Hantavirus Update
For some, this is like Deja vu all over again - travelers on a cruise ship infected by a strange virus, exposed individuals quarantined to special facilities, alarmist internet postings, and scientific commentary and responses, to include "the risk to the general public is low."
In 2020 I served as the Local Health Officer for both Asotin County Health District and Spokane Regional Health District (SRHD). As Local Health Officer for SRHD, I worked with the Department of Health and the CDC to accept four travelers from a cruise ship who were infected with a "novel corona virus" into the Special Pathogens Unit (SPU) housed at Sacred Heart Hospital. Given the fear that was increasing as this virus spread globally and nationally, there was concern this would unintentionally allow what became known as SARS-CoV2 into the community. But in reality - it was likely already circulating and it didn't spread from the SPU. Unfortunately, as days became weeks and months, fear grew as the understanding of COVID-19 increased, information changed with this new knowledge, and internet misinformation spread with the speed of a keystroke.
An outbreak of Andes virus on the Hondius Cruise Ship is so far associated with 11 confirmed or suspected cases of Hantavirus Pulmonary Syndrome worldwide including three deaths. Although both situations received significant media attention and sparked fear in some, there are major and notable differences between then and now.
Most strains of hantavirus are not transmitted person-to-person. The Andes strain, which is found mainly in South America, can be, although it's far less contagious than SARS-CoV2.
SARS-CoV2 and hantavirus are both 'zoonotic,' meaning it comes from contact with animals, the former from bats, the latter from wild rodents. In contrast with SARS-CoV2, however, the Andes hantavirus is better understood as it was identified in the 1990s.
People typically become infected with the virus by inhaling microscopic particles from these rodents’ urine, feces, or saliva, such as when they clean cabins.
Knowing how it spreads assists with ensuring it doesn't. Past Andes hantavirus outbreaks typically involved close contact with an infected and symptomatic person, such as caring for them. At this time there have been no infections from asymptomatic individuals.
Airborne transmission shouldn't be discounted, however. We learned this the hard way during COVID-19, and there are reports of individuals becoming infected with minimal close contact. Due to lessons learned during COVID-19, extra precautions have been taken for transporting, monitoring, and treating symptomatic and asymptomatic individuals with potential exposure.
Because of the lessons learned during COVID-19, the number of individuals who have been exposed have been limited. There are currently 41 people from 16 U.S. states that have potentially been exposed during the current Andes hantavirus outbreak and are being monitored for symptoms, including six Washington residents. No Asotin County residents have been identified as potentially exposed.
Hantavirus cases have been documented nationally for decades, with 15-40 cases occurring on average each year. Most cases in the United States are the Sin Nombre virus, a strain of hantavirus endemic to the West and Southwest which is spread from deer mice. This strain is not transmitted person-to-person.
Symptoms are non-specific, including fever, fatigue, muscle aches, headache, and gastrointestinal symptoms.
WA has an average of 0-5 cases of hantavirus/HPS reported each year, often in individuals who inhaled virus particles while cleaning or doing other activities in an area with rodent droppings. There have been roughly 60 documented cases since surveillance began in 1993, primarily east of the Cascades. Notably, the first case of hantavirus in Washington this year was recently identified in Chelan County. And while no cases have been identified in Asotin County, nearby counties like Spokane, Grant, Whitman, and Adams have all documented past cases and hantavirus-related fatalities.
The bottom line is that the risk of infection from hantavirus is low, especially if some common practices are performed when coming into contact with evidence of rodents, such as using wet-cleaning methods when cleaning rodent droppings, dead or trapped rodents, or nesting materials.
I don't want to dismiss hantavirus infections, however, as they can be deadly. And if we've learned nothing from the past, nothing is an absolute as more is learned with time, good science, and public health practice.
You can find out more information about hantavirus and what's happening in Washington at https://doh.wa.gov/newsroom/washington-health-officials-assisting-hantavirus-investigations-involving-two-different-virus