Kisii County recorded the first Covid-19 case after a person who had travelled from Tanzania in May 14 tested positive for the virus.
Samples were taken on May 15 to KEMRI which gave the results on Wednesday morning.
Twenty-three of the locals who were in the containment area with the victim at the Kenya Medical Training College (KMTC) Kisii will be re-tested.
"We have since transferred him from quarantine centre to the isolation unit at the Kisii Teaching and Referral Hospital," says Kisii County Governor James Ongwae.
14 contacts of the said individual have also been put into quarantine at the KMTC Kisii.
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The individual had been working in some hotel in Morogoro, Tanzania.