The leader of the Volta a Portugal Santander, Daniel Freitas (Radio Popular Boavista), was forced to withdraw from the event before Wednesday's stage 6 due to a suspected COVID-19 case within the team.
Caja Rural-Seguros RGA and Euskaltel-Euskadi departed the race due to pairs of COVID-19 positives on Tuesday. Now, Radio Popular Boavista is the third outfit to pull out, with organisers insisting they "continue to comply with all health safety standards".
The Atum General-Tavira-Maria Nova Hotel team, who had two positives with roommates Emanuel Duarte and David Livramento dropping out before stage 5, now lead the race with Alejandro Marque, who holds a five-second advantage over Amaro Antunes (W52-FC Porto).
Rally Cycling's Ben King won stage 6 with a solo attack on the 182.4km stage from Viana do Castelo to Fafe.
The Volta a Portugal organisers announced they had detected 15 virus cases associated with the event, but said "they are all asymptomatic or with mild symptoms".
It is so far the largest cluster of COVID-19 positives associated with a professional bike race since 45 motorcycle police officers tested positive for the coronavirus after the 2020 Vuelta a España.
"The 82nd Tour of Portugal Santander is being an event of great sporting success, of great joy and vitality," the race organisation said in a press release. "In the last 12 hours, more than 375 tests were carried out in the caravan, including all teams and staff and all people already vaccinated. Only one case was identified.
"In the coming days, we will continue to follow all procedures and recommendations, we will continue to promote best practices and take all necessary decisions carefully."
The highly-infections Delta variant of the SARS-CoV-2 virus is currently causing 98 per cent of COVID-19 cases in Portugal. Health officials blamed the European Champions League tournament, which visited Porto in late May, for the variant's spread.
Vaccinations are highly effective in preventing severe disease, and approximately 70 per cent of Portuguese residents have received at least one dose. However, even vaccinated individuals can become infected with the virus and potentially spread it.
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