A cruise ship that left Perth earlier this month has ended its journey to Singapore with some unhappy passengers who were infected with norovirus.

It is understood by that at least 16 passengers on board the ship had symptoms of the virus before everyone disembarked on the final day of the trip in Singapore.

The ship had 2,000 passengers on board.

Symptoms of norovirus generally last between one and three days. Medical experts recommend regularly washing your hands to avoid contracting the disease.

A spokesman for Carnival Australia said that despite initial reports, the vast majority of passengers on board the ship were not impacted by the norovirus.

“The vast majority of the 2000 guests on Sun Princess were unaffected but it takes relatively few cases of illness to be reported for on-board sanitation measures to be increased,” the statement provided to read.

“Creating and maintaining a healthy on-board environment is always a priority with the highest public health standards employed based on best international practice. On-board sanitation was swiftly stepped up following some guests reporting gastrointestinal symptoms confirmed as being due to Norovirus.

“Out of an abundance of care and in line with best practice, extra cleaning of the terminal was also carried out on Wednesday.”

Carnival Australia’s cruise ships feature casinos, pools and sporting facilities.

This article originally appeared on Over60.