A NSW Health team has developed a blood test for coronavirus they believe could help slow down the community spread of the deadly pandemic.

The NSW Health Pathology team based at Sydney's Westmead Hospital developed the serology test, or blood test, for COVID-19 which can identify the presence of antibodies produced to fight the virus.

This means the test should be able to detect whether someone has been infected with the virus , even if they have recovered.

Two people wearing face masks walk out of the emergency entrance at Westmead Hospital, in Sydney's west. (Kate Geraghty / Sydney Morning Herald)

"While this is not a test used for the diagnosis of individual cases, serology testing will help public health experts investigate how the virus is spreading in the community, so they can gain better insight into the full scope of the outbreak," NSW Health Pathology's Director of Public Health Pathology, Professor Dominic Dwyer said.

"Knowing the true number of COVID-19 cases and the extent of the virus' spread is crucial to slowing this pandemic and making informed public health decisions.

"Thanks to this breakthrough, we are much better placed to answer questions we could not have answered before through the current diagnostic testing."

A researcher works on the virus at their lab in Westmead Hospital. (NSW Health)

A passenger on board the Ruby Princess cruise ship died today from coronavirus.

The 70-year-old woman became the state's seventh person to die from coronavirus.

There have been eight virus related deaths in Australia.

The total number of confirmed cases in NSW of the virus is 818, with 13 people seriously ill in hospital ICU.

Every act of social distancing can have a dramatic impact on the spread of coronavirus. (Australian Government)

How is coronavirus transmitted?

The human coronavirus is only spread from someone infected with COVID-19 to another.

This occurs through close contact with an infected person through contaminated droplets spread by coughing or sneezing, or by contact with contaminated hands or surfaces.

What are the symptoms of someone infected with coronavirus?

Coronavirus patients may experience flu like symptoms such as a fever, cough, runny nose, or shortness of breath.

In more severe cases, infection can cause pneumonia with severe acute respiratory distress.

What is the difference between COVID-19 and the flu?

The symptoms of COVID-19 and the flu are very similar, as they both can cause fever and respiratory issues.

Both infections are also transmitted the same way, via coughing or sneezing, or by contact with hands, surfaces or objects contaminated with the virus.

The speed of transmission and the severity of the infection are the key differences between COVID-19 and the flu.