Rhinovirus

Question 1

category of rhinovirus

Answer 1

Enterovirus, including coxsackieviruses,
echoviruses;
Family: picornaviridae

Question 2

properties

Answer 2

Small icosahedral, non enveloped
+ssRNA
Divided into RhVA, RhVB, RhC based on their
sequence similarity & cell entry receptors

Question 3

Virulence Factors

Answer 3

4 viral capsid proteins: VP1, VP2, VP3, VP4
Labile at acidic pH

Question 4

Season

Answer 4

Spring, summer, fall/autumn

Question 5

Incubation Period

Answer 5

48-72 hrs

Question 6

Survival time

Answer 6

2 hrs-7 days

Question 7

Epidemiology & risk
factors

Answer 7

Upto 50% of common colds
RF:
- Smoking
- Very young or old
- Exposure to infected contacts
- Touching the conjunctivae or the nose
with contaminated fingers or objects
- crowding(day care settings)

Question 8

Vaccination

Answer 8

No - many different serotypes

Question 9

other clinical conditions

Answer 9

Exacerbate asthma, COPD. Can lead to -
- Secondary infections of sinuses &
middle ear
- LRTI - pneumonia, bronchiolitis in young
children & immunocompromised adults
- Viral pneumonia

Question 10

Pathogenesis

Answer 10

90% of RhA & RhB attach to ICAM(intracellular
adhesion molecule) & 10% use LDL(low density
lipoprotein) to attach to the host cell and enter →
host cell release IL, chemokines→ inflammation
→ mucosa secretes NO, VEGF, EGF →activate fibroblast/myofibroblast → releasematrix proteins → airway remodeling of
mucosa

Question 11

Pathogenicity

Answer 11

● Relatively stable in environment: enable
transmission
● Non-enveloped: not sensitive/less
sensitive to surface cleaners eg alcohol,
disinfectants
● Optimum temp for growth is 33-35C -
URTI
● Antigenic drift(mutations overtime) -
High no. of viral serotyp

Question 12

Scenario

Answer 12

ONLY COLD no other sx