Infectious Disease #2 Flashcards Preview

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Flashcards in Infectious Disease #2 Deck (74)
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1
Q

HIV Screening Recommendations:

A

All adults ages 18-64 (once in lifetime)

+ risk factors (yearly)

Pregnant women (once)

Pregnant women- high risk (2nd test in 3rd trimester)

Newborns (if mother is HIV + or high risk)

*30% transmission from breast feeding **

2
Q

HIV risk factors?

A
Homosexual males
Bisexual males
Women with at-risk male partner
Women with multiple male partners
IV drug abusers
Blood transfusions (high risk areas)
Infants of HIV + mothers or high-risk
3
Q

Early detection is key for?

A

Antiretroviral therapy
Appropriate immunizations
Prophylactic antibiotics

4
Q

HIV screening tests?

A
HIV-1 p24 antigen
HIV-1 antibody
HIV-2 antibody
HIV-1/2 antibody
HIV-1/2 Ab/Ag 
Rapid HIV-1/2 Ab
5
Q

HIV confirmation tests?

A
WB HIV-1 Ab
WB HIV-2 Ab
Immunoblot-HIV-2 Ab
IFA HIV-1 Ab
HIV RNA NAAT (qualitative testing)
6
Q

HIV rapid tests?

A

Urine or saliva

*low risk that wants a screening **

7
Q

Which HIV test detects the viral protein p24 in blood?

A

p24 direct serologic antigen assay

8
Q

In the p24 test, how early is the infection detectable? and it is detectable before antibody ______________?

A

16 days after infection

seroconversion

  • you cant detect HIV for up to three months b/c we have not ABS to it yet because it is hiding in the CD4 cells **
9
Q

4th generation enzyme-linked immunoassay target of detection and days to positivity?

A

IgM and IgG Abx and p24 antigen

15-20 days

10
Q

HIV _________ test uses PCR to replicate a very small amount of HIV RNA to a detectable amount

A

HIV viral load test

11
Q

HIV diagnostic testing algorithm?

A

4th gen. HIV-1/2 immunoassay

then,

type the HIVm( is it 1 or 2)

then,

RNA testing

12
Q

Determines “amount” of HIV in serum?

A

HIV RNA (quantitative)

13
Q

HIV RNA aids in?

A

Marker for prognosis

Disease progression

Response to treatment

Indication for treatment

Indicates course of disease more accurately than any other test

14
Q

HIV RNA is extremely sensitive to < __ copies/ml

A

50

15
Q

HIV RNA determines baseline viral load with _ measurements - weeks apart?

A

2 measurements

2-4 weeks apart

16
Q

What are HIV Resistance Assays?

A

Assess viral strains (genotyping)

Useful in selecting therapies

Useful if patient is failing therapy

17
Q

Aspergillosis organism?

A

Aspergillus fumigatus

  • affects lungs sinuses and can go into the brain = it is inhaled
  • *
  • most of us have an immunity towards it already but AIDS and chemo patients and people with liver and organs transplant patients can become colonized with this.
  • *
18
Q

Aspergillosis Tests?

A

PCR form tissue biopsy
Galactomannan
Fungal Ab

19
Q

ELISA detecting molecule in cell wall of the fungus for Aspergillosis testing?

A

Galactomannan

20
Q

beta-D-glucan?

A

fungal ABS for fungal Ab test

21
Q

What Aspergillosis test is not highly reliable, not specific and can use blood and CSF samples?

A

Fungal Ab test

  • “not good first line, or we do this first” it depends on the patient severe or not severe?**
  • a lot of these patients get thrombocytopenia so careful not to make them bleed if your are doing a biopsy if they have the condition **
22
Q

Candidiasis is a ________ dx?

A

clinical

23
Q

what do you see on a KOH prep with Candidiasis?

A

yeast and spores - hyphae

24
Q

Candidiasis ?

A
Clinical diagnosis
KOH prep - yeast and spores ( hyphae)
Vaginal pathogens probe (microscopy)
Blood culture revealing fungemia
Beta-D-glucan testing

diabetics and chemo patients

25
Q

Coccidiomycosis labs?

A

ELISA for IgM Ab early in the disease process

CSF

26
Q

a patient has Coccidiomycosis and you read of their labs that they are having “persistent rising IgG complement fixation titers”, what does this suggest?

A

disseminated disease

27
Q

Coccidiomycosis and CSF sample?

A

Complement fixing Ab (>90% of cases)

IgG titers keep getting higher and higher

*meningitis? we can see coccidia in the CSF as well**

28
Q

Coccidiomycosis is common in patients with what?

A

HIV

29
Q

Cryptococcis is common from?

A

pigeon droppings inhaled

30
Q

what is the most common cause of fungal meningitis ?

A

Cryptococcis

31
Q

How do you culture PULMONIC Cryptococcis?

A

Culture of resp secretions or pleural fluid

32
Q

Cryptococcosis CSF culture results?

A

Gram stain shows budding encapsulated fungi

+ capsular polysaccharide antigen is diagnostic - looking for the antigen in the CSF - what Indian stain is it?

