A rare case of suspected human-to-human hantavirus transmission aboard a Dutch-flagged cruise ship in the Atlantic Ocean has triggered an international health response after three people died and several others were infected, according to the World Health Organization (WHO).
The outbreak has raised global public health concerns because the passengers onboard came from more than 20 countries, according to the United Nations. However, the WHO has stressed that the situation is not comparable to the early stages of the COVID-19 pandemic.
Hantavirus refers to a group of rodent-borne viruses that can cause severe illness in humans under certain conditions. While sporadic infections are reported worldwide each year, human-to-human transmission remains rare.
WHO’s chief of Epidemic and Pandemic Preparedness and Prevention, Dr. Maria Van Kerkhove, told reporters in Geneva on Tuesday, May 5, that the cruise ship had stopped at several islands off the coast of Africa, “some of which have a lot of rodents.”
The ship departed Argentina on April 1. Of the 147 people onboard, eight developed infections and five cases have been confirmed as hantavirus infections, WHO Director-General Tedros Adhanom Ghebreyesus said during a press briefing Thursday, May 7.
Success
You are now signed up for our newsletter
Success
Check your email to complete sign up
Three people — including a Dutch couple — died, while one person remains critically ill and three others are experiencing mild symptoms, according to a WHO statement issued May 5.
“There could be some source of infection on the islands as well for some of the other suspect cases,” said Dr. Kerkhove. “However, we do believe that there may be some human-to-human transmission that’s happening among the really close contacts” including the deceased husband and wife and others who shared cabins.
Addressing comparisons with COVID-19, Tedros told AFP on Wednesday that the current outbreak differs significantly from the early coronavirus pandemic.
“WHO currently assesses the risk to the global population from this event as low and will continue to monitor the epidemiological situation and update the risk assessment,” the organization said.
Tedros said the WHO has informed 12 countries whose nationals disembarked at St. Helena. Those countries include Canada, the Netherlands, Germany, Denmark, New Zealand, St. Kitts and Nevis, Singapore, Sweden, Switzerland, Turkey, the United Kingdom, and the United States.
How the outbreak began
The WHO said it was notified May 2 about a cluster of severe respiratory infections aboard the cruise ship. Between April 6 and April 28, infected passengers developed fever, gastrointestinal symptoms, pneumonia, acute respiratory distress syndrome, and shock.
Laboratory testing conducted May 2 at South Africa’s National Institute for Communicable Diseases confirmed hantavirus infection.
Humans can contract hantavirus through exposure to infected rodents, including contact with their urine, saliva, or feces, or through contaminated surfaces.
Hantavirus Pulmonary Syndrome (HPS) is characterized by headache, dizziness, fever, chills, muscle pain, nausea, vomiting, diarrhea, abdominal pain, and severe respiratory distress.
Human-to-human spread of hantavirus is uncommon. According to the WHO, transmission between humans has previously been linked only to the Andes virus strain found in Latin America, usually through prolonged close contact. Limited secondary infections among healthcare workers have also been reported in the past.
“The outbreak is being managed through coordinated international response, and includes in-depth investigations, case isolation and care, medical evacuation and laboratory investigations,” the WHO said.
WHO issues advisory
Health authorities in Cabo Verde, the Netherlands, Spain, South Africa, and the United Kingdom are participating in the international response effort. The cruise ship has remained off the coast of Cabo Verde in the central Atlantic since May 4.
The WHO has issued health guidance for passengers, crew members, and response personnel.
“In the context of the current outbreak, passengers and crew members should practice frequent hand hygiene, remain vigilant of Hantavirus symptoms and undertake active symptom monitoring for 45 days,” the organization said.
The WHO advised that suspected HPS patients should be transferred quickly to emergency or intensive care units for monitoring and supportive treatment.
“Initial management should include supportive care with antipyretics and analgesics as needed. For confirmed hantavirus, antibiotics are not routinely indicated. However, before a definitive diagnosis is established (and bacterial infection is a diagnostic possibility), or if superadded bacterial infection is suspected, empiric broad-spectrum antibiotics may be appropriate,” the WHO said.
According to U.N. News, there is currently no specific antiviral treatment for hantavirus infection beyond supportive care.
“Typically, people will develop respiratory symptoms, so respiratory support is really important,” Dr. Kerkhove said, adding that some patients may require mechanical ventilation and intensive care.
