Amplifying hosts are important because they increase the amount of virus in the environment.

Amplifying hosts are important because they increase the amount of virus in the environment.

• A. They are not infected
• B. They always die quickly
• C. Produce the most airborne FMD virus per day
• D. They directly kill hosts

Answer: (C)

Amplifying hosts are animals in which the virus replicates to high levels and is shed in large amounts, raising the amount of virus present in the environment and increasing the chances of transmission. In diseases like foot-and-mouth, these hosts release substantial quantities of virus in secretions and aerosols, so their infection markedly boosts environmental contamination and airborne transmission risk. Saying that they produce the most airborne FMD virus per day emphasizes this idea: high replication and heavy shedding in a host lead to more virus in the air and surroundings for others to encounter. The other options miss the point: a host that isn’t infected cannot amplify the virus; a host that dies quickly doesn’t necessarily contribute significantly to ongoing environmental contamination; and amplification is about producing and shedding virus, not about directly killing other hosts.

Amplifying hosts are animals in which the virus replicates to high levels and is shed in large amounts, raising the amount of virus present in the environment and increasing the chances of transmission. In diseases like foot-and-mouth, these hosts release substantial quantities of virus in secretions and aerosols, so their infection markedly boosts environmental contamination and airborne transmission risk. Saying that they produce the most airborne FMD virus per day emphasizes this idea: high replication and heavy shedding in a host lead to more virus in the air and surroundings for others to encounter.

The other options miss the point: a host that isn’t infected cannot amplify the virus; a host that dies quickly doesn’t necessarily contribute significantly to ongoing environmental contamination; and amplification is about producing and shedding virus, not about directly killing other hosts.