3. Direct Fluorescent antibody (DFA) stain
Collect cells from base of fresh vesicular lesion
Stain with Fl antibody specific for HSV and/or VZV
Look for fluorescent cells (virus infected) using fluorescence
microscope
More sensitive & specific method than Tzanck prep for
virus detection (DFA 80% vs. Tzanck 50%)
Tzanck prep= Giemsa staining cells from lesion
-/examine for multinucleated giant cells of Herpes
virus
Tzanck
Tzanck
DFA
4. • Enzyme immunoassay (EIA) –
Antigen/antibody complex formed – then bound to
a color producing substrate
Used most often
Detection of non-culturable viruses – Rotavirus
Influenza A and B , & Respiratory syncytial virus (RSV)
from nasal/NP swab – point of care
• Membrane EIA Liquid/well EIA
5. Molecular Amplification (DNA or RNA)
• Rapid/Sensitive/Specific for numerous viruses
• Exceeds sensitivity of culture/ new Gold standard
Respiratory viruses
HSV and Enterovirus detection from CSF
Culture <=20% PCR >=90%
Tests of diagnosis not cure – can shed residual virus for 7 –
30 days after initial positive test
• CMV - Quantitative assays in transplantation
• Hepatitis B and C detection and viral load
• HIV viral load
6. • Inner tube wall coated with monolayer of cells plus
liquid growth media
• Three types of cell lines:
Primary cell lines – direct from animal or human organ
into culture tube subculture once
Rhesus monkey kidney-RMK
Diploid – semi continuous cell lines– Can survive 20 – 50
subcultures into new vials –
Human diploid fibroblast cells, example: MRC-5-Microbiology
Research Council 5
Continuous cell lines – can survive continuous passage
into new vials,
Tumor lineage, HEp-2 and HeLa
7. Patient specimens inoculated into cell culture
tubes, incubated, then read under light
microscopy for “Cytopathic effect” – the effect
the virus has on the cell monolayer
• The pattern of destruction is specific for each
virus type
8. Spin Down Shell Vial Culture –
•Speed up virus detection
•Cell monolayer on coverslip/vial
•Specimen inoculated into vial
•Centrifuge vial to induce virus invasion into cells
•Incubate @ 35C, 24-72 hours
•Direct fluorescent antibody stain of coverslip – target
early virus antigens (those first formed )
Cover slip
9. Viral transport media (VTM) - Hanks balanced
salt solution with antibiotics
• Also known as Universal Transport Media (UTM)
• Transport of lesions, mucous membranes and throats –
specimens collected with swab
• Cell protective, protect the cell / protect the virus
Short term transport storage 4˚C
Long term transport(>72hours) storage-70˚C
VTM specimens filtered (45nm filter) to eliminate
bacteria in specimen prior to being placed onto cell
monolayer
10. Most likely - HSV
Intermediate
• Adenovirus
• Influenza A and B
• Enterovirus
Least likely
• Respiratory Syncytial Virus (RSV)
• Cytomegalovirus (CMV)
• Varicella Zoster virus (VZV)
• Amplification preferred for these viruses due to transport
issues
13. Double stranded DNA virus
Eight human Herpes viruses
• Herpes simplex 1
• Herpes simplex 2
• Varicella Zoster
• Epstein Barr
• Cytomegalovirus
• Human Herpes 6, 7, and 8
Latent infection with recurrent disease is the hallmark of
the Herpes viruses
Latency occurs within small numbers of specific kinds of
cells, the cell type is different for each Herpes virus
15. Herpes simplex 1 & 2 do well in culture
• Produce CPE within 24-48 hrs
• Human diploid fibroblast cells (MRC-5)Observe for characteristic CPE
Negative fibroblast
Cell line
HSV CPE
16. Cytology/Histology – multinucleated giant cell,
intranuclear inclusions
Cannot differentiate
from VZV
Amplification (PCR)
Serology – more useful for proof of past infection than
for acute diagnosis
