Mycoviro Reviewer Notes (Prelims-Finals) PDF

MYCOVIRO REVIEWER NOTES PRELIMS - FINALS ENDEMIC MYCOSES Pathogenesis of Coccidioide 1. Coccidioidomycosis 2. Blastomycosis  Most people who are infected by C. 3. Paracoccidioidomyc...

MYCOVIRO REVIEWER NOTES PRELIMS - FINALS ENDEMIC MYCOSES Pathogenesis of Coccidioide 1. Coccidioidomycosis 2. Blastomycosis  Most people who are infected by C. 3. Paracoccidioidomycosis immitis, develop a cell-mediated 4. Histoplasmosis (delayedhypersensitivity) immune response that restricts the growth of the Coccidioidomycosis organism.  Disease  One way to determine whether a person Coccidioides has produced adequate cell-mediated immitis causes immunity to the organism is to do a skin Coccidioidomycos test is.  In general, a person who has a positive skin test reaction has developed Properties  C. immitis is a sufficient immunity to prevent dimorphic fungus disseminated disease from occurring. that exists as a  If, at a later time, a person's cellular mold in soil and as a spherule in tissue. immunity is suppressed by drugs or disease, disseminated disease can occur  Dissemination from the lungs to other organs occurs in people who have a Transmission & Epidemiology defect in cell-mediated immunity. Coccidioide  The fungus is endemic in arid regions of the southwestern United States and Clinical Findings of Coccidioide Latin America.  People who live in Central and Southern  Infection of the lungs is often California, Arizona, New Mexico, asymptomatic and is evident only by a Western Texas, and Northern Mexico, a positive skin test and the presence of geographic region called the Lower antibodies. Sonoran Life Zone, are often infected.  Some infected persons have an influenza  In Soil it forms hyphae with alternating like illness with fever and cough. arthrospores and empty cells.  About 50% have changes in the lungs Arthrospores are very light and are (infiltrates, adenopathy, or effusions as carried by the wind. seen on chest x-ray. 10% develop  They can be inhaled and infect the lungs. erythema nodosum or arthralgias.  This syndrome is called "valley fever" or Pathogenesis of Coccidioide "desert rheumatism"; it tends to subside spontaneously.  In the lungs, arthrospores form  Disseminated disease can occur in spherules that are large, have a thick, almost any organ; the meninges, bone, doubly refractive wall, and are filled with and skin are important sites. endospores.  Upon rupture of the wall, endospores KEY CONCEPT: are released and differentiate to form new spherules. 1. Characterized by distinct geographic  The organism can spread within a person areas of distribution caused by by direct extension or via the dimorphic environmental molds bloodstream. 2. 90% are initiated by inhaling conidia of  Granulomatous lesions can occur in the causative fungi virtually any organ but are found 3. infection occur in immunocompromised primarily in bones and the central individuals nervous system (meningitis). 4. serologic test for serum antibodies to the endemic fungi have diagnostic and prognostic value 1 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS SUBCUTANEOUS MYCOSES eosinophilic materials which are deposition of antigen-antibody SPOROTRICHOSIS complexes and complement. Sporothrix schenckii  Culture: Sabourauds agar  thermally dimorphic  Treatment: infection is self limited fungus  administration of saturated solution of  at ambient temp Potassium iodide in milk is effective but grows as mold hard to tolerate producing branching,  oral itraconazole septate hyphae and  for systemic disease: amphotericin B conidia  at 35-37C in vitro as a CONTROL small budding yeast  minimize accidental inoculation  use fungicides Sporothrix schenckii  considered as occupational risk ( forest  grows well on routine agar rangers, horticulturist) media and at RT  young colonies: blackish and CHROMOBLASTOMYCOSIS shiny becoming wrinkled and subcutaneous mycotic infection