Coqueluche - Bordetella pertussis
Mise à jour 12/2005 Guidelines CDC
Pertussis is characterized as an acute bacterial infection of the respiratory tract that is caused by B. pertussis, a Gram-negative bacterium.
It is transmitted person-to-person through aerosolized droplets from cough or sneeze or by direct contact with secretions from the respiratory tract of infectious persons. It is highly contagious, with 80% secondary attack rates among susceptible persons.
The clinical presentation of pertussis consists of 3 stages.
The incubation period averages 7 to 10 days, ranging 5 to 21 days.
Diagnosis relies on culture of nasopharyngeal aspirate or Dacron swab for B. pertussis on Regan Lowe or Bordet-Gengou culture medium or the detection of B. pertussis DNA by polymerase chain reaction. The aim of these guidelines is to provide the current recommended antimicrobial agents for the treatment of and postexposure prophylaxis for pertussis.
- The first is the catarrhal period (1 - 2 weeks), which is characterized by an insidious onset of coryza, mild fever, and nonproductive cough. Infants can have apnea and respiratory distress.
- Next is the paroxysmal period (2 - 6 weeks), consisting of paroxysmal cough, inspiratory "whoop," and posttussive vomiting.
- The final stage is the convalescent period (2 or more weeks) when paroxysms gradually decrease in frequency and intensity.
Erythromycin, a macrolide agent, has been the antimicrobial choice for treatment of or postexposure prophylaxis for pertussis.
After thorough literature searches and reviews of clinical trials, additional macrolides, clarithromycin and azithromycin, have been added to the CDC recommendations of the treatment of and prophylaxis for pertussis in persons aged 1 month or older.
For infants younger than 1 month, azithromycin is preferred; erythromycin and clarithromycin are not recommended. Infants younger than 1 month who receive a macrolide should be monitored for IHPS.
Erythromycin and clarithromycin are inhibitors of the cytochrome P450 enzyme system (CYP3A subclass) and, therefore, can interact with other drugs that are metabolized by this system.
The most commonly reported adverse effects of oral macrolides are gastrointestinal (eg, nausea, vomiting, abdominal pain and cramps, diarrhea, and anorexia) and hypersensitivity reactions (eg, rashes).
For erythromycin, rare cases of serious cardiovascular adverse events, including electrocardographic QT/QTc interval prolongation, cardiac arrest, torsades de pointes, and other ventricular arrhythmias, have been observed after concomitant use of other drugs.
The recommended regimens include:
For postexposure prophylaxis, administer course of antibiotic to close contacts within 3 weeks of exposure, especially in high-risk settings, such as infants younger than 12 months or women in the third trimester; same doses as in treatment schedule.
- Infants aged younger than 6 months: 10 mg/kg per day for 5 days.
- Infants and children aged 6 months or older: 10 mg/kg (maximum, 500 mg) on day 1, followed by 5 mg/kg per day (maximum, 250 mg) on days 2 to 5.
- Adults: 500 mg on day 1, followed by 250 mg per day on days 2 to 5.
- Infants younger than 1 month: not recommended.
- Infants and children aged 1 month or older: 15 mg/kg per day (maximum, 1 g per day) in 2 divided doses each day for 7 days.
- Adults: 1 g per day in 2 divided doses for 7 days.
Infants younger than 1 month: not preferred because of risk for IHPS. Azithromycin is the recommended antimicrobial agent. If azithromycin is unavailable and erythromycin is used, the dose is 40 to 50 mg/kg per day in 4 divided doses. These infants should be monitored for IHPS.
- Infants aged 1 month or older and older children: 40 to 50 mg/kg per day (maximum, 2 g per day) in 4 divided doses for 14 days.
- Adults: 2 g per day in 4 divided doses for 14 days
Alternative agent: TMP-SMZ
- Infants younger than 2 months: contraindicated.
- Infants aged 2 months or older and children: TMP, 8 mg/kg per day; SMZ, 40 mg/kg per day in 2 divided doses for 14 days.
- Adults: TMP, 320 mg/day; SMZ, 1,600 mg/day in 2 divided doses for 14 days.
Patients receiving TMP-SMZ might experience gastrointestinal adverse effects, hypersensitivity skin reactions, and rarely, Stevens-Johnson syndrome, toxic epidermal necrolysis, blood dyscrasias, and hepatic necrosis.
For prevention and surveillance, vaccinate children aged 6 weeks to 6 years with tetanus toxoid and diphtheria and acellular pertussis vaccine; a new recommendation is expected regarding a single dose of tetanus toxoid and reduced diphtheria and acellular pertussis vaccine for adolescents and adults aged younger than 65 years.
Report all cases to local and state health departments.
Recommended Antimicrobial Agents for the Treatment and Postexposure Prophylaxis of Pertussis
2005 CDC Guidelines