TORONTO -- As a measles epidemic spreads through Samoa and neighbouring countries, the World Health Organization is warning of a potential escalation due to holiday travel.

According to the latest data from the Samoan government, which was released Sunday, there have been more than 5,200 confirmed and suspected cases of measles in Samoa this year, including 1,648 hospitalizations and 72 deaths. There have also been 440 non-fatal cases of the virus logged in Tonga and 15 in Fiji, according to the WHO.

The WHO says there are a number of factors making this outbreak potentially more dangerous than others, including a lack of experience managing measles due to its longtime absence from the area and a high level of movement to and from the region.

"Many (pacific island countries] are popular tourist destinations and with the upcoming holidays, the number of travellers is expected to increase," the organization wrote Sunday in its latest update on the outbreak.

Population movement, whether it involves foreign workers or tourists, is considered to be one of the largest factors behind the spread of measles into areas where it has previously been eradicated.

According to the Samoa Tourism Authority – which has issued two press releases in the past month describing the country as "open for business" and safe for travellers – the country logged 13,544 tourists in October, down from 16,207 the previous month. Nearly 600 Canadians have visited the islands this year.

The country has also introduced a requirement that all visitors have up-to-date vaccinations when they arrive.

MASS IMMUNIZATIONS

Measles outbreaks have occurred this year in several parts of the Pacific region where the disease had previously been dormant for a long time, including New Zealand and Cambodia.

Samoa has been particularly hard-hit because of a lack of measles vaccination coverage. While Tonga and Fiji are both believed to have more than 90 per cent of their populations vaccinated against the disease, the WHO estimates that only 31 per cent of Samoans have received the first dose of the vaccine, and only 13 per cent made it on to the second dose.

The vast majority of the measles cases reported in Samoa have been in children under the age of five. The country embarked on a mass vaccination campaign of children and women up to 35 years old in late November, expanding it earlier this month to include all adults aged 60 or younger.

The campaign has apparently been successful. The government reported that as of Saturday, approximately 93 per cent of eligible Samoans had received vaccinations, bringing the country close to the 95-per-cent level required for herd immunity.

New cases continue to be diagnosed, however, with 54 more coming to light between Friday afternoon and Saturday afternoon.