The MMR vaccine, which is used to immunise children against measles, mumps and rubella. Photo: Tom Lee / Stuff
American Samoa has confirmed its second case of measles in a four year old boy and now has 49 probable cases.
The boy from Tafuna goes to the same school as the eight-year-old girl who was the first confirmed case announced on April 18 in the US territory - three weeks after she was seen at a community centre with symptoms on March 27.
All 49 probable cases to date are in children aged from two months to 13-years old.
Department of Health epidemiologist Scott Anesi said the latest confirmed case would "definitely" be labelled as community transmission.
"The signs and symptoms of the probable cases [are] matching, the new case is linked to the original case as well," Anesi said.
"We know for sure that there is a linkage of transmission locally."
Anesi said the territory is forecasting "sporadic clusters" in highly populated areas and in people who are unvaccinated.
"Not specific surges, as long as we continue to keep up our vaccinations."
Anesi said the Department of Health would more accurately be able to model the outbreak when test results sent to Hawaii earlier this week returned.
Samoa still measles free
Meanwhile in Samoa, the director general of health, Aiono Dr Alec Ekeroma said there are no probable cases in the country but it was "only a matter of time".
"Measles will arrive in Samoa, it's a very infectious disease and now it's just across the border 80 miles away," Aiono said.
"I'm hoping really that it will be delayed by a few more weeks to get our vaccination rates even higher than what it is now."
Aiono said closing the border between Samoa and American Samoa was "too harsh", but travellers from American Samoa would require proof of their measles, mumps and rubella (MMR) vaccination to enter the country, and would also be subject to screening tests.
Aiono hoped there would be enough time to boost the vaccination rate - currently 90 per cent for the first dose and 60 per cent for the second - before the disease gets in.
"I'm hoping really that it will be another two [or] three weeks before it comes and gives us more time to get the vaccination rate up to 80 per cent for the MMR two."
In line with American Samoa, the first MMR one dose in Samoa has been lowered from one-year to six months.
This handout picture released from UNICEF Samoa shows nurse April Wilson (L) and team leader Luisa Popo preparing vaccinations during a nationwide campaign against measles in the Samoan town of Le'auva'a. Photo: AFP PHOTO / ALLAN STEPHEN / UNICEF
In 2019, the country experienced a devastating measles epidemic that originated from Auckland, resulting in 83 deaths.
Aiono said the situation would be better than 2019 because of the now higher vaccination rate, which was about 25 percent when the outbreak occurred.
Samoa has extended its school holidays by a week to try and reduce the risk of measles spreading.
Public health emergency to remain in place
American Samoa is in a state of emergency, and will remain in place until at least May 24 when the declaration expires.
It allows the Department of Health and American Samoa Government to use all necessary powers to contain the risk of the disease spreading.
The state of emergency means all schools are closed in the territory, including early childhood education, day-care centres and the community college.
Anesi said someone from the Department of Health was still looking into the origins of the measles cases but it was no longer a priority.
"At this point in time the shift is really focused on identifying as many cases in the community as we can find," he said.
"Basically ramping up our testing, identifying cases that are symptomatic and getting them tested."