17. Transmission: close contact
Latency: dorsal root ganglia
Diseases:
• Chickenpox (varicella)
• Shingles (zoster – latent infection)
Serious disease in immune suppressed or adult patients which
progress to pneumonia or encephalitis
Histology – multi-nucleated giant cells like those of
Herpes simplex
Serology useful for immune status check
Amplification useful for disease diagnosis
Effective vaccine has lowered incidence of VZV
18. Varicella-Zoster Diagnosis
Cell culture at 5 – 7 days
Limited # of infected foci in
monolayer
Sandpaper look to the
monolayer background with
scattered rounded cells –
Diploid fibroblast cells
Young wet vesicular lesions are best
for culture and/or molecular testing
19. Transmitted by blood transfusion , vertical and
horizontal transmission to fetus, also by close contact
Latency: Macrophages
Disease: Infection asymptomatic in most individuals
• Congenital – most common cause of TORCH
• Perinatal
• Immunocompromised – Primary disease most serious
Laboratory Diagnosis:
• Cell culture CPE (Human diploid fibroblast)
• PCR and quantitative PCR (best method)
• Histopathology
Treatment: ganciclovir, foscarnet, cidofovir
20. Cell culture -
CMV infected fibroblast monolayer
with grape like clusters of rounded
cells
Histopathology – Intranuclear and
Intracytoplasmic inclusions – known
as OWL EYE inclusions
21. Transmission - close contact, saliva
Latency - B lymphocytes
Diseases include:
• Infectious mononucleosis
• Lymphoreticular disease
• Oral hairy leukoplakia
• Burkitt’s lymphoma
• Nasopharyngeal Carcinoma
• 1/3 Hodgkin’s lymphoma
Will not grow in cell culture
Serology most used for diagnosis
EBV infection with B cell
transformation
22. HA react with antigens phylogenetically
unrelated to the antigenic determinants
against which they were raised
Human HAs secondary to EBV are detected
by the ability to react with horse or cattle
rbcs (theory of the Monospot test)
HA rise in the first 2 - 3 weeks of EBV
infection, then rapidly fall at @ 4 weeks
23. VCA = viral capsid antibody
EBNA = Epstein Barr nuclear antigen
EA = early antigen
24. Anti-EBV antibodies Interpretation
VCA IgM VCA IgG EBNA-1 IgG
Negative Negative Negative No immunity
Positive Negative Negative Acute infection
Positive Positive Negative Acute infection
Negative Positive Positive Past infection
Negative Positive Negative Acute or past infection1
Positive Positive Positive Late primary infection
Negative Negative Positive Past infection
Serologic Diagnosis of EBV
31. DNA virus
Parvovirus B19
• Erythema infectiosum (Fifth disease) – headache
rash and cold-like symptoms in the child
• In pregnant, infection in 1st
trimester, hydrops fetalis
leading to miscarriage
• Aplastic crisis in patients with chronic hemolytic
anemia and AIDS
• Histology - virus infects
mitotically active erythroid
precursor cells in bone marrow
• Molecular and Serology methods
to aid diagnosis
Slapped face appearance
of fifth disease
33. Diseases:
Skin and anogenital warts,
Benign head and neck tumors,
Cervical and anal intraepithelial neoplasia and cancer
HPV types 16, 18, & 45 = 94% Cervical CA
HPV types 6 and 11 = 90% Genital warts
Pap Smear for detection of HPV
Hybrid capture DNA probe for detection and typing
PCR – FDA cleared platforms for detection/typing
Three vaccines - 1°to guard against HPV 6,11,16,18
Pap smear
34. • JC virus [John Cunningham]
Progressive multifocal leukoencephalopathy -
Encephalitis of immune suppressed
Destroys oligodendrocytes in brain
• BK virus
Causes latent virus infection in kidney
Progression due to immune suppression
Hemorrhagic cystitis
• Histology/PCR to aid diagnosis
Giant Glial Cells of JCV
35.
