ENVELOPED RNA VIRUSES

Question 1

Influenza Virus

Answer 1

respiratory droplets, direct contact w/ respiratory secretions

influenza A, B, C

Question 2

FILOVIRIDAE

Answer 2

longest viruses

Question 3

Ebola virus

Answer 3

Natural Host: fruit bats
Transmission: direct contact w/ fluids/fomites, infected bats or primates (apes/monkeys)

Ebola

Question 4

Coronavirus

Answer 4

prominent club-shaped spikes

Reservoir: Horseshoe bat
Immediate host: Civet cat
Transmission: Respiratory Droplet

common colds, severe acute respiratory syndrome, middle east respiratory syndrome, covid-19

Question 5

Dengue virus

Answer 5

Four serotypes: DEN-1, 2, 3, 4 (specific lifetime immunity)
Bite of Aedes albopictus mosquito

reservoir: man

dengue fever

Question 6

Hepatitis C Virus

Answer 6

reservoir: humans
blood-borne

setting: IV drug users, needle sticks

Hepatitis C

Question 7

Rubella virus

Answer 7

Respiratory droplets, transplacentally, direct contact with nasopharyngeal secretions

rubella/german measles, congenital rubella syndrome

Question 8

Human Immunodeficiency Virus (HIV)

Answer 8

*reverse transcriptase which converts a single stranded RNA viral genome into a double-stranded viral DNA *

original source: chimpanzees

direct sexual contact, transplacental & breastfeeding, contaminated needles

Question 9

influenza

Answer 9

acute, viral respiratory Infection with fever, chills, headache, aches, and pains throughout the body, sore throat, cough, and nasal drainage

Question 10

Influenza A

Answer 10

worldwide epidemics (pandemics)

MCC (mucociliary clearance first line of defense of the pulmonary system) of respiratory infections

ex.) Avian Flu

Question 11

Influenza B

Answer 11

human virus, no animal source of new RNA segments

major outbreaks, does NOT lead to pandemic

Question 12

Influenza C

Answer 12

mild respiratory tract infection; does NOT cause outbreaks

Question 13

ebola

Answer 13

targets endothelial cells, phagocytes, hepatocytes

can progress to DIC, diffuse hemorrhage, shock

high mortality rate (100%)

Question 14

common colds

Answer 14

second to rhinovirus as the most common cause of common colds

Question 15

severe acute respiratory syndrome

Answer 15

SARS-COV-1

receptor: angiotensin-converting enzyme-2 (ACE-2)

alveolar edema
atypical pneumonia to ARDS
CXR: interstitial “ground-glass” infiltrates

Question 16

middle east respiratory syndrome

Answer 16

MERS-CoV binds to CD-26

viral respiratory illness

Question 17

COVID-19

Answer 17

caused by SARS-COV-2 (binds to ACE2)

Question 18

dengue fever

Answer 18

“back breaking fever”

capillary permeability, abnormalities of hemostasis

Question 19

hepatitis C

Answer 19

immune attack by cytotoxic T cells
(resembles hep B but milder)

alcohol enhances

Question 20

rubella/german measles

Answer 20

Cephalocaudal appearance of maculopapular rash

Postauricular lymphadenopathy: most characteristic clinical feature

Enanthem: Forchheimer’s spots (petechiae on soft palate; not pathognomonic)

natural infection leads to lifelong immunity

Question 21

HIV

Answer 21

infects and kills helper (CD4+) T lymphocytes

loss of Th17 cells → bloodstream infections on normal flora of COLON

two most characteristic manifestations of AIDS are Pneumocystis pneumonia and Kaposi’s sarcoma