Examples of COVID outbreaks among wildland firefighters

From firefighters to an Area Command Team

firefighter Dixie Fire California
A firefighter and another person at Diamond Mtn. Rod on the Dixie Fire. Photo by Luanne Baumann. Posted August 11, 2021.

Over the last few days we ran across a number of examples of COVID outbreaks among wildland firefighters.

Dixie Fire

In an August 20 article, the Redding Record Searchlight, a Northern California newspaper, reported that CAL FIRE said there have been 14 positive cases at the Dixie Fire’s West Zone fire camp.

The positive cases include five from one crew, two from the same dozer, two from the same water tender and five “random cases,” the agency said. “These personnel were immediately released from the incident.”

Two of the cases led to hospitalizations, with one individual now in San Diego, who Cal Fire said is “doing well.” A second person, now in Redding, is “showing improvements,” the agency said.

The information below came from the Wildland Fire Lessons Learned Center.

Area Command, October 2020

In October of last year while working on the August Complex of fires, 9 of the 14 members of an Area Command Team that were working out of the Shasta-Trinity National Forest Supervisor’s Office in Redding tested positive. The first case was discovered after the team had been released and they were all in travel status followed by days off. That made it difficult to contact everyone. Some family members of individuals who tested positive also became infected. Given these unintended outcomes, a Facilitated Learning Analysis was initiated to develop lessons learned that could be shared with the wildland fire community.

The next four all occurred in California this year:

Hotshot crew, May

Four days after the crew began their season, one person tested positive. The crew Superintendent and Forest took immediate action to identify close contacts; 19 employees were identified. Of the 19, 7 were fully vaccinated (and returned to work immediately) and 12 were placed into quarantine (some at home and some in hotels).

Fuels module, May

On May 14th a fuels module member developed COVID-like symptoms; the person received a positive COVID test on May 16th. Contact tracing identified 10 close contacts (7 other fuels crew members and 3 additional employees who worked in the building). All of the close contacts were encouraged to get tested for COVID-19 and advised to quarantine (although 4 had been vaccinated, it was not used in the decision). One unvaccinated individual lived in barracks and moved to a hotel on the 16th. A second individual (the supervisor of the module) tested positive on May 17th.

Two additional cases were confirmed later that week (4 total in the cluster); none of the vaccinated employees tested positive or showed any symptoms. At the time of the review (June 2), one of the sick employees had returned to the office and others were teleworking. One of the four individuals was contacted by county public health, two were contacted by state public health, the fourth individual was never contacted by any public health department.

The four vaccinated employees did not get sick while four of the seven unvaccinated employees ultimately tested positive

Hotshot crew, July

An Interagency Hotshot Crew (IHC) finished a 14-day assignment with 18 crewmembers and arrived home June 22, 2021 (the IHC had 2 additional crewmembers who returned early and were not exposed); no employees were aware of exposure or had symptoms. The IHC was off duty on June 23-24, 2021 for mandatory rest.

On June 24th a crewmember developed a fever and took the initiative to get a COVID test immediately; the test returned a positive result the same day. Contact tracing found that the 17 other crewmembers were close contacts within 48-hours prior to the onset of symptoms. All of the close contacts were other IHC crewmembers (during travel home) and no other personnel were identified.

Of the 18 crewmembers who returned from assignment on June 22nd, 3 were fully vaccinated and returned to work on June 25th. The remaining employees (15) have not returned to work; the sick employee was put into isolation and the remaining close contacts on the crew were told to self-quarantine for 14-days by unit leaders. The 2 crewmembers who returned early (1 vaccinated) were not impacted.

None of the vaccinated employees got sick while 6 of the unvaccinated employees have tested positive.

Engine crew plus others, July

On July 6, 2021, the local county public health contacted the Forest Service regarding an employee who had been exposed to a confirmed case of COVID-19. The employee had no symptoms and received negative test results (rapid test and PCR test). Public health advised the employee to quarantine for 10 days.

No other FS employees were involved in this exposure since they were considered a secondary contact because the employee was exposed outside of work.

The employee in quarantine impacted the availability of a fire engine during high fire danger, therefore an employee from a different station began working on the engine on July 6, 2021.

On July 7, 2021, the employee covering for the engine (from the other station) developed COVID-like symptoms and tested positive for COVID-19 on the same day.

This cluster involves 12 employees, with only 1 vaccinated and one who was in quarantine and not exposed. By July 12, 6 of the unvaccinated employees tested positive for COVID -19. All unvaccinated employees (10) were placed into quarantine. One employee chose to stay in a hotel and all others remained at their residences.

The vaccinated employee did not get sick while 6 of 11 unvaccinated employees have tested positive for COVID-19.


Lessons to be learned?

