Pertussis (Whooping Cough)

Pertussis is one of the most common vaccine-preventable diseases in children under 5 years. The cough is the danger: violent, paroxysmal, and severe enough to make breathing, eating, and drinking hard. In infants it kills. Keep the airway clear, watch the work of breathing, and start antibiotics early.

What is Pertussis?

Pertussis (whooping cough) is a respiratory tract infection marked by a paroxysmal cough.

• First identified in the 16th century. In 1906, Bordet isolated the most common causative organism, Bordetella pertussis.
• Vaccination cut reported cases by more than 99% from the 1930s to the 1980s.
• It remains a significant cause of morbidity and mortality in infants younger than 2 years.

Pathophysiology

Humans are the sole reservoir for B pertussis and B parapertussis.

• Bordetella pertussis, a gram-negative pleomorphic bacillus, is the main causative organism.
• It spreads via aerosolized droplets from an infected person's cough, attaching to and damaging ciliated respiratory epithelium from the nasopharynx down to the bronchi and bronchioles.
• A mucopurulent sanguineous exudate forms in the respiratory tract, compromising the small airways and predisposing to atelectasis, cough, cyanosis, and pneumonia.
• Transmission occurs through face-to-face contact, shared confined space, or contact with oral, nasal, or respiratory secretions.

Statistics and Incidences

Since the early 1980s, pertussis incidence has cycled upward, with peaks every 2-5 years.

• In 2010, the CDC reported 27,550 US cases with 27 related deaths.
• In 2011, adolescents (ages 11-19 years) and adults together accounted for 47% of cases, while children aged 7-10 years accounted for 18%.
• Annual worldwide incidence is estimated at 48.5 million cases, with nearly 295,000 deaths per year.
• From 2001-2003, females accounted for 54% of US cases.
• From 2001-2003, of patients with pertussis: 23% were younger than 1 year, 12% were aged 1-4 years, 9% were aged 5-9 years, 33% were aged 10-19 years, and 23% were older than 20 years.

Clinical Manifestations

The incubation period is 3-12 days. Pertussis runs about 6 weeks, divided into catarrhal, paroxysmal, and convalescent stages, each lasting 1-2 weeks.

• Stage 1, catarrhal phase. Nasal congestion, rhinorrhea, and sneezing, variably with low-grade fever, tearing, and conjunctival suffusion. Pertussis is most infectious during this phase but can stay communicable for 3 or more weeks after the cough starts.
• Stage 2, paroxysmal phase. Paroxysms of intense coughing lasting up to several minutes. In older infants and toddlers, paroxysms are occasionally followed by a loud whoop; posttussive vomiting and turning red with coughing are common.
• Stage 3, convalescent phase. A chronic cough that may last for weeks.

Assessment and Diagnostic Findings

The criterion standard for diagnosis is isolation of B pertussis in culture.

• Chest radiography. May reveal perihilar infiltrates or edema with variable atelectasis.
• Blood work. Leukocytosis with absolute lymphocytosis occurs during the late catarrhal and paroxysmal phases. In infants aged 90 days or younger, serial WBC monitoring is crucial for risk and prognosis.
• Cultures. Blood cultures are uniformly negative because B pertussis grows only in respiratory epithelium. Recovery rates are highest during the catarrhal or early paroxysmal phase and low after the fourth week of illness.
• PCR assay and ELISA. PCR and antigen detection are increasingly used: greater sensitivity, faster results, and usable later in the course. A positive PCR or culture is the case definition for reporting to the CDC or WHO, though some recommend confirming with ELISA before declaring an epidemic.

Medical Management

Supportive therapy is the mainstay in active infection.

• Hospitalization. Strongly consider it for patients at risk for severe disease and complications.
• Diet. No special diet, but maintain a clinically age-appropriate one.
• Activity. Guided by clinical course; in general, activity as tolerated.
• Monitoring. Most patients older than 1 year can be treated as outpatients if they do not meet admission criteria.

Pharmacological Management

Antimicrobials given during the catarrhal phase may ameliorate the disease.

• Antibiotics. The Committee on Infectious Disease (COID) of the American Academy of Pediatrics recommends promptly treating all household and close contacts with erythromycin to limit secondary transmission.
• Vaccines. Active immunization increases resistance; vaccines consist of microorganisms or cellular components that act as antigens.

Nursing Management

Nursing Assessment

• Airway patency. A patent airway is always the first priority.
• Auscultation. Listen for normal or adventitious breath sounds.
• Respirations. Note quality, rate, pattern, depth, nasal flaring, dyspnea on exertion, splinting, accessory muscle use, and the position the patient takes to breathe.

Nursing Diagnosis

• Ineffective airway clearance related to copious, tenacious bronchial secretions.
• Impaired breathing pattern related to decreased airway patency.

Nursing Care Planning and Goals

• Maintain clear, open airways with normal breath sounds, normal rate and depth, and effective cough after treatments and deep breaths.
• Demonstrate increased air exchange.
• Identify methods to improve secretion removal.
• Recognize the significance of sputum changes (color, character, amount, odor).
• Identify and avoid factors that inhibit airway clearance.

Nursing Intervention

• Teach coughing and breathing. Take a deep breath, hold for 2 seconds, then cough two or three times in succession.
• Promote effective coughing. Teach optimal positioning (sitting), pillow or hand splints, use of abdominal muscles, quad and huff techniques, incentive spirometry, and the value of ambulation and frequent position changes.
• Position the patient. Upright if tolerated; check regularly to prevent sliding down in bed.
• Push fluids. Encourage oral intake up to 3 liters per day within cardiac and renal limits.
• Give medications as prescribed. Antibiotics, mucolytics, bronchodilators, and expectorants; note effectiveness and side effects.
• Chest physiotherapy. Postural drainage, percussion, and vibration as ordered.

Evaluation

Goals are met when the patient maintains clear airways with normal breath sounds and effective cough, shows increased air exchange, identifies methods to improve secretion removal, recognizes sputum changes, and avoids factors that inhibit airway clearance.

Documentation

• Individual findings: factors affecting the patient, interactions, social exchanges, specifics of behavior.
• Cultural and religious beliefs and expectations.
• Plan of care.
• Teaching plan.
• Responses to interventions, teaching, and actions performed.
• Attainment or progress toward desired outcomes.