The coronavirus invades most bodies the same ways, through the nose or throat via virus-laden droplets. From there, it can run very different courses.
Covid-19 struck Elizabeth Schneider in Seattle like a storm. Her temperature spiked to 39.4 degrees Celcius, and she slept 18 or 19 hours a day. For Dr. Jonathan Peterschmitt in eastern France, the disease was mild. He lost taste and smell, developing a light cough, muscle pain and night sweats.
By the time a public-health official called Erin Calver of Cochrane, Alberta, telling her she had tested positive, she could say only a few words before running out of breath. The official told her to call 9-1-1. Angela Fugazza, an octogenarian in northern Italy where the pandemic has hit hard, tested positive but has had no symptoms.
The strikingly different symptoms that survivors and victims’ families recount present a spectrum that is among the coronavirus’s enigmas. For many people, the infection stays in the upper respiratory tract, causing fever, congestion, a dry cough and a sore throat. It can also move to the lower respiratory tract, inflaming the lungs and turning into a deadly form of pneumonia.
Some people develop no symptoms, one factor making the virus difficult to detect and contain. Others experience mild symptoms that make it hard to distinguish from a cold or the flu.
A few factors could explain such different outcomes: viral mutations could unleash more-virulent strains; people could be exposed to different amounts of the virus, and prior health conditions.
The virus is mutating, but so far there isn’t evidence a particularly deadly strain is emerging. “We haven’t seen changes in the clinical presentation or manifestation of the virus since the epidemic started in December that would lead us to believe that there’s a hypervirulent strain,” said Dr. Albert Ko, professor of epidemiology and medicine at the Yale School of Public Health.
The other two factors appear significant, he said. The elderly, men and people with chronic diseases have higher Covid-19 mortality rates. Some epidemiologists have suggested part of the explanation could be weakened immune systems among the elderly or higher smoking rates among men that lead to other chronic pulmonary and cardiovascular problems.
Those factors don’t explain why the disease hit Jared Diamond of San Antonio, a 51-year-old nonsmoker, so hard. “I’ve known him for 29 years, and he’s the healthy one,” said his wife, Robin Diamond, who hasn’t shown signs of infection.
Mr. Diamond was hospitalized in intensive care a few days after he started feeling ill March 16, she said. His lungs filled with fluid, and he couldn’t talk without coughing. A little over a week later, he was put on a ventilator. “It’s just crazy how fast it progressed, and how he just kept getting worse,” Mrs. Diamond said.
One theory scientists are researching is that the receptors the coronavirus uses to bind to cells—called ACE2 receptors, for Angiotensin converting enzyme 2—play a role, said Dr. Ko. It is possible the receptor in older people is more prevalent or shaped in a way that binds better with the virus, he said.
In the most severe cases of Covid-19, one factor doctors and scientists are investigating is the response of the immune system itself. The pathogen appears to be triggering an overactive immune response in some people, including relatively healthy ones, in which proteins called cytokines are rapidly released into the bloodstream, damaging the lungs and other organs.
‘Sick but not feeling sick’
When Dr. Peterschmitt, 34, of France learned he had the virus, he wasn’t worried. His experience as a doctor had taught him it is often not about the type of virus that infects people but about the condition of the infected people. Dr. Peterschmitt, who lives in a village near Mulhouse, was healthy.
He believes all his four children, aged 1 to 7, have been infected, although three didn’t complete tests because of the discomfort caused by the nasal swab. Two haven’t had symptoms. The others have experienced mild symptoms; his son had a runny nose and his daughter had a cough.
“We need to explain to them about the virus,” he said. “To tell them that we are sick but not feeling sick. That we stay home not for us but for other people.”
Scientists are trying to understand why children generally get less sick than adults, a phenomenon that occurred with other diseases caused by coronaviruses, such as SARS and MERS. The ACE2 receptors are thought to be one possible factor. Another theory is that their immune systems are less developed and don’t respond to the virus as aggressively.
Even though children appear less likely to get severely ill, they aren’t completely immune. And some older adults get only mild cases.
Ms. Fugazza of northern Italy, age 81, said she had no symptoms and might not have been tested for coronavirus had a 52-year-old relative not been suffering from severe muscle pains and a high fever. The two had been living together for about a month at Ms. Fugazza’s home in Codogno, the heart of Italy’s coronavirus outbreak.
The hospital has released the relative, Ms. Fugazza said. “They say that elderly people die, but apparently not all of us,” she said. “You have to be a little bit lucky.”
‘Something I wouldn’t wish on anyone’
Many who avoid the most serious lung infections aren’t lucky enough to experience only mild symptoms. Covid-19 can punish even young and relatively healthy people. Ms. Schneider of Seattle said she didn’t know she had it initially. By the time she found out through a flu study, most of her symptoms had subsided.
Still, running a 103-degree fever was frightening. “That kind of scared me,” said Ms. Schneider, 37. Her temperature dropped to 101 for a couple of days, then to 100. She felt intense soreness throughout her body. For days, she got out of bed mostly only to shower. “It definitely was something I wouldn’t wish on anyone.”