caused fuzzy with age by traumatic inoculation  produces branching septate all are dematiaceous fungi having hyphae and distinctive small melanized cell walls conidia clustered at the end of Phialophora verrucosa tapering conidiophores Fonsecaea pedrosoi Fonsecaea compacta Rhinocladiella aquaspersa DIAGNOSIS Cladophialophora carrionii specimen: biopsy materials or exudate from granulomatous or infection are chronic and with slow ulcerative lesions development of progressive Microscopic examination: KOH or granulomatous lesion that in time induce calcofluor white stain hyperplasia of the epidermal tissue histopathologic sections :  stain with Gomori methenamine silver stain the cell wall black  Periodic acid schiff red color to the cell walls fluorescent antibody staining asteroid body often seen in tissue particularly in identification: endemic area  based on the mode of conidiation such as  in tissue appear the same with spherical Mexico,South brown cells term MURIFORM or Africa and SCLEROTIC BODIES that divide by Japan transverse  hematoxylin and eosin stained tissue this asteroid body consist of central basophilic yeast cell with radiating extension of 2 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS PHIALOPHORA VERRUCOSA conidia produced from flask DIAGNOSIS shape phialides with cup  10%KOH shape collarettes  sabourauds agar with antibiotic mature, spherical to oval conidia extruded from the TREATMENT phialide accumulate around  surgical incision therapy of choice for it small lesion  chemotherapy with flucytosine or itraconazole FONSECAEA PEDROSOI  relapse is common polymorphic genus may exhibit EPIDEMIOLOGY  Phialides  mainly in tropics  chains of blastoconidia  saprophytic ( vegetation, soil)  sympodial,rhinocladiella type  occurs chiefly on the legs of barefoot conidiation agrarian workers following infection  form short branching chain of  wearing shoes and legs protection for blastoconidia as well as sympodial prevention conidia  not contagious FONSECAEA COMPACTA  spherical with broad base connecting the conidia PHAEOHYPHOMYCOSIS RHINOCLADIELLA AQUASPERSA  infection characterized by the presence  produce lateral or terminal conidia from of darkly pigmented septate hyphae in a lengthening conidiogenous cell - tissue sympodial process  both cutaneous and systemic infection causative agent Exophiala jeanselmei Phialophora richardsiae Bipolaris spicifera Wangiella dermatitidis  in tissue the hyphae are large brain abscess are usually fatal but when recognized they are treated with amphotericin and surgeryleading cause CLADOPHIALOPHORA CARRIONII of cerebral phaeohyphomycosis is  produce branching chain of conidia by Cladophialophora bantiana. distal budding produce elongated conidiophores with long branching chains of oval conidia 3 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS MYCETOMA  chronic subcutaneous infection  causative agent usually found on soil  local swelling of the infected tissue and interconnecting often  draining,sinuses or fistulae that contains granules which are microcolonies of the agent.  actinomycetoma: a mycetoma caused by actinomycete  eumycetoma ( maduromycosis, Madura foot) is a mycetoma caused by a fungus  mycetoma occurs worldwide but common among impoverished people  prevalent in India,Africa,Latin America DIAGNOSTIC LABORATORY TEST  dissected granules from biopsy material for examination ( color, texture, size, FUNGAL AGENTS OF MYCETOMA  Pseudallescheria boydii presence of hyaline or pigmented  Madurella mycetomatis hyphae  Madurella grisea  culture on appropriate culture media  Exophiala jeanselmei  Acremonium falciforme TREATMENT  surgical debridement or excision and chemotherapy  color of the granules may provide  Pseudallescheria boydii: treated with information about the agent topical nystatin or miconazole  pseudallescheria boydii and  Madurella infection: itraconazole, Acremonium falciforme : white ketoconazole, amphotericin