Week 10 Flashcards
which hepatitis can be vacinated agaisnt
A and B
Which Hepatitis are transmited enterically
- A and E (“Vowels in the Bowels”)
Which genus is hepatitis A from
Hepatovirus
Which family is Hepatitis A in
Picornavirus (like rhinoviruses)
What are main impacts of Hepatisis A
acute but self-limiting inflammation of the liver
What characteristic of hepatitis A virus is critical in fecal-enteral transmission?
lack of lipid envolope (HAV and HEV is stable in bile)
What allows hepatitis A and E to have large outbreaks
direct route to outside (anal transmission) allows for large outbreaks
Hepatitis A - incubation period
15-45 days for replication
Hepatitis A - why it causes symptoms abrubpty
virus is present in blood and shed in stools within a few days of exposure
Hepatitis A - onset of symptoms is…
abrupt
Hepatitis A - serum markers of infection (3)
- ALT and AST (liver serum transaminases) increases
- bilirubin increases
- IgM antibody for HAV
Prevention of Hepatitis A
Vaccine
Symptoms of Hepatitis A (9)
- fever, malaise, anorexia, N/V, RUQ pain
- dark urine, light clay coloured stools, frank icterus
- jaundice
Hepatitis A - risk factors (4)
- close contact with an active case
- sexual behaviour
- food and water borne transmission
- visiting developing countries
Hepatitis A - recovery (3)
- always acute, complete recovery is the rule
- does not cause chronic hepatitis/carrier state
- lifelong immunity
Hepatitis A - age as a factor
- under 2 = rarely diagnosed with hepatitis
- under 6 = asymptomatic
- over 40 = risk of hepatic failure –> transplant
Hepatitis A - who gets immunization (3)
- international travellers
- homosexually sexually active men
- illicit drug users
Hepatitis E - genus of virus
- calcivirus
Hepatitis E - incubation period
40 days
Hepatitis E - pregnant women
cause fatality in 15-20% of cases in women infected during third trimester of pregnancy (fulminant hepatitis = hepatic failure)
Hepatitis E - where do outbreaks occur
typically developing countries
Hepatitis E - diagnositis
- HEV-IgG antibody
- absence of markers for other hepatis viruses
Which Hepatitis vaccines are RNA based
- Hepatitis A, C, D, E, G
Hepatitis E - vaccination?
China has produced a vaccine but it is not availiable globally
Hepatitis B - family
Hepadnaviridae
Hepatitis B - acute infection severity
- asymptomatic to fulminant hepatitis
Hepatitis B - types of infection
Acute and Chronic
Hepatitis B - amount of chronic infections globally
350 million with chronic infection
Hepatitis B - complications are associated with which type of infection
Chronic infection
Hepatitis B - pathogenesis
cell-mediated immune response of the host
Which Hepatitis strains are DNA based
Hepatitis B
Chronic Hepatitis B - potential complications (2)
1) HBV –> cirrhosis –> cancer
2) hepatitis D development
Hepatitis B - incubation period
50-150 days (more serious health problem)
Hepatitis B - marker of infectivity
- HBSAg - first marker (before elevation in AST and ALT serum transaminases)
Hepatitis B - marker of recovery
HBSAb - immunity and recovery
Hepatitis B - what if both markers are absent (period between recovery and infectivity)
- IgM antibody
Hepatitis B - transmission
infected blood or serum, body secretions (oral/sexual contact)
Hepatitis B - at risk populations (5)
- people with multiple partners
- men who have sex with men
- healthcare worksers
- injection drug users
- mother to child
Chronic Hepatitis B - common symptoms (3)
- nonspecific/mild
- lack of energy
- malaise
Chronic Hepatitis B - symptoms w hen immune complexes are present
- myalgias
- arthralgias skin rash
- glomerulonephritis
Chronic Hepatitis B - unnoticed (2)
- can be slow to notice symptoms
