Three wards at Mater Dei were closed and disinfected over the past week as the hospital fought a spike in COVID-19 cases, sources have confirmed.
However, there is concern that healthcare workers who are not based in these wards – the medical admissions unit 1, surgical 5 and ear, nose and throat (ENT) – but visit them to attend to patients there, might also be infected.
The biggest outbreak was at ENT, where at least 10 people, including healthcare workers, were infected, the sources said.
Healthcare workers are among select groups of people being routinely tested for COVID-19 in order to identify patients that may not be showing any symptoms.
A Health Ministry spokesperson had not replied to questions about the hospital wards at the time of writing.
287 healthcare workers in quarantine
On Monday, Superintendent of Public Health Charmaine Gauci revealed that 287 healthcare workers are currently in quarantine and described this as a "substantial number".
A source said this number was nearly double that of the initial weeks of the outbreak in Malta.
In March there were some 150 healthcare workers quarantined at any one point in time, and most of them were in self-isolation as they had returned from abroad.
Earlier on Monday the Medical Association of Malta warned that the high number of cases last week for four consecutive days occurred two weeks after the first easing of measures by the government.
Last Monday MAM, like Mater Dei management, urged its members not to let their guard down as most of Malta was doing and wear personal protective equipment and keep up their cleaning protocol recommended by infection control authorities.