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Virology 2018

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Viology 2018 Powerpoint

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Virology 2018

  1. 1. Margie Morgan, PhD, MT(ASCP), D(ABMM)
  2. 2. 1.Direct Staining for Antigen 2. Enzyme Immunoassay 3.Viral Cell Culture 4. Molecular Amplification
  3. 3.  Direct Fluorescent antibody (DFA) stain  Collect cells from base of fresh vesicular lesion  Stain with DFA specific for HSV and/or VZV  Look for fluorescent cells (virus infected) using fluorescence microscope  More sensitive & specific method than Tzanck prep (DFA 80% vs. Tzanck 50%)  Tzanck prep= Giemsa stained cells from lesion -/examine for multinucleated giant cells of Herpes Tzanck Tzanck DFA
  4. 4. • Enzyme immunoassay (EIA) –  Antigen/antibody complex formed – then bound to a color producing substrate  Used most often for:  Detection of non culturable viruses like Rotavirus  Point of Care: Influenza A /B , & Respiratory syncytial virus (RSV) • Membrane lateral flow EIA Liquid/well EIA
  5. 5. • Inner tube wall of tube coated with monolayer of cells in liquid growth media • Three types of cell lines:  Primary cell lines – direct from animal or human organ into culture tube , will only survive one subculture  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 – survive continuous passage into new vials,  Tumor lineages, HEp-2 and HeLa
  6. 6.  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 of the cell monolayer is specific for each virus type
  7. 7. Spin Down Shell Vial Culture – •Speed up viral cell culture •Cell monolayer is on a coverslip •Specimen inoculated into vial with coverslip •Centrifuge vial to induce virus invasion into cells •Incubate @ 35C, 24-72 hours •Direct fluorescent antibody stain of cells – target early virus antigens (those first formed ) Cover slip
  8. 8.  Molecular Amplification (for DNA or RNA) • Rapid/Sensitive/Specific for numerous viruses • Exceeds sensitivity of culture/ Standard of Practice for:  Respiratory viruses  Meningitis/Encephalitis  Lesions - HSV • Tests of diagnosis not cure – can continue to shed residual virus for 7 – 30 days after initial positive test  Molecular quantitative assays • CMV - Quantitative assays in transplant patients • Hepatitis B and C detection and viral load • HIV viral load
  9. 9.  Viral transport media (VTM) - Hanks balanced salt solution with antibiotics, cell protective • Also known as Universal Transport Media (UTM) • Transport of lesions, mucous membranes, nasal & throat specimens collected with swab  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. 10.  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  Latency (hallmark of Herpes viruses) occurs within small numbers of specific kinds of cells, the cell type is different for each Herpes virus
  11. 11.  Transmission: direct contact/secretions  Latency: dorsal root ganglia  Diseases • Gingivostomatitis • Herpes labialis • Ocular • Encephalitis • Neonatal • Disseminated in immune suppressed Therapy – Acyclovir, Valacyclovir
  12. 12.  Herpes simplex 1 & 2 • Produce CPE within 24-48 hrs • Human diploid fibroblast (MRC-5) • Observe for characteristic CPE Negative fibroblast Cell line HSV CPE – cell rounding starting on the edge of the monolayer. Histology/Cytology Multinucleated Giant Cells Cannot Differentiate from VZV Molecular Amplification Serology – best for past infections
  13. 13.  Transmission: close contact  Latency: dorsal root ganglia  Diseases: • Chickenpox (varicella) • Shingles (zoster – latent infection)  Serious disease in adults and immune suppressed with progression to pneumonia and/or encephalitis  Ramsay-Hunt syndrome – facial nerve / facial paralysis  Histology – multi-nucleated giant cells  Serology useful for immune status check  Cell culture – growth 5-7 days, fibroblasts  Sandpaper like appearance with rounded cells  Amplification useful for disease diagnosis  Effective vaccine has lowered the incidence of VZV in children
  14. 14.  Transmitted by blood transfusion , vertical and horizontal transmission to fetus, or close contact  Latency: Macrophages  Disease: Infection asymptomatic in most individuals • Congenital – most common cause of TORCH • Perinatal • Immunocompromised – 1° disease most serious than recurrent  Laboratory Diagnosis: • Cell culture CPE (Human diploid fibroblast) • PCR and quantitative PCR (best method)  Due to persistent shedding - do quantitative PCR to detect high viral loads, most consistent with ongoing infection • Histopathology – Intranuclear and intracytoplasmic inclusions (Owl eye)  Treatment: ganciclovir, foscarnet, cidofovir
