Module 4 Flashcards
What are the most serious blood borne pathogens?
HBV (Hepatitis B)
HCV (Hepatitis C)
HIV (AIDS)
If you are not wearing gloves what is your risk of contracting HBV, HCV and HIV after a stick with a contaminated needle?
HBV - 30 % (non-immune)
HCV - 3%
HIV 0.3 %
By how much does wearing gloves reduce your chance of contracting HBV/HCV/HIV through a needle poke and why?
50% because the blood is wiped off on the glove before it passes through.
Which blood borne pathogens is immunization available for?
Hep A and B
Not Hep C or HIV
What does antigen mean?
Virus, infectious (bad news)
What does antibody mean?
immunity - good news (except for HIV)
Why is the presence of antibodies not good news with HIV?
The virus will still not be destroyed because it hides inside cells of the immune system, the cells will be destroyed, the immune system will be compromised and death will result.
What does hepatitis mean?
Inflammation of the liver
What is hepatitis?
A viral infection of the liver, but may also be caused by alcohol, parasites, drugs, chemical toxins and other agents.
What are the symptoms of hepatitis?
Jaundiced skin and sclera (white of eyes)
Dark urine
Pale feces
What are hepatitis A and E?
Transmitted via feces contaminated food and water.
because you AtE them
What was hepatitis previously called?
Infectious hepatitis (but all hep is infectious) Short incubation hepatitis (but incubation varies)
Describe the process of Hep A
Replicates in the epithelial lining of oral cavity and intestine, enters blood stream, invades liver, replicates in liver cells, bile leaving liver transports more HAV to the intestine (feces).
Describe the body of Hep A
It is naked (unenveloped).
What is the incubation period for Hep A?
15-50 days
What is the usual result of Hep A?
Usual symptoms, no permanent damage, usually do not die.
Are people with Hep A usually chronic carriers?
No
How is Hep A diagnoses?
Blood test looking for elevated liver enzymes and Hep A antibodies
What is the prevention control in place for Hep A?
- Feces are highly infective so careful had washing after contact with fecal matter.
- No carriers should handle food as the virus can live in food for days
- Do not come in contact with saliva
When is the Hep A vaccine recommended?
- Travellers of countries with poor sanitation
- Identified contacts of people with Hep A
What was Hepatitis B previously called?
Serum hepatitis (but found in other body fluids too) Long incubation hepatitis (but incubation time varies)
What is Hepatits B?
Small, enveloped virus that is unusually stable for being enveloped, it can resist freezing, moderate heat and some disinfectants.
Describe the Hep B body?
Nucleic acid core surrounded by a protein coat which is surrounded by a spiked envelope.
what are the 3 antigenic areas of the Hep B viral partible?
Hep B surface antigen (outer envelope)
Core antigen (protein coat)
“E” antigen (protein coat)
Describe the process of Hep B
Enters through blood or mucous membrane –>blood stream –> replicates in liver –> carried by blood to othe body fluids (tears, saliva, semen, mothers milk, vaginal secretions etc.)
What are the symptoms of Hep B?
Usually no symptoms (asymptomatic)
If a patient does have symptoms with Hep B what are they?
Jaundice
Liver inflammation symptoms (malaise, anorexia, nausea, vomiting, abdominal discomfort).
What is the incubation period of Hep B?
3 months
Are infected people chronic carriers of Hep B?
Yes, 5-10%
Carriers are a reservoir of HBV and may be infectious for 6-7 years.
Increases chance of liver cancer.
What is a fulminant infection of Hep B
Rapid and Severe
1-3%
Liver failure/death
How is Hep B transmitted?
Blood to blood or blood to mucous membrane activities: Blood: - sharing needles - sex - tattoo/acupuncture - shared razors/toothbrushes - needle sticks - blood stained bandages/clothing
By body fluid:
- sex
- saliva aerosols
- CPR
Mother to baby
How long are blood stained bandages/clothing infectious of Hep B for?
One week @ room temp
What is the drug that treats chronic Hep B?
Interferon, antiviral drug
How is Hep B diagnosed?
Blood test for Hep B surface antigen
How is Hep B prevented?
Vaccination
Gloves, goggles, protective clothing
Immune Globulin
What is Immune Globulin?
A product administered within 48 hrs of a healthcare worker has being exposed to Hep B (short term prevention).
How many cases of Hep are type C?
20%
What is the biggest cause of hep C?
Intravenous drug use
How is Hep C transmitted?
Blood
Ineffectively by sexual transmission
Mother to baby
What are the symptoms of hep C?
80% are asymptomatic
Is hep C chronically carried?
Yes, 60-90%
What is the result of chronic Hep C?
20 % liver cirrhosis
Increased hepatic cancer
Chronic fatigue
What is Hep D?
Defective virus that can only replicate in combination with Hep B
What is Hep E?
Spread by fecal oral route, similar to Hep A but higher mortality rate.
Is the Hep C viral body enveloped?
Yes
Difference between HIV/AIDs?
HIV is asymptomatic
AIDS symptoms present
What is HIV?
An enveloped RNA retrovirus with glycoprotein spikes
Describe the makeup of HIV
The core
- centre
- 2 strands of RNA
- contains reverse transcriptase used to produce viral DNA from RNA
The protein coat
- surrounds core
- several proteins (protein 24 is one of them)
The Lipid envelope
- spikey lipid bilayer
- binds virus to host cell via spikes
Is HIV very hardy?
No, can survive outside host for 1 week
Routine sterilization, disinfection and cleaning are fine.
Describe the process of HIV?
- Binding to host via spike (glycoprotein meets the membrane receptor on Tcells or CD4 cells of the immune system.
- Penetration - shed protein coat
- Reverse transcription - viral DNA rewrites host cell DNA
- Dormant period - variable time
- Viral replication - cell activated, synthesized and ready to infect others
What is the cellular effect of HIV?
Kills helper Tcells and CD4 cells (immune system)
immune system is compromised, AIDs is the result
How is HIV diagnosed?
Blood test for antibodies
How quick are antibodies present after contracting HIV?
4-12weeks
What is a negative window?
Negative screen test does not rule our infection, person is infected but detectable levels of antibodies are not yet present.
What is the Western Blot?
Confirmatory test of HIV, identifies several specific HIV antibodies
Describe the progression of HIV infection?
Contact –> primary infection (no symps) –> latent period (2 yrs) slow destruction of cells –> clinical AIDS (open to various infections, death)
What is a normal CD4 count?
600
Below 200 in AIDS
How is HIV/AIDS cured?
No cure for AIDS
ZDV/AZT is a drug that slows viral replication in HIV
How is HIV transmitted?
Blood, most infectious body fluid
What is more contagious, Hep B or HIV?
Hep B
What incidents would be considered significant exposure to blood?
- Patient blood contacts broken skin of HC worker
2. Patient blood contacting the mucous membrane of a HC worker
Steps for a HC worker to follow when coming in contact w/ patient blood.
- Bleed freely, wash w/antimicrobal soap and water
- Disinfect w/alcohol or iodine
- Contact appropriate service to document
- Blood test
- Treatment
What are HAART
antivirals, administered after contact w/ blood
What are some recent viral concerns to Canadians?
Sars
West Nile
H1N1 Flu
