Q 01/05

How long after exposure do influenza symptoms typically begin?

A) A few hours

B) About two days

C) About a week

D) About a month

Answer · why

B) About two days

About two days, within a range of one to four. Flu then tends to strike abruptly, where a cold usually creeps up with a runny or stuffy nose.

Q 02/05

Which virus, unrelated to influenza, is the leading cause of the vomiting bug nicknamed 'stomach flu'?

A) Rhinovirus

B) Epstein-Barr virus

C) Norovirus

D) Poliovirus

Answer · why

C) Norovirus

Norovirus. True flu is an infection of the airways, and vomiting is uncommon in adults who catch it, though children with flu do sometimes get it.

Q 03/05

Which animals are the primary reservoir of influenza A viruses?

A) Farmed chickens

B) Aquatic birds

C) Migratory songbirds

D) Birds of prey

Answer · why

B) Aquatic birds

Aquatic birds. Wild ducks can carry the virus in their gut without getting sick, and with a reservoir like that on the wing, the WHO calls eradicating...

Q 04/05

In 2024, H5N1 bird flu jumped species and began spreading through which US farm herds?

A) Sheep

B) Cattle

C) Horses

D) Donkeys

Answer · why

B) Cattle

Cattle. The virus passed between dairy herds in several states, and some farm workers caught it from the cows, mostly with mild symptoms; tests showed...

Q 05/05

In the subtype name H1N1, what does the H stand for?

A) Haemagglutinin

B) Histocompatibility

C) Helicase

D) Haemolysin

Answer · why

A) Haemagglutinin

Haemagglutinin. The protein is named for a lab quirk, its knack of making red blood cells clump together; on the virus it is the spike that latches on...