The more susceptible are institutional or day-care workers, travelers, those eating improperly treated food or drink, and people who have contact with individuals already infected.

For most individuals infected with tainted blood, the test turns positive within several weeks, but sometimes not for six months, or even longer.

For example less than 5% of individuals infected with polio develop disease.

Most individuals infected by H. pylori will never experience clinical symptoms despite having chronic gastritis.

Also, individuals infected at birth will carry the virus for life, regardless of future vaccination.

However, it appears that immunoreactivity to this antigen is variable in individuals infected with other filarial nematodes.

The total number of individuals infected in Milwaukee is not known but is estimated to be in the hundreds and perhaps thousands.

A 1986 study in the United States found that all individuals symptomatically infected with Blastocystis reported recent travel history to less developed countries.

Sexual behavior of individuals infected with the human immunodeficiency virus: the need for intervention.

Exposure to human papillomavirus, even in individuals already infected with the virus, appears to increase the risk of precancerous changes.