Infectious diseases

• Bacterial Meningitis most common organisms

  • Neisseria meningitidis
  • Streptococcus pneumonia
  • Haemophilus influenza type b
• Viral meningitis most common pathogens:

  • Enteroviruses (most common) - echovirus, coxsackievirus
  • Mumps
  • HSV
  • Herpes zoster
  • HIV
  • Measles
  • Influenza
• Bacterial meningitis on LP:

  • Cloudy/turbid
  • WBCs elevated - mainly leukocytes
  • Elevated protein
  • low serum glucose (will be normal in viral)
  • Elevated opening pressure
• The mycobacterium tuberculosis complex includes M. Tuberculosis (most common), M. bovis and M. africanum
• Samples to test for TB are stained with Ziehl-Neelson stain for acid-fast bacilli
• Cellulitis affects the deeper layers of the dermis and subcutaneous tissues usually in the lower limbs

  • Staphylococcus aureus
  • Streptococcus pyogenes
• Flucloxacillin and doxycycline are first line antibiotics for cellulitis
• Treatment for active TB:

  • Isonazid, rifampicin, pyrazinamide and ethambutol for 2 months
  • Isonizid and rifampicin for a further four months
• Latent TB is treated with three months of isonizid and rifampicin or six months of isonazid only
• Methicillin-resistant Staphylococcus aureus (MRSA) refers to Staphylococcus aureus bacteria that have become resistant to beta-lactam antibiotics (e.g., penicillins, cephalosporins and carbapenems).
• Eradication of MRSA usually involves a combination of chlorhexidine body washes and antibacterials
• Tonsillitis common causes:

  • Viral - rhinovirus
  • Bacterial - group A beta-haemolytic streptococcus
• Antibiotic for bacterial tonsillitis - phenoxymethylpenicillin
• Shingles is causes by the herpes zoster - caused by reactivation of the varicella zoster virus (chickenpox)

  Oral antiviral given within 72 hours if severe - aciclovir