While the Delta variant, which began spreading widely in the United States in July, changed how easily it is to become infected even among those who are vaccinated, it is still true that a vaccination greatly reduces a person’s chance of severe infection, hospitalization, and death.

Here are the final paragraphs from an excellent, detailed article published August 18, 2021 at Healthline:

Vaccines are highly effective even if they’re not perfect

The COVID-19 vaccines were developed to stop developing severe forms of the disease that can lead to hospitalization and death. In that aspect, they have been extremely successful even if the vaccines are not 100 percent effective.

While it is true that some partially and fully vaccinated people have developed COVID-19, breakthrough infections should not be a concern for most of the population. Doctors, however, do still recommend people exercise caution in areas with low vaccination rates and high transmission.

Vaccines also greatly reduce the likelihood of mild and symptomatic infections as well as prevent death and hospitalization.

Kullar noted that the Delta variant is both more contagious and transmissible, and those who are harboring the Delta variant can carry as much as a 1,200 times higher viral load than the original strain.

“Given all of this information, it is important for everyone not only to get fully vaccinated but also follow infection prevention measures, such as wearing a face mask in the public, physically distancing from others, and avoiding large crowds until we round the turn of this surge.”

Smoke and air quality, August 21, 2021

Air Quality, PM2.5 & PM10, at 6:32 a.m. PDT Aug 21, 2021
Air Quality, PM2.5 & PM10, at 6:32 a.m. PDT Aug 21, 2021. AirNow.gov

The map above shows the air quality, PM2.5 and PM10, at 6:32 a.m. PDT Aug 21, 2021.

The map below is the forecast for the distribution of wildfire smoke at 3 p.m. PDT Sunday August 22.

Forecast for near surface smoke
Forecast for near surface smoke at 3 p.m. PDT August 22, 2021.

Forecast for strong winds closes Highway 50 near Caldor Fire

Fire officials have documented the destruction of 179 residences

8:28 a.m. PDT August 21, 2021

Caldor Fire map
Caldor Fire map. The black line was the perimeter at 8:25 p.m. Aug. 20, 2021. The red dots represent heat detected by a satellite at 3:09 a.m. PDT Aug 21.

The 82,000-acre Caldor Fire southwest of Lake Tahoe is under a Red Flag Warning Saturday for conditions that could push the blaze northeast toward Highway 50.

The updated weather forecast for the fire area Saturday at 4,400 feet is for 14 mph southwest winds beginning at 11 a.m. gusting to 21 mph. The relative humidity will drop from the overnight high of 55 to 60 percent to the high 20s. There will be a 35 percent cloud cover with a high of 75 degrees.

To see all articles on Wildfire Today about the Caldor Fire, including the most recent, click HERE.

About two-thirds of the fire perimeter was active enough Friday night and early Saturday morning for satellites to detect intense heat.

Firefighters reported that winds decreased during the night and spot fires continued to become established in the dense timber stands and clear cuts due to the large amount of extremely dry dead and down material. The increase in relative humidity during the night allowed crews to conduct firing operations.

On the east side, satellites detected heat at 3:09 a.m. north of the Omo Ranch, and south, east, and northeast of Jenkinson Reservoir. The fire was also very active on the entire east side near Morrison, Iron Mountain, Iron Mountain Ridge, Voss, Meiss, and Caldor. At that time the fire was less than a mile south of Highway 50 at Riverton, and about two miles south of the highway near Kyburz. On the south side, satellite data overnight detected it was two miles north of Highway 88 at the closest point, Gold Note Ridge.

Crews have documented 179 residences that have been destroyed. Approximately 15,000 remain threatened.

Resources assigned to the fire Friday evening included 28 crews, 142 fire engines, and 20 helicopters for a total of 1,558 personnel.


8:27 p.m. PDT August 20, 2021

Caldor Fire map
Caldor Fire map. The red dots represent heat detected by an aircraft at 2:48 p.m. PDT August 20, 2021. The fire perimeter was mapped earlier.

With strong winds in the forecast for Saturday officials have closed a portion of Highway 50 near the Caldor Fire which has burned over 75,000 acres 18 miles southwest of Lake Tahoe in California.

The closure began at 4:30 p.m. Friday. Highway 50 will be closed in both directions from the Sly Park Road exit to Twin Bridges. It will be open between Meyers and Twin Bridges for local residents only who reside between Meyers and Twin Bridges. These residents will be subject to providing identification and proof of residency. No traffic will be allowed west of Twin Bridges. (This information was acquired at 7 p.m. PDT Friday, Aug. 20, 2021, and could change.)

At 3 p.m. Friday the north edge of the Caldor Fire was about a half mile south of the highway. (See the map above.) A Red Flag Warning will be in effect Saturday from 11 a.m. through 8 p.m. The weather forecast for Saturday at 4,600 feet is for southwest and west-southwest winds beginning at 8 a.m. increasing in strength by 11 a.m. to 16 mph gusting to 25 mph, or 30 mph in some areas. The relative humidity will drop to 25 percent or lower. Skies will be clear with a high of 75 degrees.