33
Q

Histoplasmosis comes from?

A

bird and bat droppings

34
Q

Geographic location for Histoplasmosis?

A

found in the Ohio river valley and mississippi river valley

35
Q

What is Histoplasmosis ?

A

acute pulmonary infection that lasts one week to six months

36
Q

Histoplasmosis CXR?

A

miliary infiltrates

37
Q

Histoplasmosis Labs: Ferritin 9?

A

elevated - maybe liver involvement

38
Q

Histoplasmosis Labs: CBC w/ diff?

A

Pancytopenia with disseminated forms

  • can affect bone marrow production cells and we can get pancytopenia
  • *
39
Q

Histoplasmosis Labs: UA assay + serum polysaccharide. antigen assay (83% sensitive) can be used for what??

A

Urine antigen assay can be used to follow treatment

  • we treat the patient and we see that the titers are decreased confirming treatment is working?**
40
Q

Pneumocystic organism?

A

Pneumocystis jirovecii

41
Q

Culture of Pneumocystis jirovecii by?

A

BAL

42
Q

Treatment for Pneumocystis jirovecii?

A

bactrim

  • we treat it with bactrim and we culture it from bronchial lavage = the X-ray looks worse than the patient is**
43
Q

Parvovirus B19 AKA?

A

slap check disease

44
Q

Parvovirus B19 serum test indications?

A

organ donors

children with vague symptoms

45
Q

Parvovirus B19 symptoms (vague?)?

A

fever
rash
arthralgias
coryza

  • we do not usually test for it cause it is a clinical diagnosis **
46
Q

Parvovirus fetal infection test?

A

B19 DNA in amniotic fluid

47
Q

Parvovirus ELISA of IFA: latent infection?

A

IgG

48
Q

Parvovirus ELISA of IFA: acute infection?

A

IgM

49
Q

Mumps amylase test result?

A

elevated

50
Q

Munps shows elevated what?

A

amylase and serum IgM and 4-fold rise in IgG titers

51
Q

If a kid has mumps, what are the two most common complications?

A

septic meningitis or vesticular involvement - orkytis

52
Q

Rubella AKA?

A

german measles

53
Q

Rubella test results?

A

4 fold rise in IgG titers

Elevated IgM titer

54
Q

What are other viral infections that can give a rubella test a FALSE positive ?

A

EBV
CMV - cytomegalovirus
Parvovirus
RF

*concerning infection with pregnant woman = congenital defects **

55
Q

Measles test results?

A

Elevated IgM

4 fold rise in IgG titers

56
Q

What is Measles?

A

viral illness mostly in children

we vaccine against it

not really any severe complications from it

57
Q

Measles rash progression?

A

rash first appears on the neck and face

then,

spreads quickly to cover entire body

58
Q

Rabies testing?

A

DFA of skin biopsy

Viral isolation from CSF and Saliva

*almost 100% fatal 100% of the time**

59
Q

Rabies treatment?

A

we put rabies IgG ( rabies immunoglobulin) around the bite, and we give them rabies shot , wash the bite, and mark sure the tetanus is up to date……on opposite side of the body you give them the booster ( how ever many days until the booster course is completed) - it is very import to vaccine people that are at high risk.

60
Q

West Nile Virus testing?

A

Serum or CSF

61
Q

West Nile Virus indications?

A

Flu like sxs in an area that WNV is common

Screening donated blood

62
Q

West Nile Virus vector?

A

mosquito

63
Q

What is West Nile Virus? background?

A

RNA virus (Flavavirus family)

Transmitted by household mosquitoes

64
Q

West Nile Virus initial test?

A

ELISA or IFA

65
Q

What will ELISA show with WNV infection?

A

IgM (10 days after sxs start)

66
Q

WNV confirmatory test?

A

2nd IgM 3-4 weeks later

WNV RNA

IgM in CSF - if meningitis like symptoms

67
Q

Interfering factors with WNV?

A

Other flavavirus infections (Japanese encephalitis)

68
Q

Normal WNV results?

A

No Ab to WNV

69
Q

Indication to test for HSV (herpes)?

A

Identify acute herpetic infections

Pregnant women (deliver 6-8 weeks?)

Immunocompromised patients - HIV/AIDS at higher risk of infection

*we talk about zoster (shingles) and varicella ( chicken pox) and genital herpes = all in the herpes family**

70
Q

HSV GS testing and result?

A

Viral Culture is GS

90% accuracy
sensitivity 50%
specificity near 100%

more accurate picture of the disease process going on

*unroof the vesicle and get some of the fluid = better accurate result **

71
Q

HSV serologic testing?

A

more disseminated disease

ELISA or IFA - measuring IgG

72
Q

What does ELISA for HSV 9 herpes) differentiate?

A

differentiates between Type 1 and Type 2 or varicella or zoster

  • no hx of blisters of sores and the have a positive HSV1 result then it is not a great prognostic tool **
73
Q

HSV PCR is used on?

A

CSF

74
Q

Get _____________ results and then order PCR.

A

preliminary