A measles epidemic in Samoa has killed 20 people - mainly children - as hundreds of new cases emerge across the Pacific Islands every day.In Samoa - the worst affected nation - a state of emergency has been declared as the government said 19 out of the 20 people who have died from measles are aged four and under.The government said 202 cases were recorded in the 24 hours before Friday morning, including one death.Image:Children 19 and under are not allowed to attend public gatheringsUNICEF said over the past few days almost five new cases have been diagnosed every hour.A low vaccination rate has raised major concerns, as have parents turning to alternative healers in desperation.Since the outbreak started at the end of October, 1,644 cases have been reported in Samoa, which has a population of just under 200,000.Samoa has a low vaccination rate - estimated at 28-40% by UNICEF - with its vaccination programme briefly suspended last year when two babies died after being given an MMR jab which was actually expired anaesthetic.Tonga and Fiji, who have also experienced outbreaks but much less severe, have a vaccination rate of 99% and 81% respectively.In Samoa a compulsory vaccination programme has been ordered under the state of emergency.Schools and the country's only university are closed, and children up to the age of 19 are banned from public gatherings and medical facilities.Pregnant women are not allowed to go to work if they were not vaccinated before becoming pregnant, the order states.UNICEF is distributing more than 110,000 doses of measles vaccine to Samoa, while Australia and New Zealand have sent doctors and supplies.But as the virus spreads, some parents are turning to alternative therapies which are putting children at further risk.Image:UNICEF is providing emergency vaccinations for SamoansA local businessman is attracting customers with "kangen water" which he claims has healing properties - but is just filtered tap water.Fritz Alaiasa Neufelt is claiming the spray, which people are paying for, cannot cure measles but can alleviate the symptoms, he told ABC.As more people bring their children to him, gatherings - banned under the emergency order - are forming, meaning there is a high chance of measles spreading.Children under five are the most vulnerable to measles which is transmitted via droplets from the nose, mouth or throat.Initial symptoms usually appear 10-12 days after infection, and include a high fever, runny nose, bloodshot eyes and tiny white spots on the inside of the mouth, according to the World Health Organisation (WHO).Image:A mother mourns for her child who died from measlesSeveral days later, a rash develops, spreading from the face downwards.As well as death, measles can result in blindness, encephalitis (an infection that causes brain swelling), severe diarrhoea and severe respiratory infections such as pneumonia.In 2017, WHO declared the UK had eliminated measles; however, in August that status was removed after 991 cases were confirmed in 2018, compared with 284 in 2017.The increase was blamed on a decline in children receiving the second dose of the MMR vaccine.Social media has been partly blamed for the decline, with anti-vaxxers sharing incorrect information dating back to discredited research by now-struck off doctor Andrew Wakefield who falsely linked the MMR vaccine to autism in 1998.