However, as many other infections can increase the risk of this disease, influenza may only be an important cause during epidemics.

During epidemics the virus was effectively everywhere, which explains why public health officials were unable to isolate a source.

The humans controlling the players also mimicked the behavior of real populations during historical epidemics.

Burial was especially crucial during epidemics, when corpses might increase the spread of infection.

Transmission from person to person, even to health care workers during epidemics, is rarely documented.

It is routinely given when children are 12 - 15 months old, but is sometimes given earlier during epidemics.

During epidemics in local populations, the fatality rate has ranged from 15% to 50%.

If the same were true in humans, then heterozygotes would have had an advantage during typhoid epidemics.

Essential oils can be sprayed around the sick room to prevent the spread of infection during epidemics.

During several epidemics, he risked exposing himself and worked hard caring for fellow inmates.