Two positive cases were detected in the Indian camp ahead their practice game in Durham while England had to field a back squad in the series against Pakistan after finding multiple positive cases.
Kusal Mendis, Niroshan Dickwella and Danushka Gunathilaka were filmed by fans roaming the streets after a lost match despite restrictions on movement of players owing to the COVID-19 threat.
The move comes after three England players and four members of the support staff tested positive for the virus after the last ODI against Sri Lanka in Bristol on Sunday.
"You go for training, you come back to the room, you go to the gym and you come back to the room. It becomes very difficult for the players," he said of the experience.
The IPL 2021 will commence on Friday with Mumbai Indians locking horns against Virat Kohli-led Royal Challengers Bangalore at the MA Chidambaram Stadium in Chennai.
He also feels that the decision to let spectators watch the England series in Chennai from the stands will have a positive bearing in the future.
Curran had spent two months in a biosecurity bubble in the United Arab Emirates -- which hosted this year's Indian Premier League -- before travelling for England's ongoing tour.