Viruses and other infections Flashcards
The following are true regarding the diagnosis of HSV, except.
A. Serologic test is the best method for both HSV1 and HSV2
B. Tzanck smear has a high sensitivity
C. Viral cytopathic effects can be visualized in culture after 1-3 days
D. Human diploid fibroblasts and Hep-2 are used for culture
A.
Remarks: Serology has limited utility in HSV diagnosis
The traditional diagnostic criteria for infectious mononucleosis is the Hoagland criteria which include the following, except. A. >80% lymphocytes B. >10% atypical lymphocytes C. fever, pharyngitis and adenopathy D. Positive serologic test
A.
Remarks: It should be >50% lymphocytes
Which of the following EBV serologic markers are detectable for life after infection? A. Early antigen B. IgG-VCA C. IgG-EBNA D. Heterophile E. Both B and C
E.
Which of the following is the principle for a positive heterophile (Monospot) tested with sheep red blood cells?
A. Agglutination of horse erythrocytes by serum absorbed with guinea pig kidney
B. Agglutination of beef erythrocytes by serum absorbed with rabbit kidney
C. Agglutination of sheep erythrocytes by serum absorbed with guinea pig liver
D. Agglutination of horse erythrocytes by serum absorbed with beef
A.
Remarks: Principle is greater agglutination with kidney (horse or guinea pig) than beef.
Which of the following indicate acute primary infection with EBV?
A. (+) IgM anti-VCA, IgG anti-VCA and anti-EBNA
B. (+) IgG anti-VCA, IgG EA and anti-EBNA
C. (+) IgM anti-VCA only
D. (+) IgM anti-VCA, IgG anti-VCA and IgG EA
D.
Which condition associated with EBV will be most likely EBER negative by In situ hybridization?
A. Hodgkin lymphoma
B. Nasopharyngeal carcinoma
C. Oral hairy leukoplakia
D. lymphoid tissues during infectious mononucleosis
E. Endemic-type Burkitt lymphoma
C.
Which of the following immunohistochemistry has excellent correlation with EBER ISH? A. NMP22 B. LMP1 C. PD-L1 D. EBER1
B.
Give the family of virus causing the ff diseases:
- Cikungunya
- Dengue
- Yellow fever
- Ebola
- Rotavirus infection
- Crimean-Congo Hemorrhagic Fever
- HIV
- Polio
- Hepatitis C
- Marburg
- Avian influenza - be specific
- Croup in children
- Molluscum contagiosum
- Variola
- Togavirus
- Flavivirus
- Flavivirus
- Filovirus
- Rotavirus under Reoviridae
- Bunyavirus
- Retrovirus
- Poliovirus under Enteroviridae
- Flavivirus
- Filovirus
- Influenza A subtype H5N1 under Orthomyxovirus
- Parainfluenza 1 and 2 under Paramyxovirus
- Poxvirus
- Poxvirus
The following viruses exhibit Cowdry type A inclusion, except. A. Varicella B. Herpes simplex virus C. Polio virus D. Yellow fever
C.
The following exhibit intranuclear inclusion, except. A. Cytomegalovirus B. Measles C. Rabies D. Polio virus
C.
What is the most common mutation of HBeAg-negative chronic Hepatitis B characterized by fluctuating aminotransferases and a tendency towards fulminant hepatitis?
A. mutation in the C region with adenosine for guanine in position 1896
B. mutation in the S region with guanine for adenosine in position 1896
C. mutation in the C region with guanine for adenosine in position 1896
D. mutation in the S region with adenosine for guanine in the position 1896
A.
What can be seen in the window period of hepatitis B infection? A. HBV DNA B. IgM anti-HBC C. IgG anti-HBC D. Anti-HBe
B.
In a needle prick accident, what has the best utility in evaluating hepatitis contamination? A. serum HBsAg B. serum ALT and AST C. HBV DNA PCR D. serum HBeAg
C.
Remarks: HBV DNA appears 3 weeks before HBsAg appears making it useful in evaluating patients after needle prick accidents.
