Infectious Diseases

• What is infection?

  A process of tissue invasion by microorganisms, characterised by multiplication of these microorganisms in the body of the host to produce disease

  
  

  Can be bacteria, viruses, fungi, parasites, protozoa
• What does cross-infection imply?


  The transmission of infection between patients as well as patients and health care professionals
• What information should you obtain in order to make a diagnosis?

  
• What investigations can you undertake after diagnosis?

  
• What are the most common viral infections?

  CMV

  Hepatitis virus

  HSV 1 and 2

  HIV

  Measles virus

  Mumps virus

  Rubella virus

  Influenza virus

  adenovirus
• How is herpes simplex spread?

  Type 1 spread by infected saliva

  Type 2 spread by sexual contact
• What is the incubation period for herpes simplex?

  2-12 days
• What are the clinical features of herpes simplex (1)?

  
• What are the clinical features of herpes simplex (2)?

  Can cause skin, eye and genital infections.

  
• What are the complications of herpes simplex?

  Encephalitis- affects temporal lobes

  Neonatal- serious since mortality is 60%

  ^Due to transfer of HSV-2 during parturition

  Indication for a caesarean section

  Erythema multiforme

  Eczema herpeticum
• How can you treat herpes simplex?

  Acyclovir, valacyclovir
• What is herpes zoster?

  Reactivation of varicella zoster virus
• What are the clinical features of herpes zoster virus?

  
• What are the complications of herpes zoster virus?

  Post-herpetic neuralgia

  Neurological e.g. meningitis (inflammation of lining of brain and spinal cord)
• How do you treat herpes zoster virus?

  Acyclovir

  reduces pain/accelerates healing but no effect on post-herpetic neuralgia
• What is the Epstein-Barr virus?

  This is a member of the herpes group and causes infectious mononucleosis
• What is the incubation period for Epstein-Barr virus?

  4-14 days
• What are the clinical features of infectious mononucleosis?

  
• What are the possible complications of infectious mononucleosis?

  Hepatitis

  Respiratory obstruction

  Ruptured spleen (rare-told to avoid sports)
• How do you diagnose EBV?

  Monospot testtreatment is supportive
• What is chicken pox caused by?

  Varicella zoster virus
• What is the incubation period for varicella zoster virus?

  14-16 days
• What are the clinical features of chicken pox?

  
• What are the possible complications of chicken pox?

  They're rare but include:

  Cellulitis or impetigo

  Pneumonia

  Neurological e.g. acute cerebellar ataxia, Reye's syndrome

  Congenital abnormalities
• What are the treatments for chicken pox?

  Antihistamines

  Acyclovir (severe cases/complications)
• What is mumps caused by?

  Paramyxovirus (RNA)
• What is the incubation period for paramyxovirus in mumps?

  16-21 days
• How is mumps spread?

  By droplets from saliva & nasopharyngeal secretions
• What are the clinical features of mumps?

  Asymptomatic in 40%

  Fever, malaise, "angle pain"

  Enlargement of one or both parotids

  Earache and displacement of earlobe

  Parotid papillae inflamed

  Difficulty in swallowing

  Submandibular glands may be affected
• What are the possible complications of mumps?

  Neurological: aseptic meningitis, encephalitis (inflammation of the brain)

  Orchitis: 20-25% in post pubertal

  Non-parotid mumps: ovaries, thyroid, pancreas, breasts
• What are the treatments for mumps?

  Good oral hygiene

  Scrotal support

  Bed rest in meningitis
• What are childhood exanthemas (widespread rash)?

  Measles

  German measles

  Enteroviral infection

  Infectious mononucleosis

  Scarlet fever

  Erythema infectiosum

  Roseola infantum

  Drug eruption
• What is measles caused by?

  Paramyxovirus (RNA)
• What is the incubation period for paramyxovirus in measles?

  10 days
• What are the clinical features of measles?

  
• What are the possible complications of measles?

  Gingivostomatitis (infection of the mouth and gums)
• Describe the treatment of measles.

  Treatment is supportive whilst any complications are treated as appropriate
• What is German measles caused by?

  Rubella virus (RNA)
• What is the incubation period for rubella in German measles?

  14-21 days
• What are the clinical features of German measles?