(Reuters) - The cyclist Fernando Gaviria is one of only a handful of COVID-19 patients worldwide to have had the disease twice after his UAE Emirates team doctor confirmed on Wednesday that his test result during the Giro d'Italia was not a false positive.
Colombian Gaviria was withdrawn from the Giro on Tuesday after testing positive for the second time after a first infection in February.
"In Fernando's case he is asymptomatic the second time around. This is not a false positive as he has undergone confirmation testing and this confirms his repeat infection," Jeroen Swart told Reuters.
Gaviria spent four weeks in a hospital after showing COVID-19 symptoms at the UAE Tour last winter.
Swart said Gaviria was one of very few people worldwide who have been infected twice with the novel coronavirus.
Other isolated cases of reinfection have been reported around the world, including in Asia, Europe and the United States.
Swart reiterated concerns raised by other scientists about what the reinfection cases show about immunity.
"The antibody response to the virus has been shown to be transient and these antibodies start to wane after 3 to 4 months," he said, adding that at 6 months they are "mostly undetectable" in many people who were infected early on in the epidemic,"
He said that in his view, it was now "clear... that the risk of re-infection is real."
(Reporting by Iain Axon, Julien Pretot; additional reporting by Kate Kelland in London; Editing by Christian Radnedge)