While more hantavirus cases are expected to emerge having originated from a cluster centred on the cruise ship MV Hondius, World Health Organisation officials have said that this outbreak does not represent the start of a Covid-style pandemic.
The comments came in the course of a WHO media briefing this afternoon hosted by the organisation’s Director General, Dr Tedros Adhanom Ghebreyesus, who said that given the incubation period of the Andes virus, which is the specific species of hantavirus involved in the current scenario, “it’s possible that more cases may be reported”.
The briefing comes amid an unfolding outbreak of hantavirus centred on a cluster of passengers aboard the cruise ship MV Hondius, which is currently travelling up the west coast of Africa, from Cape Verde to the Canary Islands, where it has been granted permission to dock despite concerns from local inhabitants.
According to the WHO, it was notified of a cluster of passengers aboard the MV Hondius with “severe respiratory illness” May 2.
By May 4, seven cases had been identified, including three deaths, one critically ill patient and three individuals reporting “mild symptoms”.
The organisation says that the outbreak is being “managed through a coordinated international response,” made up of “in-depth investigations, case isolation and care, medical evacuation and laboratory investigations”.
While human hantavirus infection is primarily acquired through contact with infected rodents, human-to-human transmission has been reported in previous outbreaks of the Andes virus.
The WHO describes it as a “rare but severe disease that can be deadly”.
The latest information provided by Dr Ghebreyesus today is that eight cases have been reported altogether, including three deaths. Five of the cases have been confirmed as hantavirus, while the other three are suspected.
“In previous outbreaks of Andes virus, transmission between people has been associated with close and prolonged contact, particularly among household members, intimate partners and people providing medical care.
“That appears to be the case in the current situation,” Dr Ghebreyesus said.
According to the WHO Director General, the first case was in a man who developed symptoms April 6 and died on the ship April 11. No samples were taken, and hantavirus was not suspected because of the similarity of the man’s symptoms to other respiratory diseases.
The second death was the man’s wife, who went ashore when the ship docked at the island of Saint Helena in the course of its journey from Argentina to Cape Verde.
The woman was symptomatic, and “deteriorated” during a flight to Johannesburg April 25, dying the next day. South Africa’s National Institute of Communicable Diseases confirmed samples taken as being hantavirus.
The third death was of a woman on the ship who developed symptoms April 28 and died later that week on May 2.
Dr Ghebreyesus said that another man presented to the ship’s doctor April 24 and was evacuated April 27 from Ascension Island to South Africa, where he remains in intensive care.
A WHO infectious diseases expert boarded the ship in Cabo Verde, and has since been joined by two doctors from the Netherlands and an expert from the European Centre for Disease Prevention and Control, all of whom are intended to stay on the ship until it reaches the Canary Islands.
Three other patients were passengers with symptoms who were evacuated to the Netherlands for treatment, where two remain in a stable condition in hospital, while the third is asymptomatic and is now in Germany, the WHO Director General said.
The eighth case was a man who disembarked in Saint Helena, and following advice from the ship’s operator, he reported himself with symptoms in Zurich, Switzerland, where he was confirmed to be infected with hantavirus.
The Geneva University Hospital later sequenced the virus and confirmed it as the Andes virus.
Dr Ghebreyesus said that the WHO is “aware of reports of other people with symptoms who may have had contact with one of the passengers”.
“In each case, we are in close contact with the relevant authorities.
“Given the incubation period for Andes virus, which can be up to six weeks, it’s possible that more cases may be reported,” he said.
The WHO Director General said that while the outbreak is a “serious incident”, the organisation assesses the public health risk as “low”.
Speaking on the same panel, WHO official and Infectious Diseases Epidemiologist Maria Van Kerkhove said that “this is not coronavirus”.
“This is a very different virus, we know this virus. Hantaviruses have been around for quite a while….I want to be unequivocal here: This is not SARS-CoV-2. This is not the start of a Covid pandemic. This is an outbreak that we see on a ship. There’s a confined area, we have five confirmed cases so far.
“This is not the same situation we were in six years ago. It doesn’t spread the same way, like coronaviruses do. It’s very different. It’s that close, intimate contact that we’ve seen. And most hantaviruses do not transmit between people at all. Most hantaviruses are transmitted from rodents or their feces or their saliva, their droppings, to people.
“Only this one particular virus, the Andes virus, which has been identified here, we’ve seen some human-human transmission,” Dr Van Kerkhove said.
A total of 146 people from over 20 different countries remain aboard the MV Hondius following “strict precautionary measures,” such as staying in cabins, disinfecting the cabins and isolating those who show symptoms.
In the meantime, contact tracing efforts are underway in at least 12 different countries following the April 24 disembarkation of more than two dozen people on the island of Saint Helena, who have since travelled to a further three continents, on top of Europe.
Health officials in the US, Canada, Singapore and the UK are monitoring a number of individuals, some of whom are self-isolating, and most of whom were aboard the MV Hondius before leaving.
However, some individuals being monitored were not aboard the vessel, but came in close contact with those who were, such as a KLM airline crew member who had contact with the woman who died in South Africa late last month.
The WHO Director General said that the couple that presented the first two cases had travelled through a number of South American countries, including Argentina, on a bird-watching trip before boarding the ship.
This included visits to sites where the species of rat that is known to carry the Andes virus was present.