What is Hantavirus and How is it Spread?

Hantavirus is a family of viruses that live naturally in rodents without making them sick, though People become infected primarily by inhaling aerosols from the feces, urine, or saliva of mice carrying the virus. Human-to-human transmission is rare, but possible, according to a Spanish nonprofit organization.

The strain responsible for the recent cruise ship outbreak is the Andes hantavirus, native to South America. According to an infectious disease expert at VCU Health, hantavirus strains are specific to certain geographic locations. With the most recent situation, the concern is about the Andes hantavirus from South America. The risk of a wider cruise ship-related outbreak of hantavirus is extremely low. Hantavirus outbreaks in Caribbean cruises or even Mediterranean cruises are extremely unlikely.

In the Americas, there are hundreds of cases each year. The WHO estimates that there are between 10,000 and 100,000 infections annually, concentrated mainly in East Asia and Northern and Central Europe, where the disease is endemic but mild.

Historical Context and Mortality Risk

In 2018, the most dangerous hantavirus outbreak occurred in Epuyén, a small rural town in the province of Chubut in southern Argentina. Eleven people who had gathered for a birthday celebration died. Others became seriously ill but survived. The case fatality rate was 32 percent—similar to that of the early stages of the COVID-19 pandemic. The outbreak started with a single introduction of the virus from a rodent, the long-tailed pygmy rice rat, but three people with symptoms attended social gatherings and became “super-spreaders,” according to a study published by researchers in the New England Journal of Medicine.

Today, the world is watching the Dutch-flagged cruise ship MV Hondius. The World Health Organization has reported eight cases, three of them fatal, linked to this outbreak. Several dozen people who have been in contact with passengers on the ship are being monitored.

According to the WHO, the hantavirus poses a low risk to public health. The organization has advised against unnecessary panic but has emphasized the importance of monitoring and tracing potential cases.

Symptoms and Response Measures

Hantavirus symptoms often begin with mild, flu-like symptoms. In more severe cases, the virus can progress to hantavirus pulmonary syndrome, which is associated with the Andes strain and has a fatality rate of up to 50 percent. According to Frankfurter Rundschau, the initial symptoms include high fever, severe fatigue, and headaches, with the disease progressing rapidly in some cases.

Arrangements are underway to repatriate passengers from the MV Hondius after three people on board died. The ship departed Cape Verde following the evacuations and is en route to the Canary Islands. The U.S. Centers for Disease Control and Prevention is actively monitoring U.S. passengers who were aboard the ship.

Experts stress that the risk of a wider cruise ship-related outbreak of hantavirus is extremely low. The virus is rare and not easily transmitted between humans. However, in enclosed spaces like a cruise ship, the potential for human-to-human transmission increases slightly. According to VCU Health, hantavirus outbreaks in Caribbean or Mediterranean cruises are extremely unlikely.

In Germany, hantavirus is already present and is primarily transmitted by the Rötelmaus, a species that inhabits forests and nearby gardens. The incubation period can vary widely, from two to four weeks, with some cases taking up to 60 days to manifest symptoms. The initial phase of the disease resembles the flu but is generally more severe.