The two men aged 65 and 67 had been on the MV Hondius and also the same flight as a confirmed hantavirus case from St Helena to Johannesburg on April 25, the CDA said a day earlier. The confirmed case did not travel to the city-state and died in South Africa.

The CDA’s National Public Health Laboratory conducted testing with “multiple samples collected from the individuals”, that confirmed that hantavirus, including the Andes virus, was “not detected”, it said in a statement late Friday.

As a precaution, the two men will remain in quarantine for 30 days from the date of last exposure, and testing will be conducted again before release from quarantine, CDA added, saying “the risk to the general public in Singapore remains low”.

Both men had arrived in Singapore in early May before being isolated and monitored at Singapore’s National Centre for Infectious Diseases (NCID).

One was reported to have a runny nose but was otherwise well, and the other was asymptomatic, the CDA said Thursday.

The MV Hondius has been at the centre of an international health scare since May 2, when the UN’s health agency was informed that three passengers had died and the suspected cause was hantavirus.

Eight cases, including three deaths, had been linked to the cluster on the cruise ship by Wednesday, according to CDA.

The rare disease is usually spread from infected rodents, typically through urine, droppings and saliva.

However, experts have confirmed that the version of the virus detected aboard the Hondius is a rare strain that can be transmitted between humans.