Long queues formed at various hospitals as doctors, nurses and medical assistants registered for the industrial action, aimed primarily at forcing the border shutdown, the South China Morning Post (SCMP) said in a report.
"Closing the border entirely is the only effective way to prevent the spread of the virus," University of Hong Kong microbiologist Ho Pak-leung told a radio programme.
Ho said that closing the border would not be discriminatory or go against the World Health Organization's 2005 International Health Regulations, a legal instrument which includes specific measures for ports, airports and ground crossings to limit the spread of diseases.
He added that anyone entering the city from the mainland carried the same risk of infection, whether they are a Chinese citizen, a Hong Kong resident or a foreign national.
More than 3,000 non-essential hospital workers were expected to take part in the strike's first wave on Monday, a day after Chief Executive Carrie Lam refused to meet the Hospital Authority Employees Alliance, an 18,000-strong union which emerged last December during the anti-government protests, said the SCMP report.
The alliance has threatened to step up its action, with more than 6,000 essential personnel joining the strike on Tuesday if the government refuses to respond by 6 p.m. on Monday.
China's death toll from the new coronavirus increased to 361 on Monday, surpassing the number of fatalities of its SARS crisis two decades ago.
In Hong Kong, where there were 15 confirmed cases, the government had closed six of its 15 border checkpoints, and refused entry to travellers coming from Wuhan.
But it had resisted calls that the closure should cover everyone coming from China and be extended to all border checkpoints.
( With inputs from IANS )