Viruses Flashcards
Dengue family
Flaviviridae
Dengue serotypes
4
Dengue principal vector
Aedes aegypti
Dengue Transmission. When?
Febrile viremic stage, after 8-12 days incubation
DHF. Who usually gets it?
Primarily children under 15
Dengue, pathognomonic sign?
None!
Critical stage in dhf?
Defervescence, 24 hours before and after
Critical stage dhf. What happens?
Circulatory collapse and hemorrhagic signs
Thrombocytopenia
100,00/mm^3
Normal platelet count
150,000/mm^3
Test for increased capillary fragility
Tourniquet/Hess test
DHF. Liver, characteristic cell
Councilman bodies
Can dengue viruses cross the BBB?
Yes, on occasion
DHF effect on RES?
Increased proliferation of RES cells
Among the most common of human diseases
Viral respiratory infections
Most common cause of respiratory infection
Rhinovirus
Major cause of common cold
Rhinovirus
Rhinovirus incubation period
1-2 days
Counterpart of rhinovirus in children
Respiratory syncytial virus
RSV lipid envelope proteins
G for attachment
F for fusion
RSV incubation period
4-6 days
Major respiratory pathogen of young children
Respiratory syncytial virus
Rsv. More protective, serum antibody or nasal IgA?
Nasal IgA
RSV management for some infants
Ribavirin
Ribavirin mode of action
Nucleoside analogue
RSV vs Rhinovirus
Serology is helpful in diagnosing RSV
Mumps virus
Paramyxoviridae
Mumps transmission
Respiratory droplets
Mumps usual presentation
Bilateral parotitis
Mumps. Aside from parotid glands, what else can swell?
Testis
Pancreas
Measles other term
Rubeola
German measles other term
Rubella
Chickenpox and shingles
Varicella, varicella zoster
Viral infections with cutaneous manifestations
Measles German measles Chickenpox, shingles Herpes simplex virus Human papilloma viruses Others- human parvovirus b19, smallpox
Reservoir for Rubella
Humans ONLY
Rubella route
CD46 of host to glycoprotein H of virus
c3 convertase inactivator
Prominent involvement of Waldeyer’s ring
Rubella
Measles rash product of which immunological cells
T cell reaction
Cell mediated immunity
Hypermutated defective measles viruses, cant form envelope cause
Subacute sclerosing panencephalitis
Measles inclusion body encephalitis
Pathognomonic of measles
Koplik spots
Koplik spots location
Near opening of Stensen’s duct
Measles. Characteristic cells in lymphoid organs:
Warthin-Finkeldey cells
WF cells are?
Fusion of infected cells
Blotchy purplish generalized rash, runny nose, sore eyes
Measles
Rabies family
Lyssaviridae
Rabies stages
Prodrome
Neurologic phase
Coma
Rabies Viruses are taken up by what kind of nerve endings?
Unmyelinated
Rabies movement
Centripetal from axons to CNS then Centrifugal from CNS to various organs
Rabies settles where
Usually salivary glands
Rabies Histopath findings?
Almost none
But some show Negri bodies
Pathognomonic of rabies
Negri bodies
Negri body pref. site of formation
Hippocampal neurons
Neurologic phase hydrophobia of rabies
Exaggerated respiratory tract protective reflex
Neurologic phase rabies symptoms
Furious and dumb, delirium, anxiety, agitation, paralysis
Polio family
Enterovirus
Polio major strains?
3
Ingredient of attenuated vaccine can revert to wild type, most pathogenic strain
Polio 3
Most virulent polio strain?
Polio 1
Strains present in vaccines for polio?
All 3
Killed, formalin fixed
Salk
Live, attenuated
Sabin
Kind of vaccine used in the Phil Expanded Program
Sabin, live attenuated
Less immunogenic vaccine
Salk
Polio first infects the?
Oropharynx
Polio stats invading CNS?
1/100
Stats, percent of symptomatic in polio infected population?
