MMSC 420 Exam 4 Questions and Answers Already Passed
donor testing (transfusion transmitted infections) - Answers certain blood borne pathogens can
be transmitted from an infected donor to a transfusion recipient through blood products, certain
screening methods can help to decrease this risk
-medical screening: temp, BP, weight, etc.
-donor questionnaire: questions about history helps to distinguish risk factors
-standard serological testing
donor serological testing - Answers -type and screen
-HbsAg (HBV surface antigen)
-anti-Hbc (HBV core antigen)
-anti-HCV
-anti-HIV 1/2
-anti-HTLV I/II
-STS syphilis (RPR)
-NAT test for HCV, HIV and WNV (earlier detection)
-chagas disease
hepatitis B (HBV) - Answers -transmitted by blood and body fluids (sexual, parenteral or
perinatal)
-symptoms variable
-chronic form associated with hepatocellular carcinoma (HCC)
-HBsAg is good for detection of early infection (can be positive from week 2 to 12)
-HbeAg is good marker for current infectivity
-NAT not used in US because disease is not endemic
-vaccine availible
-very virulent, survives for a week on surfaces
hepatitis C (HCV) - Answers -transmitted in blood and body fluids
-incubation of 2-26 weeks
,-infection may be asymptomatic
-many infected become chronic carriers
-develops into hepatocellular carcinoma (HCC), number one cause of liver transplant
-NAT for viral RNA has decreased the window period to 10-30 days
-anti HCV tests: preliminary tests can have false positives, followup with RIBA for confirmation
hepatitis D (HDV) - Answers -infection is only found in patients with HBV coinfection (needs
HBV antigen to make envelope protein)
-testing is not done because if a donor is HBV positive they will already be rejected
hepatitis A (HAV) - Answers -transmitted via fecal oral route
-rarely fatal
-no chronic infection
-RARELY transmitted in blood, no testing required
hepatitis E (HEV) - Answers -transmitted by fecal oral pathway
-no chronic state
-can cause liver failure in pregnant females and be very fatal
-testing is done via anti-HEV titers of EIA
hepatitis G (HGV) - Answers -transmitted in blood, parenteral, fecal oral and sexual transmission
-most common hepatitis virus, but does not actually cause liver inflammation (hepatitis)
-detected via RT PCR
HIV (types 1 and 2) - Answers -transmitted sexually and parenterally
-high risk populations: gay men, IV drug users, sexual partners of high risk populations
-causes AIDS
-primary infection is asymptomatic, followed by long clinical latency
-antibody testing: window period is 22 days, screening test has to be followed by confirmatory
test if positive (IFA or WB)
-NAT: window period decreased to 4-7 days
, human T cell lymphotrophic virus (HTLV I and II) - Answers -transmitted sexually, parenterally,
and vertically by breastfeeding
-RNA retrovirus that is latent with no symptoms for many years
-causes T cell lymphoma and HTLVI-I associated myelopathy/ tropic spastic paraparesis (HAM,
HAM/TSP)
-EIA is used to screen blood units
-units that are >7 days old and leukoreduced decrease risk of transmitting virus (requires WBCs
to survive)
west nile virus - Answers -transmitted from mosquito vectors that pick up virus from bird host
and transmit to humans
-can cause encephalitis
-usually subclinical, but can be fatal especially to elderly individuals
-incubation is 3 to 14 days
-ELISA testing can be used, but some false negs occur
-NAT decreases window period
CMV - Answers -transmitted through infected body fluids
-most adults have been exposed by age 40, virus is latent in the body for many years
-infection is usually asymptomatic and people don't know they're exposed
-infection is severe to immunocompromised invdividuals: fetuses, immunocompromised and
BMT recipients
-anti-CMV negative leukoreduced blood is given to high risk populations
-detected via ELISA, fluorescence, indirect hemagglutination or viral culture
epstein barr virus (EBV) - Answers -asymptomatic infection of B lymphocytes
-many adults are seropositive
-not tested for in blood units because its not an issue for the general population (can be
transfusion transmitted but doesn't matter)
-issue for organ transplant patients
parvovirus B19 - Answers -asymptomatic infection in adults
donor testing (transfusion transmitted infections) - Answers certain blood borne pathogens can
be transmitted from an infected donor to a transfusion recipient through blood products, certain
screening methods can help to decrease this risk
-medical screening: temp, BP, weight, etc.