Strong winds with no cloud cover and 25 percent humidity could push the fire to Highway 50 and possibly across the roadway. However a dense smoke layer could reduce solar preheating of the fuels and attenuate the spread somewhat. The Hot-Dry-Windy Index for Saturday predicts the area will be below the 50th percentile, which would not indicate extreme spread of a fire. This weather event will be a good test of the Index.

Many areas are under evacuation orders. InciWeb has the details.

On Friday the fire activity increased after noon when the wind began coming out of the south at 6 to 10 mph gusting to 23.

The fire spread is being driven by a heavy component of dead and down fuels and drought-stressed vegetation. Live fuels are cured to levels normally seen in late September, and the vegetation is extremely receptive to spotting. Fuel moistures are historically low.

Fire officials have documented the destruction of 118 residences.

Resources assigned to the fire include 18 crews, 109 fire engines, and 13 helicopters for a total of 1,118 personnel.

USFS engine crews on the initial attack of the Caldor Fire
USFS engine crews on the initial attack of the Caldor Fire, August 14, 2021. USFS photo.

French Fire prompts evacuations near Lake Isabella, California

The fire has burned more than 11,000 acres

9:53 a.m. PDT August 21, 2021

French Fire map
Map of the French Fire. The red dots represent heat detected by a satellite at 2:49 a.m. PDT August 21, 2021.

Friday night the French Fire west of Isabella Lake near Kernville, California grew a bit to the north and southwest while under the influence of a light and variable wind from the south, east, and southeast. (See the map above) The relative humidity which was in the 30s and 40s Friday rose into the 40s again Friday night.

The weather forecast for Saturday calls for stronger winds in the afternoon, 11 mph out of the northwest gusting to 16 mph, with the relative humidity around 40 percent. By 6 p.m. the humidity will begin climbing rapidly, reaching 80 percent by 8 p.m. and remaining above 60 percent the rest of the night.

To see all articles on Wildfire Today about the French Fire, including the most recent, click HERE.

The Incident Management Team reports that the fire has destroyed two structures and burned 11,295 acres. They expect the fire to continue to move toward the communities of Alta Sierra, Alta Sierra Ski Resort, Isabella Highlands Community, Dutch Flat Community, and surrounding areas. Evacuations are still in effect.

Resources assigned to the French Fire Friday evening included 28 hand crews, 52 fire engines, and 5 helicopters for a total of 883 personnel.

French Fire evacuation map
French Fire evacuation map. Accessed at 10 a.m. PDT August 21, 2021. Posted by Kern County Fire Department.

6:22 p.m. PDT August 20, 2021

The French Fire in Kern County, California started Wednesday, August 18, around 4:30 p.m. on the west side of Lake Isabella. (See map above.) On Thursday firefighters were faced with shifting winds driving the fire in several directions, but in the afternoon wind from the southwest and later the south pushed the fire northwest and north.

Friday morning 5 to 10 mph east and northeast winds gusting at 12 to 18 drove the blaze to the west and northwest, but after 3 p.m. 8 to 12 mph winds gusting out of the south at 15 to 18 mph pushed the fire vigorously to the north.

French Fire, looking south-southeast from Shirley Peak
French Fire, looking south-southeast from Shirley Peak at 1:12 p.m. PDT August 20, 2021.

The fire burned over the location of the Shirley Peak camera, but hours later it was still transmitting images of very dense smoke through a dirty lens.

At about 3 p.m. Friday InciWeb reported the following evacuation orders:

  • Wagy Flat Road east to Lake Isabella, between Old State Road south to Keyesville.
  • Keyesville south, from the intersection of Black Gulch Road and Forest Route 26S06, continuing east to Highway 155.

Kern County has posted an evacuation map.

Friday morning the fire was mapped at 4,272 acres, but the push to the north in the afternoon likely added significantly to that number.

Thursday evening resources assigned to the fire included 15 hand crews, 47 engines, and 5 helicopters for a total of 650 personnel. On Friday the number of personnel had increased to 809.

The GOES-17 satellite could easily photograph the smoke plume Friday afternoon as the intensity increased significantly.

French Fire satellite photo
French Fire, photographed by GOES-17 at 5:36 p.m. PDT August 20, 2021.
French Fire 1249 p.m. PDT August 20, 2021
French Fire. The red dots represent heat detected at 12:49 p.m. PDT August 20, 2021. Later in the afternoon the wind shifted and drove the fire to the north. The finger of red dots on the west side turned out to be false positives.

