What is hantavirus and through what means does it transmit?
means does it: The Andes strain of hantavirus has been confirmed in some passengers aboard the cruise ship MV Hondius, which is currently on track to dock in the Canary Islands. This strain is notable because, unlike most hantaviruses, it can rarely be passed from person to person. The outbreak on the ship has resulted in three confirmed cases and five suspected cases linked to the virus.
Details of the Outbreak on MV Hondius
- Confirmed cases include a Dutch woman who died, a British passenger in intensive care in South Africa, and a Swiss passenger receiving treatment in Zurich.
- Suspected cases involve a British man, a Dutch crew member, and a German national, who have been medically evacuated to the Netherlands for treatment.
- Two other British passengers are isolating at home after potential exposure but have not shown symptoms.
- The ship was traveling from Argentina across the Atlantic to Cape Verde and had visited remote wildlife areas.
It remains unclear how the virus was introduced onto the ship. A Dutch couple who died had traveled in South America before boarding, suggesting possible exposure during their travels. Further genetic testing may help determine the source of the outbreak.
Means Does It Transmit: How Hantavirus Spreads
Hantaviruses are a family of viruses primarily linked to rodents such as rats and mice. Transmission usually occurs through contact with dried urine, droppings, or saliva from infected rodents. The virus can be inhaled when these materials are stirred into the air, or it can be transmitted through rodent bites.
The Andes strain is unique because it can spread from person to person, although this is very rare. Transmission between humans requires very close, prolonged contact with someone showing symptoms. This differs from viruses like the flu, which spread through respiratory droplets from coughing or sneezing.
According to the World Health Organization (WHO), the virus is not spread by casual contact or from a distance. On the cruise ship, the virus is believed to be spreading through a combination of close human contact and possible exposure to rodents.
Symptoms and Illnesses Caused by Hantavirus
Hantavirus infections can cause two severe illnesses:
- Hantavirus Pulmonary Syndrome (HPS): Symptoms often start with fatigue, fever, and muscle aches, followed by headaches, dizziness, chills, and abdominal problems. Respiratory symptoms can develop, leading to severe breathing difficulties requiring urgent medical care. The Andes strain is mainly associated with HPS, which has a mortality rate of 20-40%. The incubation period ranges from one to eight weeks.
- Haemorrhagic Fever with Renal Syndrome (HFRS): This illness begins with flu-like symptoms and can progress to affect the kidneys, causing low blood pressure, internal bleeding, and acute kidney failure.
There is no specific treatment for hantavirus infections, but early medical support such as oxygen therapy, mechanical ventilation, and dialysis can improve survival. Patients with severe symptoms may require intensive care.
Prevention and Control Measures
Onboard the MV Hondius, passengers are confined to their cabins to limit exposure. Experts emphasize the importance of measures including:
- Isolating infected patients
- Regular handwashing
- Tracing and monitoring close contacts
- Applying infection control protocols
These steps are critical to stopping the spread of the virus, especially given the potential for rare person-to-person transmission of the Andes strain.
Global Context and Risk
Hantaviruses are named after a river in South Korea and include more than 20 viral species worldwide. Most cases occur through rodent exposure, with the Andes virus primarily found in Argentina and Chile. An outbreak in Argentina in 2018 was traced to a single person who spread the virus to 34 others, resulting in 11 deaths.
The risk of infection for the global population is considered very low, and there is currently no evidence of spread beyond the ship. Worldwide, there are an estimated 150,000 cases of HFRS annually, mostly in Europe and Asia. In the United States, 890 cases were reported between 1993 and 2023.
There are no widely available vaccines for hantavirus, although some vaccines are used in China and South Korea against local strains.