The state also reported 23 new fatalities, raising the death toll to 827, it added.
Of the 23 deaths, six each are reported from Kolkata and North 24 Parganas district, followed by five from Howrah, two from Malda and one each from Hooghly, South 24 Parganas, Purba Medinipur and Jalpaiguri, it added.
The previous highest single-day spike was on Sunday when 895 cases were reported.
Kolkata reported 366 new infections on Wednesday, the maximum in a day so far. Districts recording high incidence of cases include North 24 Parganas (223), Howrah (106) and South 24 Parganas (103).
The number of active COVID-19 cases now stands at 7,705, the bulletin said, adding that 501 patients have recovered from the infection since Tuesday.
BJP MP Locket Chatterjee and National Institute of Cholera and Enteric Diseases (NICED) director Shanta Dutta were discharged from hospitals on Wednesday after they tested negative for the virus, health department sources said.
Meanwhile, West Bengal Chief Minister Mamata Banerjee attributed the surging coronavirus cases to the rise in the number of laboratories testing samples of suspected COVID-19 patients.
"There are over 50 testing laboratories now and 9,000 to 10,000 tests are being conducted every day. Ten per cent of them testing positive is quite normal. Since the number of testing, tracing and tracking are increasing, the number of infections is also rising.
"But there is nothing to be scared of. If you get yourself treated on time, there is nothing to worry about," she said.
During a meeting with doctors of several state-run hospitals, the chief minister urged them to pay equal attention to non-COVID-19 patients also.
Banerjee said junior doctors, who are worried about their career as COVID-19 has jeopardised the academic system, institutes, need not worry.
"They will face no problem in their academic career. It's the responsibility of the government," she said.
Meanwhile, the Tata Medical Centre in Kolkata has shut down all of its eight operation theatres and suspended all surgeries for two days from Thursday for sanitization after around 20 doctors, nurses and other support staff associated with surgery unit tested positive for Covid19, an official said. SCH NN TIR TIR