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A family suffered weeks of dizziness and nausea. A doctor’s hunch uncovered the cause.

They would start to improve but within hours their symptoms returned

(Cam Cottrill for The Washington Post)

Brooke Stroud was flummoxed and upset. How, the Washington clinical psychologist wondered, had her teenage houseguest gotten sick so quickly with the unidentified illness that had struck Stroud’s family of five at the end of 2020?

Stroud, her husband Stephane Carnot, and their daughter Olivia, then 17, had consulted primary care doctors in a fruitless attempt to identify the cause of their headaches, dizziness, vomiting and exhaustion. The pattern of their flu-like illness was perplexing: One or more of them would start to feel better, but within hours their symptoms would always return.

Ultimately it was the suggestion made by an infectious-disease expert more than 1,000 miles away that proved to be spot on, leading to a diagnosis and recovery.

“We’d been horribly sick for three weeks,” said Stroud, who believes her judgment was compromised by illness and a misplaced focus on covid-19, which seemed omnipresent nine months into the grinding pandemic. “I feel guilt that I exposed my kids to this.”

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“Totally drugged”

Stroud was the first to become ill. On Dec. 18, 2020, she logged into a morning meeting from her Georgetown home and told the other participants she wasn’t feeling well. She had felt out of sorts for several days, but seemed distinctly worse.

“I felt totally drugged,” she said. As the day progressed, she developed a 100-degree fever. By evening, Carnot and two of their children who had recently returned for the holidays — 19-year-old Alex, who attends college in North Carolina, and Olivia, a senior at a Virginia boarding school — had severe headaches, were vomiting and felt achy.

Stroud suspected they had contracted the coronavirus. Her husband managed to snag an appointment for a PCR test, which came back negative.

Stroud’s internist tested her for the coronavirus and the virus that causes the flu. The results were negative. She spoke to her children’s pediatrician who was concerned, but recommended rest and fluids. If their parents had tested negative for the coronavirus, the doctor told Stroud, now 52, there seemed little reason to test them or schedule an office visit.

By Dec. 23, Stroud said, everyone was so exhausted that they mostly stayed in bed. The couple’s oldest child, 21-year-old Sebastien, arrived from Vermont where he attended college. Within hours he, too, was ill.

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Stroud decided a second opinion might be wise. On Christmas Eve, she saw her husband’s internist who ordered blood tests; they revealed nothing that would explain her symptoms. “We canceled our [Christmas] plans and hunkered down under the covers,” she said.

Stroud had noticed something curious but wasn’t sure what it meant — or if it meant anything. Olivia felt better when she took a walk. And Stroud, who was working from home, observed that when she worked in a carriage house on their property, so did she.

Weighing the risk

A few days before New Year’s Eve, Olivia underwent tests for coronavirus, parvovirus, which causes a respiratory illness that is typically mild, and Epstein-Barr virus, which causes infectious mononucleosis, an illness common among teenagers. All were negative. She had been scheduled to fly to New Orleans to spend a few days visiting classmate Caroline Schieffelin. The pair was then scheduled to fly back to Washington to stay at Olivia’s house for the two weeks required by their school before returning to campus in mid-January.

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Too sick to travel, Olivia canceled the trip. Stroud called Schieffelin’s parents to ask whether Caroline should come to Washington in view of the family’s unidentified illness.

“I put together a risk/benefit ratio,” recalled Caroline’s father John Schieffelin, an infectious-disease specialist at Tulane University School of Medicine. Schieffelin, who studies survivors of Ebola and Lassa fever, a viral illness that causes bleeding that can be fatal, said he balanced the risk of his daughter contracting whatever was ailing Olivia’s family — which was probably reduced in infectiousness because they had been sick for several weeks — to the alternative: Caroline spending two weeks alone in her dorm room.

He okayed the trip, and Caroline flew to Washington to stay with her friend.

But shortly after her arrival, Olivia told her mother that Caroline had vomited and was battling a severe headache.

Stroud said she “almost had a conniption. I was mortified that she had gotten whatever this was.”

Caroline was on a video call with her father on the evening of Jan. 5, 2021, when Stroud knocked on her door to ask if she needed anything. The parents began chatting.

Schieffelin had been struck by Caroline’s observation that she felt better in certain parts of the large house and worse in others. “I said, ‘That’s weird and not normal,’ ” Schieffelin recalled telling his daughter.

He mentioned this to Stroud and added, “Not to be a paranoid parent, but this really sounds like it could be carbon monoxide poisoning. People are getting sick way too quickly . . . it sounds environmental.”

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Schieffelin said the symptoms reminded him of the annual spate of carbon monoxide deaths in New Orleans, many of which result from indoor use of portable generators during hurricane season.

Unintentional poisoning

Health officials estimate that each year 400 Americans die and 4,000 are hospitalized as a result of unintentional poisoning from carbon monoxide (CO), the chemical produced by the incomplete burning of natural gas or other products that contain carbon. In addition to generators, sources include vehicle exhaust, stoves and heating equipment, including furnaces and gas water heaters.

Mild to moderate poisoning can cause symptoms that are frequently described as “flu-like.” Dizziness, confusion, headache and weakness are common, as are nausea and vomiting. But unlike the flu, which does not improve with exposure to fresh air, the symptoms of CO poisoning often do.

Higher levels of CO can result in fainting, permanent brain damage and death, and are a particular risk for people who are sleeping or drunk and may die before showing symptoms. Health officials emphasize that anytime carbon monoxide is suspected, it is important to immediately evacuate to fresh air and call 911.

Stroud told Schieffelin that none of their doctors had suggested the possibility of carbon monoxide. She doubted that could be the culprit, she added, because an alarm system with various kinds of detectors, including one for CO, had been installed in their 162-year-old house a few years earlier. But, she added, they would buy a portable CO detector, long recommended by the U.S. Consumer Product Safety Commission, to see what it showed.

Carbon monoxide safety tips for your home

Early the next morning, Jan. 6, Carnot bought one at a hardware store, brought it home and plugged it in. The alarm sounded immediately, confirming Schieffelin’s hypothesis.

Stroud called 911; members of the D.C. fire department arrived within minutes. Firefighters ordered everyone out of the house until they could pinpoint the source of the leak, which was found quickly. A clamp on the furnace had come loose and was spewing the odorless, colorless gas throughout the four-story house. Concentrations in some areas, particularly where several bedrooms are located, were the highest. Tests at the scene also showed elevated levels of CO in the blood of everyone who had been in the house.

Tunnel vision?

“It was all over fairly quickly,” Stroud said. No one required medical attention. (In some cases, people exposed to high levels of CO need treatment with hyperbaric oxygen, which rapidly pushes the poison out of the blood and replaces it with oxygen.)

Schieffelin said his daughter called him as the fire department was arriving and later that day after everyone was back in the house. He also spoke to Stroud. “We were just glad everyone was okay,” he said.

Stroud was baffled by the failure of her alarm system to warn of the exposure. She quickly discovered that her system did not include a CO detector; it had been installed a year before D.C. required them in residences. “I thought we were covered,” she said. “We weren’t.”

The family has since purchased and deployed four plug-in detectors, one on each level of their home. Every time she goes into the basement storage room she eyeballs the once-faulty furnace connection.

The incident left Stroud shaken, particularly when she contemplated what might have happened. One of her doctors, she said, urged her to tell her story to warn others of the danger posed by the overlooked and insidious hazard.

“I’m wondering if we’d been seen in the pre-covid era whether someone might have thought of this” sooner, Stroud said.

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