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Emergency And Acute Medicine – Pertussis
Pertussis is an acute respiratory tract infection transmitted by small respiratory droplets. The organism attaches to respiratory epithelial cells via fimbriae and produces toxins that cause ciliary dysfunction, accumulation of debris, increased mucus production, and inflammatory infiltration. Bronchiolar congestion, obstruction, and necrosis may develop. Airway obstruction from mucus plugging can lead to hypoxia, hypoventilation, and increased intrathoracic or intracranial pressure. Secondary bacterial pneumonia may worsen respiratory failure. Central nervous system injury may result from encephalitis, hypoxia, or elevated intracranial pressure. Uncomplicated illness typically lasts 6–10 weeks, although about half resolve in under 6 weeks. Mortality is highest in infants under 1 year, especially those younger than 1 month. Most deaths are due to secondary bacterial pneumonia. The incubation period is usually 7–10 days. Disease is most common in young children, but incidence is increasing among adolescents. Adults serve as the primary reservoir. Peak incidence occurs in late summer and fall. Vaccination with Tdap provides prevention. The causative organism is Bordetella pertussis, a fastidious gram-negative pleomorphic bacillus.
The illness classically progresses through three phases, although infants may not follow distinct stages. The catarrhal stage lasts 1–2 weeks and resembles a mild upper respiratory infection with rhinorrhea, low-grade fever, malaise, sore throat, lacrimation, and mild cough. The paroxysmal stage lasts 1–6 weeks and is characterized by severe coughing spells that end with a sudden inspiratory “whoop.” Paroxysms may be associated with cyanosis, apnea (especially in infants under 6 months), post-tussive emesis, and altered mental status due to hypoxia. The convalescent stage lasts 2–12 weeks with gradual improvement and decreasing frequency of cough. Adults and partially immunized children often have milder or atypical presentations, sometimes limited to persistent cough without a classic whoop.
Diagnosis in the emergency setting is primarily clinical, especially when a characteristic paroxysmal cough is observed or there is a known exposure. Laboratory confirmation may support the diagnosis. PCR testing from a posterior nasopharyngeal swab or aspirate has high sensitivity and specificity but may produce false positives and false negatives depending on timing and prior antibiotic use. Culture on Bordet–Gengou medium remains the gold standard due to high specificity but has low sensitivity and requires 7–12 days for results. Serology is useful later in the course. Leukocytosis with marked lymphocytosis is common and correlates with disease severity. Chest radiographs are often normal but may show perihilar infiltrates, atelectasis, or secondary pneumonia.
Differential diagnoses include other causes of prolonged or paroxysmal cough such as infections with Bordetella parapertussis, Chlamydia species, adenovirus, pneumonia, bronchiolitis, influenza, reactive airway disease, foreign body aspiration, and cystic fibrosis.
Initial management focuses on airway and respiratory support. Oxygen supplementation and suctioning of mucus plugs are important, particularly in infants. Droplet precautions are required for 5 days after initiation of effective antimicrobial therapy. Adequate hydration must be maintained. Continuous monitoring is recommended during severe paroxysms, especially in infants. Antibiotics are most effective during the catarrhal phase but are still indicated during the paroxysmal phase to reduce transmission. Azithromycin is the first-line agent. Alternatives include clarithromycin, erythromycin, or trimethoprim–sulfamethoxazole, although erythromycin carries a risk of pyloric stenosis in neonates. Bronchodilators and corticosteroids are generally not recommended. Tdap vaccination should be offered when appropriate, including during each pregnancy between 27 and 36 weeks gestation to protect newborns.
Admission is indicated for patients under 1 year of age, those with apnea, cyanosis, pneumonia, encephalitis, or significant respiratory distress. Children without respiratory compromise may be discharged with close follow-up, hydration guidance, and avoidance of cough triggers such as smoke and pollutants. Postexposure prophylaxis with antibiotics is recommended for all close contacts regardless of age or immunization status. Patients may return to school or work after 5 days of appropriate antibiotic therapy.
Complications include epistaxis, subconjunctival hemorrhage, pneumonia, pneumothorax, subcutaneous or mediastinal emphysema, bronchiectasis, hernias, rectal prolapse, seizures, encephalitis, intracranial hemorrhage, and spinal epidural hemorrhage. Infants require particular vigilance due to high risk of apnea and severe respiratory compromise. Cases must be reported to public health authorities, and strict droplet precautions are essential to prevent spread.
