Contagious Period of Viral Diseases


Determine the period of contagiousness associated with viral diseases to help build a chart that details the variation of contagious periods for different infections.

Early Findings

Findings Related to the Contagious Period of Viral Diseases

  • Types of viral infections include encephalitis, the common cold, pharyngitis, gingivostomatitis, hepatitis, skin infections, cardiovascular infections, eye infections, parotitis, pneumonia, myelitis, pancreatitis, gastroenteritis, and sexually transmitted diseases.
  • The length of contagiousness of viral infections is somewhat dependent on the type of virus causing the infection.
  • Certain viruses cause viral infections more frequently. As an example, rhinovirus is the virus most responsible for causing the common cold. However, more than 200 other viruses also cause colds.
  • There are 219 types of viruses that can cause viral infections in humans.
  • This chart shows a selection of common upper respiratory viruses and when they are seasonally active (rhinovirus, coronavirus, enterovirus, adenovirus, parainfluenza virus 2 and 3, respiratory syncytial virus, influenza, metapneumovirus, and group A streptococcus).
  • In general, patients infected with a flu virus are contagious between the following window: 1 day before symptoms start and 5-7 days after they get sick with symptoms. The flu affects between 5 to 20 percent of the population in the United States each year.
  • Cold patients are generally contagious for 1-2 days before their symptoms start to two weeks after being exposed to the virus. The United States has 1 billion cases of the cold each year.
  • Stomach virus patients are contagious for an indeterminate time before their symptoms start, and it lasts for up to two weeks after recovery depending on the virus causing the affliction. Acute gastroenteritis caused by norovirus (the most common source) affects 19 to 21 million people in the United States each year.
  • Per WebMD, the most common viral infections in the United States are chlamydia, influenza A and B, herpes simplex 1 and 2, norovirus, pneumonia, hepatitis C, HIV, and the common cold.

In addition to this public search, we scanned our proprietary research database of over 1 million sources and were unable to find any specific research reports that address your goals.

Summary of Early Findings in Relation to Goals

For the first hour of research, the project was outlined to determine if the requested research is available.

The amount of time a person is contagious for once affected by a viral infection depends in part on the type of virus causing the infection. The number of viruses that can cause common infections (such as the common cold) is more than 200. The length of contagiousness associated with each individual virus type is not readily available based on a high-level search.

The general length of contagious duration associated with common viral infections caused by different viruses is available, however.

Based on these findings, we propose the following next steps to complete the request:

Proposed next steps:

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