  15. 15.  Transmission - close contact, saliva  Latency - B lymphocytes – • cell receptor CD21  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 – Heterophile antibody – patient serum reacts with horse and cattle rbcs (Monospot test)  PCR techniques developed EBV infection with B cell transformation
  16. 16. 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 infection Positive Positive Positive Late primary infection Negative Negative Positive Past infection VCA = viral capsid antibody Serologic Diagnosis of EBV
  17. 17.  HH6 • Roseola [sixth disease] • 6m-2yr high fever & rash  HH8 • (1) Kaposi’s sarcoma • (2) Castleman disease • (3) Primary effusion lymphoma Onion skin pattern of Castleman disease 1 1 1 2 3
  18. 18.  DNA - non enveloped/ icosahedral virus  Latent: lymphoid tissue  Transmission: Respiratory and fecal-oral route  Diseases: • Pharyngitis (year round epidemics) • Pneumonia • Gastroenteritis in children  Adenovirus types 40 & 41 • Kerato-conjuctivitis – red eyes for @ 2 weeks • Disseminated infection in transplant patients • Hemorrhagic cystitis in immune suppressed
  19. 19.  Diagnosis • Cell culture (CPE) • Amplification (PCR)* superior for respiratory infection • Stool antigen detection by EIA (40/41 strains) • Supportive treatment only – no specific viral therapy • Histology - Intranuclear inclusions / smudge cells – membranes become blurred Round cells 2 – 5 days with Stranding – HeLA or Hep-2 cells
  20. 20.  DNA virus - humans only  Parvovirus B19 • Erythema infectiosum (Fifth disease) – headache rash and cold-like symptoms in the child • Hydrops fetalis - in pregnant, infection in 1st trimester, leading to miscarriage • Aplastic crisis in pre-existing bone marrow stress • Chronic hemolytic anemia HIV/AIDS • Arthritis and Arthralgias • Histology - virus infects mitotically active erythroid precursor cells in bone marrow • Molecular and Serologic methods to aid diagnosis Slapped face appearance of fifth disease
  21. 21.  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  PCR – Detection with typing of many HPV types  Guidelines suggest both PAP and HPV PCR for women 30 - 65 years of age / 5 years  Three vaccines - 1°to guard against HPV 6,11,16,18 Pap smear
  22. 22. • JC virus [John Cunningham]  Progressive multifocal leukoencephalopathy -  PML -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
  23. 23.  Enveloped DNA virus  Spectrum of the Hepatitis B symptomatology • Acute phase - disease varies from subclinical hepatitis to icteric hepatitis fulminant, acute, and subacute hepatitis • Chronic phase - chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC) during the chronic phase • Vaccinate to prevent • Therapies available to treat • PCR and Serology for diagnosis
  24. 24.  Surface Antigen Positive • Active Hepatitis B or Chronic Carrier, if detected  Do Hep B Quantitation  Do Hep e antigen – if positive, 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
  25. 25.  Parenteral transmission - drug abuse, blood products or organ transplants (prior to 1992), poorly sterilized medical equipment, sexual  Effects humans and chimpanzees  Approx 3.2 mil persons in US have chronic HepC  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 lead to liver transplantation
  26. 26.  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 FDA cleared that can cure >= 85% of patients infected with Hepatitis C
  27. 27. •Dengue – “breakbone fever” •Vector Aedes mosquito / Asia and the Pacific •Disease  Fever, severe joint pain, rash  Small % progress to hemorrhagic fever •Serology -IgM for acute infection  Zika virus •Vector: Aedes mosquito •2016 outbreak began in South America (Brazil) and spread to central America, Caribbean and US (Miami) •Clinically a milder disease than Dengue in most adults •Neurologic tropism  Microcephaly in fetuses borne to infected moms  Potential developmental issues in infected children  Guillain- Barre syndrome •Diagnosis: Serum antibody IgM / PCR serum, urine, amniotic fluid and CSF
  28. 28.  Yellow fever  Vector – Aedes aegypti  Most cases mild with 3-4 days fever, headache, chills, back pain, fatigue, nausea, vomiting  15% cases toxic phase with jaundice due to liver damage, hemorrhagic issues, with 20 – 50% fatality rate  Diagnosis confirmed by serum PCR  Outbreaks possible when large numbers of infected mosquitoes are introduced into a heavily populated area, endemic in Africa, Central and South America • Large outbreak in Brazil 2018  No specific anti-viral drugs  Vaccine – life long immunity