Pertussis is an acute respiratory tract infection transmitted by small respiratory droplets. The organism attaches to respiratory epithelial cells via fimbriae and produces toxins that cause ciliary dysfunction, accumulation of debris, increased mucus production, and inflammatory infiltration. Bronchiolar congestion, obstruction, and necrosis may develop. Airway obstruction from mucus plugging can lead to hypoxia, hypoventilation, and increased intrathoracic or intracranial pressure. Secondary bacterial pneumonia may worsen respiratory failure. Central nervous system injury may result from encephalitis, hypoxia, or elevated intracranial pressure. Uncomplicated illness typically lasts 6–10 weeks, although about half resolve in under 6 weeks. Mortality is highest in infants under 1 year, especially those younger than 1 month. Most deaths are due to secondary bacterial pneumonia. The incubation period is usually 7–10 days. Disease is most common in young children, but incidence is increasing among adolescents. Adults serve as the primary reservoir. Peak incidence occurs in late summer and fall. Vaccination with Tdap provides prevention. The causative organism is Bordetella pertussis, a fastidious gram-negative pleomorphic bacillus.
The illness classically progresses through three phases, although infants may not follow distinct stages. The catarrhal stage lasts 1–2 weeks and resembles a mild upper respiratory infection with rhinorrhea, low-grade fever, malaise, sore throat, lacrimation, and mild cough. The paroxysmal stage lasts 1–6 weeks and is characterized by severe coughing spells that end with a sudden inspiratory “whoop.” Paroxysms may be associated with cyanosis, apnea (especially in infants under 6 months), post-tussive emesis, and altered mental status due to hypoxia. The convalescent stage lasts 2–12 weeks with gradual improvement and decreasing frequency of cough. Adults and partially immunized children often have milder or atypical presentations, sometimes limited to persistent cough without a classic whoop.
Diagnosis in the emergency setting is primarily clinical, especially when a characteristic paroxysmal cough is observed or there is a known exposure. Laboratory confirmation may support the diagnosis. PCR testing from a posterior nasopharyngeal swab or aspirate has high sensitivity and specificity but may produce false positives and false negatives depending on timing and prior antibiotic use. Culture on Bordet–Gengou medium remains the gold standard due to high specificity but has low sensitivity and requires 7–12 days for results. Serology is useful later in the course. Leukocytosis with marked lymphocytosis is common and correlates with disease severity. Chest radiographs are often normal but may show perihilar infiltrates, atelectasis, or secondary pneumonia.
Differential diagnoses include other causes of prolonged or paroxysmal cough such as infections with Bordetella parapertussis, Chlamydia species, adenovirus, pneumonia, bronchiolitis, influenza, reactive airway disease, foreign body aspiration, and cystic fibrosis.
Initial management focuses on airway and respiratory support. Oxygen supplementation and suctioning of mucus plugs are important, particularly in infants. Droplet precautions are required for 5 days after initiation of effective antimicrobial therapy. Adequate hydration must be maintained. Continuous monitoring is recommended during severe paroxysms, especially in infants. Antibiotics are most effective during the catarrhal phase but are still indicated during the paroxysmal phase to reduce transmission. Azithromycin is the first-line agent. Alternatives include clarithromycin, erythromycin, or trimethoprim–sulfamethoxazole, although erythromycin carries a risk of pyloric stenosis in neonates. Bronchodilators and corticosteroids are generally not recommended. Tdap vaccination should be offered when appropriate, including during each pregnancy between 27 and 36 weeks gestation to protect newborns.
Admission is indicated for patients under 1 year of age, those with apnea, cyanosis, pneumonia, encephalitis, or significant respiratory distress. Children without respiratory compromise may be discharged with close follow-up, hydration guidance, and avoidance of cough triggers such as smoke and pollutants. Postexposure prophylaxis with antibiotics is recommended for all close contacts regardless of age or immunization status. Patients may return to school or work after 5 days of appropriate antibiotic therapy.
Complications include epistaxis, subconjunctival hemorrhage, pneumonia, pneumothorax, subcutaneous or mediastinal emphysema, bronchiectasis, hernias, rectal prolapse, seizures, encephalitis, intracranial hemorrhage, and spinal epidural hemorrhage. Infants require particular vigilance due to high risk of apnea and severe respiratory compromise. Cases must be reported to public health authorities, and strict droplet precautions are essential to prevent spread.
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