A temporary vaccination service has been set up for a school community in Adelaide's southern suburbs after four students tested positive for measles.
SA Health issued a measles outbreak alert yesterday after three teenagers contracted the infectious disease.
The health authority said those cases were linked to a positive infection in another teenager reported on September 14, who had returned from overseas.
"My team and I are very concerned about this outbreak … we don't normally see such amount of spread," the state's chief public health officer Nicola Spurrier said.
"It is one of the most infectious communicable diseases that we know about and in an unvaccinated population, one case on average spreads to 14 other people.
"We're not sure if there are other cases brewing in the school."
SA Health and the Holdfast Bay Council have established a temporary vaccination clinic for the Brighton Secondary School community, which will operate at the Brighton Masonic Hall on 1 Commercial Road at Brighton from 2pm-6pm on Friday.
South Australia now has eight cases this year, the highest since 2016.
SA Health said the teenagers were in multiple locations while infectious, including a school and a shopping centre.
Exposure sites
Kilburn: Costco on Thursday, September 17 from 1:30pm–3:15pm and Costco Petrol Station from 2:45pm–3:35pm.
Hyde Park: El Mexicano Restaurant on Thursday, September 17 from 6:30pm–9:00pm and St Louis cafe from 8:30pm–9:30pm.
Oaklands Park: Kmart Westfield Marion on Friday, September 18 from 1:30pm–6:00pm and Monday, September 21 from 3:15pm-7:00pm.
Morphett Vale Stadium on Saturday, September 19 from 2:40pm–5:00pm
North Brighton: Brighton Secondary School on Friday 18 September from 9:00am–3:00pm.
Exposure sites from the September 14 case
Singapore Airlines Flight SQ431 from Maldives to Singapore on Monday, September 7 at 1:10pm.
Singapore Airlines Flight SQ279 from Singapore to Adelaide on Monday, September 7 at 11:20pm.
Adelaide Airport on Tuesday, September 8 from 7:20am–9:30am.
North Brighton: Brighton Secondary School on Wednesday, September 9 from 8:45am–3:45pm and Thursday, September 10 from 3:15pm–4:30pm.
Adelaide Metro Bus 265 travelling from Adelaide CBD to Marion Centre Stop 29 to terminus on Thursday, September 10 from 4:30pm–5:00pm.
Measles takes seven to 18 days to incubate and two weeks for a rash to appear.
The virus spreads by respiratory aerosols — such as through coughing and sneezing, or through touching surfaces — which remain a risk to others for up to 30 minutes after the person has left the area.
Professor Spurrier said there may still be other cases, and reminded people who may have been at an exposure site to consider whether they have been previously vaccinated.
Two doses of a measles-containing vaccine are considered effective at preventing illness.
Additional boost may be needed
Professor Spurrier said measles had been increasing in countries that had previously eradicated the disease, including the US, UK and Canada.
She also warned some people may require an additional dose to boost their immunity against the disease.
"[People born] from 1966 onwards may have only had one dose up until being born in the late 1980s," she said.
"If you're not sure, it is not harmful at all to have another dose."
The disease presents with a fever, cough, runny nose and sore eyes initially and usually progresses to a rash.
Serious complications that may require hospitalisation include pneumonia, ear infection and brain inflammation. Extreme cases can cause death.
SA Health advises people who suspect they have measles to phone their doctor before any visit.
The school's principal Rhoni McFarlane said she was appreciative of a temporary vaccination service for the school community.
"It's always concerning when the health and welfare of our community is at stake so our message is to follow health instructions and get immunised if you have not yet been," she said.