Dixie Fire grows to 678,000 acres near Susanville, California

 Updated at 8:20 p.m. PDT Aug. 19, 2021

At 7 p.m. local time CAL FIRE released an update on the Dixie Fire. The acreage figure was about 22,000 higher than the number from 12 hours earlier, and now stands at 699,666 acres.

At least 659 residences have been documented as destroyed and 137 commercial buildings.

(To see all articles on Wildfire Today about the Dixie Fire, including the most recent, click HERE.)

The fire is being managed by two Incident Management Teams, one on the west side and the other on the east side. In CAL FIRE’s twice daily updates the “Current Situation” section is broken down into the West and East Zones. After closely reading them for a week, it became obvious that they are written by two different people with different views on what information should be included. Below are their updates from today at 7 p.m. These are typical:

“Dixie Fire West Zone: Firefighters continue to build and bolster containment lines on the Dixie Fire. Fire remained active under northeast winds, with spotting and torching contributing to fire growth. Smoke from other fires nearby did limit activity in some places, but not enough to prevent additional growth. Fuel moistures are historically low which is contributing to the critical fire behavior. There are many considerations before allowing an area to be repopulated. A methodical, multi-pronged process of inspection and evaluation must be conducted to ensure the health, safety and welfare of all the residents affected. This process includes guaranteeing roads are safe for travel and basic utilities to infrastructure is secured. Damage assessment is ongoing, and the number of damaged and destroyed structures may change as teams are able to access the fire area safely. Please see below for information affecting your area.”

Dixie Fire East Zone: West Zone and East Zone crews, equipment, and aircraft have maintained aggressive engagement on the portion of the fire near Janesville. Along Honey Lake, the northern edge near fruit grower’s road has remained in its current footprint due to the continued northeasterly winds. Fire line was constructed on the south end from Highway 395 to the Walker fire scar. In an additional priority area, rotary aircraft supported crews in the Genesee Valley this morning when they were able to fly. After aerial retardant application, the spot fire remains at approximately the same footprint of 30 to 40 acres and firefighters are constructing and reinforcing contingency lines to the south. The fire on the north side of Beckwourth Genesee Road is currently backing down the middle slopes and crews continue to construct lines to mitigate impacts to structures in the Genesee Valley.”

Below is the map showing the boundary between the two zones, revised August 16.

Dixie Fire, new East and West Zones

Next, is the satellite photo showing smoke from fires in Washington, Oregon, and California.

Satellite photo, Western Fires at 6:26 p.m. PDT Aug 19, 2021
Satellite photo, Western Fires at 6:26 p.m. PDT Aug 19, 2021.

10:46 a.m. PDT August 19, 2021

Dixie Fire map, northwest area
Dixie Fire map, northwest area. The red areas represent heat detected by a satellite at 3:26 a.m. PDT August 19, 2021. The white line was the perimeter at 8:55 p.m. August 18, 2021. The brown areas had extreme heat when the fire was mapped Wednesday evening.

The spot fire that started five miles east of the Dixie Fire near Highway 395 has grown to about 20,000 acres. It crossed the highway in at least two places but firefighters were able to limit the spread east of the roadway. Approximately five miles of the eastern side of the fire is now alongside Highway 395 west of Honey Lake between Janesville and Milford.

The blaze is still very active in Wilcox Valley and on the west side of the 2019 Walker Fire.

Thursday morning the Incident Management Team reported that the fire had burned 678,000 acres.

Dixie Fire map, northeast area
Dixie Fire map, northeast area. The red areas represent heat detected by a satellite at 3:26 a.m. PDT August 19, 2021. The white line was the perimeter at 8:55 p.m. August 18, 2021. The brown areas had extreme heat when the fire was mapped Wednesday evening.

Westwood has still been spared. Seven miles east of the community the fire has approached Highway 36 but has not grown east past the 2016 Willard Fire. It is six miles west of Susanville.

The northwest area remains very active and continues to march through Lassen Volcanic National Park. I estimate that about 40 percent of the 106,452-acre park has has burned.

The slopover south of Highway 36 east of Mill Creek was very active Wednesday and has burned approximately 2,000 acres. This is 13 air miles west of Chester.

The weather forecast predicts dry, breezy conditions for the next several days. Friday afternoon through Sunday should bring strong winds out of the southwest.

Wildfire smoke and air quality maps, August 19, 2021

Forecast for vertically integrated smoke
Forecast for vertically integrated smoke at 10 p.m. PDT Aug. 19, 2021.

Smoke from wildfires will have serious impacts Thursday in California, Washington, and eastern Canada. The smoke forecast for 10 p.m. PDT is above.

The map below depicts the air quality at 7:26 a.m. PDT Aug. 19, 2021, by AirNow.

Air quality: ozone, PM2.5, & PM10
Air quality: ozone, PM2.5, & PM10 at 7:26 a.m. PDT Aug. 19, 2021. AirNow.