Roughly one in every 70 Samoans has caught measles in a devastating outbreak that has killed dozens of children in the Pacific nation.

Samoa is appealing for donations and support to combat a horrific and spiralling measles outbreak gripping the Pacific nation.

At least 42 Samoans are dead and 3143 have contracted the preventable disease - about 1.6 cent of the entire country - in a major health crisis.

Radio NZ reports the capital Apia has an "eerie and quiet" feel amid widespread "concern and fear" of the disease's deadly reach.

The Samoan government has declared a state of emergency, closed schools and made immunisations compulsory as it hunkers down in a bid to stop the disease spreading.

According to the Samoa Observer, the police force has threatened to charge or arrest people who contravene emergency orders by taking children to public gatherings.

Mobile vaccination units, staffed with health workers and police, are travelling around the country to up vaccination rates - estimated to be just a third of the population; one of the lowest proportions in the the world.

The country's immunisation rates for measles have crashed in recent years according to the World Health Organisation, slumping from near herd immunity rates of 90 per cent in 2013 to the critical level today.

Anti-vaccination beliefs were emboldened last year when two children were killed in a bungled vaccination.

That case led to the jailing of two nurses for manslaughter, a further lack of trust in immunisation - and arguably, the crisis unfolding this month.

Each daily update brings fresh confirmation of suffering.

On Friday (AEDT), the government reported another 213 cases and three deaths - the fourth straight day of more than 200 new cases.

Most of the dead are young.

Eighteen of those to die had not reached their first birthday; a further 20 were aged between one and four years old.

In a country of just 200,000 people, 1601 children under five have caught measles, putting intolerable strain on the country's health system.

To understand just how hard Samoa has been hit, a similar rate in Australia would see 380,000 infections - or a city roughly the size of Canberra.

Both Australia and New Zealand have provided nurses and vaccinations to support their Pacific neighbour.

On Friday, Kiwi Foreign Minister Winston Peters a announced a fresh round of support, including 100,000 vaccines and an oxygen production machine to "help meet unprecedented demand".

"New Zealand will deploy up to 15 ICU specialists, as well as additional Samoan-speaking doctors and nurses, to work alongside medical staff from Samoa and other partners and provide relief," he said.

The situation is so traumatic, New Zealand is looking to send psychological support to health workers "who have been confronted with some distressing cases in very demanding conditions".

The Samoan government has also launched an online appeal for donations to a government bank account.

There are also current but lesser outbreaks in Fiji, the Philippines and Tonga.

As Samoa spirals, New Zealand's own outbreak - its worst since the 1990s - appears to be reaching a conclusion.

New Zealand has recorded 2113 cases of the disease this year, peaking in September when almost 200 cases were recorded each week.

Auckland was the hardest hit, with three-quarters of infections occurring in New Zealand's biggest city.