Virus

During a 6-week period in 2003 in a long term care facility for elderly persons, 56 residents and 26 staff developed respiratory illness in a long-term facility; 12 residents died (Louie et al, 2005)

About 15%-20% of hospitalized Lassa fever patients will die from the illness. It is estimated that the overall mortality rate is 1%, however during epidemics mortality can climb as high as 50% (Wikipedia)

In 2007, influenza caused 411 deaths: 79 of them in persons aged 75-84 years and 139 of them in persons aged 85 years and older (Xu et al, 2007)

Hand, Foot, and Mouth Disease caused by enterovirus in China between 2008 and 2009 was studied and the case fatality ratio was 0.03% (Zhang et al, 2011)

Mortality was higher in infants with severe hepatitis (83%) than in infants with infection of the central nervous system (19%) (Modlin, 1986)