B  Madurella grisea and Exophiala  Exophiala jeanselmei: flucytosin jeanselmei : black  Madurella mycetomatis: dark red to EPIDEMIOLOGY AND CONTROL black granules these granules are hard  proper cleaning of wounds wearing shoe and contain intertwined septate hyphae 4 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS OPPORTUNISTIC MYCOSES two simple morphologic test that will distinguish C. albicans from other sp. PREDISPOSING FACTORS Of candida  road spectrum antibiotic use  steroid use after incubation in  hematologic malignancies serum for 90 mins at  transplant recipients 37C C.albicans will  systemic chemotherapy produce true hyphae  AIDS or germ tube CANDIDIASIS  members of the normal flora of the skin, nutritionally deficient mucous membranes and gastrointestinal media C. albicans tract produce large,  most prevalent systemic mycosis spherical most common agent chlamydospores  C. Albicans  C. Parapsilosis  C. Glabrata  C. Tropicalis spectrum of disease  Immunocompetent  Widespread use of fluconazole has  oral thrush precipitated the emergence of more  vulvovaginitis : curd like discharge azole-resistant species such as C. krusei  Intertrigo and C. lusitaniae  skin infection: satellite lesion  can cause both cutaneous and systemic  Onychomycosis infections  Immunocompromised morphology and identification  pseudomembranous esophagitis  grow as oval,budding yeast cells (3-6 um  subcutaneous nodules in size)  right sided endocarditis  form pseudohyphae  C. albicans is dimorphic; in addition to diagnostic laboratory tests yeast and pseudohyphae it can produce  specimens: swabs and scrapings from true hyphae superficial lesions, blood, spinal fluid,  Agar media with in 24 hrs at 37C tissue biopsies, urine, exudates and  produce soft, cream colored colonies materials from removed intravenous with a yeasty odor catheters  pseudohyphae apparent as submerged microscopic examination: growth below the agar surface  gram stained smears  histopathologic slides for pseudohyphae and budding cells  skin or nail scrapings (10% KOH) and calcofluor white culture  RT or at 37 C  presence of pseudohyphae serology  circulating wall mannan ( latex agglutination)  enzyme immunoassay more specific 5 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS Cryptococcosis pathogenesis  Cryptococcus neoformans  infections: wound, burns the cornea , Characteristics external ear , sinuses  oval yeast with narrow based bud  aspergilloma (fungus ball) in lung cavities surrounded by a wide  allergic bronchopulmonary aspergillosis  polysaccharide capsule seen in india ink  asthmatic symptoms with expectoration positive latex agglutination test of brownish bronchial plugs Transmission  grows abundantly in soil containing bird droppings( pigeon)  transmission by inhalation of airborne yeast cells spectrum of disease  asymptomatic lung infection  Meningitis  Encephalitis morphology and identification  produce whitish mucoid colonies within 2-3 days  spherical budding yeast cells ( 5-10 um in size)  with non staining capsule mucormycosis  saprophytic molds with non septate hyphae with walls and branches at right angles  rhino-orbital cerebral infection with eschar formation  leading pathogen: Rhizopus oryzae  clinical form: rhinocerebral mucormyosis Aspergillus fumigatus characteristics  exist only as molds  septate hyphae that form v shaped branches transmission:  widely distributed in nature inhalation of airborne conidia 6 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS laboratory diagnosis  direct examination or culture of nasal discharge, tissue or sputum  look for broad hyphae with uneven thickness,irregular branching and sparse septation Pneumocystis pneumonia  agent: Pneumocystis jiroveci Characteristics  indeterminate organism  major surface glycoprotein undergoes programmed rearrangement 7 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS VIROLOGY DNA VIRUSES  adsorption to host cell receptor  