With HBV DNA PCR, how many copies per ml of serum is considered active replication?
> 10 ^ 5 copies / ml
When does molecular assays in Hepatitis B begin to be of value? Give at least 3 scenarios?
- Monitoring therapy
- Distinguishing replicative from nonreplicative infection (>10^5/ml = replicative)
- Equivocal serologic tests
- Needle prick accidents - molecular is not the first line though
In terms of therapy response rate, which hepatitis C genotypes have the highest response rates? A. genotypes 1 and 2 B. genotypes 2 and 3 C. genotypes 3 and 4 D. genotypes 4 and 1
B. - genotypes 2 and 3
Remarks: genotype 3 is associated with metabolic syndrome. genotype 1 - most common and has a low response rate.
Genotypes 4-9 have not been sufficiently studied yet.
According to the HIV republic act 8504, for infants less than 18 months old, how soon will you repeat PCR testing when the patient is breastfeeding? A. 2 weeks after last breastfeed B. 4 weeks after last breastfeed C. 6 weeks after last breastfeed D. 8 weeks after last breastfeed
C. - at least 6 weeks after last breastfeed
Remarks: 2 positives are required before confirming a positive result.
Aside from Kaposi sarcoma, what are the other two conditions associated with HHV8?
- Primary effusion lymphoma (PEL)
2. Multicentric Castleman disease seen in HIV+ patients
In HIV infection, which of the following has the best utility in predicting long-term prognosis? A. CD4 count B. Quantification of circulating HIV RNA C. p24 serum protein D. p41 serum protein
B.
Remarks: Viral load is basically the quantification of circulating HIV RNA.
*CD4 counts - short term prognosis, basis for starting therapy and susceptibility to infections
*Viral load - long term prognosis and disease progression
What is the best diagnostic test to assess presumed exposure to HIV? A. Anti-HIV antibodies in ELISA B. p24 in Western Blot C. p41 in Western Blot D. Real time PCR HIV RNA
D.
Remarks: Just like in Hepatitis B, viral RNA is best in determining exposure for the virus.
A positive HIV RNA should be confirmed with ELISA or Western blot.
What is the best way of HIV detection in neonates? A. Anti-HIV antibodies in ELISA B. p24 in Western Blot C. HIV proviral DNA D. PCR using Umbilical cord blood
C. - HIV proviral RNA is equally useful
Remarks: ELISA and Western blot is not useful in neonatal HIV detection due to circulating maternal antibodies. Umbilical cord should not be used!
The following are true regarding rapid plasma reagin (RPR) test, except.
A. It is more sensitive than VDRL
B. Reagent include Cardiolipin with Charcoal
C. Test is more stable than VDRL and can be stored
D. Requires complement inactivation by heating the serum
D.
Remarks: It does not require complement inactivation
Which of the following serologic tests is best for post-streptococcal glomerulonephritis? A. ASO B. Anti-DNAse B C. Anti-NAD D. Anti-streptokinase
B.
In ASO titer, Todd units are used to report the result. What is the definition of Todd units?
A. The amount of antibody that neutralizes two and a half minimal doses of Streptolysin O (SLO)
B. The amount of antigen that neutralizes two and a half minimal doses of SLO
C. The amount of antibody that neutralizes one and a half minimal doses of SLO
D. The amount of antigen that neutralizes one and a half minimal doses of SLO
A.
A positive OX-2, OX-19 is seen in the Weil Felix agglutination test. Which of the following is not a suspected organism? A. Rickettsia prowazekii B. Rickettsia typhi C. Proteus vulgaris D. Proteus mirabilis
D.
Remarks: Proteus vulgaris is OX-2 and Ox-19 positive. Proteus mirabilis is OX-K positive just like R. tsutsugamushi (Scrub typhus).
Coxiella burnetii is negative for all.
How will a patient with a titer of rheumatoid factor of 1:20 be reported as?
Negative or repeat after 2 weeks
Remarks: RF titer - 20-40 weakly positive.
80 or greater is positive.