The Japanese man who is in his seventies first tested positive on the Diamond Princess cruise ship. He first tested positive on February 14 and was kept aboard during his quarantine.
He then disembarked and was put in further quarantine at a medical facility in Tokyo.
The victim got the all-clear on March 2, according to Japanese news agency NHK.
The man returned home to the Kansai region via public transport but then started showing more symptoms of the virus again.
He reportedly began developing a fever of 39C (102F) on Thursday, March 12.
The cruise ship passenger went to hospital for a re-test and confirmed positive on March 14.
However, this is not the first case of an individual being reinfected.
At this current moment, it is not completely clear to experts how the virus behaves.
Hospital director in Beijing Li Qingyuan believes that certain individuals, including those who are have a weakened immune system, might be at a higher risk of contracting the virus again, according to USA today.
They also said that those infected with Mers-CoV are unlikely to be reinfected after they recover.
However, it is currently not yet known whether similar immune protection will be observed for patients with Covid-19, according to The Sun.
Officials are concerned that the UK Government’s policy of allowing large numbers to contract the illness with the hopes of creating alleged “herd immunity” is not a good decision as it is uncertain whether people will become permanently immune to COVID-19 like other illnesses.
Head of virology at the National Institute for Biological Standards and Control, Dr Nicola Rose, said: “With flu, for example, it comes and goes in waves.
“This may well be the case here. We really don’t know whether there will be herd immunity or not.”
People who are showing signs of infection in the UK should follow hygiene steps outlined by the NHS.
The advice includes keeping a distance away from people who are sick, limiting unnecessary travel, washing hands regularly with soap and water and disinfecting surfaces, tools, keyboards and phones.
Other advice includes people not touching their face or beard and covering their mouths when they cough and sneeze.