Dozens of Britons currently self-isolating following a hantavirus outbreak could potentially contract the virus and transmit it to sewer rats, doctors have cautioned. Medical professionals warn that if humans pass the deadly Andes strain of hantavirus to the tens of millions of brown rats inhabiting Britain's sewers, the situation could escalate dramatically.
Reverse Zoonosis Threat
Experts are increasingly concerned that rats could become infected with the Andes strain, thereby exacerbating the outbreak. The worry stems from the possibility that individuals who were aboard the MV Hondius cruise ship or who have had contact with passengers might develop hantavirus and spread it through the sewage system. One doctor, speaking anonymously to The Telegraph, expressed deep concern: "I am incredibly concerned that patients who are self-isolating may develop the virus and then pass it on through the sewers and infect sewer rats. Then all hell could break loose." This phenomenon, where humans transmit pathogens to animals, is known as 'reverse zoonosis'. The Andes strain has previously been spread in Argentina by long-tailed pygmy rice rats.
Scientific Uncertainty
While no studies have confirmed that hantavirus can infect brown rats in Britain's sewers, there is also no evidence to the contrary. Tens of millions of brown rats live in the UK's sewage systems, with an estimated 20 to 50 percent already carrying the Seoul strain. Dr. Giulia Gallo, a postdoctoral scientist at the Pirbright Institute in Surrey, noted: "I can see where the concern for reverse zoonosis comes from... While I think the risk for reverse zoonosis is low based on evolution studies and related hantaviruses, we do not have the data supporting that statement that it would definitely not happen."
Expert Opinions Diverge
However, some experts consider the risk to be 'extremely low'. Professor Michael Marks, an infectious diseases expert at the London School of Hygiene & Tropical Medicine, stated: "Based on the existing data this seems very unlikely. Overall therefore I think the risk of a reverse zoonosis is extremely low." Professor Paul Hunter of Norwich Medical School added that reverse zoonosis of hantavirus in brown rats was 'not impossible' but improbable because "you would need close contact with a rat or mouse for it to happen." He further explained that infected rats would require close contact with other rats for the virus to spread through the sewers.
UK Response and Related Incidents
On Friday, the UK dispatched a rapid response mobile laboratory to the island of St Helena following the hantavirus outbreak on the cruise ship. This came as ten Britons connected to the MV Hondius outbreak were repatriated in an effort to protect them from infection. The UK Health Security Agency (UKHSA) confirmed that a three-person team from the UK Public Health Rapid Support Team (UK-PHRST) had been sent to the British overseas territories of St Helena and Ascension in the South Atlantic, responding to a request for assistance from the island's government. In a separate incident on Wednesday, hundreds of Britons were confined on a cruise ship in France after a passenger died and dozens exhibited symptoms of suspected norovirus. French authorities quarantined over 1,700 passengers and crew aboard the Ambition cruise ship docked in Bordeaux. A 92-year-old British passenger died on May 10, and around 50 people showed signs of norovirus. While norovirus is not currently linked to the passenger's death, medical journals indicate it can cause heart failure in elderly patients. The Ambition ship, carrying a majority of 1,233 passengers from Britain or Ireland, arrived in Bordeaux on Tuesday.