36. Enveloped DNA – Hepadna virus
Hepatitis B clinical disease
• 90% acute
• 1% fulminant
• 9% chronic
Carrier state can lead to cirrhosis and
hepatic cell carcinoma
Therapies under investigation
• Serology for diagnosis
• Vaccinate to prevent
37. Surface Antigen Positive
• Active Hepatitis B or Chronic Carrier
Do Hep B Quantitation
Do Hep e antigen – Chronic carrier and worse prognosis
Core Antibody Positive
• Immune due to prior infection,
acute infection or chronic carrier
Surface Antibody Positive
• Immune due to prior infection or vaccine
39. Spread parenterally - drug abuse, blood products
or organ transplants (prior to 1992), poorly
sterilized medical equipment, sexual (low risk)
Effects only humans and chimpanzees
Approx 3.2 mil persons in USA have chronic
Hepatitis C
Seven major genotypes (1-7)
• Acute self limited disease that progresses to a
disease that mainly affects the liver
• Type 1 virus most common in USA
• Infection persists in @ 75-85%/ no symptoms
• 5 - 20 % develop cirrhosis
• 1-5 % associated with hepatocellular CA
• Can require liver transplantation
40. Diagnosis:
• Hepatitis C antibody test
If Hep C antibody detected perform
RNA quantitative assay for viral load
Genotype of virus for proper therapy selection/duration
Assessment of liver disease - ? cirhhosis
No vaccine available
Antivirals currently in clinical trials and/ or FDA
cleared that can cure >= 85% of patients infected
with Hepatitis C
41. •Dengue – “breakbone fever”
Vector Aedes mosquito / Asia and the Pacific
Fever, severe joint pain, rash
Small % progress to hemorragic fever
Chikungunya virus
Vector Aedes mosquito with origin in Asia and African
continents
Recent migration to the Caribbean and SE USA with
mosquito migration
Travel advisory to the Caribbean
Acute febrile illness with rash followed by extreme joint
pain, less fatalities than Dengue / no hemorrhagic phase
•Diagnosis – Serology(IgM, IgG) and PCR
42. West Nile
• Vector Aedes and Culex mosquito
• Common across the US, Bird primary reservoir, horses
also at risk
• Fever, Headache, Muscle weakness, 80% asymptomatic.
Small % progress to encephalitis. Meningitis, flaccid
paralysis
Zika virus
• Vector Aedes mosquito
• Common in South America (Brazil)
• Clinically like a mild form of Dengue
• **Microcephaly in fetuses born to infected mothers
Diagnosis
• Immunoassays for Antibody & PCR (serum and CSF)
43. >20 outbreaks since discovery in 1976
• current outbreak Dec 2013 - West Africa
• Prolonged due to area effected is high population with limited
medical reaources
Transmission direct contact with bodily fluids – fatality rate 55%
• Animal reservoir (?) fruit bats
Asymptomatic are not contagious
Fever, weakness, myalgias, headache, travel history
• Consider malaria and typhoid
Susceptible to hospital disinfectants
Testing (EIA, PCR) at CDC – pos >= 4 days of illness
44. SARS - Severe Acute Respiratory Syndrome –
Outbreak in China 2003 – spread to 29 countries
Initially dry cough and/or shortness of breath development of
pneumonia by day 7-10 of illness Lymphopenia in most cases
Laboratory testing public health laboratories (CDC) -antibody
testing enzyme immunoassay (EIA) and reverse transcription
polymerase chain reaction (RT-PCR) tests for respiratory, blood, and
stool specimens.
• MERS - Middle East Respiratory Syndome
• Isolated to Arabian peninsula (2012)
• Direct contact with infected camels
• Close human to human contact can spread infection – no
outbreaks – 30% fatality rate
• Fever, rhinorrhea, cough, malaise followed by shortness of breath
45.
