Adult Physical Dysfunction Rehabilitation Lab: Week 1 - Infection Control & Safety

Prion Diseases

• Nature: Prions are infectious agents primarily composed of protein.

• Impact: All known prion diseases affect the structure of the brain or other neural tissue.

• Current Status: They are currently untreatable and universally fatal.

• Example: Creutzfeldt-Jakob Disease (CJD):

  • Initial Symptoms: Rapidly progressive dementia, leading to memory loss, personality changes, and hallucinations.

  • Accompanying Physical Problems: Speech impairment, jerky movements (myoclonus), balance and coordination dysfunction (ataxia), changes in gait, rigid posture, and seizures.

  • Disease Duration: Highly variable, but sporadic (non-inherited) CJD can be fatal within months or even weeks (Johnson, $1998$).

• Related Condition: "Mad cow's disease" is another example of a prion disease.

Air-borne Transmission

• Tuberculosis (TB):

  • Nature: A common and often deadly infectious disease caused by various strains of mycobacteria.

  • Impact: Primarily attacks the lungs but can affect other parts of the body.

Droplet Transmission

• Mumps (Epidemic Parotitis):

  • Nature: Viral disease.

  • Symptoms: Most typically causes painful swelling of the salivary glands (classically the parotid gland). Painful testicular swelling (orchitis) and rash may also occur.

• Chickenpox (Varicella Zoster Virus - VZV):

  • Nature: A highly contagious illness caused by primary infection with VZV.

  • Symptoms: Usually begins with a vesicular skin rash mainly on the body and head (rather than the periphery). Lesions become itchy, raw pockmarks, which mostly heal without scarring.

  • Transmission: Spreads easily through coughs or sneezes of infected individuals or direct contact with secretions from the rash.

  • Immunity: Following primary infection, there is usually lifelong protective immunity from further episodes of chickenpox.

  • VZV in Adults: VZV is one of eight herpes viruses infecting humans; it commonly causes chickenpox in children and both shingles and postherpetic neuralgia in adults (rarely in children).

• Rubella (German Measles):

  • Nature: Disease caused by the rubella virus.

  • Transmission: Transmitted via airborne droplet emission from the upper respiratory tract of active cases. The virus can also be found in urine, feces, and on the skin.

  • Carrier State: There is no known carrier state; the reservoir exists solely in active human cases.

  • Incubation Period: $2$ to $3$ weeks, with an average incubation period of $28$ days.

  • Pregnancy Risk: Infection of a pregnant mother by Rubella virus can be serious for the fetus.

• Influenza (Flu)

• Pertussis (Whooping Cough):

  • Nature: Highly contagious disease caused by the bacterium Bordetella pertussis.

Transmission by Direct Contact

• Methicillin-Resistant Staphylococcus Aureus (MRSA):

  • Nature: A bacterium responsible for several difficult-to-treat infections in humans.

  • Other Names: Also known as Multidrug-Resistant Staphylococcus Aureus or Oxacillin-Resistant Staphylococcus Aureus (ORSA).

• Clostridium difficile (C. Diff):

  • Nature: A species of Gram-positive bacteria of the genus Clostridium.

  • Cause of Disease: Causes diarrhea and other intestinal diseases when competing beneficial bacteria are eliminated by antibiotics.

  • Harmful Mechanism: The bacterium releases toxins that can cause bloating, constipation, and diarrhea with abdominal pain, which may become severe.

Human Immunodeficiency Virus (HIV)

• Nature: A lentivirus (a member of the retrovirus family) that causes Acquired Immunodeficiency Syndrome (AIDS).

• AIDS: A condition in humans where the immune system progressively fails, leading to life-threatening opportunistic infections.

• Infection Occurs By: Transfer of specific bodily fluids:

  • Blood

  • Semen

  • Vaginal fluid

  • Pre-ejaculate

  • Breast milk

• Presence in Fluids: HIV is present in these fluids as both free virus particles and within infected immune cells.

• Four Major Routes of Transmission:

  • Unsafe sex

  • Contaminated needles

  • Breast milk (from infected mother)

  • Perinatal transmission (from an infected mother to her baby at birth)

• Impact of Screening: Screening of blood products for HIV has significantly reduced (largely eliminated) transmission through blood transfusions or infected blood products in the developed world.

Hepatitis (Inflammation of the Liver)

• General Definition: Inflammation of the liver characterized by the presence of inflammatory cells in the tissue of the organ.

• Progression: Can be self-limiting (healing on its own) or can progress to fibrosis (scarring) and cirrhosis (advanced scarring).

• Hepatitis A (HAV):

  • Nature: Acute infectious disease of the liver caused by the hepatitis A virus.

  • Transmission: Most commonly transmitted by the fecal-oral route via contaminated food or drinking water.

  • Prevalence: Approximately $10$ million people worldwide are infected with HAV annually.

  • Incubation Period: Between $2$ and $6$ weeks; the average incubation period is $28$ days.

• Hepatitis B Virus (HBV):

  • Nature: A species of the genus Orthohepadnavirus.

  • Consequences: Infection with HBV can lead to cirrhosis and hepatocellular carcinoma (liver cancer).

• Hepatitis C (HCV):

  • Nature: Infectious disease affecting the liver, caused by the hepatitis C virus.

  • Transmission: Spread by blood-to-blood contact.

  • Symptoms: Infection is often asymptomatic (without noticeable symptoms).

  • Chronic Infection Progression: Once established, chronic infection can progress to liver scarring (fibrosis) and advanced scarring (cirrhosis), which typically becomes apparent after many years.

  • Severe Complications: In some cases, those with cirrhosis may develop liver failure or other complications, including liver cancer or life-threatening esophageal varices and gastric varices.

Other Conditions (Ectoparasitic Infections)

• Scabies (Sarcoptic Mange / The Itch):

  • Nature: A contagious ectoparasitic skin infection.

  • Cause: Caused by the mite Sarcoptes scabiei.

  • Characteristics: Characterized by superficial burrows on the skin and intense pruritus (itching).

• Pediculosis Capitis (Head Lice Infestation):

  • Nature: Colonization of the hair and skin by the parasitic insect Pediculus humanus capitis.

Personal Protective Equipment (PPE)

• Further information and visual demonstrations on Personal Protective Equipment (PPE) can be found via the provided YouTube links:

  • https://www.youtube.com/watch?v=06xA-tsnBEY

  • https://www.youtube.com/watch?v=IYR6pghiQIM