Missed opportunities for measles vaccination among departing travelers from Japan to India

Extract

Large-scale sporadic measles outbreaks have recently occurred in countries that have previously eliminated endemic measles.¹ In Japan, for example, a measles outbreak in 2017 was started by a Japanese man in his 20s who had returned from Indonesia, and led to 60 reported cases in five cities.² Most measles cases are related to overseas travel. Overseas travelers should, therefore, be vigilant about their measles vaccination status and ensure that if necessary, they are vaccinated against the disease before traveling.¹ This study aimed to find the proportion of Japanese backpackers traveling in India who were eligible for a measles-containing vaccine before traveling, and the number who actually received one.

We targeted Japanese backpackers who were at least 18 years old staying at a guesthouse in Paharganj, New Delhi, India. We conducted two cross-sectional surveys from September 8 to 30 2018 (first survey) and from December 27 2018 to January 14 2019 (second survey) and collected data using a self-administered questionnaire. The questionnaire contained questions on sex, age, travel duration, presence of chronic illness, history of measles vaccination and illness, and pre-travel vaccinations. A total of 222 Japanese backpackers participated in the surveys (107 in the first and 115 in the second, giving a 64.9% participation rate overall). Of these 222 participants, 75.7% were male, 48.6% were 18 to 25 years old, 37.9% planned to travel for 2 weeks or more, 21.2% had a chronic illness (one with a hematologic disease), and 96.0% had overseas travel experience. Before traveling, just 73 participants (32.9%) checked their routine childhood vaccinations using their own records. In total, 84 participants (37.8%) were expected to have a pre-existing immunity to measles and 49 (22.1%) had been vaccinated against at least one disease before traveling. Although 138 (62.2%) were eligible for a measles-containing vaccine because they had no or unknown measles vaccination status and/or no or unknown history of measles illness (Figure 1), none had received a measles-containing vaccine before traveling. Of these 138 participants, 10 had received other vaccines.