In both studies the patients were retested within a week of ending treatment, however, so that in some cases infection may have persisted.

Onset time is highly variable and the average asymptomatic infection persists for over a year.

He also said the usual five-day treatment was often inadequate to clear the body of Giardia when the infection had persisted for a long time.

When the infection persisted, he was sent to New York for diagnosis and treatment.

Some bacterial infections may be associated with severe abdominal pain and may persist for several weeks.

About sixty rounds of vaccination were carried out in the country before 2007, and the infection persists.

But sometimes the infection persists, and if the viral strain is a cancer-causing one, precancerous changes may eventually occur.

Some experts say it is possible that the infection persists for life, although this has not been proved.

Although the symptoms resolve, even with treatment the infection persists and enters a chronic phase.

Scientists believe that the infection persists for life.