Microbiology: Streptococcal Infections Overview

Streptococcal Infections

• Streptococcal Pharyngitis (Strep Throat)

  • Caused by Group A Streptococcus (S. pyogenes)
  • Transmitted through respiratory droplets and direct contact
  • Symptoms include sore throat, fever, swollen lymph nodes, and white patches on the tonsils
  • Treated with antibiotics, typically penicillin or amoxicillin.

• Scarlet Fever

  • Caused by the same bacteria as strep throat when a toxin is produced
  • Characterized by a red rash, high fever, and strawberry tongue
  • Transmitted through infected individuals or contaminated objects
  • Managed with antibiotics and supportive care.

• Necrotizing Fasciitis

  • Severe infection often caused by S. pyogenes
  • Rapidly destroys tissue and can lead to systemic shock
  • Transmission via skin breaks or after surgical procedures
  • Requires aggressive treatment including surgery and intravenous antibiotics.

Complications of Streptococcal Infections

• Rheumatic Fever

  • Potentially arises after untreated streptococcal throat infection
  • Affects heart, joints, skin, and nervous system
  • Can cause long-term heart damage and requires anti-inflammatory medication.

• Post-Streptococcal Glomerulonephritis

  • Kidney inflammation following streptococcal infections
  • Symptoms include hematuria and hypertension
  • Usually resolves with minimal long-term effects but requires monitoring.

• Toxic Shock Syndrome

  • Rare but life-threatening condition linked to streptococcal infections
  • Symptoms include fever, rash, and multi-organ dysfunction
  • Treatment involves immediate antibiotics and supportive care.

Upper Respiratory Infections

• Haemophilus Influenzae Infections

  • Causes conditions like otitis media and sinusitis
  • Symptoms include ear pain, fever, and nasal congestion
  • Vaccination has reduced incidence; treated with antibiotics.

• Streptococcus Pneumoniae Infections

  • Leading cause of bacterial pneumonia and sinusitis
  • Symptoms include cough, fever, chest pain, and difficulty breathing
  • Comprehensive vaccination programs have decreased prevalence; treated with appropriate antibiotics.

Causative Agents, Transmission, Signs, and Symptoms

• Whooping Cough

  • Causative agent: Bordetella pertussis
  • Transmission: airborne droplets from coughs or sneezes
  • Symptoms: severe coughing fits, respiratory distress, and vomiting
  • Treatment: antibiotics and supportive care.

• Bacterial Pneumonia

  • Causative agents: various bacteria including Streptococcus pneumoniae
  • Transmission: respiratory droplets, aspiration, or blood
  • Symptoms: cough, fever, chills, chest pain, and difficulty breathing
  • Treatment: targeted antibiotics and sometimes hospitalization.

• Tuberculosis

  • Causative agent: Mycobacterium tuberculosis
  • Transmission: airborne via inhalation of droplets from an infected person
  • Symptoms: persistent cough, fever, night sweats, and weight loss
  • Treatment: combination antibiotic therapy over an extended period.

• Legionnaire's Disease

  • Causative agent: Legionella pneumophila
  • Transmission: inhalation of aerosolized water contaminated with bacteria
  • Symptoms: high fever, cough, shortness of breath, muscle aches, and headaches
  • Treatment: antibiotics effective against Legionella and supportive care.

Rhinovirus Infection Effects

• Causes the common cold, leading to symptoms such as runny nose, sore throat, coughing, and sneezing
• Increases mucus production and inflammation in the upper respiratory tract
• Can lead to secondary infections like sinusitis or otitis media in vulnerable populations.

This quiz covers key aspects of streptococcal infections, including their complications and details on upper respiratory infections caused by Haemophilus influenzae and Streptococcus pneumoniae. Additionally, it addresses various bacterial infections such as whooping cough, bacterial pneumonia, tuberculosis, and Legionnaire's disease, along with their transmission, symptoms, and treatments. Test your knowledge on these critical microbiological topics!