The deadly hantavirus outbreak aboard the MV Hondius cruise ship has put citizens and health authorities on high alert.
Experts believe a few passengers were infected with the Andes strain of hantavirus, which has a mortality rate of up to 40% because it affects the lungs and kidneys, which are critical for survival.
Hantavirus is typically transmitted to humans by inhaling particles from infected rodent droppings, urine or nesting materials.
While less common, infection can also occur through rodent bites.
Hantavirus made headlines in March of last year when it was determined to be the cause of death for Betsy Arakawa, the classical pianist married to Oscar winner Gene Hackman.
In the case of the infected passengers aboard the MV Hondius cruise ship, the World Health Organization insisted that no rodents had been found on the liner, suggesting that the ship’s specific conditions and close quarters allowed the virus to spread from person to person, a transmission exclusive to the Andes strain.
In person-to-person transmission, the virus is typically spread during the early phase of the illness, before the body’s immune system has started responding and the infection is at its most transmissible.
The virus generally can live up to four days, but it can survive longer depending on the environment.
Testing for hantavirus
Hantavirus infection can be confirmed via a blood test that measures IgM and IgG levels, antibodies that tend to spike early and late in the course of infection.
According to WHO, hantavirus infection has also been confirmed by polymerase chain reaction (PCR) tests that detect fragments of the virus’s genetic material.
The incubation period for hantavirus infection lasts about two weeks.
Symptoms usually appear one to eight weeks after exposure and include fever, headache, muscle aches, abdominal pain, nausea or vomiting. These initial symptoms are frustratingly vague and can lead to a misdiagnosis of COVID or the flu. Additionally, 30% of patients initially present as asymptomatic.
Following initial symptom onset, depending on the strain of the disease, a patient may develop hantavirus pulmonary syndrome (HPS), which affects the lungs and heart, or hemorrhagic fever with renal syndrome (HFRS), which compromises the kidneys.
Hantavirus pulmonary syndrome (HPS)
Typically, the Andes strain causes hantavirus pulmonary syndrome (HPS), which can be life-threatening and is characterized by a cough, shortness of breath and fluid accumulation in the lungs.
HPS symptoms, specifically breathing problems, typically present four to 10 days after the initial phase of the illness. If and when fluid fills the lungs, the patient will require intubation to breathe.
Experts say the Andes strain has historically and disproportionately affected healthy men in their 30s.
“It can progress to this more critical stage where you start to get respiratory symptoms and respiratory failure and cardiac collapse,” Dr. Emily Abdoler, an infectious disease physician at University of Michigan Health, told NBC News.
“It causes a collapse of body systems critical for survival on a second-by-second basis,” she warned.
Patients affected by HPS can deteriorate within hours.
Experts maintain that around 40% of patients who develop HPS die from it.
Hemorrhagic fever with renal syndrome (HFRS)
Normally, the Asian strain of hantavirus causes HFRS, which affects the kidneys.
HFRS symptoms develop more rapidly than those associated with HPS, often within two weeks, and can include blurred vision, inflammation or redness in or around the eyes and a butterfly-shaped rash on the cheeks.
However, it can take up to eight weeks for symptoms to begin.
As the virus progresses, patients routinely experience a sharp decline in blood pressure that can cause lightheadedness, nausea and confusion, as well as internal bleeding and, eventually, kidney failure.
Patients admitted at this late, critical stage are typically placed in intensive care and put on dialysis to filter toxins.
It is important to note that not everyone who is infected will experience serious illness.
According to NBC News. 40% will develop mild symptoms, while the remaining 60% will develop the aforementioned life-threatening symptoms.
Experts note that for many victims, the body’s immune response, rather than the infection itself, causes death.
There is no specific treatment for hantavirus. Patients are typically given care that targets symptoms, including medications to reduce fever, IV fluids to treat dehydration and a class of pharmaceuticals known as vasopressors, which boost blood pressure to ensure vital organs receive essential nutrients, such as oxygen.
For patients with HPS, early admission to a hospital is critical, as oxygen therapy and a ventilator may be needed. Extracorporeal membrane oxygenation (ECMO) machines are used when the heart and lungs fail.
For HFRS, care includes hydration and maintenance of oxygen and blood pressure. If caught early, patients can take the antiviral ribavirin via IV.
How deadly is hantavirus?
Hantavirus pulmonary syndrome is much more deadly than hemorrhagic fever with renal syndrome.
The mortality rate for HPS is about 35%-40%, while HFRS’s mortality rate ranges from less than 1% to 15%, depending on the specific virus.
How can you reduce your risk of a hantavirus infection?
- Don’t leave your pet’s food and water where mice can reach it.
- Trap all mice.
- Air out closed spaces where the mice made their home.
- Use a disinfectant to soak down nests and droppings.
- Don’t sweep rodent droppings into the air.
- Move hay, wood and compost piles far from your home.
- Get rid of trash and junk piles that could draw rodents.
