RNA - SENSE Flashcards
Orthomyxoviridae disease
Influenza Virus ( A,B and C)
Paramyxoviridae
a. Measles Virus
b. Mumps Virus
c. Parainfluenza virus 1 and 2
Rhabdoviridae
Rabies virus
Filoviridae
Ebola virus
Formerly known as Bunyavirus
Hantaviridae
(+/-) RNA
Reo
Double capsid
Reo
+ RNA via DNA
Retrovirus
Orthomyxoviridae size (influenza)
80 to 100 nm
ORTHOMYXOVIRIDAE morphology
Large, pleomorphic, spherical, enveloped, single stranded, segmented and negative sense RNA
ORTHOMYXOVIRIDAE transmission
Respiratory Droplets
Orthomyxoviridae spectrum of disease and incubation period
INFLUENZA OR FLU
1 to 4 days
Orthomyxoviridae complication
fatal bacterial superinfections (S. aureus and S. pneumoniae)
Reye’s syndrome
Orthomyxoviridae treatment
● Oseltamivir (DOC) and Zanamivir
● Amantadine and Rimantadine
● Vaccine (both influenza A and B)
Orthomyxoviridae
The envelope is covered with two different types of spikes:
Hemagglutinin
Neuraminidase
bind to cell surface receptors
Hemagglutinin
rod shaped spikes bound to cell surface receptor.
Hemagglutinin
facilitate the release of mature virions from
infected cell
Neuraminidase
Mushroom shapes spikes
Neuraminidase
Assist viral movement to the mucous to adjacent
cells
Neuraminidase
cause of the greatest number of serious acute
illnesses
Influenza
are only known to infect humans.
Influenza b and c
Distinguishing the 3 influenza based on
antigenic differences in the matrix protein or nucleoprotein
Antigenic shift occurs only in
INFLUENZA A
Antigenic drift occurs in
all viral influenza virus
Worlwide epidemic (pandemics)
Influenza A
How many antigenically distinct types of hemagglutinin
16
How many antigenically distinct types of neuraminidase
9
Major outbreaks of influenza
INFLUENZA B
Does not lead to pandemic
INFLUENZA B
Mild respiratory tract infections
INFLUENZA C
Does not cause outbreak of influenza
Influenza C
Major change based on the reassortment of segments of the genome RNA
Antigenic shift
Example of antigenic shift
Human influenza a virus combines with swine influenza a virus
Sudden change in the molecular structure of a microorganism
Antigenic shift
Minor changes based on mutations in the genome RNA
Antigenic drift
Slow and proggressive change in the composition of the microorganism
Altered immunological responses and susceptibility
Antigenic drift
Of all the Identification of Respiratory
viruses,____________ is the gold standard.
RT-PCR
PARAMYXOVIRIDAE
a. Measles Virus
b. Mumps Virus
c. Parainfluenza virus 1 and 2
MEASLES VIRUS morphology
Enveloped, helical, non-segmented, ss negative
RNA
MEasles virus transmission
Respiratory droplets
Measles virus measles pathogenesis
Measles virus > cell lining of the URT > blood > reticuloendothelial cells > blood to the skin > cytotoxic T-cells attack the measles virus infected vascular endothelial cells in the skin › rash › virus can no longer be recovered > no virus spread
Measles virus disease
Red measles, rubeola,
“first disease”
Red measles, rubeola, first disease incubation period
Incubation Period: 10-14 days
( 4 days before and 4 days after the onset of rash infections)
Red measles, rubeola, “first disease”
Features
Koplik spots
Red measles, rubeola, first disease
Complications
otitis media, giant cell pneumonia, SSPE, bronchiolitis oblierans
Red measles, rubeola, first disease
Cardinal Signs
(3Cs) : cough, coryza, conjunctivitis (+ fever) and Koplik spots
Measles virus diagnosis
Multinucleated giant cells
(Warthin Finkelday bodies)
Measles virus
Treatment and Prevention
● Vitamin A supplementation
● Measles vaccine
● MMR vaccine
● Post exposure prophylaxis
Mumps morphology
Enveloped, ss negative RNA helical symmetry;
non-segmented
Mumps virus transmission
Respiratory droplets
Mumps pathogenesis
URT then spread through the blood and infects the:
● Parotid glands > Parotitis
● Testes > Orchitis
● Ovaries
● Meninges > Aseptic Meningitis
● Pancreas > Pancreatitis
Prevention mumps virus
MMR Vaccine
Parainfluenza 1 & 2 morphology
Enveloped, ss negative RNA helical symmetry;
non-segmented
Transmission parainfluenza 1&2
Respiratory droplets
Parainfluenza 1&2 spectrum of disease
Laryngotracheobronchitis or croup (“Steeple sign” on X-ray)
Treatment parainfluenza
Racemic epinephrine
Rhabdoviridae
Rabies virus
Rabies morphology
Bullet-shaped, enveloped helical non-segmented
(-sRNA)
Rabies virus transmission
Animal (dogs, cat, skunks, racoons and bat)
- Via animal bite
(retrograde transport)
Rhabdoviridae diagnosis
Negri bodies and imunofluorescent antibody
test (IFAT)
Rabies treatment
Pre-exposure:
● Vaccine (PVRV or PDEV or PCEV - DO, D7, and D21/28) |
Post-exposure:
● Vaccine +/- Immunoglobulin
Touching or feeding animals, licks on intact skin
Category 1 No treatment
Minor scratches or abrasions without bleeding or licks on broken skin and nibbling of uncovered skin
Category 2 Vacinne
Single or multiple transdermal bites or scratches; contamination of mucous membranes with saliva from licks; exposure to bat bites/scratches All Category Il exposures on head and neck areas
Category 3 Vacinne+ Immunoglobulin
Rabies incubation
2 weeks to 6 years (depending on the site of the bite)
Prodome of rabies
Nonspecific symptoms of fever, headache, sore throat, fatigue, nausea
1st rabies symptom:
● pain, itchiness, paresthesia
Rabies acute neurological
Encephalitis/Furious rabies
Paralytic/Dumb rabies
Associated with heightened aggression and agitation
Encephalitic / Furious Rabies
Phobic spasms: hydrophobia, aerophobia
Encephalitic / Furious Rabies
Associated with lethargy and paralysis
Paralytic / Dumb Rabies
Occurs secondary to respiratory center dysfunction
Death due to rabies
Filoviridae
Ebola virus
Ebola virus transmission
Direct contact, fomites, infected bats or primates
Ebola virus Morphology
Enveloped, helical, non-segmented SRNA
Ebola virus natural host
Fruit bat (Pteropodidae family)
Ebola virus pathogenesis and disease
Targets endothelial cells, phagocytes, hepatocytes
Abrupt onset of flu-like symptoms, diarrhea/vomiting, high fever, myalgia
Can progress to DIC, diffuse hemorrhage, shock
High mortality rate (100%)
Diagnosis ebola virus
ELISA, Antigen Test, RT-PCR
Treatment and prevention ebola virus
Supportive care; strict isolation
Formerly known as bunya viridae
Hantaviridae
Hantaviridae morphology
Large, spherical or pleomorphic, enveloped,
single-stranded
Hantaviridae transmission
Exposure (inhalation) to aerosolized rodent excreta
Hantaviridae primary host
Deer mouse
Diagnosis hantaviridae
NAAT from serum
whole blood
bronchoalveolar lavage fluid or tissue
serologic assays for hantavirus-specific IgM or IgG antibody
Treatment for hantaviridae
Currently there is no vaccine for hantavirus, and
therapeutics are only in experimental stages