- may be unnoticed until cirrhosis and end-stage liver disease is present
Chronic Hepatitis B - serum qualities
- persistent HBSAg
- failure to develop HBSAb for 6 months
Chronic Hepatitis B - recovery
- 1% per year become spontaneously immune
- no known cure
Hepatitis B - Prevention
- vaccine with HBSAg antigen
Hepatitis B Vaccine - populations (5)
- all people with lifestyle risk factors
- medical personel
- lots of sexual partners
- houshold contacts of HBV carriers
- infants of HBV carrier mothers
Hepatitis C - family
Flavivirus
Hepatitis C - pathology
- slowly progressive liver disease that is asymptomatic until the late development of liver disease/liver cancer
Hepatitis C - symptom prevelance
only 5% of cases
Hepatitis C - potential for chronic infection
70% develop chronic infection
Hepatitis C - potential for spontaneous recovery
40%
Hepatitis C - diagnosis
- increased serum transaminases
- confirmed with HCV Ab (marker of infection)
Hepatitis C 0 risk factors (4)
- intravenous drug abuse (in the remote past sometimes after a single episode)
- 60-90% of IV drug abusers have Hep C
- exposure to untested/non heat treated blood products
- some sexual transmission (0-5%)
Hepatitis C - incubation period
2-26 weeks
Hepatitis C - symptoms (6)
- asymptomatic
- nonspecific (fatigue, malaise, anorexia, weight loss)
- typically not jaundice or fulminant hepatitis
Hepatitis C - serious consequences
- progressive liver fibrosis –> cirrhosis
- end stage liver disease
- hepatocellular liver cancer
Hepatitis C - risk factors for progressive liver fibrosis (5)
- age of aquisition over 40
- male sex
- alcohol consumption over 50g/day
- immunocompromised state
- genotype of the virus
Hepatitis D
-
Hepatitis C - genotypes of the virus
- many (6+)
Hepatitis D - Genotype number
3
Hepatitis D transmission
- blood borne
- rarely sexual and perianal transmision
Hepatitis D and Hepatitis B
- can be acquired at the same time
- Hepatitis B must be present for Hepatitis D to infect
- Hepatitis D can make Hepatitis B worse
Hepatitis D - vaccination?
no vaccine is availiable for D but hep B vaccine will prevent it
What is diarrhea
- passage of more than 300 grams of stool per day
- due to excretion of excess fecal water (60-90%)
What is acute diarrhea
- diarrhea lasting 2 weeks or less
- often associated with infectious causes
What is acute gastroenteritis
- less than 2 weeks of vomitting and diarrhea
Infectious entercolittis - pathogenic mechanisms (3)
- ingestion of preformed toxins in contaminated foods
- infection by toxigenic organism proliferating in the gut lumen producing an enterotoxin
- infection by enteroinvasive organisms that proliferate in the lumen and invade/destroy mucosal epithelial cells
Rotavirus - type of genetic material
RNA viruses
Rotavirus - belongs to which family
Reoviridae
Rotavirus - serogroups
- A, B, C
Rotavirus - group A serotypes
1, 2, 3, 4
Rotavirus - common age group
- children under 5
- most severe in ages 3-24 months (hospital)
- under 3 months protected by transplancental antibodies
Rotavirus - transmission
- fecal oral route
Rotavirus - impact on intestine
- localizes in duodenum and proximal jujenum
-destruction of villous epithelium
Rotavirus - portal of exit
- virus shed before and for days after clinical illness (very few infectious ririons are needed to cause disease in susceptible host)
Rotavirus - common complication
- malabsorption complication is common, takes 3-8 weeks to resolve
Rotavirus - diagnosis (3)``
- electron microscopy of stool
- detection of antigen via latex agglutination
- enzyme immunoassay
Rotavirus - therapy
supportive, primarily oral rehydration
Rotavirus - prevention
oral vaccine is avaliable and may be given in infancy