virion moves to the nucleus where replication occurs  ss DNA has hairpin loop on both ends All DNA viruses have Parvovirus that provide ds areas for the cellular double stranded DNA polymerase to initiate synthesis of DNA except progeny genome All DNA viruses have Papilloma  viral mRNA syntheisze by cellular RNA linear DNA Polyoma and polymerase from ds DNA intermediate except Hepadna  progeny virions are assembled in the All DNA viruses are Poxvirus nucleus icosahedral except  B19 virus replicates only when the cell is All DNA viruses Poxvirus in S phase replicate in the  Reason why the virus replicates in red nucleus except cell precursors but not in mature red cells NAKED DNA VIRUSES TRANSMISSION AND EPIDEMIOLOGY respiratory route PARVOVIRIDAE transplacental  Parvovirus B 19 ( fifth disease) or blood donated for transfusion erythema infectiosum number 19 panelB occurs worldwide humans natural reservoir  Important properties animals not a source of infection  very small (22nm)  Genus Erythrovirus  non enveloped  ss DNA  genome negative strand DNA (no virion polymerase)  icosahedral symmetry  one serotype slapped cheek, fifth disease 8 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS aplastic anemia CHRONIC B 19 INFECTION LABORATORY DIAGNOSIS FIFTH DISEASE/ APLASTIC ANEMIA: DETECT IGM B 19 CAN BE ISOLATED FROM THROAT SWAB IMMUNOCOMPROMISED NO ANTIBODY ( VIRAL DNA IN BLOOD USING PCR) FETAL INFECTION (PCR) hydrops fetalis TREATMENT AND PREVENTION No specific treatment pooled immune globulins may have beneficial effect in immunocompromised infected individual no vaccine, no chemoprophylaxis ADENOVIRIDAE ADENOVIRUS  important properties  no enveloped  ds linear DNA  icosahedral nucleocapsid  the only viruse with a fiber protruding from each of the 12 vertices of the capsid  fiber: organ of attachment and is a ARTHRITIS hemagglutinin  41 known antigenic types REPLICATIVE CYCLE attachment via its fiber uncoats viral DNA moves to the nucleus viral DNA replication in the nucleus virus is released by lysis of the cell not budding 9 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS TRANSMISSION AND EPIDEMIOLOGY  chlorination of swimming pool (prevent aerosol droplet waterborne conjunctivitis) fecal oral route  sterilization of eye equipment direct inoculation of conjunctivas ( keratoconjunctivitis) endemic worldwide outbreaks occur among military recruits due PAPOVAVIRIDAE to close living conditions HUMAN PAPILLOMA VIRUS serotypes 3,4,7 cause respiratory disease  characteristics type 18,19 cause epidemic  non enveloped keratoconjunctivitis  ds circular DNA type 11,21 cause hemorrhagic cystitis  icosahedral nucleocapsid type 40,41 cause infantile gastroenteritis  at least 100 types  with predilection to certain tissues  Upper respiratory tract -skin warts : HPV 1 to 4  pharyngitis - genital warts: HPV-6 ,11  pharyngoconjunctival fever  acute respiratory disease (fever, sorethroat ,coryza, conjunctivitis)  lower respiratory tract  Bronchitis  atypical pneumonia  hemorrhagic cystitis( hematuria, dysuria)  gastroenteritis with non bloody diarrhea in children younger than 2 years old viral DNA is integrated into host cell DNA in the vicinity of cellular oncogenes and E6 and E7 are overexpressed E 6 and E7 target vital oncogene c-myc (marker for cancer forms including cervical LAB DIAGNOSIS cancer) cell culture modulate cellular proteins that regulate cell detection of 4 fold or higher rise in antibody cycle titer E6 bind to p 53 tumor suppressor protein complement fixation agglutination inhibition TREATMENT AND PREVENTION no antiviral theraphy prevention:  live attenuated vaccine against serotypes 4,21,7 used only by the military. No longer available production discontinued after 1999  careful handwashing  environmental surfaces disinfected by sodium hypochlorite 10 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS TRANSMISSION AND EPIDEMIOLOGY skin to skin contact genital contact genital warts most common sexually transmitted disease skin warts common in children and young adults PATHOGENESIS infect squamous epithelial cells induce within the cell cytoplasmic vacuoles called koilocytes (hallmark of infection) E6 and E7 protein of HPV type 16 bind more strongly to p53 HPV type 16 causes carcinoma than other type genital warts: condylomata acuminata HPV 6 and HPV 11 - operates at the end of G1 phase - checks whether: 1. if conditions are favorable for the cell to divide, if not cell may enter into G0 ohase. 