Infectious Disease Module 2: Bacterial Infections

Overview

Focus: Bacterial Infections
Key Infections Covered: Clostridioides difficile (C. diff), Staphylococcus infections, Streptococcal infections, Pseudomonas infections.

Type: Anaerobic bacteria (does not need oxygen)
Survival: Can live up to months
Transmission: Fecal-oral route
Common in Hospitals: Nosocomial infection
Symptoms: Persistent diarrhea, watery and loose stool, can lead to fatal colon inflammation
Risk Groups: Antibiotic users, those over 65, living with an infected person
Precautions: Contact precautions necessary, especially around patients
Treatment: Probiotics and specific antibiotics
Cleaning: Requires bleach or commercial disinfectant wipes, let air-dry for 2 minutes

Type: Anaerobic
Transmission: Direct contact
Risk Groups: Older adults, surgery/burns, open wounds, insulin-dependent diabetes, chronic diseases, neutropenic patients
Symptoms: Local abscess, fever, chills, pain, swelling, cellulitis
Common Strain: MRSA (Methicillin-resistant Staphylococcus aureus)
Precautions: Contact precautions, hand hygiene
Pathogenesis: Entry through secretions or traumatic inoculation, abscess formation, can lead to bacteremia
Treatment: Antibiotics (specific to strain), vancomycin for MRSA

Group A (GAS): Transmitted via respiratory droplets
Types and Symptoms:
- Pharyngitis (Strep throat): Fever, sore throat, swollen tonsils, abdominal pain
- Scarlet Fever: Fever, sore throat, strawberry tongue, rash
- Impetigo: Small vesicles, localized mainly in toddlers, linked to poor hygiene and minor skin trauma
- Erysipelas: Superficial cellulitis with fever and chills, red and shiny skin
- Cellulitis: Red linear streaks, very tender, swollen lymph nodes
- Necrotizing Fasciitis: Rapidly spreads causing severe skin necrosis, high mortality rate
Pneumonia: Can cause sepsis, commonly in immunocompromised, vaccinations recommended for those over 65, symptoms include fever, productive cough, delirium in elderly
Complications: Empyema, bacteremia, meningitis
Treatment: Aggressive debridement, IV antibiotics, prophylactic antibiotics post-op

Type: Opportunistic, prefers moist environments
Association: Acute COPD exacerbations, wound infections, UTI, sepsis
Symptoms: Depend on infected area, can include respiratory issues, bacteremia, CNS involvement, soft tissue infections, osteomyelitis
Treatment: Ciprofloxacin is effective, requires proper hand hygiene, cleaning, sterile techniques
Transmission: Via moist surfaces or improper hygiene

Cleaning and Precautions: Emphasis on proper cleaning protocols, hand hygiene, and contact precautions
Risk Factors: Elderly, immunocompromised, recent surgery or trauma, living in close quarters

Next Steps: Come to class with questions for further discussion.