In FMD, which host category is described as reflecting virus activity but not being a major driver of transmission?

In FMD, which host category is described as reflecting virus activity but not being a major driver of transmission?

• A. Amplifying hosts
• B. Indicator hosts
• C. Maintenance hosts
• D. Sentinel hosts

Answer: (B)

Indicator hosts are species that reflect virus activity without driving transmission. They become infected and show evidence of infection (such as seroconversion or mild/subclinical signs), signaling that Foot-and-Mouth Disease virus is circulating in the area. However, they do not contribute much to onward spread because their population density, contact patterns, or viral shedding are insufficient to sustain transmission chains. This distinguishes them from maintenance hosts, which keep the virus in a region over the long term, and from amplifying hosts, which produce large amounts of virus and can accelerate spread. Sentinel hosts are used for surveillance to provide early warning of infection, but they’re not the primary drivers of transmission either. So the category described as reflecting virus activity but not driving transmission is indicator hosts.

Indicator hosts are species that reflect virus activity without driving transmission. They become infected and show evidence of infection (such as seroconversion or mild/subclinical signs), signaling that Foot-and-Mouth Disease virus is circulating in the area. However, they do not contribute much to onward spread because their population density, contact patterns, or viral shedding are insufficient to sustain transmission chains.

This distinguishes them from maintenance hosts, which keep the virus in a region over the long term, and from amplifying hosts, which produce large amounts of virus and can accelerate spread. Sentinel hosts are used for surveillance to provide early warning of infection, but they’re not the primary drivers of transmission either. So the category described as reflecting virus activity but not driving transmission is indicator hosts.