2. check the DNA for any damage before it proceed to the next phase (S phase) 3. If DNA damage is detected, proteins will prevent the formation of active cyclin/cdk complex 4. Inhibiton of cyclin/cdk complex formation will stop the progression of the cell cycle 5. DNA repair mechanism will be activated to rectify the DNA damage. skin plantar warts HPV 1 through HPV 4 11 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS function: maintain and generate myelin that Ca of uterine, penis,anus, pre malignant surrounds axons lesion ( intraepithelial neoplasia) HPV 16 and HPV 18 LAB DIAGNOSIS presence of koilocytes in the lesions DNA hybridization serological test detection of antibodies cell culture not use TREATMENT AND PREVENTION podophyllin ( genital warts) BK POLYOMA VIRUS alpha interferon only causes disease in liquid nitrogen for skin warts immunocompromised hosts plantar warts can be removed surgically or causes hemorrhagic cystitis and treat with salicylic acid nephropathy in patients solid organs ( kidney) cidofovir for severe HPV infection and bone marrow transplants 9 to 26 years old JC POLYOMA VIRUS  only causes disease in immunocompromised host  causes progressive multifocal leukoencephalopathy (PML) in patients with AIDS  demyelinating disease that affects oligodendrocytes characterized by deficits in speech,coordination and memory 12 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS ENVELOPED DNA VIRUSES Human herpesvirus 8 associated with Kaposis sarcoma Several herpesviruses cause CA in animals : leukemia in monkeys HERPESVIRIDAE HERPES SIMPLEX VIRUSES CHARACTERISTICS enveloped virus with icosahedral HERPES SIMPLEX VIRUSES (HSV) nucleocapsid and linear double stranded DNA Transmission large ( 120-200 nm in diam) HSV- 1 : saliva or direct contact replicate in the nucleus HSV- 2 sexual or transvaginal form intranuclear inclusions HSV 1 and 2 are structurally and obtain their envelope by budding from the morphologically indistinguishable nuclear membrane can be distinguish by two main criteria antigenicity and location of lesion HSV - 1 :above the waist HSV - 2 : below the waist distinguish by restriction endonuclease pattern of their genome DNA and by type specific monoclonal antisera humans are the natural host known for causing latent infection Herpes simplex virus 1 and 2, Varicella - zoster virus cause vesicular rash in primary and reactivation Cytomegalo virus, Epstein- Barr do not cause vesicular rash Epstein - Barr virus associated with Burkitts lymphoma and nasopharyngeal CA 13 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS PATHOGENESIS vesicle filled with virus particles and cell debris Herpes simplex type 2 site of latency  genital herpes HSV 1 trigeminal ganglia  aseptic meningitis HSV 2 lumbosacral ganglia  neonatal herpes ( contact within birth multinucleated giant cells are seen on Tzanck canal) smear large pink to purple intranuclear inclusions (Cowdry type A) genital herpes VARICELLA ZOSTER VIRUS characteristics enveloped virus with icosahedral nucleocapsid and linear double stranded DNA typical skin lesion : vesicles spectrum of diseases Transmission Herpes simplex virus type 1 respiratory droplets and by direct contact  gingivostomatitis with lesions  herpes labialis (lips) pathogenesis  keratoconjunctivitis infects the URT, them spreads via the blood  Temporal lobe encephalitis to the skin  herpetic whitlow (fingers) becomes latent in the dorsal root ganglia, herpes gladiatorum which may reactivate as zoster Varicella (chicken pox) Zoster ( shingles) varicella  incubation period 14-21 days  vesicular centrifugal rash ( dewdrop on a rose petal appearance complications * pneumonia * encephalitis * REYE`S syndrome herpetic whitlow 14 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS Zoster GIANT CELLS WITH OWLS - EYE painful vesicles along dermatomal NUCLEAR INCLUSIONS distribution debilitating pain ( postherpetic neuralgia) Spectrum of disease congenital CMV infection - systemic CMV infection RAMSAY HUNT SYNDROME involve geniculate ganglion causes facial nerve paralysis CYTOMEGALOVIRUS Characteristics enveloped with icosahedral nucleocapsid and linear ds DNA cultured in shell tubes negative heterophil test transmission - human body fluids, cross the placenta, organ transplantation 15 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS RNA VIRUSES ENTEROVIRUSES  Poliovirus POSITIVE STRAND ACT AS M RNA AND  naked nucleocapsid with ss + polarity BE DIRECTLY TRANSLATED INTO RNA PROTEINS  oral fecal transmission  replicates in motor neurons in anterior horn of spinal cord, causing paralysis  host range limited to primates NEGATIVE STRAND THEY NEED TO BE TRANSCRIBED INTO COMPLIMENTARY POSITIVE SENSE RNA SPECTRUM OF DISEASE  asymptomatic infection GENERALITIES ON RNA VIRUSES  abortive poliomyelitis : most common  ALL VIRUSES HAVE SINGLE STRANDED clinical form EXCEPT  mild,febrille illness headache,sore throat,  Reovirus nausea and vomiting  Rotavirus  non paralytic poliomyelitis : aseptic  ALL RNA VIRUSES REPLICATE IN THE meningitis CYTOPLASM EXCEPT  paralytic poliomyelitis: flaccid paralysis;  Orthomyxovirus permanent motor nerve damage  Retrovirus NAKED RNA VIRUSES: PICORNAVIRIDAE  small (20-30 nm)  non enveloped  icosahedral nucleocapsid  single stranded RNA genome  Genome RNA has positive polarity (RNA strand can serve  directly as m RNA and translated directly to protein)  replicate in the cytoplasm of cells 2 GROUPS OF MEDICAL IMPORTANCE  histopathology : Cowdry type B  Enteroviruses inclusions  replicate optimally at 37C  prevention: vaccine  stable under acid condition (pH3-5)  killed (Salk IPV) live,  attenuated (Sabin  Rhinoviruses OPV)  grow better at 33 C  acid labile 16 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS  transmission: fecal- oral route RHINOVIRUS HEPATITIS A VIRUS  common colds  naked nucleocapsid virus with a ss-  naked nucleocapsid viruses with ss + positive- RNA polarity RNA  Fecal oral transmission  more than 100 serotypes  children frequently infected  transmitted by aerosol droplets and  self limited hand to nose contact  Anti - HAV IgM most important test  replicate better at 33 C  also know as Enterovirus 72  affect primarily the nose and conjunctiva  only one serotype rather than the lower respiratory tract  no antigenic relationship with other hepatitis viruses COXSACKIEVIRUSES  characteristics  note:  naked nucleocapsid with single stranded,  Coxsackie virus, Poliovirus and Echo positive polarity RNA virus are Enterovirus  transmission: oral fecal  Most common cause of aseptic  group classification based on meningitis pathogenicity in mice  other Enterovirus － Group A predilection for skin and mucous － Enterovirus 70: acute hemorrhagic membranes conjunctivitis , no therapy － Group B cause disease in various organs － Enterovirus 71: viral central nervous as the heart, pleura,pancreas and liver system disease ( meningitis ,encephalitis, － Both Grp A and B can affect the meninges paralysis) and motor neurons to cause paralysis CALCIVIRIDAE SPECTRUM OF DISEASE  ss RNA non enveloped  Group A specific disease  Icosahedral symmetry  Herpangina : fever, sore throat and Family tender vesicles in oropharynx  Sapporo  Hand - foot and mouth disease: vesicular  Norovirus rash on hands and feet and ulcerations  Norwalk virus ( Norovirus) epidemic in the mouth viral