Update: Prevention and Treatment of Pertussis
Last updated: 03/31/2006
Pertussis, an infection caused by Bordetella pertussis, is a uniquely human disease that is transmitted by person-to-person contact via aerolized droplets. It is the only childhood illness for which routine vaccination is recommended and incidence is increasing.
Despite high vaccination rates, pertussis is on the rise. Approximately 25,000 cases were reported in 2004, the most reported since 1959. The standard pertussis vaccines have been given in combination with diphtheria and tetanus toxoid (DTap) at ages two, four, six, fifteen to eighteen months and four to six years. However, the effect of the vaccine lasts only for five to ten years, and the infection itself does not cause complete immunity. Thus, adolescents and adults may be susceptible to the disease despite adequate vaccination.
Two new Tetanus Toxoid, Reduced Diptheria Toxoid and Acellular Pertussis vaccines adsorbed (Tdap) were approved for use in 2005: Boostrix (approved for patients ten to eighteen years old) and Adacel (approved for patients eleven to sixty-four years old). Currently these two agents are recommended to replace the Tetanus and diphtheria toxoid (Td) vaccines in adolescents. Additionally, all patients nineteen to sixty-four years old should receive one dose of Tdap.
Approximately eighty to ninety percent of patients with pertussis will clear the bacteria without the use of antibiotics within three to four weeks from onset of cough; however, treatment is often warranted in severe disease or high risk patients.
Trimethoprim-sulfamethoxazole (TMP-SMX) and the macrolide antibiotics are the drugs of choice for pertussis infection. It should be noted that no macrolides are indicated for use in patients younger than six months of age. Azithromycin is preferred in patients less than one month of age due to fewer case reports of side effects in this age group. Azithromycin or clarithromcyin can be used in patients older than one month, and TMP-SMX is an alternative for patients older than two months of age. While erythromycin can be used in patients older than one month, its utility is limited due to severe gastrointestinal side effects.
Macrolide antibiotics may also be administered for postexposure prophylaxis for close contacts. Risk of adverse effects of treatment should be weighed against benefits of prophylaxis to determine ne-cessity. Administration of the prophylactic agent must occur within twenty-one days of onset of cough in the index patient to prevent symptomatic infection. Severe and sometimes fatal pertussis related complications can occur in patients less than twelve months, especially those less than four months of age. Prophylaxis should be strongly considered in symptomatic people less than one year of age or in women in the third trimester of pregnancy. Those drugs used to treat pertussis can also be used for prophylaxis. Additional information is available at www.cdc.gov.