A Seattle man has been identified as the third person in the United States to be infected twice with the new coronavirus.
The unidentified man, 60, first contracted COVID-19 in March at a nursing home in Washington state and became so ill that he had to be hospitalized for 40 days.
Five months later, in July, he tested positive again after moving to another facility, but this time his illness was mild and he recovered.
Since then, genetic tests have revealed that the man is infected with two different strains.
The researchers say that because the patient was not very ill during his second attack, this suggests that he developed some antibodies during the first attack, even if it was not enough to prevent re-infection.
A resident of a nursing home in Seattle in the 1960s first tested positive for coronavirus on March 6, and then again on July 29. Pictured: Nurse Karen Hayes cares for a patient in the emergency room at COVID-19 at Harborview Medical Center in Seattle, Washington, May 7
Pictured is a diagram of all coronavirus strains documented in Washington state. Genetic tests have shown that the strain that caused the man’s first infection is similar to that of Wuhan (dark blue), and the second variant (green) came to the United States from Europe.
According to a press release published last month, the man, who has a history of severe emphysema, tested positive for the virus on March 6.
Researchers believe he may have fallen ill from a nursing home employee who recently returned from a trip to the Philippines with a respiratory infection.
He was hospitalized after experiencing severe symptoms such as fever, chills, cough, chest pain and difficulty breathing. He even developed pneumonia.
Chest X-rays reveal larger than normal lungs as a result of trapped air and he receives extra oxygen and steroids.
The patient was hospitalized for nearly six weeks and was discharged after receiving two negative tests on day 39 and day 41.
In July, after moving to another nursing home, the patient reported being exposed to coughing residents.
He was sent to the emergency department on July 29 after coughing for two weeks and having difficulty breathing, where he received a positive test for the second time.
The researchers said his second illness was much less severe and he recovered after being treated with remdezivir and dexamethasone.
Genetic tests revealed that the two strains in March and July were different enough to show true reinfection, not relapse.
According to the team, genetic sequencing shows that the first infection was caused by a strain closely related to that of Wuhan, China, and the second infection was caused by a variant that arrived in the United States via Europe.
Corresponding author Dr. Jason Goldman, an infectious disease specialist at the Swedish Medical Center, told The Seattle Times that after publishing the findings, which have yet to be reviewed, the team is investigating more possible cases of reinfection.
“It’s not unexpected that this happens because we know that immunity is reduced in other respiratory infections, such as the flu,” Goldman said.
“But I was a little surprised to find him in my own hospital, and we still don’t know at what level of immunity you need to be protected,” he said.
Scientists believe he may have been re-infected because his immune system was compromised during the initial illness.
“There’s probably something in this patient’s immune system that’s not actually working well,” Goldman said.
There are two other known cases in the United States of patients who have been infected with coronavirus twice.
The first is a 25-year-old man from Nevada who fell in April with a mild illness and then was positive again in June with a more serious case.
The second is a 42-year-old male clinician working at a military hospital in Virginia, who tested positive in March and then again in May.
Recently, an 89-year-old Dutch woman became the first person in the world to die after being re-infected with the virus.