gastroenteritis oral fecal transmission  Group B specific disease  Pleurodynia ( Bornholm REOVIRIDAE: Respiratory enteric orphan disease,epidemic myalgia, devils grip)  dsRNA 60 to80 nm fever and severe pleuritic type chest pain  Nonenveloped, icosahedral symmetry  Myocarditis and Pericarditis : (most  replicates in the cytoplasm common cause): fever,chestpain and  Rotavirus signs of congestive failure  fecal-oral  Viral gastroenteritis  Group A and B  common cause of childhood diarrhea  Aseptic meningitis  No vaccine ORTHOMYXOVIRIDAE ECHOVIRUSES  ECHO: Entero Cytopathic Human Orphan  now known to cause aseptic meningitis, upper respiratory tract infection, febrile illness with and without rash, infantile diarrhea and hemorrhagic conjunctivitis 17 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS  Influenza virus There are 4 types of seasonal influenza viruses, types A, B, C and D. Influenza A and B viruses circulate and cause seasonal epidemics of disease. Influenza A viruses  are further classified into subtypes according to the combinations of the hemagglutinin (HA) and the neuraminidase (NA), the proteins on the surface of the virus  Currently circulating in humans are subtype A(H1N1) and A(H3N2) influenza viruses.  The A(H1N1) is also written as A(H1N1)pdm09 as it caused the pandemic in 2009 and subsequently replaced the seasonal influenza A(H1N1) virus which had circulated prior to 2009.  Only influenza type A viruses are known to have caused pandemics.  Influenza B viruses are not classified into subtypes, but can be broken down into lineages. Currently circulating influenza type B viruses belong to either B/Yamagata or B/Victoria lineage.  Influenza C virus is detected less frequently and usually causes mild infections, thus does not present public health importance.  Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people. Transmissions: Seasonal influenza spreads easily, with rapid transmission in crowded areas including schools and nursing homes. 18 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS Due to the constant evolving nature of influenza viruses  WHO Global Influenza Surveillance and Response System (GISRS) – a system of National Influenza Centers and WHO Collaborating Centers around the world – continuously monitors the influenza viruses circulating in humans and updates the composition of influenza vaccines twice a year. Seasonal influenza is characterized  composition of the vaccine (trivalent) that targets the 3 most representative by a sudden onset of virus types in circulation (two subtypes  fever of influenza A viruses and one influenza  cough (usually dry) B virus).  headache  Starting with the 2013–2014 northern  muscle and joint pain hemisphere influenza season, a 4th  severe malaise (feeling unwell) component is recommended to support  sore throat and a runny nose. quadrivalent vaccine development.  The cough can be severe and can last 2 Quadrivalent vaccines include a 2nd or more weeks. influenza B virus in addition to the  Most people recover from fever and viruses in trivalent vaccines, and are other symptoms within a week without expected to provide wider protection requiring medical attention. against influenza B virus infections.  can cause severe illness or death especially in people at high risk  The effects of seasonal influenza epidemics in developing countries are not fully known  99% of deaths in children under 5 years of age with influenza related lower respiratory tract infections are found in developing countries using:  A number of inactivated influenza  direct antigen detection vaccines and recombinant influenza  virus isolation vaccines are available in injectable form.  detection of influenza-specific RNA by  Live attenuated influenza vaccine is reverse transcriptase-polymerase chain available as a nasal spray. reaction (RT-PCR). PARAMYXOVIRUSES  Rapid influenza diagnostic tests  Helical and enveloped (RIDTs) are used in clinical settings, but  with only one long ssRNA genome. ( no they have lower sensitivity compared to reassortment) RT-PCR methods and their reliability  replicate in both nucleus and cytoplasm depends largely on the conditions under five genera which they are used 1. Mumps 2. parainfluenza 1to 4  One influenza A(H1N1), one influenza 3. measles A(H3N2), and one or two influenza B 4. RSV viruses (depending on the vaccine) are 5. Metapneumovirus included in each season’s influenza vaccines. 