Approach Considerations
Supportive therapy is the mainstay of treatment in patients with active pertussis infection. [23] The goals of therapy include limiting the number of paroxysms, observing the severity of cough, providing assistance when necessary, and maximizing nutrition, rest, and recovery. Oxygenation, breathing treatments, and mechanical ventilation should be provided as necessary. Infants should be carefully observed for apnea, cyanosis, or hypoxia.
Inpatient care is required for patients with pertussis who have intractable nausea and vomiting, failure to thrive, seizures, or encephalopathy or for patients with sustained hypoxemia during coughing paroxysms who require supplemental oxygen.
Hospitalization should be strongly considered for patients at risk for severe disease and complications, including infants younger than 3 months; infants aged 3-6 months, unless observed paroxysms are not severe; premature young infants; and infants or children with underlying pulmonary, cardiac, or neuromuscular disease.
Patients with pneumonia, apneic or cyanotic spells, hypoxia, or moderate to severe dehydration should be considered for admission. Patients who are severely ill may require treatment in an intensive care unit (ICU).
For the hospitalized patient, in addition to standard precautions, droplet precautions are recommended for 5 days after initiation of effective therapy or until 3 weeks after the onset of paroxysms if appropriate antimicrobial therapy is not given.
Continuously monitor the heart rate, respiratory rate, and oxygen saturation of hospitalized patients, especially in relation to coughing paroxysms. Coughing, feeding, vomiting, and weight changes should be recorded. Pay attention to the young infant's hydration and nutritional status.
Diet and activity
No special diet is indicated, although a clinically age-appropriate diet should be maintained. Infants who cannot tolerate oral feedings may require intravenous fluids.
Activity for patients with pertussis should be guided by clinical course. In general, patients engage in activity as tolerated.
Consultations
Consultation with subspecialists usually is not indicated; however, if the diagnosis is unclear or the clinical course warrants, infectious disease specialists or other subspecialists should be consulted.
Transfer
Transfer of patients is not usually indicated unless inpatient therapy and monitoring are warranted and facilities for these are not available at the original institution. Need for transfer should be evaluated on an individual basis. Standard monitoring and transfer protocols should be followed.
Monitoring
Most patients older than 1 year can be treated on an outpatient basis if they do not fulfill the criteria for hospital admission. Frequent outpatient reevaluations are required; frequency of observation should be individualized based on the patient's age, disease severity, and presence of comorbid conditions.
Pharmacologic Therapy
Although antimicrobial agents initiated during the paroxysmal stage do not affect the duration and severity of illness, they can hasten the eradication of Bpertussis in the respiratory tract and help to prevent spread. Antibiotics may prevent or alleviate secondary bacterial infection.
For patients of all ages azithromycin is the preferred agent.
Erythromycin and clarithromycin are not recommended in infants younger than 1 month, because their use has been associated with increased risk for infantile hypertrophic pyloric stenosis (IHPS). Azithromycin is the recommended agent for the youngest patients, although it also carries some risk for IHPS. Patients who are aged 2 months or older with hypersensitivity to macrolides may be treated with trimethoprim-sulfamethoxazole.
Prophylaxis
The effectiveness of prophylaxis for exposed, susceptible persons has not been determined; however, it is recommended for household and close contacts of the patient. Regimens include the following:
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Azithromycin (5 d)
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Erythromycin (14 d)
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Alternative regimen - Clarithromycin 7.5 mg/kg twice daily for 14 days (the effectiveness of clarithromycin has not been proven but is inferred)
Immunization
Prevention through immunization remains the best defense in the fight against pertussis. However, because nearly all of the fatal cases of pertussis occur in infants who are too young to have been immunized, novel strategies must be explored to protect these patients.
An option may be to immunize neonates with acellular pertussis vaccine. However, immunogenicity of the vaccine in newborns and possible induction of tolerance to B pertussis antigens need to be investigated.
Evidence is overwhelming that parents and older siblings are the primary source of infection in young infants. The incidence of pertussis in preadolescents, adolescents, and adults has increased and may be responsible for the increasing number of cases observed in young infants in some countries. A study from the Netherlands concluded that 35-55% of pertussis cases in infants could be prevented if immunity to pertussis in parents were maintained or boosted. [33]
In December 2005, the American Academy of Pediatrics approved recommendations from the Committee on Infectious Diseases (COID) for universal vaccination of adolescents at the 11- or 12-year visit to boost protection against pertussis. [34, 35] The FDA has licensed 2 tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) products for use in children aged 10-18 years (Boostrix; GlaxoSmithKline Biologicals, Rixensart, Belgium) and for patients aged 11-64 years (Adacel; Sanofi Pasteur, Toronto, Canada). Tdap has replaced tetanus in the childhood and adult immunization schedules. It has been shown to be effective in outbreaks in the short term. Long-term effectiveness studies are ongoing.
