Does Florida fog contain Serratia Marcescens? Fogvid-24 rumors swirl. What to know

Yahoo

10-02-2025

Large parts of the Sunshine State have been fogged in for the last week. Is it a bioweapon attack on American soil?
Fog is a common, natural occurrence that has a variety of possible sources. Most often in Florida, it happens when either warm energy from the ground radiates into space on a clear night, cooling the ground and the air right above it and causing the water vapor to condense into tiny cloud droplets, or when warm, moist air from the Atlantic Ocean or the Gulf of America (formerly the Gulf of Mexico) sweeps over a colder land surface.
Fog forms regularly in Florida, especially as the state approaches its dry season. So far it has caused some cruise ships some extra navigational difficulties and delayed one Falcon 9 SpaceX launch while others went up, dense fog or no dense fog.
But social media has been swarming with frightened accusations of nefarious origin including mysterious particles, a metal or chemical taste, unusually dry ground, lingering respiratory issues and the possibility it's a military bioweapons test.
An X user named Maskless in Florida! in Homosassa said last Tuesday, "we are once again being sprayed like bugs with a chemical fog. Respiratory issues are skyrocketing, chest colds you can't get over and our Governor does nothing to stop it." Sue Pear #MAHA pointed out there was no moisture. MomOfTheSouth was one of several people posting video of visible particles swirling in the fog, saying "I don't ever remember seeing fog like this."
There have also been reports since January that samples of the fog have been tested in an unnamed laboratory and found to contain high levels of the bacteria Serratia Marcescens. No link is ever provided.
It's the latest in a widespread claim across the U.S. that the dense fog blanketed large areas of the country in the last two months, nicknamed Fogvid-24, was making people sick.
No laboratory report test results have been presented, only referenced in social media posts.
In January, the Daily Mail reported on the rumored fears of an unannounced germ warfare test and a Florida resident told the British tabloid the conditions made her feel ill.
Weather conditions have been perfect for it, according to Megan Tollefsen, Coastal Hazards Program Leader at the National Weather Service in Melbourne. The state has been under an area of high pressure with lighter local winds and clear skies, and that sets the stage.
"When you have just enough moisture present closer to the surface, this can make conditions even more favorable for fog development," she said in a phone call Monday morning. "Because conditions have been so favorable, we've seen these visibility reductions down to less than a mile plenty of times, and even down to the low of a quarter of a mile in some spots."
Several videos on social media of people shining lights into the fog seem to reveal swirling particles. Are those bacteria?
"If you shine, you know, any kind of light in the fog, what you're actually seeing are the very, very small water droplets. They can reflect light," Tollefsen said. "Similar to when you're out driving and you turn your high beams on in fog. You get that flashback from the light.
"So that is likely what people are seeing," she said.
A 2001 study found that inhalation of moist, humid fog can induce coughing in people and potentially bronchoconstriction in patients with asthma.
But there is also a nationwide surge in flu, COVID-19, RSV, norovirus infections and plain old colds going on right now. A Centers for Disease Control and Prevention flu report for the week of Jan. 25 showed almost 30% of lab tests for flu were positive and the rate was trending higher. Respiratory infections tend to peak in the winter months every year when people are enclosed together in close spaces.
More detailed numbers are not currently available as the Trump administration halted all communications from the CDC in January and the latest Respiratory Virus Hospitalization Surveillance Network update ends at Jan,. 18, 2025. According to the page, "CDC's website is being modified to comply with President Trump's Executive Orders."
Serratia Marcescens is a common bacteria in the family Enterobacteriaceae and an opportunistic pathogen in humans that is often found in damp conditions such as bathrooms and soil. It is best known for the ability of some strains to produce a pigment that ranges from pale pink to dark red, making it very useful in experiments.
It was commonly used in the first half of the 20th century as a biological marker for studying the spread of infections, according to Medscape.com, because doctors believed it to be harmless to humans.
Infections are often picked up during hospital or nursing home stays and can include catheter-associated bacteremia, urinary tract infections, and wound infections.
In September 1950, the U.S. Navy conducted a secret experiment to release balloons full of S. Marcescens over the San Fransisco Bay area in a test called "Operation Sea Spray."
"Its aim was to determine the susceptibility of a big city like San Francisco to a bioweapon attack by terrorists," the Smithsonian Magazine said in 2015. It was a success by those standards, as testing revealed a dramatic spread of the bacteria across the city and the surrounding suburbs, proving that cities like San Fransisco were vulnerable to germ warfare.
However, 11 locals developed very rare and serious urinary tract infections following the experiment — with their urine showing a distinct red hue — and one man recovering from prostate surgery died. Cases of pneumonia also shot up, although no connection has been verified. The release of S. Marcescens may also have permanently changed the area's microbial ecology, according to the San Fransisco Chronicle.
Former President Richard Nixon halted all germ warfare tests in 1969. "Operation Sea Spray" did not become public knowledge until 1976.
Conditions look favorable for more fog in the nights and mornings through Wednesday, Tollefsen said, when winds will start to pick up.
"We've got this front funnel boundary that'll kind of start to approach the area Thursday into Friday," she said. "That all will cause winds to increase a little bit more and keep the lower levels of the atmosphere a little bit better mixed, which makes it more difficult for fog to develop.
"So over potentially two more days of fog," Tollefsen said, "and then a bit of a pattern change, Thursday, Friday and into the weekend as well."
Dense fog overnight and in the mornings means lowered visibility and greater chances of accidents. The National Weather Service in Jacksonville advises drivers to:
Slow down! Add more time to reach your destination.
Use low-beam headlights.
Leave plenty of distance ahead of you to account for sudden stops.
This article originally appeared on Sarasota Herald-Tribune: Fogvid-24? Florida's dense fog brings rumors about bioweapons