Vanderbilt Pertussis Exposure Study: PEP in Vaccinated Healthcare Workers Following Pertussis Exposure
Condition: Pertussis
MeSH terms: Whooping Cough
Study type: Interventional

Summary: 
      The purpose of this study is to compare the effectiveness of two strategies of post-exposure
      prophylaxis (PEP) in healthcare workers (HCWs) who have been vaccinated with acellular
      pertussis vaccine and have been exposed to pertussis Secondary Objectives include a
      comparison of the costs of each PEP strategy and an assessment for risk factors associated
      with healthcare-associated acquisition of pertussis.
    

Detailed description: 
      Pertussis, caused by the bacterium Bordetella pertussis, is an acute respiratory tract
      infection transmitted to susceptible persons through aerosolized respiratory droplets and
      direct contact with respiratory secretions. Classic pertussis disease is characterized by
      three phases of illness: the catarrhal phase where persons note cough and coryza; the
      paroxysmal phase where persons develop a spasmodic cough with post-tussive vomiting and an
      inspiratory whoop; and the convalescent phase, during which symptoms slowly resolve. The risk
      of transmission of the organism is compounded by the nondescript nature of symptoms early in
      the course of illness, particularly in adults. Classically recognized as a disease of infants
      and children ("whooping cough"), the incidence of pertussis infection in adolescents and
      adults has increased in recent years. Persons >15 years of age now make up more than twenty
      percent of reported cases. This increase is likely due to several factors, including waning
      protection from childhood vaccination and natural infection, an increased appreciation for
      disease in adolescents and adults, and the improved ability of clinicians to diagnose
      pertussis recognition through the use of serologic methods.

      Healthcare workers (HCWs) are at increased risk for acquiring pertussis infection due to
      regular contact with infected patients and waning protection from childhood vaccination or
      from natural pertussis infection. Healthcare-associated outbreaks of pertussis have also been
      increasingly recognized and have been reported from a diverse range of healthcare facilities.
      Such outbreaks are often due to under-recognition of pertussis with subsequent failure to
      isolate suspected cases, waning immunity from childhood vaccination or disease, and the
      increasing incidence of pertussis infection in adults and adolescents. Infected HCWs can then
      serve as vectors of infection to other susceptible contacts including patients, other
      employees, and even their own children.

      Vaccination is an effective tool for the prevention of pertussis. In 2005, two tetanus
      toxoid, reduced diphtheria toxoid, and reduced antigen quantity acellular pertussis vaccines
      (Tdap) were licensed for use in adolescents and adults. In view of the increasingly
      recognized problem of healthcare-associated and transmitted pertussis infection, the Centers
      for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices
      (ACIP) targeted HCWs as a priority group for pertussis vaccination in 2006, primarily to
      reduce the risk of spread of pertussis within health care institutions.

      Until the licensure of Tdap, the only method to reduce transmission of pertussis after
      healthcare-associated exposure to persons with pertussis was post-exposure prophylaxis (PEP)
      with antibiotics and employee furlough. Close contacts exposed to a pertussis-infected
      patient or staff member are routinely treated with macrolide therapy (erythromycin or
      azithromycin), and exposed HCWs who develop a cough-illness are restricted from work for 5
      days while on antibiotic therapy. PEP is believed to prevent symptomatic infection in the
      exposed person if administered within 21 days of cough onset. Traditionally, decisions
      regarding PEP for exposed HCWs involve detailed assessments of the degree of patient contact,
      the risk for development of severe or complicated pertussis, and regular evaluation and
      follow-up for the occurrence of symptoms. These are often time-consuming efforts that are
      usually the responsibility of infection control or occupational health personnel. With the
      licensure of Tdap and with the recommended vaccination of HCWs, it is now hoped that
      vaccination will eliminate the need to provide antibiotic PEP, particularly in
      recently-vaccinated HCWs. However, this has not been confirmed with a randomized clinical
      trial, and, therefore, no definitive formal recommendation can be made regarding
      modifications of PEP in vaccinated HCWs. Two potential strategies exist for the management of
      vaccinated HCWs following an exposure to a person with pertussis: a) provision of universal
      antibiotic therapy or b) careful daily observation of vaccinated HCWs for the development of
      symptoms without antibiotic prescription. A comparison of these two strategies will be the
      focus of this study.
    

Intervention name(s): Antibiotic PEP; Antibiotic PEP
Intervention type(s): Drug; Drug
Intervention description(s): Azithromycin 1000mg po x 1, then 500mg po Q day for 4 days; TMP-SMX DS one BID for 14 days; TMP-SMX DS po BID for 14 days
Intervention MeSH terms: Anti-Bacterial Agents; Antibiotics, Antitubercular
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Pertussis; Healthcare worker; Post-exposure prophylaxis; Vaccination; Pertussis in healthcare workers following occupational; exposure to pertussis