Loading Ahead of the Easter long weekend, Premier Gladys Berejiklian urged the public "not to leave your home unless you absolutely have to". A cluster of 12 coronavirus cases at Gosford Hospital was among 416 coronavirus transmissions that NSW health authorities have not been able to trace back to their source. The first case was detected on March 27. Within two weeks, two elderly patients, four family members and six nurses and doctors had tested positive for coronavirus. Several more staff were sent home to self-isolate as NSW Health authorities traced the contacts of the confirmed cases to identify anyone who may have come into contact with them while they were infectious.

The affected ward has since been designated a dedicated COVID-19 unit for low-risk patients. Both patients in the hospital cluster have been isolated in single patient rooms and were recovering well, chief executive of Central Coast Local Health District Dr Andrew Montague said. Dr Montague said the health district had taken several precautions to prevent the spread of the virus within its hospitals, including splitting emergency departments into general and high-risk "red" COVID sections to separate patients with respiratory symptoms, screening staff before each shift and restricting visitors to one person per patient per visit. Staff wearing face masks outside the Royal Prince Alfred Hospital (RPA) in Camperdown, Sydney. Credit:AAP Similar protocols have been introduced to all public hospitals, but the undetected community transmissions that have become the overriding concern for all state and territory governments are still finding ways inside.

A cluster of 23 COVID-19 cases in Tasmania's North West Regional Hospital – including 15 staff and five patients, and one discharged patient – accounts for more than one-fifth of the state's 107 confirmed coronavirus cases. Another 60 staff have been told to self-isolate. In Melbourne's The Alfred Hospital, a cluster of at least 15 cases – including five cancer patients (three of whom died) and 10 staff – knocked out more than 100 healthcare workers who had to self-isolate for 14 days. Loading Last week the Herald reported two radiation therapists at Westmead Hospital tested positive for coronavirus, prompting two cancer patients and roughly 20 radiation oncology staff to self-isolate. Ryde Hospital was the nucleus of Australia's first cluster, that spread between the north-west hospital, the Dorothy Henderson Lodge aged care facility, two high schools, defence personnel and had links to a case at Liverpool Hospital.

Up to 200 staff across Liverpool and Ryde hospitals were quarantined for 14 days as a result. The risk of clusters within hospitals is not unique to Australia. Major clusters in parts of the US and Europe have been traced back to hospitals. In March, Vietnam locked down one of its major hospitals after the country's biggest cluster of 16 people was linked to the facility. Healthcare workers have been identified as a high risk group for exposure to the virus.

On Wednesday night, NSW Health revealed 127 confirmed cases in the state were healthcare workers during a teleconference with Australian Medical Association NSW members, though not all had contracted the virus at work. But healthcare workers, patients and visitors in Sydney and Melbourne have said protocols designed to limit exposure in hospitals were not uniformly enforced. Loading Several clinicians in NSW, Queensland and Victoria have documented hand sanitiser that was zip-tied to dispensers being cut free and stolen. Signs indicating that patients are allowed only one designated visitor are ignored, with up to four family members gathering at the bedside of older patients.