zoonotic viral dz

Question 1

list the zoonotic viruses

Answer 1

rabies, hantavirus, filovirus, arenavirus, paramyxovirus, arbovirus, HIV, influenza, SARS-CoV and MERS-CoV

Question 2

Which zoonotic viruses transmit from animals to humans but do not exhibit human to human
transmission under natural conditionsWhich zoonotic viruses transmit from animals to humans but do not exhibit human to human
transmission under natural conditions

Answer 2

Rabies virus, Sin Nombre virus, West Nile virus

Question 3

Which zoonotic viruses Transmit from animals to humans and can cause limited cycles of human to human transmission

Answer 3

Lassa fever virus, Machupo virus, Ebola virus, Marburg virus, Nipah virus, Monkeypox virus

Question 4

Which zoonotic viruses Originated or persist in animals but can cause self-sustaining chains of
transmission in humans (human to human OR vector to human)Which zoonotic viruses Originated or persist in animals but can cause self-sustaining chains of
transmission in humans (human to human OR vector to human)

Answer 4

influenza, SARS, HIV, yellow fever, Dengue,

Question 5

main source of rabies transmission

Answer 5

dogs (worldwide) and bats/ skunks in colorado. 30-50% occur in children living in poverty. Also occurs in racoons, bats, skunks, foxes. Transmission via bite or mucosal contamination with infectious material (saliva). Each host harbors a unique rabies virus variant

Question 6

rabies virus structure

Answer 6

rhabdoviridae lyssavirus- Bullet-shaped virion. non-segmented negative-strand RNA genome (12 kb). lipid envelope. Post-exposure prophylaxis is effective against all strains
of Rabies virusrhabdoviridae lyssavirus- Bullet-shaped virion. non-segmented negative-strand RNA genome (12 kb). lipid envelope. Post-exposure prophylaxis is effective against all strains
of Rabies virus

Question 7

Rabies clinical

Answer 7

Incubation: 1-3 months (can be up to 1 year). Furious (encephalitic) form (80%): Difficulty swallowing, Hydrophobia (Terror and excitation with spasm of inspiratory muscles, larynx, and pharynx precipitated by attempts to drink),
Episodes of hallucination, Hypersalivation,Brain stem dysfunction-coma-death. Paralytic form (20%): Lack of major features of furious form, Quadriparesis, Multiple organ failure-deathIncubation: 1-3 months (can be up to 1 year). Furious (encephalitic) form (80%): Difficulty swallowing, Hydrophobia (Terror and excitation with spasm of inspiratory muscles, larynx, and pharynx precipitated by attempts to drink),
Episodes of hallucination, Hypersalivation,Brain stem dysfunction-coma-death. Paralytic form (20%): Lack of major features of furious form, Quadriparesis, Multiple organ failure-death

Question 8

rabies pathogenesis

Answer 8

virus replicates at site of wound > infects neurons innvervating site of wound > retrograde spread through axons (no viremia) > replication in motor neurons and local dorsal root ganglia > centrifugal spread along nerves to salivary glands, skin, cornea > sx develop

Question 9

rabies diagnosis

Answer 9

Detect rabies virus antigen or RNA in serum, CSF, saliva, skin sample from neck (check animal brains if animal is available). Can use direct fluorescence assay, RT-PCR, ELISA. Negri bodies eosinophilic inclusion bodies of virus particles in the cytoplasm of infected neurons) are seen upon autopsy

Question 10

rabies post exposure prophylaxis

Answer 10

Immediately wash with soap and water. 1. Human rabies virus immunoglobulin (HRIG): Passive-immunization around area of wound—neutralize virus no later than 7 days after first vaccine dose. 2. Rabies virus vaccine (4 dose vaccine schedule): Inactivated vaccine. Administered IM at different site than HRIG. Additional doses at days 3, 7, and 14

Question 11

rabies prevention

Answer 11

mass vaccination of dogs is cheaper than PEP

Question 12

Hantavirus structure and transmission

Answer 12

Segmented (3), negative sense, ssRNA genome.

Question 13

diseases caused by hantavirus

Answer 13

Hemorrhagic fever with renal syndrome (HFRS) and Hantavirus pulmonary syndrome (HPS)

Question 14

Hantavirus transmission

Answer 14

Chronically infected rodents (absence of overt disease) transmit from rodent to rodent via scratching, biting. Human infection primarily due to exposure to aerosols of rodent urine. Mucus membrane contact and skin breaches are also consideration.

Question 15

What is the main hantavirus in North America and what is the disease it causes

Answer 15

Sin Nombre virus- causes hantavirus pulmonary syndrome

Question 16

Hantavirus pulmonary syndrome prodrome clinical sx/ labs

Answer 16

prodrome: fever, chills, myalgia for 3-7 days. Then pain in legs and back. Presence of productive cough at onset of illness is NOT consistent with HPS. Laboratory findings: Low platelet count, Neutrophilia, Elevated LDH and AST. Rodent exposure

Question 17

Hantavirus pulmonary syndrome disease progression

Answer 17

Transition from prodrome to respiratory failure is rapid: 12-24 hours. Tachypnea, Tachycardia
Pulmonary edema and inflammation, Crackles or rales on lung examination. Hypotension and shock. In severe cases, patients require intubation and mechanical ventilation. Death due to respiratory failure, shock, and myocardial dysfunction

Question 18

HPS treatment

Answer 18

limited to supportive care, respiratory support, blood oxygenation if severe.

Question 19

Hemorrhagic fever with renal syndrome

Answer 19

influenza-like symptoms for 1 week (high fever, headache, malaise, chills). This phase is followed by a hypotensive phase characterized by thrombocytopenia and petechial hemorrhage. Approx. 10-15% of patients exhibit shock and renal failure contributes to over half all deaths

Question 20

Filoviruses structure

Answer 20

Two genera: ebolavirus and Marburgvirus. Non-segmented negative-sense RNA genome. Bacilliform to filamentous morphology, Nucleocapsid (viral proteins + -RNA genome), Matrix protein, Envelope (derived from host PM), Membrane glycoprotein

Question 21

filoviruses transmission

Answer 21

spread among animals (bats, apes) can then spread to humans. Human to human spread then occurs via contact btw bodily fluids (blood, urine, saliva, etc). Virus can enter via cuts or abrasions, or mucus membranes. Droplet transmission possible, but not airborne

Question 22

droplet vs airborne transmission

Answer 22

In the droplet route, the pathogen falls to the ground in large droplets. The pathogen doesn’t make it very far away from the source of the fluid. In the airborne route, a virus can travel more than 30 feet in tiny droplets and can stay in the air for minutes or hours

Question 23

Where do most filovirus outbreaks occur

Answer 23

remote regions of central Africa

Question 24

Ebola early sx

Answer 24

2-21 days after exposure: fever, headache, fatigue, diarrhea, vomiting, weakness, stomach pain, unexplained bleeding, joint/ muscle aches

Question 25

Ebola treatment

Answer 25

IV fluids/ electrolyte balance, maintain oxygen status and BP, treat infections if they occur

Question 26

Henipavirus - family, diseases,

Answer 26

new genus within the family Paramyxoviridae (Mumps, Measles, RSV). Causes respiratory and neurological complications. High pathogenicity in humans, low in pigs, subclinical in bats

Question 27

What factors contributed to emergence of Nipah virus

Answer 27

Pig farming, fruiting failure of forest trees (drough conditions, forest fires), forest fruit bats migrated to orchards and pig farms

Question 28

HIV-1 vs HIV-2

Answer 28

HIV-1: pandemic virus. HIV-2: restricted to W. Africa