Confirmed cases of hantavirus are rising on a cruise ship sailing the Atlantic, fueling fears of a wider outbreak. The World Health Organization (WHO), however, assessed the current situation as "manageable" and cautioned against excessive alarm.
According to the WHO on the 7th (local time), confirmed cases reported on the cruise ship MV Hondius have increased to 5. WHO Director-General Tedros Adhanom Ghebreyesus said at a news conference in Switzerland that "so far 8 cases, including 3 deaths, have been reported, and 5 of them have been confirmed as hantavirus," adding, "the remaining 3 are suspected cases." As of the previous day, only 3 were confirmed, but 2 suspected cases were additionally confirmed.
Ghebreyesus said, "This hantavirus is the Andes variant found in Latin America, and its incubation period can be up to 6 weeks," adding, "there is a possibility of additional confirmed cases."
The Andes variant is known as a rare type of hantavirus that can spread between people. According to the WHO, the first deceased were a Dutch couple who, before departure, visited Argentina, Chile and Uruguay and joined a bird-watching tour, and they may have visited rodent habitats known to carry the virus during that time.
The concern is that sources of infection may have already spread to multiple countries. The cruise called at Saint Helena, a British territory, on the 24th of last month, and 29 passengers disembarked at that time. The first deceased's spouse disembarked with the husband's body, traveled to Johannesburg, South Africa, and died. Adding in the dozens of passengers who already returned home after the trip and the passengers and crew on the flight taken by the second deceased, the contact range could be broader.
The WHO has begun a coordinated response with the countries involved. It is tracing the first infected person's movements with Argentina and is also working to provide 2,500 diagnostic kits to laboratories in five countries. It also notified 12 countries that are home countries of passengers who disembarked at Saint Helena.
Despite concerns about spread, the WHO currently assesses the public health risk level as low. Ghebreyesus said, "It is a serious matter, but the public health risk is low," stressing, "treating patients, protecting the remaining passengers, and blocking further spread are the top priorities." Maria Van Kerkhove, head of epidemic management at the WHO, also drew a line, saying, "This situation is not the start of a pandemic like COVID-19," and "the transmission pattern is entirely different."
Meanwhile, the cruise ship where infections occurred anchored off Cape Verde, was denied entry at several ports, and is heading to Spain's Canary Islands. The WHO plans to further determine the virus's characteristics and any mutations based on genome sequencing under way in South Africa, Switzerland and Senegal.
Hantaviruses are mainly transmitted when rodent excreta or saliva become airborne. Rare person-to-person transmission has also been reported. The incubation period can last for weeks, and initial symptoms resemble the flu; in severe cases, it can damage lung and kidney function and lead to fatal outcomes. The virus is also known to have been first discovered and named by the late Korean virologist Lee Ho-wang along the Hantan River.