SELECTED MEDICALLY IMPORTANT VIRUSES Flashcards
ADENOVIRIDAE
viral conjunctivitis
1
ADENOVIRIDAE
acute respiratory disease
Serotype 3, 4, 7, 21
ADENOVIRIDAE
epidemic keratoconjunctivitis
Serotype 8, 19 –
hemorrhagic cystitis
Serotype 11, 21
– infantile gastroenteritis
Serotype 40, 41
Dx: Cell culture – ______
grape-like CPE
Currently, there are five recognized hepatitis viruses:
○ HAV ○ HBV ○ HCV (previously known as non-A, non-B (NANB) ○ HDV ○ HEV
Hepatitis is diagnosed ______ through the identification of specific antigens or antibodies.
serologically
member of the family picornaviridae in the genus Enterovirus.
● possesses ssRNA, + sense, icosahedral symmetry, and no envelope; 24 nm to 30 nm.
● a very stable virus, can withstand temp of 56oC to 60oC for 1 hr., and is acid stable.
Hepatitis A Virus (HAV)
Infections are facilitated by poor sanitation, international travel, crowded conditions, and poor personal hygiene practices. ● Another route of infection is through the ingestion of contaminated shellfish, such as clams, oysters, and mussels.
● Raw or improperly treated sewage that enters the water supply is another source of infection.
● The virus can be spread through the congenital route, from mother to baby at birth, if the mother is acutely infected at this time.
● Children in school and day care, prisoners, and those with poor personal hygiene are at an increased risk.
Hepatitis A Virus (HAV)
HAV enters the blood through _______ or intestinal epithelial cells and replicates in hepatocytes and Kupffer cells.
oropharyngeal
_______ is a measure of the total antibody to HAV, which include Ab to both IgM and IgG.
Anti-HAV
______ is a measure of past infection to HAV
Anti-HAV
_______ is a measure of IgM-specific antibody to HAV and if positive suggests acute HAV infection is present.
Antibody to IgM (HAVIgM)
If anti-HAV is present and anti-HAV IgM is absent, ____________ is indicated.
a past HAV infection
Member of the family Hepadnaviridae and is DNA-containing virus with a complex capsid and icosahedral arrangement.
● is a 42nm to 47nm envelope with circular DNA, which is partially double stranded and partially single stranded.
● It is very stable and resists freezing, heating, acidic conditions, which facilitates its transmission.
● has a complex structure; the double-shelled form, known as the Dane particle, is recognized as the whole-virus particle.
Hepatitis B Virus (HBV)
______is the outer lipid component; this outer envelope circulates in the blood as a viral particle either bound to protein or as a free, noninfectious protein, which is spherical or tubular
The inner core of the virus contains ______, which surrounds the partially double stranded DNA and DNA polymerase, which is needed for viral replication.
_______ also is a component of the core antigen.
HBsAg
HBcAg
HBeAg
- indicates the person is infectious -found in high levels during acute and chronic infection
- used to make the HBV vaccine
HBsAg
indicates acute or chronic infection
-not found with vaccine
HBcAg
- associated with the nucleocapsid gene found during acute and chronic HBV
- presence indicates replicating virus and high levels of HBV
HBeAg
The original name for HBV infection was “_______” because of the contamination of vaccines in WWII with serum that contained HBV.
serum hepatitis
After exposure, HBV may incubate for 50 to 180 days, with an average incubation time of ___.
● The virus replicates in the ____
● HBV disease has an insidious onset, with initial signs of fever, rash, or arthritis.
90 days
liver.
Present at the onset of infection.
● The first serological marker to appear and can be detected 30 to 60 days after exposure.
● It disappears as the liver enzymes return to normal and the patient recovers.
● Persistence of this for more than 6 months may indicate chronic infection.
● It is present in acute, active, chronic, and carrier states of HBV infection.
HBsAg
Present in acute and chronic hepatitis and is a marker of infectivity.
● Persistence of HBeAg usually indicates chronic liver disease.
● It usually appears soon after HBsAg.
HBeAg
● It is the total antibody to HBsAg.
● It appears 2 to 6 weeks after HBsAg is gone and usually persists for life.
● The presence of this generally indicates recovery or immunity after the HBV immunization.
Anti-HBsAg
● It is an indicator of recent acute infection.
● It is usually present for 6 months.
● Acute infection is indicated when anti-HBcAg-IgM is present with HBsAg.
Anti-HBcAg-IgM
Total antibody to HBcAg (IgG and IgM) appearing after HBsAg but before anti-HBsAg appears; thus it sometimes is referred to as the “core window”.
● It is present in high levels at the onset of symptoms but drops to low levels, and levels may persist for 5 to 6 years.
● indicates current or previous infection and is not associated with recovery or immunity.
Anti-HBcAg
● This does not appear until HBeAg disappears.
● It is usually associated with a favorable outcome, recovery, and reduced infectivity.
Anti-HBeAb
● It is an RNA-containing virus with a lipid envelope, (+) sense, and a size of 30nm to 60nm.
● Member of the family Flaviviridae and in the genus Hepacivirus.
● Formerly known as non-A, non-B (NANB) hepatitis.
● The genome encodes for a large protein, which is cleaved into structural and nonstructural proteins
Hepatitis C Virus (HCV)
_____was the most frequent cause of post-transfusion hepatitis, responsible for approximately 90% of all cases.
HCV
● Also known as delta virus; is a small virus with size of 35nm to 37nm, which possesses ssRNA and is infective only in the presence of HBV.
● It is an incomplete virus, which can cause acute or chronic hepatitis only when HBV also is present.
● It is transmitted through routes similar to those of HBV, such as percutaneous or mucosal contact with infectious blood or body fluids, and is acquired through coinfection or superinfection in those who are infected with HBV.
● Serological testing to detect HDV antigen, IgM antibody to HDV, and total antibody to HDV is available.
● Hepatitis B vaccination can prevent HDV in those persons who are not infected with HBV.
Hepatitis D Virus (HDV)
