what is hepatitis?
inflammation of the liver
which hepatitis virus is the most commonly occuring viral hepatitis?
what are the modes of transmission for HAV?
what is the incubation period for HAV?
when is HAV the most communicable?
2-3 weeks before the onset of jaundice (preicteric)
how are the signs and symptoms defined?
- defined by jaundice
what is the icteric phase of HAV and who does it appear in?
- jaundice is present
- mostly adults rare in children
what is the preicteric phase and what are its symptoms?
- abrupt onset of flu-like symptoms (long and severe)
- liver is enlarged and tender to palpation
what is the anicteric phase?
- absence of jaundice
- 2-3 times more prevalent than icteric
- often misdiagnosed because it resembles the flu
how can you get HAV immunity?
- AntiHAV in serum 2-3 weeks after onset
- vaccine available
how can you prevent the transmission of HAV?
- personal hygiene-handwashing
- cooking food- 185 degree will inactivate virus
- sanitation- public health
how do you prevent HAV in the dental setting?
- standard precautions
- disposable materials
who are the risk groups for HAV that should be vaccinated?
- Travelers to places with high HAV
- Homosexual men
- drug users
- clotting disorders
- chronic liver disease
- children living in places with high rate of HAV
what hepatitis virus has had an increased incidence in the past 20 years?
what fluids carry infectious HBV?
- vaginal fluids
what are the modes of transmission for HBV?
- percutaneous-intravenous, subcutaneous
- blood transfusion
- needle stick
- sexual exposure
- perinatal-in utero
what is a risk population?
those that have an increased prevalence of infection, increase chances or likelihood of infection and increased prevalence of disease carriers
who are the individuals at high risk for HBV?
- infants-born to HIV infected mothers
- IV drug users
- Mental institutions-pt and staff
- hemodialysis-pt and staff
- recipients of blood products
- liver disease
- male prisoners
- health care presonnel-low risk if following ppe
- contact with HBV carriers
- military populations in countries with high endemic
- returning travelers who stayed more than 3 months or were treated
- morticians and embalmers
- immigrants and refugees
- sexual contact- multiple partners
what is the incubation period for HBV?
- 2-6 months
- average of 60-90 days
what indicates the communicability of HBV and when is it no longer detectible in blood?
- presence of HBsAG indicates communicability, found in blood as early as 30 days postexposure
- after jaundice no longer detectible in blood.
what is the transient subclinical infection of HBV?
- no icteric stage
- transient infection-rapid strong immune response
what is the disease process of acute type B HBV?
- onset is slower than other hep viruses
- cannot be distinguished on basis of clinical signs and symptoms
- period of illness is longer than hep A
what are the symptoms of acute type b HBV?
rash itching and joint pains
what percentages of children and infants become carriers of HBV?
- 5-10% infected after age five
- 30% infected between ages 1-5
- 90% infected at birth
How is immunity of HBV obtained other than vaccine?
- presence of anti-HB's in serum-had an exposure
- unknown presence-subclinical HBV
what are three ways to prevent HBV?
- transmission in infancy and childhood-immunoprophylaxis
- enforce blood bank control measures
- enforce sterilization/disposable syringes and needles
what are the two types of active HBV immunizations?
- plasma derived
- recombinant DNA
how is plasma derived vaccines for active immunization of HBV prepared?
prepared by using purified and formalin-treated HBsAg from plasm of chronic HBsAg carrier, it inactivates viruses
how is recombinant DNA vaccine for active immunization of HBV prepared?
synthesis HBsAg in culture of yeast, it is purified and sterilized
what is the effectiveness for HBV vaccines?
- 20-39 years 95% effective
- children 99% effective
what is the most common chronic blood-borne infection in the US?
what was hepatitis C originally called?
hep non A, non B
how is HCV transmitted?
- percutaneous-blood, needles, syringes, transfusions
- nonpercutaneous-sexual transmission, perinatl exposure
what is the disease process for HCV?
- onset-no clinical symptoms or abdominal pain, nausea, vomiting and jaundice
- acute infection-chronic infection
- chronic liver disease
what are the risk factors of having HCV?
severe liver disease
what are the principle risk factors of transmitting HCV?
- blood transfusion before 1991
- IV drug us
- intranasal cocaine user
- tattooing, ear/body piercing
- organ transplantation
what are the prevention and control methods for HCV?
- no vaccine
- strict standard procedures
- behavior modification
- same measures for hep B
what is Hep D coinfection with?
HBV-cannot cause infection except in the presence of HBV
how is hep D transmitted?
- multiple exposures to HBV
- blood and body fluids
- contaminated needles
what are the characteristics of hep D
- more severe than hep B alone
- higher mortality rate
- abrupt onset, signs and symptoms resemble HBV
what are the three parts of the disease process?
what is coinfection?
acute HDV occurring with acute HBV may lead to resolution of both types. If HBV is cleared HDV is cleared
what is superinfection?
acute HDV is superimposed on an existing carrier of HBV. HBV unchanged but delta state develops
what is superimposition?
chronic delta hepatitis superimposes on the chronic HBsAg carrier
what is the prevention of Hep D?
- same as hep B
- immunization for hep B protects against hep D
what is hep E similar to?
how is hep E transmitted?
- contaminated water
- person-person thru oral-fecal route
who is affected more with hep E?
adults affected more than children
what affect does hep E have on pregnant women?
high mortality rate
how can we prevent and control hep E?
- sanitary disposal of waste