46. Diverse group of > 60 viruses – SS RNA
• Infections occur most often in summer and fall
• Polio virus - paralysis
Salk vaccine Inactive Polio Vaccine (IPV)**
Sabine vaccine Live Attenuated Vaccine (OPV)
• Coxsackie A – Herpangina
• Coxsackie B – Pericarditis/Myocarditis
• Enterovirus – Aseptic meningitis in children, hemorrhagic
conjunctivitis
• Echovirus – various infections, intestine
• Rhinoviruses – common cold
• Grow in cell culture (Diploid mixed cell – Primary Monkey
Kidney)
• PCR superior for diagnosis of meningitis (CSF) and more rapid
and sensitive for all sites
48. Fecal – oral transmission, contaminated food or person to person
80% develop symptoms – jaundice & elevated aminotransferases
Usually – short incubation (15- 50 days), abrupt onset, low
mortality, no carrier state
Diagnosis – serology, IgM positive in early infection to differ from
other Hepatitis viruses
Antibody is protective and lasts for life
Vaccine available
50. Hemagglutinin and Neuraminidase glycoproteins spikes
on outside of viral capsid
• Gives Influenza A the H and N designations – such as
H1N1 and H3N2
• Antigenic drift - minor change in the amino acids of
either the H or N glycoprotein
Cross antibody protection will still exist so an
epidemic will not occur
• Antigenic shift - genome re assortment with a “new”
virus created/usually from a bird or animal/ this could
create a potential pandemic
H5N1 = Avian Influenza
H1N1 = 2009 Influenza A
51. Disease: fever, malaise …. death
Diagnosis
• Cell culture obsolete [RMK]
• Enzyme immunoassay (EIA) on paper membrane can be used
in point of care
• Amplification (PCR) gold standard for detection
Treatment: Amantadine and Tamiflu (Oseltamivir)
• Seasonal variation in susceptibility
Vaccinate to prevent
Influenza B
• Milder form of Influenza like illness
• Usually <=10% of cases /year
53. Measles
• Fever, Rash, Dry Cough, Runny Nose,
Sore throat, inflamed eyes (photosensitive)
Can invade lung (see HE of Lung)
• Respiratory spread - very contagious
• Koplik’s spots – bluish discoloration inner
lining of the cheek
• Subacute sclerosing panencephalitis [SSPE]
Rare chronic degenerative neurological disease
Persistent infection with mutated measles virus due to
lack of immune response
• Diagnosis: Clinical symptoms and Serology
• Vaccinate – MMR (Measles, Mumps, Rubella) vaccine
• Treatment: Immune globulin, vitamin A
Measlessyncytium
54. Types 1,2,3, and 4
Person to person spread
Disease:
• Upper respiratory tract infection in adults –
more serious in immune suppressed
• Croup, bronchiolitis and pneumonia in
children
Heteroploid cell lines (Hep-2) for culture
PCR methods are gold standard
Supportive therapy only available
55. Person to person contact
Classic infection is Parotitis, but can
cause infections in other sites:
T
56. Respiratory disease - common cold to pneumonia, bronchiolitis to
croup, serious disease in immune suppressed
• Classic disease: Young infant with bronchiolitis
Transmission by contact and respiratory droplet
Specimen: Naso-phayrngeal, nasal swab, nasal lavage
Diagnosis: EIA, cell culture (heteroploid cell lines), PCR is gold
standard, lung biopsy
Treatment: Supportive, ribavirin Histology
Classic CPE = Syncytium formation
In heteroploid cell line
57. 1st
discovered in 2001 – community acquired
respiratory tract disease in the winter
Common in young children – but can be seen in all
age groups
• @95% of cases in children <6 years of age
• Upper respiratory tract disease
• 2nd
only to RSV in the cause of bronchiolitis
Will not grow in cell culture
Amplification (PCR) for detection
• Specimen: Nasal swab or NP
Treatment: Supportive
59. Winter - spring seasonality
• 6m-2 yrs of age most serious
• Gastroenteritis with vomiting and fluid loss –
most common cause of severe diarrhea in
children
• Fecal – oral spread
Major cause of death in 3rd
world countries
Diagnosis – cannot grow in cell culture
• Enzyme immunoassay, PCR
Vaccine available
Rota = Wheel
EM Pix
61. Spread by contaminated food and water, feces &
vomitus – takes <=20 virus particles to cause
