"There is a sense of chaos in the other hospitals and we do not know what to do. Staff are starting to leave and many are opting to retire or apply for holidays.
"The truth is that mortality is even higher than what is being reported by the authorities, at least in the hospital where I work.
"It is killing three to four patients daily, and it has been going on for more than three weeks."
Another doctor, who did not want to be named, claimed: "We are being advised not to put on the death certificate the real cause of death."
"The anti-viral drugs only started to be used in the last couple of days and they are not effective if the illness is already advanced, but they are definitely making the death toll drop dramatically."
In Mexico City, officials considered closing down the public transport system as masks were issued at underground stations and bus stops across the city.