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Scientists comment on a statement from the UK Health Security Agency (UKHSA) on hantavirus, travel arrangements and isolation for British nationals aboard the MV Hondius cruise ship.
Dr Raymond Alvarez, immunologist, virologist, and CEO of Ichor Biologics (a biotechnology company developing antibody-based therapeutics for infectious diseases, including hantavirus) and formerly Assistant Professor at the Icahn School of Medicine at Mount Sinai, said:
Are these plans and measures evidence-based and sensible based on what we know from evidence about this virus?
“Yes, key measures, including self-isolation, monitoring for symptoms, contact tracing, and support for close contacts, are exactly the kinds of precautions that have been demonstrated to previously reduce the transmission risks associated with Andes virus infection clusters. In previous outbreaks, once infection control measures were implemented, the potential for transmission was significantly reduced.
“Andes hantavirus does not spread through casual contact, and person-to-person transmission, where it occurs, typically requires close, prolonged exposure, often around the early symptomatic phase. Based on the evidence, these plans are proportionate, as they reduce the already low risk situation further while allowing public health officials to monitor anyone who may have been exposed.
“Therefore, rather than reflecting a risk to the public, these plans represent precautionary measures and a controlled public health response.
Short quote version: “These measures are evidence-based and proportionate. Self-isolation, monitoring, and contact tracing are exactly the right tools for a virus like Andes hantavirus, where transmission is rare, close-contact dependent, and controllable with appropriate public health precautions.”
Prof Piet Maes, President-elect of the Hantavirus Society, and Virologist at the Plotkin Institute, University of Brussels, said:
“The measures described by UKHSA appear cautious, but proportionate and evidence-based given the unusual circumstances of this Andes virus cluster. ANDV and its related lineages are exceptional among hantaviruses because limited person-to-person transmission has been documented, typically after close or prolonged contact with symptomatic individuals.
“For the general public in the UK, the risk remains very low. The current measures are targeted specifically at a well-defined exposed group and should not be interpreted as an indication of broader community risk or expected widespread transmission.
“Approaches to monitoring exposed contacts have varied historically across endemic regions in South America, with some protocols using follow-up periods of approximately three to four weeks depending on the exposure risk. The longer monitoring period currently being applied by UKHSA reflects a particularly cautious approach in the context of this international cluster and the remaining uncertainties regarding exposures on board.
“An important aspect will be active follow-up during the monitoring period. Clinical monitoring combined with appropriately timed laboratory testing, including molecular testing where feasible, may help support early detection should additional infections occur.
“Overall, these measures seem sensible and precautionary, with the aim of identifying any potential secondary cases early while keeping the risk to the wider public very low.”
Dr Giulia Gallo, Postdoctoral Scientist in the Viral Glycoproteins Group, The Pirbright Institute, said:
What is the risk to the UK general public once these people have returned?
“People from the ship will be closely followed up. They are required to self-isolate for 45 days, and they will be routinely tested for the virus. UKHSA and WHO believe that the risk for the population remains very low.
Is a 45 day isolation period plus monitoring and testing sensible for all those who were on board the MV Hondius (and who currently don’t have symptoms)?
“Yes, the symptoms can take up to 6 weeks to develop. Passengers and crew on the ship are requested to self-isolate for few days longer than 6 weeks, to allow readily detection and action in case anyone develops symptoms. On top of that, diagnostic kits have been delivered and will be used to routinely test people in quarantine.”
Prof Sir Peter Horby, Moh Family Foundation Professor of Emerging Infections and Global Health, and Director of the Pandemic Sciences Institute, University of Oxford, said:
“I believe the UKHSA, FCDO and NHS are taking all the right and necessary measures to protect the UK citizens involved in this challenging incident and to protect the broader UK population. Repatriation and isolation is the right thing to do, morally and scientifically. It will ensure the UK citizens from the MV Hondius potentially exposed to this virus receive the medical monitoring they need whilst minimising the risk of further infections. If any of the returnees do get ill, they will quickly receive the best possible care in the NHS under strict isolation.
“The approach is stringent because this virus can cause severe disease, but the risk to the general population is very low. Of course, we need to investigate and carefully monitor the situation to spot any divergence from how we expect this virus to behave, but so far the virus is behaving in a way we know it can.
We know there can be limited person to person transmission following close and prolonged contact with an infected person but that public health measures can readily stop transmission and bring the outbreak to an end.
“It’s important that we also use this incident to learn more about Andes Hantavirus infection and disease so we are better prepared for future cases and outbreaks.”
Prof Jonathan Ball, Deputy Vice-Chancellor and Professor of Molecular Virology, Liverpool School of Tropical Medicine, said:
“The incubation period – the time from when someone is infected, to when they start to show symptoms – can be up to several weeks, so having a long period of isolation with regular observations and testing is a sensible approach to pick up any missed infections and limit the risk for any human to human transmission.
“For this particular hantavirus – the Andes virus – we have suspected that the virus can be spread from human to humans perhaps more readily than other hantavirus, but this is still inefficient and requires very close contact, probably over relatively long periods of time. This means that the risk that the returned passengers pose to the wider public is very very small indeed.”
SMC comments on Thurs 7 May on update from UKHSA re two people having had returned to the UK having been on board the MV Hondius, are not currently reporting symptoms and are self-isolating:
Previous SMC comments from Wed 6, Tues 5 and Monday 4 May on hantavirus situation at that time:
Declared interests
Dr Raymond Alvarez: “Dr. Alvarez is the CEO and co-founder of Ichor Biologics, which is actively developing antibody therapeutics targeting hantavirus. He may therefore have a potential financial and professional interest in the development of treatments for this disease. He has received research funding and support related to antibody discovery and infectious disease research. He has no other relevant advisory roles, industry affiliations, or conflicts of interest to declare beyond those stated.”
Prof Piet Maes: “I have no conflicts or interest to declare.”
Dr Giulia Gallo: “I have no conflict of interest.”
Prof Sir Peter Horby: “I am Executive Director of the International Severe Acute Respiratory and emerging Infections Consortium (ISARIC) which is undertaking research to learn more about Andes Hantavirus infection and disease.”
Prof Jonathan Ball: “No CoIs.”