1%
Typical histo feature of acute poliomyelitis?
Neuronophagia
Destruction of nerve cells by phagocytes
Neuronophagia
Causes significant number of fetal death in utero
Parvovirus B19
Smallpox official repositories
CDC in the US
Central Laboratory in Russia
Hand foot and mouth disease culprit
Coxsackie virus usually type A16
Coxsackie family
Picornaviridae
Coxsackie histo features
Intraepidermal spongiotic vesicles
Coxsackie pattern of presentation
Enanthem then exanthem
Rash on mucous membranes
Enanthem
Skin rash
Exanthem
Molluscum contagiosum family
Pox
Molluscum strains?
3
Molluscum histo feature in germinal layer of skin?
Molluscum body
Hyaline acidophilic granular massin molluscum contagiosum?
Molluscum body
Characteristic skin lesion, molluscum
Painless nodules with small whitish core (central umbilication)
Molluscum transmission
Direct body contact
Through fomites
Sexually
Herpes, #groups, #viruses?
3 groups of 9 viruses
Neurotropic alpha group
Hsv1 Hsv2 VZV
Lymphotropic beta group
CMV, HSV6, HSV7
Causes exanthema subitum
HSV6
Herpes Gamma group
EBV, HSV8 (Kaposi)
Viruses able to remain latent in their natural hosts- almost always recurring in later life
Herpes viruses
Herpes virus lesion, histo
Cowdry type A
Large pink to purple, contain intact and disrupted virions, push darkly stained host cell chromatin to edges of nucleus
Cowdry type A intranuclear inclusions
Hsv3
Herpes zoster
Hsv4
Epstein barr
Hsv 5
Cmv
Hsv 8
Kaposi’s Sarcoma
Major infectious cause of corneal blindness
HSV1
Major cause of fatal sporadic encephalitis
HSV1
Herpes in the genital tract?
Automatically tested for HIV
Genital herpes
Mostly HSV2, but may be present in HSV1
HSV1 and 2, replication site?
Skin and mucous membranes at site of entrance of virus
Hsv characteristic cell
Multinucleated (single nucleus which became polynucleated) giant HSV infected cell
Varicella initial infection in children
Chicken pox
Lethal systemic infection of VZVin immunocompromised hosts
Hemorrhagic varicella
Characteristic VZV histo
Nuclear inclusion bodies with groundglass appearance
EBV can cause?
Burkitt lymphoma
Nasopharyngeal CA
EBV transmission
Human contact, saliva - kissing!
EBV infects which cells?
B cells
Two forms of infection of B cells
Minor - lytic
Major - integration into genome
Proteins associated with EBV driven polyclonal activation and proliferation
EBNA2
LMP1
Type of antibody which increases infectivity of EBV for B cells
IgA
Diagnosis EBV infection
Positive heterophil/ monospot test
Atypical lymphcytosis
Absolute lyphocytosis criteria
12000-18000 cells per ml
60% lymphos
Many atypical
Cytomegalovirus devastating in what population?
Infants
Immunocompromised people
Cmv infects and remains latent in?
WBCs
CMV histiocytes
With clear halos and large intranuclear inclusions
Most common neoplasm in aids patients
Kaposi’s sarcoma
Kaposi antigen for staining
Factor VIII related stain
HPV common warts
1 2 4
HPV condylomata acuminata
6 10 11 40-45
HPV squamous cell dysplasias and CA
16, 18, 31
Transmission hpv
Direct contact
Hpv infected cells display a characteristic cytopathic effect
Koilocytosis
Large squamous cells with shrunken nuclei enveloped in large cytoplasmic vacuoles
Koilocytes
Condyloma lata
Syphilis, 2nd stage
Condyloma acuminata
HPV 6 10 11 40-4
Epithelial hyperplasia term
Acanthosis
Hyperchromic nucleus with perinuclear halo, squamous cell
Koilocyte
