Pneumococcus
(Streptococcus pneumoniae)
Copyright © 2020 C.E. by Dustin Jon Scott
Introduction
Streptococcus pneumoniae, also known as “pneumococcus” is a gram-positive, non-motile, facultatively anaerobic, diplococcal, hemolytic bacterium of the phylum Firmicutes, in the Streptococcaceae family of the Lactobacillales order within the Bacilli class. Its ecological niche is the nasopharynx of small children (Henriques-Normark & Tuomanen, 2013).
Hemolysis
Modes of hemolysis differ in pneumococcus depending on environment:
- α-Hemolysis or “Green Hemolysis” — pneumococcus is α-hemolytic under aerobic conditons.
- β-Hemolysis or “Complete Hemolysis” — pneumococcus is β-hemolytic under anaerobic conditions.
Polysaccarides & Pathogenicity
Pathogenic strains of S. pneumoniae are characterized by antiphagocytic polysaccharide capsules that sterically hinder access of leukocytes (Henriques-Normark & Tuomanen, 2013)
Epidemiology
“Pneumococcal infections are thought to spread from person to person via droplets/aerosols and nasopharyngeal colonization is a prerequisite for pneumococcal disease.” (Henriques-Normark & Tuomanen, 2013)
Pneumococcal Diseases & Symptoms
Pneumonia
Common symptoms include:
- fever/chills
- cough
- rapid breathing
- difficulty breathing
- chest pain
- death — in 5% of patients (Henriques-Normark & Tuomanen, 2013).
Additional symptoms known to occur in senescents:
- confusion
- lack of alertness
Pneumonal meningitis
Common symptoms include:
- stiff neck
- fever
- headache
- confusion
- photophobia
- death — in 20% of patients (Henriques-Normark & Tuomanen, 2013)
Septicemia
Common symptoms include:
- confusion
- shortness of breath
- elevated heart rate
- pain or discomfort
- over-perspiration
- fever/chills
- death — in 30% of patients (Henriques-Normark & Tuomanen, 2013)
Treatment of Pneumococcal Infections
Pneumococcal Vaccine
Pneumococcal Polysaccharide Vaccine (PPSV)
Words go here.
- PPSV23 or Pneumovax23® —
Pneumococcal Conjugate Vaccine (PCV)
Words go here.
- PCV 13 or Prevnar® 13 (Pneumococcal 13-valent conjugate vaccine [Diphtheria CRM197 Protein]) — protects against serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23.
PCV 13 Clinical Information
Indications & Usage
According to the FDA website:
- Children ages 6 weeks to 5 years — active immunization against serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and23F. Active immunization against otitis media caused by serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F (no efficacy data are available for serotypes 1, 3, 5, 6A, 7F, and 19A).
- Children ages 6-17 years — active immunization against serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and23F.
- Adults ages 18+ years — active immunization against serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F.
Administration & Dosage
According to the FDA website:
- Children ages 6 weeks to 5 years — four-dose immunization series consisting of a 0.5 mL intramuscular injection administered at 2, 4, 6, and 12-15 months of age.
- Children ages 6-17 years — a single dose.
- Adults ages 18+ years — single dose.
Important Safety Information
According to Pfizer’s Prevnar 13 website and the FDA website, contraindications and adverse effects include:
- Allergy risk — those who have previously had allergic reactions to any component of Prevnar 13 should not take the drug. Medications which include diphtheria toxoid may provoke severe allergic reactions.
- Immunocompromised individuals — such as those suffering illness-related immunodificiency or individuals undergoing immunosupressive therapy should not take this drug.
- Premature infants experienced apnea as the most common adverse effect.
- Infants & toddlers — pneumonia, gastroenteritis, and bronchitis occured in 0.9%.
- Children & adolescents — experienced redness, swelling, or tenderness at injection site as the most common adverse effects.
- Adults pain, redness, swelling at injection site, rash, joint pain, muscle pain, limited arm movement, fatigue, headache, fatigue, fever/chillds, decreased appetite, and vomiting.
References
van de Beek, Diederik; de Gans, Jan; Tunkel, Allan R.; Wijdicks, Eelco F.M. (5 January 2006). Community-Acquired Bacterial Meningitis in Adults. New England Journal of Medicine. 354 (1): 44–53. doi:10.1056/NEJMra052116. ISSN 0028-4793. PMID 16394301.
Wyeth LLC./Pfizer Inc. (2017). Prevnar 13. Retrieved January 26th, 2020 C.E., from https://www.prevnar13.com/
Birgitta Henriques-Normark and Elaine I. Tuomanen (2013). The Pneumococcus: Epidemiology, Microbiology, and Pathogenesis. Cold Spring Harbor Laboratory Press. doi: 10.1101/cshperspect.a010215
FDA information: https://www.fda.gov/media/107657/download