LO 4 Flashcards
(38 cards)
Describe direct transmission or contact
- Transfer of microorganisms from a specific person or host reservoir (Source) directly to another person (host)
- E.g. STDs, bloodborne diseases, skin diseases
Describe indirect transmission or contact
- Transfer of microorganisms from a specific person (source) to an inanimate object, to another person (host)
- E.g. common cold, hepatitis B and C
Describe transmission via droplets
- Physical particles greater than 5 micrometers
- This method can lead to both cross infection or autogenous infection
- E.g. flu, rubella, mumps, herpes
Describe transmission via airborne particles or aerosols
- In physical particles less than 5 micrometers that can be inhaled
- A surgical mask won’t protect against these, a particulate receptor would be needed
- E.g.tuberculosis, chickenpox, measles
_________ can result from any of the primary routes of transmission and involves introduction of a microorganism from one area of the body to another
Autogenous (self infection)
Transmission of microorganisms through contaminated dental unit water lines is an example of ________
Waterborne transfer
Describe waterborne transfer
- Transmission of microorganisms through contaminated dental unit water lines
- Portions of biofilm in waterlines dislodge, they are carried through the water line and can be expelled into the patient’s mouth during dental procedures
- The two significant concerns for dentistry are Legionella pneumophilia and pseudomonas
_______is the single most important source of potentially pathogenic microorganisms and dentistry
The patient’s oral cavity
What are the four basic disease types that result in pathogenic agents present in the mouth?
- Bloodborne diseases
- Oral diseases
- Systemic disease with oral lesions
- Respiratory diseases
Describe bloodborne pathogens
- Turning infection the pathogens exist in our released into the blood or other body fluids (e.g. Semen, vaginal secretion, intestinal secretion, tears, mother’s milk, synovial fluid, pericardial fluid, amniotic fluid, saliva)
- This disease is spread from one person to another by contact with the fluids, thus are called blood-borne diseases
What are the five common types of hepatitis and their origins?
- Hepatitis A (oral-fecal route)
- Hepatitis B (direct or indirect contact with body fluids)
- Hepatitis C (direct or direct contact with body fluids)
- Hepatitis D (direct or indirect contact with body fluids)
- Hepatitis E (oral-fecal route)
What is viral hepatitis?
Inflammation of the liver
Describe hepatitis B (HBV)
- Hepatitis B is a major health problem worldwide - it is endemic (occurs regularly)
- Hepatitis B is a DNA virus that infects and multiplies in human liver cells
- It can live for weeks on surface in dry saliva, and once moist it multiplies
- Hepatitis B is one of the most difficult to kill on surfaces
- Human beings are the only known natural hosts of HBV
- About 95% of those infected with hbv undergo complete recovery without developing a carrier state
- Anyone who is positive for HBsAg (hepatitis B surface antigen) has a potential to spread the disease to others
- Milliliter of blood from an infected person may contain as many as 100 million virus particles
Hepatitis B virus is spread _______ (through the skin) or _______ (through mucous membranes) by contact with infected body fluids
- Percutaneously
- Permucosally
What are the symptoms of hepatitis B virus?
- If symptoms develop after infection, they begin to appear 45 to 180 days after exposure
- Roughly 1/3 of those infected exhibit more easily recognizable symptoms - yellowing of the skin and whites of the eyes, light colored stools, dark urine, joint pain and fever, rash and itching
- 1/3 of those infected show no symptoms at all
What are the hepatitis B disease states?
- 95% can recover without developing a carrier state (takes almost 5 years to eliminate the virus from the body)
- Chronic active hepatitis patient (later develop into liver cancer)
Describe the spread of hepatitis B virus in the dental office
- Hepatitis B still remains the most important occupational acquired disease for dental professionals
- Greatest dental occupational risk for exposure: injuries from contaminated sharps, blood in saliva, contaminated cuts and cracks on the skin, spraying of blood and saliva into open lesions on the skin or on to mucous membranes
Although hepatitis B virus is difficult to kill it is more easily killed than _______
Myobacterium tuberculosis and bacterial spores
Describe the hepatitis B vaccine
- Safe and effective vaccines for hepatitis B are available
- No successful medical treatment exists to cure this disease, that’s why prevention is of paramount importance
Describe hepatitis C
- Mostly associated with intravenous drug users, sexual activity, and blood transfusion - 1% associated with occupational exposure to health care workers
- 75% 85% of those infected with hepatitis C become chronic carriers and 20% develop chronic liver disease
- No vaccine is available
Describe hepatitis D
Successful vaccination against hepatitis B also helps prevent hepatitis D
Describe hepatitis A and E
- Does not pose occupational risk to dental workers
- Spread by oral fecal root involving consumption of contaminated food or water
- Vaccination is available for hepatitis A
- Hepatitis E is self-limiting with no chronic state
Describe HIV (human immunodeficiency virus)
- Progresses to AIDS (acquired immunoticiency syndrome)
- Involves destruction of the immune system, making someone susceptible to life-threatening opportunistic infections and Cancers
- Use of antiviral drugs has lengthen life expectancy to 25 years
- It is an RNA virus
- Typically infects t4 lymphocytes (CD4 - also known as helper T cells)
- No vaccine can be developed at the stage
- Virus production destroys lymphocytes and yields more viruses that can infect and destroy even more lymphocytes
What are the two types of HIV?
- HIV type 1 - most common
- HIV type 2 - less aggressive