Imported Measles Outbreak at Al-Buraimi Governorate, Oman, April 2020.

Measles is a childhood condition transmitted through airborne droplets. The World Health Organization (WHO) classifies measles as a deadly disease among children that is preventable through vaccination.

On April 16, 2020, the communicable disease department of Al-Buraimi Governorate, Oman, received a notification of three cases of highly suspected measles. On laboratory confirmation of measles on April 19, 2020, a further field investigation was conducted. It is well known that Oman has experienced very few cases of measles since 1995; however, Al Buraimi Governorate has experienced imported measles cases in recent years. We conducted this study to investigate the epidemiology of imported measles cases at Al Buraimi, Oman, in April 2020.

This case series retrospectively investigated the reported measles cases. The epidemiological investigation began by meeting the families of the affected children. Obtained data included clinical symptoms, exposure information, travel history, immunization, and history of contact with others.

The initial measles cases were reported on April 16, 2020, when Al-Buraimi's Government Communicable Disease Department received reports of 3 children positively confirmed with measles. These children were from Afghanistan and had been exposed to three other siblings with similar symptoms (fever, cough, and rash). Later, on April 23, 2020, two Pakistani children had a fever and cough-like symptoms, which brought the total number of positive measles cases to 8. The positively tested cases reached five from a sample of seventeen 17 children. All the diseased children were either partially vaccinated or were unvaccinated. Figure 1 shows the sequence of infection among the imported cases of measles at AlBuraimi, Oman.

Figure 1: Sequence of infection among imported measles cases, AlBuraimi Governorate, Oman, 2020.

Among the positive cases, 75% were girls, 6 were Afghani nationals, and two were Pakistani. Most of the infected children were between 10-19 years old (75%). Virus isolation and genotyping identified all the cases as Measles B3 genotype and traced the virus back to Pakistan as the country of origin. However, most cases were reported between Afghani nationals (75%) due to their low vaccination status. The cases were given MMR vaccine along with their contacts who did not have vaccination records or were unvaccinated.

Editorial notes: Measles is a very contagious disease that can claim the lives of young people. A single person with the virus can infect up to 18 people in one setting. Measles is regarded as one of the most infectious diseases despite being preventable through vaccination. ¹

Before the government placed strict containment measures, measles took the lives of many children and infants in Oman. The government initiated vaccination efforts together with the superior surveillance system to ensure that measles cases dropped. By 2012, the measles cases reported was one case for every one million individuals.^{2, 3}  The occurrence of Measles outbreaks in Oman has fallen over the years, with only 7 cases reported in the year 2011. In 2013, there were no rubella and or measles cases reported across Oman. ³ However, in spite of the country's aggressiveness towards eliminating the virus, new cases emerge every year as a result of imported cases among children of expatriates. ^2, 3

This report sought to investigate the reported imported measles cases and transmission modes. It was found that the children who tested positive for measles were either previously unvaccinated or had unknown vaccination status, pointing to the importance of vaccination towards measles prevention. The study confirmed that the greatest challenge of measles elimination in Oman is non-Omanis expatriates and unvaccinated children. It should therefore be a priority to vaccinate all expatriates' children since some of these young ones are either unvaccinated or with incomplete dosage. When everyone is vaccinated in Oman, be it nationals or foreigners, only then can the goal of having a measles-free country be realized.

References

1. Moghadam, M., Afsarkazerooni, P., Ebrahimi, M., Soltani, M., Razmpoor, A., Pirasteh, E., & Mirah-Madizadeh, A. (2014). Measles outbreak in South of Iran, where vaccine coverage was high: a case-series study. Iranian journal of public health, 43(3), 375–380.
2. Ministry of Health. (2020, August 1). Health launches national strategic directions and introduction of new vaccines - Media center display page - Ministry of health. Retrieved from https://www.moh.gov.om/en/-/--1190
3. Al Awaidy, S. (2016, October 9). Progress Towards Measles, Rubella and Congenital Rubella Syndrome Elimination: Oman Experience. Retrieved from https://www.qscience.com/content/journals/10.5339/jemtac.2016.icepq.62