From the Guidelines
Bordetella pertussis employs several virulence factors to cause whooping cough, including pertussis toxin, filamentous hemagglutinin, pertactin, adenylate cyclase toxin, and tracheal cytotoxin. Management of pertussis infection requires prompt antibiotic therapy, typically with macrolides such as azithromycin or clarithromycin, as recommended by the CDC guidelines 1. The recommended dose for azithromycin is 10 mg/kg on day 1, then 5 mg/kg days 2-5 for children, and 500 mg on day 1, then 250 mg days 2-5 for adults. Alternative treatment includes trimethoprim-sulfamethoxazole for macrolide-allergic patients.
Key Considerations
- Supportive care is essential, including respiratory support, adequate hydration, and careful monitoring for complications like pneumonia or encephalopathy.
- While antibiotics eliminate the bacteria, they may not reduce symptoms if started late in the disease course, but they remain crucial for reducing transmission.
- Prevention through vaccination with DTaP (for children) or Tdap (for adolescents and adults) is the most effective strategy, with pregnant women recommended to receive Tdap during each pregnancy (preferably between 27-36 weeks) to provide passive immunity to newborns, as supported by the Advisory Committee on Immunization Practices (ACIP) recommendations 1.
- Close contacts should receive antibiotic prophylaxis with the same regimens used for treatment, as stated in the CDC guidelines 1.
Virulence Factors and Transmission
The virulence factors of Bordetella pertussis contribute to its ability to cause disease and transmit to others. Understanding these factors is crucial for developing effective prevention and treatment strategies. The use of acellular pertussis vaccines has been recommended for infants and young children, as well as for adolescents and adults, to prevent pertussis and reduce transmission 1.
Management Strategies
Effective management of pertussis infection involves a combination of antibiotic therapy, supportive care, and prevention through vaccination. By prioritizing these strategies, healthcare providers can reduce the morbidity, mortality, and impact on quality of life associated with pertussis, as emphasized by the CDC guidelines 1.
From the Research
Virulence Factors of Bordetella Pertussis
- The virulence factors of B. pertussis include pertussis toxin, tracheal cytotoxin, adenylate cyclase toxin, filamentous hemagglutinin, and lipooligosaccharide 2
- These factors promote bacterial adhesion and invasion by altering the local environment and possess immunomodulatory properties 2
- The production of most virulence factors is coordinately regulated by a two-component signal transduction system composed of the regulator BvgA and the sensor protein BvgS 3
- The adhesins and toxins act in concert to establish infection, with some adhesins exerting their effects synergically or being redundant and functioning only in the absence of another adhesin 3
Management Strategies for Bordetella Pertussis Infection
- The development of new acellular vaccines against whooping cough and genetically attenuated B. pertussis strains to be used as recombinant live bacterial vaccine vectors for homologous and heterologous protection has been facilitated by the understanding of Bordetella virulence at the molecular level 3
- Research into the development of safer, more efficacious, less reactogenic vaccine preparations has been concentrated on the production and purification of detoxified B. pertussis virulence factors 4
- The role of major toxin virulence factors, such as pertussis toxin, adenylate cyclase toxin-hemolysin, and tracheal cytotoxin, in pertussis infection and disease pathogenesis is crucial for the development of effective vaccines and treatments 5
Key Adhesins with Immunomodulatory Properties
- Filamentous hemagglutinin is a key adhesin with immunomodulatory properties, exhibiting several binding activities that may facilitate bacterial adherence to airway mucosa and host phagocytes in the initial phases of infection 6
- Despite three decades of research on filamentous hemagglutinin, there remain many questions on its structure-function relationships, integrin interactions, and possible immunomodulatory signaling capacity 6