  29. 29. • West Nile  Vector Aedes and Culex mosquito  Common across the US  Bird primary reservoir, horses at risk  Disease  80% asymptomatic  Fever, Headache, Muscle weakness  Small % progress to encephalitis, meningitis, flaccid paralysis  Serology  PCR Cross reactions occur in serologic testing for Dengue, Zika and West Nile virus, present diagnostic problems
  30. 30.  Powassan (POW) virus  Transmitted to humans by infected ticks (Ixodes)  Approximately 100 cases of POW virus disease were reported in the United States over the past 10 years. • Most cases have occurred in the Northeast and Great Lakes region  Fever, headache, vomiting, weakness, confusion, seizures, and memory loss, can cause significant swelling in the brain  Long-term neurologic problems may occur.  There is no specific treatment
  31. 31.  Chikungunya virus  Vector Aedes mosquito  Origin in Asia and African continents with recent migration to the Caribbean and SE USA  Acute febrile illness with rash followed by extreme joint pain,  No hemorrhagic phase  When screening for ZIKA – need to rule out infection with Dengue and Chikungunya. Similar diseases with very different sequelae
  32. 32.  >20 outbreaks since discovery in 1976 • Most recent Dec 2013 - West Africa • Prolonged outbreak due to area effected had high population with limited medical resources  Transmission direct contact with bodily fluids – fatality rate 55% • Animal reservoir (?) fruit bats  Asymptomatic not contagious  Fever, weakness, myalgia, headache, travel history • Also consider malaria and typhoid in the differential  Susceptible to hospital disinfectants  Testing (EIA, PCR) at CDC – positive >= 4 days of illness  Level A agent of Bioterrorism
  33. 33. SARS - Severe Acute Respiratory Syndrome – Outbreak in China 2003 – spread to 29 countries Dry cough and/or shortness of breath with 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 PCR tests for respiratory, blood, and stool specimens. • MERS - Middle East Respiratory Syndrome • Arabian peninsula (2012) • Direct contact with infected camels • Close human to human contact can spread infection – no outbreaks – 30% fatality rate respiratory failure • Fever, rhinorrhea, cough, malaise followed by shortness of breath
  34. 34.  Diverse group of > 60 viruses – SS RNA • Infections occur most often in summer and fall • Polio virus - paralysis  Salk vaccine Inactive Polio Vaccine (IPV)** recommended • Coxsackie A – Herpangina – vesicular oral lesions • Coxsackie B – Pericarditis/Myocarditis • Enterovirus – Aseptic meningitis in children, hemorrhagic conjunctivitis, Acute flaccid myelitis EV-D68 • Echovirus – various infections, intestine • Rhinoviruses – common cold  Grow in cell culture * 5-7 days • Teardrop or kite like cells formed  PCR superior for diagnosis
  35. 35.  Fecal – oral transmission, contaminated food or person to person  Traveler’s disease  Recent outbreaks in homeless populations without adequate sanitary facilities  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
  36. 36.  Hemagglutinin and Neuraminidase are glycoprotein 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
  37. 37.  Disease: fever, malaise …. Death from respiratory complications or secondary bacterial infection  Yearly H and N types dominate, most recently H1N1 and H3N2  Diagnosis • Cell culture obsolete [RMK] • Enzyme immunoassay (EIA) lateral flow membrane can be used in point of care testing • Amplification (PCR) gold standard for detection  Treatment: Amantadine and Tamiflu (Oseltamivir) • Seasonal variation in susceptibility but Tamiflu sensitive currently  Influenza B • Milder form of Influenza like illness • Usually <=10% of cases /year  Vaccinate – Trivalent vaccine -2 A viruses/1 B virus
  38. 38. Disease • Fever, Rash, Dry Cough, Runny Nose, Sore throat, inflamed eyes (photosensitive)  Can invade lung • Respiratory spread - very contagious • Koplik’s spot – bluish discoloration inner lining of the cheek is pathognomonic • Subacute sclerosing panencephalitis [SSPE]  Rare chronic degenerative neurological disease  Persistent infection with a mutated measles virus, due to mutated virus there is total lack of an immune response Diagnosis: Clinical symptoms, Serology , PCR Vaccinate – MMR (Measles, Mumps, Rubella) vaccine Treatment: Nothing specific, Immune globulin, vitamin A H and E stain/ lung