-donor questionnaire: questions about history helps to distinguish risk factors
-standard serological testing
donor serological testing - Answers -type and screen
-HbsAg (HBV surface antigen)
-anti-Hbc (HBV core antigen)
-anti-HCV
-anti-HIV 1/2
-anti-HTLV I/II
-STS syphilis (RPR)
-NAT test for HCV, HIV and WNV (earlier detection)
-chagas disease
hepatitis B (HBV) - Answers -transmitted by blood and body fluids (sexual, parenteral or
perinatal)
-symptoms variable
-chronic form associated with hepatocellular carcinoma (HCC)
-HBsAg is good for detection of early infection (can be positive from week 2 to 12)
-HbeAg is good marker for current infectivity
-NAT not used in US because disease is not endemic
-vaccine availible
-very virulent, survives for a week on surfaces
hepatitis C (HCV) - Answers -transmitted in blood and body fluids
-incubation of 2-26 weeks
,-infection may be asymptomatic
-many infected become chronic carriers
-develops into hepatocellular carcinoma (HCC), number one cause of liver transplant
-NAT for viral RNA has decreased the window period to 10-30 days
-anti HCV tests: preliminary tests can have false positives, followup with RIBA for confirmation
hepatitis D (HDV) - Answers -infection is only found in patients with HBV coinfection (needs
HBV antigen to make envelope protein)
-testing is not done because if a donor is HBV positive they will already be rejected
hepatitis A (HAV) - Answers -transmitted via fecal oral route
-rarely fatal
-no chronic infection
-RARELY transmitted in blood, no testing required
hepatitis E (HEV) - Answers -transmitted by fecal oral pathway
-no chronic state
-can cause liver failure in pregnant females and be very fatal
-testing is done via anti-HEV titers of EIA
hepatitis G (HGV) - Answers -transmitted in blood, parenteral, fecal oral and sexual transmission
-most common hepatitis virus, but does not actually cause liver inflammation (hepatitis)
-detected via RT PCR
HIV (types 1 and 2) - Answers -transmitted sexually and parenterally
-high risk populations: gay men, IV drug users, sexual partners of high risk populations
-causes AIDS
-primary infection is asymptomatic, followed by long clinical latency
-antibody testing: window period is 22 days, screening test has to be followed by confirmatory
test if positive (IFA or WB)
-NAT: window period decreased to 4-7 days
, human T cell lymphotrophic virus (HTLV I and II) - Answers -transmitted sexually, parenterally,
and vertically by breastfeeding
-RNA retrovirus that is latent with no symptoms for many years
-causes T cell lymphoma and HTLVI-I associated myelopathy/ tropic spastic paraparesis (HAM,
HAM/TSP)
-EIA is used to screen blood units
-units that are >7 days old and leukoreduced decrease risk of transmitting virus (requires WBCs
to survive)
west nile virus - Answers -transmitted from mosquito vectors that pick up virus from bird host
and transmit to humans
-can cause encephalitis
-usually subclinical, but can be fatal especially to elderly individuals
-incubation is 3 to 14 days
-ELISA testing can be used, but some false negs occur
-NAT decreases window period
CMV - Answers -transmitted through infected body fluids
-most adults have been exposed by age 40, virus is latent in the body for many years
-infection is usually asymptomatic and people don't know they're exposed
-infection is severe to immunocompromised invdividuals: fetuses, immunocompromised and
BMT recipients
-anti-CMV negative leukoreduced blood is given to high risk populations
-detected via ELISA, fluorescence, indirect hemagglutination or viral culture
epstein barr virus (EBV) - Answers -asymptomatic infection of B lymphocytes
-many adults are seropositive
-not tested for in blood units because its not an issue for the general population (can be
transfusion transmitted but doesn't matter)
-issue for organ transplant patients
parvovirus B19 - Answers -asymptomatic infection in adults
