Both men will remained quarantined for 30 days from the date of last exposure as a precaution, and will be tested again before their release. SINGAPORE: Both Singapore residents who were onboard the cruise ship where there was an outbreak of hantavirus have tested negative, the Communicable Diseases Agency (CDA) said on Friday (May 8). CDA’s Public Health Laboratory conducted testing with multiple samples collected from both men and confirmed that hantavirus, including the Andes virus, was not