethoprm sulfamethoxasole DS BID for 14 days)
Evidence of Pertussis Infection in Each PEP Arm, Defined Using Clinical, Microbiologic, or Serologic Criteria.	6 participants	1 participants

Adverse Events

No PEP

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Antibiotic PEP

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Thomas R. Talbot

Vanderbilt University Medical Center

Phone: 615-322-2789

Email: tom.talbot@vanderbilt.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place