Whole-cell vaccination
This vaccine, used from the 1940s until the mid-1990s in the United States and from the 1940s until the 1980s in Europe, consisted of a whole cell with endotoxin given in 4 doses. About 80% of recipients acquired effective protection with this regimen. Two doses provided some immunity, whereas 1 dose provided little protection.
It was found that about 50% of patients who received the vaccine had a local reaction to it, 1 patient in 1750 had a seizure without fever, and 10.5 patients per million developed encephalitis; permanent brain damage was rare. Concern about CNS adverse effects is a major reason why many individuals chose not to be vaccinated.
Acellular vaccination
Vaccination now is recommended with acellular pertussis vaccine plus diphtheria and tetanus toxoids (DTaP) at the ages of 2, 4, 6, and 15-18 months and at age 4-6 years. A booster with Tdap (DTaP is not recommended for children aged 7 years or older) is recommended instead of 1 diphtheria-tetanus toxoid (Td) booster from age 19 years and up. Ideally, Tdap is recommended before pregnancy, but it may be given during pregnancy after 20 weeks’ gestation. [36] Additionally, the CDC recommends that all adults receive 1 dose of Tdap in order to decrease pertussis transmission in children.
After immunization, fever is reported in 3-5% of patients, persistent crying in 12 patients per 100,000, febrile seizures in 5 patients per 100,000, afebrile seizure in 2 patients per 100,000, and hyporesponsive episodes in 5 patients per 100,000. Severe neurologic sequelae have not been reported. This is about the same as it is for Td alone.
A randomized, controlled study by Pitisuttithum et al that included 450 adolescents reported that a monovalent and a combined recombinant acellular pertussis vaccine containing PTgen produced antibody responses that were greater and more sustained compared with Tdap. [51]
A study by McNamara et al that included 9801 pertussis patients aged 3 months and older reported a 60% reduction in odds of severe disease in children 7 months to 6 years of age when they received the recommended pertussis vaccine. The study also found a 30% reduction in posttussive vomiting in children and adult patients who received the age-appropriate vaccine. [37]
Maternal vaccination
The FDA approved Tdap (Adacel, Boostrix) for third trimester maternal vaccination to prevent pertussis infection in infants younger than 2 months. Since 2012, the CDC Advisory Committee on Immunization Practices has recommended pregnant women receive a dose of Tdap, regardless of the interval since their last tetanus or diphtheria toxoid-containing vaccine. [52]
A study found that the pertussis vaccine did not increase the risk for adverse birth outcomes in an observational study of 123,494 women who gave birth to a live singleton infant, including 26,229 who received the acellular pertussis vaccine (Tdap) during pregnancy. [38, 39] Crude estimates for preterm delivery were 6.3% among vaccinated women and 7.8% among unvaccinated women (adjusted risk ratio [RR] 1.03). Estimates for small for gestational age birth were 8.4% in vaccinated women and 8.3% in unvaccinated women (adjusted RR, 1.00). Women who received Tdap before 20 weeks were not at increased risk for hypertensive disorder of pregnancy (adjusted RR, 1.09). The study did find a small but statistically significant increased risk for chorioamnionitis with Tdap vaccination during pregnancy. Chorioamnionitis was diagnosed in 6.1% of vaccinated women and 5.5% of unvaccinated women, for an adjusted risk ratio of 1.19. [38, 39]
A case-control evaluation by Skoff et al on 240 pertussis cases in newborns younger than 2 months reported that the vaccine effectiveness estimate for Tdap administered during the third trimester of pregnancy was 77.7% (95% confidence interval [CI], 48.3%-90.4%) and vaccine effectiveness increased to 90.5% when looking at just the serious cases of pertussis that required hospitalization (95% CI, 65.2%-97.4%). [40]
A study by Kent et al found that maternal vaccination administered early in the third trimester may provide protection against pertussis and other pathogens for infants born prematurely. In the study, mothers of 31 (19%) of 160 premature infants received combined tetanus, diphtheria, 5-component acellular pertussis, inactivated polio vaccine in pregnancy. The study reported that compared with infants of unvaccinated mothers, those born to vaccinated mothers had significantly higher antibody concentrations at 2 months for all measured vaccine antigens. [41] Another study that included 66 mothers of infants with pertussis younger than 4 months reported that only 30% of the pregnant mothers received Tdap vaccine as recommended during their routine prenatal visit. [50]
A CDC survey reported that 48.8% of pregnant women in the United States received the Tdap vaccine in 2016, an increase from 42.1% in 2015. [42]
For the latest childhood and adolescent immunization recommendations, see the CDC immunization schedules. [35, 43]
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A photomicrograph of the bacterium Bordetella pertussis, using Gram stain technique.