19 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS PARAINFLUENZA VIRUS PARAMYXOVIRIDAE  four antigenic types Virus Hemagglutini Neuraminidase FUSION  HPIV 1 TO 4 n PROTEIN  Causes croup(swelling in upper airway) MEASLES + - +  respiratory diseases  grow in cell culture MUMPS + + +  Hemadsorption for ID RSV (respiratory syncitial virus) - - + MEASLES PARAINFLUENZA + + +  one serologic type  maculopapular rash,fever, respiratory RHABDOVIRIDAE disease  RABIES VIRUS  can be cultured  Bullet shaped enveloped virus  Hemadsorption for ID  animal reservoir: dog, cat bats, raccoons : animal bites MUMPS  negri bodies  Infect the parotid salivary glands  can infect testis, ovaries,kidneys CORONAVIRIDAE  Isolated from throat swab or urine  corona virus  Hemadsorption ID  club shaped spike ( corona) 2 serotypes RSV (respiratory syncitial virus) 1. 229E  Labile virus 2. OC43  produces typical CPE  SARS in the same group as 0C43 ground  monoclonal antibody to confirm glass infiltrate x-ray  rapid testing available FLAVIVIRIDAE METAPNEUMOVIRUS  DENGUE VIRUS  acute respiratory infections worldwide in  Aedes aegypti children and adults  Dengue IgM  annual epidemics in winter and spring  Hepatitis C virus months  diagnosis: anti HCV or HCV RNA  PCR diagnosis  chronic carriage of HCV much higher than HBV HEMADSORPTION  St Louis encephalitis, West Nile virus,  viruses produce hemagglutinin yellow fever  hemagglutinin binds to RBC  Human type O TOGAVIRIDAE  chicken  ss RNA  guinea pig  enveloped icosahedral symmetry  perform on cell cultures from respiratory  Family: Togaviridae specimens  genus: alphavirus: Arboviruses  Genus: rubrivirus: Rubella ARBOVIRUSES  Eastern and Western equine encephalitis  Bird reservoir  Mosquito vectors  symptoms: fever,encephalitis,rash  serological test commonly used 20 Compiled by: BUENO, Willa Mae  MYCOVIRO REVIEWER NOTES PRELIMS - FINALS RUBELLA VIRUS. : GERMAN MEASLES  phase 0: HIV acquired through  Transmitted by droplets sexual,blood or perinatally \  infection in children mild  Phase 1- window period: rapid viral  congenital disease serious replication but HIV test is negative  mother contracts rubella in first  Phase 2- Seroconversion: peak of trimester viral load, positive HIV test, mild flu like  vaccine available illness  serology test commonly used  Phase 3- latent period: asymptomatic CD4 goes down,last 1-15 RETROVIRIDAE: REPLICATE NUCLEUS years AND CYTOPLASM  Phase 4 - Early asymptomatic: CD4  ssRNA 500 to 200 last 5 years mild  Enveloped icosahedral symmetry mucocutneous dermatologic and  all have reverse transcriptase : DNA hematologic illness made from RNA  Phase 5 AIDS: CD 4 less than 200 lasts  integrates into the genome 2 years AIDS defining illness develop  Subfamilies:  Oncoviridae MISCELLANEOUS VIRUSES  Lentiviridae  Human T cell Lymphotropic virus (HTLV) retroviruses causing adult T cell  Human T lymphotropic viruses HTLV-1,2 leukemia and HTLV associated and 5 belong to oncoviridae associated myelopathy malignant T cells with flower in several leukemias, shaped nucleus sarcomas,lymphomas  Ebola virus  HIV lentiviridae  hemorrhagic fever  thread like viruses  PRESENCE OF REVERSE TRANSCRIPTASE  100% mortality rate  converts ss RNA into ds DNA  West Nile virus  Flavivirus  bird-mosquito-man cycle  progress to neuroinvasive disease  Japanese B virus  Flavivirus  common cause of epidemic encephalitis  transmitted by Culex mosquitoes 21 Compiled by: BUENO, Willa Mae