US receives passengers from hantavirus cruise; three placed in biocontainment

Three of the US passengers brought home from a cruise ship hit by a hantavirus outbreak have been placed in biocontainment by federal health authorities. According to Ars Technica, the US Centers for Disease Control and Prevention (CDC) said passengers under observation will be monitored for 21 days.

The disembarkation took place at Joint Base Lewis-McChord in Washington State as part of a weekend repatriation operation. Documents reviewed by Ars Technica show that 78 US nationals arrived in the first group; 12 of them were taken directly from the airport to regional hospitals. The rest were placed in observation at designated hotel facilities.

The three patients in biocontainment had been in close contact with cases on board and were displaying mild symptoms, according to officials. A CDC notice said the patients had been placed in negative-pressure units. The technical specifications of those units, including their air handling and waste management infrastructure, are designed to Biosafety Level 3 standards.

Hantavirus is a viral disease carried by rodents that can cause respiratory syndromes or kidney failure in humans. Person-to-person transmission is generally not seen; however, recent cases on the cruise ship Hondius have, according to the World Health Organization, raised concerns that the Andes strain may carry some potential for human-to-human spread.

For that reason, the observation process in the United States is being carried out particularly carefully. The CDC has asked passengers under observation to record symptoms including fever, headache, muscle pain, nausea and respiratory distress twice daily. Anyone displaying symptoms will immediately be placed into an isolation protocol.

The Washington State Department of Health said it was working in coordination with federal authorities. The state announced that it had deployed additional medical staff around the observation hotels and was exchanging information with local officials. No risk to the local population has been identified, officials said.

The Ars Technica piece also carried a written statement from CDC Director Mandy Cohen. Cohen said the situation was "closely managed but under control," and stressed that the public should not panic. Cohen said biocontainment capacity exists at 12 different facilities across the United States, and that transfers to other hospitals could be arranged if needed.

The repatriation of remaining passengers from the ship is ongoing. The remaining European and Latin American passengers on Hondius are being moved on separate flights in coordination with their home health authorities. The Canary Islands, which were on the ship's original route, had previously declined to allow it to dock, citing potential contact risk.

Doctors told Ars Technica that the patients in biocontainment are likely not to develop the disease fully. The Andes strain's symptom development period averages 14 to 21 days, which is why the 21-day observation window was set. With early treatment, the case-fatality rate can be reduced to about 20 percent.

US public discussion has begun comparing the cruise outbreak to the Middle East's MERS outbreak and the 2014 Ebola outbreak. A CDC spokesperson, however, said the transmission mechanisms of those diseases are different and that such comparisons are "not useful." Updates on the status of all passengers under observation are expected to be issued daily in the coming days.