  39. 39.  Types 1,2,3, and 4  Person to person spread  Disease: • Upper respiratory tract infection in adults and children with fever, runny nose and cough • Lower respiratory tract infection - Croup, bronchiolitis and pneumonia more likely in children, elderly and immune suppressed  PCR** methods standard of practice  Supportive therapy
  40. 40.  Person to person contact  Parotitis, other sites less common: Testes/ovaries, Eye, Inner ear, CNS  Diagnosis: clinical symptoms and serologic tests  Prevention: MMR vaccine  No specific therapy, supportive
  41. 41.  Respiratory disease - common cold to pneumonia, bronchiolitis to croup, serious disease in infants and immune suppressed • Classic disease: Young infant with bronchiolitis  Transmission by contact and respiratory droplet  Diagnosis: EIA (point of care), cell culture (heteroploid, continuous cell lines), PCR is gold standard**, and lung biopsy  Treatment: Supportive, ribavirin Classic CPE = Syncytium formation heteroploid cell line Syncytium formation In lung tissue
  42. 42.  1st discovered in 2001 – community acquired respiratory tract disease in winter • 95% of cases in children <6 years of age • Upper respiratory tract disease • Lower respiratory tract disease –  2nd only to RSV in the cause of bronchiolitis  Will not grow in cell culture  Amplification (PCR) for detection  Treatment: Supportive
  43. 43.  Winter - spring seasonality • Gastroenteritis with vomiting and fluid loss – most common cause of severe diarrhea in children 6m – 2 yrs • Fecal – oral spread  Major cause of childhood death in 3rd world countries  Diagnosis – cannot grow in cell culture • Enzyme immunoassay, PCR  Vaccine available Rota = Wheel EM Pix
  44. 44.  Spread by contaminated food and water, feces & vomitus – takes <=20 virus particles to spread infection – so highly contagious  Tagged the “Cruise line virus” – numerous reported food borne outbreaks aboard cruise liners  Leading cause of epidemic gastroenteritis – worldwide on land or sea • Fluid loss from vomiting can be debilitating  Disease course usually limited, 24-48 hours  PCR for diagnosis • Cannot be grown in cell culture
  45. 45.  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  Infectious complications: • Pneumocystis, Cryptococcal meningitis, TB and Mycobacterium avium complex, Microsporidia, Cryptosporidium, STD’s , Hepatitis B and C
  46. 46. 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 require additional testing:  HIV viral load quantitation >= 100 copies  Resistance Testing – report subtype to optimize therapy  Most isolates in USA type B •Monitor CD4 counts for infection severity
  47. 47. RNA Virus Rubella
  48. 48. Known as the “Three day measles” or 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 • Prior to Zika it was the neurotropic virus of the fetus  Deafness, eye abnormalities, congenital heart disease Diagnosis - Serology in combination with clinical symptoms Live attenuated vaccine (MMR) to prevent
  49. 49. Hantavirus
  50. 50.  1993 - Outbreak on Indian reservation in the four corner states (NM,AZ,CO,UT) brought attention to this virus  Source - urine and secretions of wild deer mouse and cotton rat  Recent outbreak from transmission from pet rats to humans  Myalgia, headache, cough and respiratory failure  Found in states west of the Mississippi River  Diagnosis by serology  Supportive therapy
  51. 51. Smallpox virus (Variola virus) Vaccinia virus
  52. 52.  Variola virus – agent of Smallpox, eradicated in 1977  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  Disease begins as maculopapular rash 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  Requires BSL4 laboratory (self contained lab)  Reported to public health department for investigation
  53. 53. Rabies virus
  54. 54.  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 progression  Rabies is a neurologic disease – classic symptom 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 Intracytoplasmi Negri bodies In brain biopsy
  55. 55.  Rare, degenerative fatal brain disorder  Transmissible spongiform encephalopathies (TSE) name established from the microscopic appearance of infected brain  Caused by type of protein - prion  Confirmation by brain biopsy  Safety – prevent transmission • Universal Precautions • Use disposable equipment when possible Spongiform change in the Gray matter

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