Hantavirus Outbreak on MV Hondius Raises Concerns
Fear often spreads faster than the virus itself, and that seems to be the case with the recent hantavirus situation, at least unless the virus changes—which seems unlikely.
So far, the only resemblance this hantavirus has with the SARS-CoV-2 virus that triggered the pandemic is their classification as single-stranded RNA viruses and their ties to outbreaks on cruise ships. Indeed, the current situation on the MV Hondius recalls the infamous Diamond Princess, which faced quarantine off Japan in early 2020 after a coronavirus outbreak affected many passengers.
But that’s pretty much where the similarities end. The MV Hondius, which set sail from Argentina, where the Andean strain of hantavirus originates, has reported eight infections and three deaths. This strain is particularly dangerous as it can lead to hantavirus pulmonary syndrome (HPS), which is, well, quite severe. The confined quarters on cruise ships create an ideal setting for such infections to spread.
Questioning the Source of the Virus
A pressing question arises: how did the virus make its way onto the ship? Was it brought by an infected animal or person? Reports suggest that a Dutch couple contracted the virus during a birdwatching trip in South America, likely from rodent excreta. If true, this implies the cases on board involved human-to-human transmission, which is rarer compared to the more typical rodent-to-human spread. It does make one wonder if the virus mutated at some point—perhaps like in the case of a flight attendant who became ill after contact with an affected passenger.
Yet, it’s important to note that the virus is not likely to have changed. Although there’s a small chance for human-to-human transmission with the Andes strain, studies indicate it happens very rarely. In Chile, for instance, a study showed only 1% of household contacts contracted the virus.
Limited Human-to-Human Transmission
Another study from Argentina also highlighted the restrictions on human transmission of the Andes virus. Between late 2018 and early 2019, there were 34 confirmed cases and 11 deaths from HPS within just a few instances of transmission.
Fortunately, hantavirus cases remain quite low in the U.S., averaging about 15 to 50 annually, and even lower in the Americas. A common variant, the Shin Nombre strain, doesn’t transmit between people. In Europe and Asia, there’s a higher volume of cases, but again, they come from strains that don’t easily spread among humans. Overall, hantaviruses primarily remain rodent-associated.
Understanding Hantaviruses
To help alleviate some of the rampant fears surrounding hantavirus, here are three key points:
1. Hantaviruses can be transmitted from person to person
Yes, it’s possible, but it requires very close contact and usually occurs only with the Andes strain.
2. It is unlikely to lead to the next pandemic
This is not very probable. The virus mainly circulates among rodents, and given the steady incidence of cases, there’s little likelihood for significant outbreaks absent major mutations.
3. Hantavirus can be very dangerous
While it’s indeed rare in the U.S. and tough to transmit, especially without direct contact with rodent droppings or secretions, the symptoms of HPS can be severe. Still, cases are much less frequent compared to common flu-like symptoms.
Public health officials in Europe and South Africa must track contacts of passengers coming off the infected vessel. Nevertheless, the risk to the broader population continues to be quite low.
As the virus’s incubation period may extend up to eight weeks, authorities should consider isolating the approximately 150 passengers and crew of the MV Hondius upon their arrival in the Canary Islands. This might involve onboard quarantine and strict cleaning protocols.
It’s vital for researchers to study the genetic makeup of the circulating Andean hantaviruses to understand their potential. Ultimately, conveying facts over fear is crucial. The key is examining the specific strain that affected those passengers.
