Health officials are optimistic that a recent hantavirus outbreak on a cruise ship, which has tragicallyclaimed three lives,will not escalate into a wider epidemic.
While human-to-human transmission is rare for hantaviruses, rigorous contact tracing is underway across several countries to identify and monitor those potentially exposed.
Hantaviruses typically spread when people inhale contaminated residue from rodent droppings.
Though human cases are uncommon, the Andes virus implicated in the cruise ship incident poses a unique concern. This strain may, in rare instances, be capable of human-to-human spread, and viruses can change. Scientists are now urgently investigating the virus to understand potential mutations and its exact transmission pathways.
What is contact tracing?
The goal of contact tracing is to alert people who might have been exposed, keep tabs on them in case they come down with symptoms, and prevent them from spreading it to others.
The process isn’t easy because people are social and mobile creatures who spend time with others, visit crowded places and travel.
In the cruise ship outbreak, fewer than a dozen people are thought to have shown any symptoms, and there have been only five confirmed cases, but many more may have been exposed.
About 140 people remain on the cruise ship headed for theCanary Islands, where they will disembark, and none has been reported to be sick.
But authorities are trying to reach the dozens of people who left the ship about two weeks after a passenger died, but before authorities knew a hantavirus was the culprit. They were from at least 12 different countries, including from several states in the U.S. — includingArizona,California,GeorgiaandTexas, according to infectious disease experts and state public health officials.
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Authorities in St. Helena — the remote, volcanic British territory in theSouth Atlanticwhere passengers got off — said they were monitoring a small number of people considered “higher-risk contacts.” They were being told to isolate for 45 days, the St. Helena government said.
British health officials say two people who were passengers aboard the ship but flew home midway through the journey are self-isolating but do not have symptoms. The U.K. Health Security Agency said “a small number” of contacts of the two are also self-isolating but not showing symptoms.
Singaporean health authorities said they were monitoring two men who disembarked at St. Helena and flew toSouth Africaand then home. The two men, who arrived in Singapore at different times, were being tested for hantavirus and were isolated at the country’s National Center for Infectious Diseases, officials said.
The U.S. government has released few details about its work on any contact tracing.
Texas officials on Thursday said public health workers there have reached the two people who left the ship April 24, who say they are not experiencing symptoms and did not have contact with a sick person while aboard. They promised to monitor themselves with daily temperature checks and contact public health officials at any sign of possible illness, officials said.
Two Canadians who disembarked are in Ontario and have been advised to self-isolate since they returned home, the province’s health minister says.
Scientists are trying to understand theAndesvirus better
Apart from tracking people, scientists are also trying to understand the germ. The Andes virus, a member of the hantavirus family found in South America, may be one of the rare hantaviruses that can spread between people. Officials inArgentinabelieve the first cases may have been contracted on a birdwatching trip in the southern city ofUshuaia.
Argentina’s Health Ministry has yet to dispatch the team, but scientists from the state-funded Malbrán Institute planned to travel to Ushuaia “in the coming days,” the ministry told The Associated Press.
Scientists are analyzing the virus's genetics to see whether it has changed in a way to make it more transmissible.
They are also trying to learn exactly how it spreads, said Dr. Jeanne Marrazzo, chief executive officer of the Infectious Diseases Society of America. They believe people are mainly infectious when they have symptoms, and, if the virus spreads, it may be transmitted through small liquid particles that blow out of an infected person when they talk, cough or sneeze.
