Washington state health officials say the number of hospitalised Covid-19 patients is doubling every 18 to 19 days in the state, reports AP.

Dr Umair Shah is the state secretary of health and said on Wednesday that the surge, driven by the Delta variant of the coronavirus, has stressed, stretched and strained hospital resources across the state.

One hospital official said hospitals throughout the state are facing their highest levels of occupancy ever, and the impact has been especially hard on regional and rural hospitals where there are no critical care beds left.

According to the state's Department of Health, 1,346 people were hospitalised with Covid-19 on Tuesday. There have been more than 488,000 confirmed coronavirus infections in Washington state during the pandemic, and 6,448 deaths related to Covid-19.