Ms. Calver of Alberta said she was watching television at home when she noticed a burning pressure across her chest followed by short spurts of stabbing pain. She wondered whether it might be linked to a cardiac ablation she’d had a couple months earlier, a procedure where small areas of the heart are damaged to try to correct heart-rhythm problems. But this felt different. She also had a slight sore throat.
She drove to the hospital that night, where a doctor looked at her blood work and told her to take it easy at home. She wasn’t swabbed for the coronavirus. Ms. Calver, 38, figured it wasn’t likely she had it, as she didn’t have a fever and hadn’t traveled internationally.
Her condition worsened. She experienced cold sweats and developed a cough. By the night of March 21, she was having trouble breathing. Back at the hospital March 22, she was tested for the coronavirus. Two days later, the public-health official phoned saying the test was positive. The official, hearing her struggle to breathe, told her to call emergency services.
Paramedics gave her a nasal cannula, which delivered oxygen, and strapped her into the ambulance. They turned the siren on, she said, and “That was the first time that I was scared.”
At the hospital, Ms. Calver remembers what seemed like a dozen medical staff wearing gowns, masks and gloves waiting for her. A doctor leaned in close and warned Ms. Calver it was possible she would need to be intubated and put on a ventilator. She might wake up in an intensive-care unit.
“I wasn’t forming sentences very well then, so I just nodded,” Ms. Calver said. “I think I cried a bit.”
The ventilator wasn’t needed. Her oxygen levels eventually stabilized. Ms. Calver was put on a five-day course of either chloroquine or hydroxychloroquine—she doesn’t know which—antimalarial drugs President Trump has promoted. The drugs haven’t been proven effective in treating the virus but are being prescribed by some doctors, and clinical studies are under way. Ms. Calver said she didn’t know whether it had helped.
It isn’t clear why some patients seem to recover quickly without significant symptoms or the need for oxygen or a ventilator. Dr. Kevin Clerkin, a physician with Columbia University Irving Medical Center, said there is an association between people with cardiovascular conditions and those who get critically ill or die after getting the coronavirus. “The thing that we don’t quite understand yet is if these people are just sicker baseline,” he said, “or if there is something about the interaction of the virus with their underlying condition.”
Ms. Calver was discharged April 5.
‘It hurt him more than he was saying’
Mr. Diamond of San Antonio wasn’t able to avoid going on a ventilator. As his lungs filled with fluid, his doctors switched him to a face mask on March 28 when the nasal cannula was no longer sufficient, Mrs. Diamond said.
He called his family and friends that night to tell them he was going on a ventilator, Mrs. Diamond said. “He said, ‘I’ll be fine. I’ll be off it in a couple days.’ ”
His condition had deteriorated rapidly since he first texted his wife to tell her he was going to the doctor less than two weeks earlier on March 16. His throat hurt and he had a fever, he told her. The doctor gave him a flu test and told him to go home and rest.
Mr. Diamond, who owns a chain of army-surplus stores in San Antonio, spent the next two days resting on his home-office couch so his wife wouldn’t catch what he had. Their 20-year-old daughter, Carly, took turns with her mother playing nurse, bringing him food, Gatorade and camomile tea. He was dehydrated and had no appetite.
“I knew it hurt him more than he was saying,” his daughter said.
He went back to the doctor, texting his wife at work to say he was still running a fever and his body ached so bad he felt it in his bones. Mr. Diamond has insisted that his wife, who has asthma and an autoimmune condition, stay away from him and the hospital.
He tested positive for the coronavirus that night and was moved to the ICU the following day. His primary doctors took turns calling Mrs. Diamond with updates on what X-rays showed. “Every time the lungs looked worse,” she said.
Covid-19 can lead to pneumonia, which is when balloon-like structures at the end of the respiratory tract, called alveoli, fill with fluid as a result of the infection. That’s when the ventilators that are in short supply world-wide come in.
When Mr. Diamond was first put on a ventilator, it was running at full capacity, his wife said. Doctors started giving him Kaletra, an antiretroviral drug from AbbVie Inc. used to treat HIV and among drugs hospitals have been trying with Covid-19. “The infectious disease doctor said we don’t know if it helps,” Mrs. Diamond said, but “It can’t hurt.”
On April 2, the doctor told Mrs. Diamond he was able to turn down the ventilator a little and he was cautiously optimistic. He has warned her, though, that it could be a long road—that even if he were to come off the ventilator, at some point, he may have to go back on.
His family didn’t have any contact with him while he was on the ventilator. He was sedated, but his nurses lowered his sedation at some point every day and tried to get him to respond with nods to basic questions. He was responsive some days but not others.
Every night, she called the hospital and asked the nurses to tell him they were praying for him and that they loved him. She knew he was likely too sedated to get the messages. Still, she said, “I just want him to know.”
On April 5, his doctor took him off the ventilator, but he remained medicated and on a lot of oxygen. His family was able to speak with him several times this week via FaceTime, but he could barely talk without coughing. In their first conversation after coming off the ventilator, he could only whisper, Mrs. Diamond said. “He said, ‘I love you.’ ”