infection – highly contagious
Tagged the “Cruise line virus” – numerous reported
food borne epidemics on land and sea
Leading cause of epidemic gastroenteritis – more
virulent GII.4 Sydney since spring 2012
• Fluid loss from vomiting can be debilitating
Disease course usually limited, 24-48 hours
PCR for diagnosis
• Cannot be grown in cell culture
63. CD4 primary receptor site
for entry of HIV into the lymphocyte
Reverse transcriptase enzyme
converts genomic RNA into DNA
Transmission - sexual, blood and blood product
exposure, perinatal
Non infectious complications:
• Lymphoma, KS, Anal cell CA, non Hodgkins
Lymphoma
64. Antibody EIA with Western Blot confirmation (old way)
Positive tests must be confirmed with a Western blot test
Western blot detects gp160/gp120 (envelope proteins), p
24 (core), and p41(reverse transcriptase)
Must have at least 2 solid bands on Western blot to confirm
as a positive result
New test - Antigen/antibody combination (4th generation)
immunoassay* that detects IgG and IgM HIV-1 and HIV-2
antibodies and HIV-1 p24 antigen to screen for established
and acute infection
Detects infection earlier (@ 2- 4 weeks
Positive patients on either test require additional testing:
HIV viral load quantitation >= 100 copies
Resistance Testing – report subtype
Most isolates in USA type B
•Monitor CD4 counts for infection severity
65. Non-compliant patients or newly diagnosed
• Pneumocystis
• Cryptococcus neoformans & Histoplasma
capsulatum (disseminated)
• TB/Mycobacterium avium complex (disseminated)
• Microsporidia and Cryptosporidium (Intestinal)
• Hepatitis B
• Hepatitis C
• STD’s – Syphilis, GC, Chlamydia
Syphilis rate high (mucosal contact)
67. Known as the “Three day measles” – German measles
Rash, low grade fever, cervical lymphadenopathy
Respiratory transmission
Congenital rubella –
• occurs in a developing fetus of a pregnant women
who has contracted Rubella, highest % (50%) in the
first trimester pregnancy
• Deafness, eye abnormalities, congenital heart disease
Diagnosis - Serology in combination with clinical
symptoms
Live attenuated vaccine (MMR) to prevent
69. USA outbreak in four corner states (NM,AZ,CO,UT)
on Indian reservation in 1993 brought attention to
this virus
Source - Urine and secretions of wild field mice
• Deer mouse (picture) and cotton rat
Myalgia, headache, cough and respiratory failure
Found in states west of the Mississippi River
Diagnosis by serology
No therapy
71. Variola virus – agent of Smallpox
Vaccinia virus - active constituent in the Smallpox
vaccine, it is immunologically related to smallpox,
• Vaccinia can cause disease in the immune suppressed, which
prevents vaccination of this population
• Eradication of smallpox (1977)
Disease begins as maculopapular rash and progresses to
vesicular rash -
• all lesions in same stage of development in one body area – rash
moves from central body outward
Category A Bioterrorism agent (can maim or kill)
Requires BSL4 laboratory (self contained lab)
Reported to public health department for investigation
72. Chicken pox – Lesions in
different stage of development
Smallpox – all lesions same
stage of development
Chickenpox vs Smallpox lesions
74. Worldwide in animal populations
• Bat and raccoons primary reservoir in US
• Dogs in 3rd
world countries
Post exposure shots PRIOR to the development of symptoms prevent
infection
Rabies is a neurologic disease – classic sympton is salivation, due to
paralysis of throat muscles
Detection of viral particles in the brain by Histologic staining known
as Negri bodies is diagnostic
Public health department should be contacted to assist with
diagnosis
75. Rabies virus particles
EM showing the bullet
shaped virus
Negri bodies –
Intracytoplasmic
brain biopsy specimen
76. Rare, degenerative fatal brain disorder
Transmissable spongiform encephalopathies
(TSE) name established from the microscopic
appearance of brain with infection
Caused by type of protein - prion
Confirmation by brain biopsy
Safety – prevent transmission
• Universal Precautions
• Use disposable equipment
when possible