The number of confirmed Japanese encephalitis cases in South Australia has grown to eight.

The Department of Health and Wellbeing says that includes one person who died earlier this month.

Of the remaining seven, five are still in hospital and two have been discharged.

A further two people in hospital remain under investigation.

“It is crucial that we all continue to take extra precautions against mosquitoes,” Executive Director of Health Protection Chris Lease said.

“People planning activities around the River Murray are warned to be especially vigilant, particularly between dusk and dawn when mosquitoes are most active.”

Most people who are infected with flaviviruses such as Japanese encephalitis virus, Kokobera virus, West Nile virus, and Murray Valley encephalitis virus are asymptomatic or develop a mild febrile illness.

A small proportion of infected people will develop encephalitis, which may be fatal or cause long-term neurological damage.

Symptoms include confusion, headaches, neck stiffness, tremors, drowsiness and seizures.

“It is important that people remain vigilant in protecting themselves against mosquito bites, particularly during periods of warmer weather when mosquito activity is high,” Dr Lease said.

Meanwhile, a man in his 50s has become the eighth NSW resident diagnosed with Japanese encephalitis, as NSW Health announces it will move on to a daily reporting system.

The latest case is a man from the Temora area in the NSW Riverina region, who was treated in hospital before being discharged.

He is continuing to recover in the community, NSW Health said in a statement on Friday.

A woman in her 40s from the Berrigan area in the Riverina region was the seventh person to be diagnosed with the virus on Wednesday.

She was treated in hospital before being discharged and is recovering at home.

The way cases of JE are announced will change from Friday onwards as the situation in the state evolves.

NSW Health will finalise new cases and locations at 4pm daily and report them the following day on the NSW Health website, similar to the way COVID-19 cases are published.

Japanese encephalitis is caused by mosquito bites and cannot be spread from human to human.

Despite cases being recorded in animals and pigs, the disease cannot be caught by eating pork or pork products.

There are no specific treatments for JE, which can cause severe neurological illness with headache, convulsions and reduced consciousness in some cases.

The best thing people can do to protect themselves and their families against JE is to take steps to avoid mosquito bites.