How can viral infections cause economic loss?

Answer 1

Because this is in the categories of Cold and Flu and Conditions and Diseases instead of agriculture, gardening or plant viruses, first the answer for viral Infectious Diseases in humans:

Influenza and other infectious human viral diseases:

In most cases, the primary economic loss would come from lost work time. This impacts both the employer and the employee who has the flu or other infection and can't work, from lost production and lost wages, respectively. There can also be economic loss due to things such as these examples:

• Lost income for parents staying home with sick children or the added costs of alternative child care when the regular child care operation cannot accept a sick child.
• Costs to create and distribute a new vaccine if the virus is a new one (as occurred in the 2009 pandemic), usually impacting government spending.
• School closings due to local outbreaks of viral infections can mean lost wages for school employees and teachers, lost parental wages or added costs from alternate child care.
• Costs of medical diagnostics, medication and care.

Viral infections in crops and plantings:

These plant infections can cause huge economic loss when they affect important economic crops like fruits, wheat, corn/maize, or tobacco plants. The plant viruses can destroy whole crops and impair the ability to produce the normal sized yields.