Lec 15: Emerging Viruses

Question 1

Emerging virus =

Answer 1

a virus that has recently made its presence felt by infecting a new host species, by appearing in a new area of the world OR by both.

Question 2

Re-emerging virus =

Answer 2

if it has started to become more common after it was becoming rare.
(ex: Foot & mouth disease virus re-emerges in UK from time to time)

Question 3

What may increase the likelihood of virus emergence and re-emergence?

Answer 3

Human activities (ex: travel, trade, close contact with animals)

Question 4

A virus jumps into a new host species =

Answer 4

evolutionary changes in the new host = resulting in a new virus
(ex: HIV from SIV)

Question 5

Recombination and reassortment result in:

Answer 5

new viable combinations of genes (ex: influenza A)

Question 6

Some ‘new’ viruses are actually

Answer 6

old viruses of which mankind has recently become aware

ex: Kaposi’s sarcoma associated herpesvirus

Question 7

Viruses in New Host Species: (2)

Answer 7

1. ) Bunyaviruses (4 Corner Virus and Sin Nombre Virus)

2. ) Paramyxoviruses (Hendra Virus)

Question 8

Viruses in New Areas: (1)

Answer 8

1.) West Nile Virus

Question 9

Viruses in New Host Species AND in New Areas: (1)

Answer 9

1.) Marburg virus

Question 10

SARS =

Answer 10

(severe acute respiratory syndrome),

Question 11

The causative agent for SARS was found to be

Answer 11

a new coronavirus

Question 12

No natural reservoir for the SARS coronavirus has been found, but

Answer 12

coronaviruses with very similar genome sequences were isolated from animals sold in markets in the region of Asia where the first SARS cases appeared

Question 13

(New strains of Influenza Virus A)
- The virions have 2 species of surface glycoproteins: (2)

• There are many ________ of ____ ____

Answer 13

1. ) haemagglutinin (H) (16 types of H antigen) and
2. ) neuraminidase (N) (9 types of N antigen).

There are many subtypes of each type

Question 14

From time to time a influenza virus emerges with a new combination of…
genes formed by…
which causes…

Answer 14

…H and N
…reassortment
…a pandemic

Question 15

Some Avian strains of influenza A virus can be transmitted from

Answer 15

wild birds to domestic poultry and can be transmitted to humans.

Question 16

The scheme for monitoring influenza virus strains provides

Answer 16

a good model for a surveillance system.

Question 17

Twice a year, WHO recommends…

Answer 17

the virus strains to be mass-produced for incorporation into influenza vaccines.

Question 18

(Dealing with Outbreaks)
good case model =
How the case proceeded: (4)

Answer 18

SARS
1.) The virus was isolated in: Feb ‘03
2.) Only 3 months later: its genome had been sequenced.
3.) The following year a paper was published reporting:
compounds that inhibit replication of the virus…
4.) While other papers reported:
the cell receptor of the virus and the structure of its replicase protein.