DEN 111 Test 3 Study Material (Part 1)

What does Hepatitis attack?

liver

What is the leading cause of liver cancer and most common reason for liver transplantation?

viral hepatitis

What are the different types of Hepatitis?

A,B,C,D,E

How does Hepatitis A spread?

contaminated food and water

(fecal to oral route)

How does Hepatitis B spread?

contact with infected body fluids

(blood, semen, saliva)

How does Hepatitis C spread?

through infected body fluids

(blood, semen)

How does Hepatitis D spread?

• direct contact with infected blood

• only in conjunction with Hepatitis B

(blood)

How does Hepatitis E spread?

• contaminated food and water

• feces of infected people

(fecal to oral route)

Which Hepatitis have vaccines?

A and B

Which Hepatitis don’t have vaccines?

C, D, and E

Incubation Period

time from exposure to an infectious agent until symptoms and signs of the disease appear

What is Yellowing associated with?

an accumulation of bilirubin in the skin (caused by liver/gallbladder disorders)

Blood borne Pathogens/Diseases

during infection pathogens exist in or are released into blood or other bodily fluids

What is the 3 rule?

• hep B 30%

• hep C 3%

• HIV .3%

What are some potential blood borne diseases?

• HCV

• HBV

• HIV

• STDs/STIs

Hepatitis A

• self-limited disease

• doesn’t result in chronic infection

• antibodies produced in response to Hep A infection last a lifetime

If an employee declines the Hep B vaccine what should occur?

employer should have them sign documentation stating the employee refused/declined the vaccine

Who pays for the HBV for dental health care workers?

the employer

What population is the highest incidence of Hep A reported?

children

What is the Incubation Period for Hep A?

• average 28 days

• can range from 15-45 days

When symptoms of Hep A occur how long do they typically last?

less than 2 months

How is Hep A confirmed?

• positive serologic test

• IgM antibody to Hep A virus

Is HAV an occupational hazard for dental workers?

no

How long can HAV live outside the body?

for months depending on environmental conditions

How can HAV be killed?

by heating to 185 degrees F for one minute

HBV Incubation Period

• average 75 days

• ranges from 45 days to 160-180 days

HBV Transmission

occurs when blood from an infected person (carrier) enters the body of a person that isn’t infected (host)

List ways HBV is transmitted

• sex

• injection drug

• birth

• contact with blood or open sores of an infected person

• needle sticks

• sharing items

HBV isn’t spread through

• kissing

• hugging

• food and water

• sharing eating utensils

• breastfeeding

• hand holding

• coughing/sneezing

Where is HBV found in highest concentrations?

in the blood

Know why TB cases reported in the US from 1985-92 increased

• inadequate funding

• increased immigration

• spread in shelters and correctional facilities

• increased spread of multi drug resistant TB

Name of microbe that causes TB

mycobacterium tuberculosis

Droplet Nuclei

respiratory droplets that can remain suspended in the air for extended periods

MOT for TB

airborne transmission

Where does TB usually reside?

lungs

What percent of persons infected with TB develop TB disease?

5%

What are the 2 main factors that contribute to the probability that TB will be transmitted to another person?

• infectiousness (load)

• level of exposure (environment and duration)

What is the strongest risk factor for development of active TB?

HIV infection

Process of TB skin test

inject small amount of tuberculin into skin, read 2-3 days later

Is the Tb skin test a diagnosis or screening protocol?

screening protocol

What is the risk level for acquiring TB in a dental office setting?

low

Name how the transmission of TB can be prevented

• respirators/masks

• environmental controls

• administrative controls

Symptoms of TB

• bad cough for 3+ weeks

• chest pain

• coughing up blood/sputum

What is Latent TB?

person is infected with mycobacterium TB but doesn’t have active TB (can live in your body and not make you sick)

What is the major problem with TB control?

rise in drug-resistant TB

What has to occur for a complete diagnosis of TB?

• medical history

• physical exam

• test for TB infection

• chest x-ray

• bacteriological

EDR-TB

Extensively drug-resistant

• rare

• resistant to nearly all medicines used to treat TB

MDR-TB

Multidrug-resistant

• TB disease caused by bacteria resistant to INF/RIF 

• also know as first line drugs

Who usually has MDR-TB or EDR-TB?

• those not taking meds properly

• those that fail to complete treatment

What does a positive reaction to the TB skin test mean?

you have been infected by someone with active TB disease

Active TB

• TB bacteria is active in the body and multiplies

• person will get sick

Latent TB (LTBI)

• person is infected with M.tuberculosis

• don’t have active tuberculosis

• tuberculosis is living in the body and not making the person sick and shows no symptoms

• not infectious (can’t spread TB bacteria)

TB Pathogenesis

tubercle bacilli multiply in alveoli where infection begins

Testing for TB

• skin test (TST)

• blood test

BCG (TB vaccine)

• not widely used in US

• given to infants/small children in countries where TB is common

• doesn’t always protect from TB

• positive TB skin test is possible (due to BCG or infection)

When should DHCW get the TB skin test?

upon hire (annual test not typically required)

What conditions increase risk of TB infection?

• diabetes

• HIV

• weakened immune system

Can you have a positive TB skin test and not be contagious?

yes, the BCG vaccine can give a positive skin test result

Which workplaces have been identified as high risk areas for TB?

• shelters

• correctional facilites

• long-term care homes

• hospitals

Additional systemic conditions of TB Active

• Potts

• meningitis

• gastrointestinal TB

• hepatic

• pericarditis

• lymphadenitis