Measles outbreak investigation in Al-Jowf – Saudi Arabia: An analytical cross-sectional study for cases reported from (January 1st to March 18th) 2019

Abstract

Background: Measles vaccine made the global efforts for measles elimination possible. Even with the vaccine coverage of 98%, an outbreak of measles was detected in Al-Jowf region in the north of Saudi Arabia between January 1st and March 18th 2019. This investigation is to describe the characteristics and epidemiology of the outbreak. And to identify the risk factors. Methods and materials: Using the surveillance data, an analytical cross-sectional study done on cases reported to the regional infection control unit from (01/01/2019) to (18/03/2019). Cases were investigated using the Saudi MOH measles standard protocols based on the WHO definitions including patients demographic and Vaccination information, the clinical criteria for measles during the prodromal period followed by the maculopapular rash and the laboratory case confirmation by measles IgM antibody detection. Epi-info7 and excel-360 were used for statistical analysis. Results: A total of 780 cases. The average age 7 years (±11 m). Geographically, 97% of the cases were from five cities are Tubarjal (89% of cases), Sakaka, Dumah Al Jandal, Maiqoa, And Al-Qurayyat. All cases were presented with rash and fever only. 64.8% of serum results came positive for measles IgM. 41% of cases under age of 5 were not due the age of vaccination (9 months). Unvaccinated cases 32% OR = 0.96 and p-value = 0.83. Cases received the mono measles vaccine before 40% OR = 1.03 and p-value = 0.87. Cases received MMR vaccine 1 dose only 11% OR = 1.63 and p-value = 0.10. Cases received MMR vaccine 2 doses 23% OR = 0.49 and p-value = 0.027. None of the cases had contact with measles patients or history of traveling. All the cases were recovered with no complications. Conclusion: The goal of this investigation is to describe the characteristics and epidemiology of the measles outbreak in Al-Jowf region (Janaury–18 March) 2019 and to identify the contributing factors. This study emphasized that vaccination is protective (OR = 0.49) specially after the second MMR dose, and the incidence is more among the unvaccinated individuals. But it may cause mild symptoms similar to the wildtype infection. The mean age was (7 years ± 11 m) this requires more investigation regarding the exposure among school-aged children. Further study needed regarding perception and attitude regarding vaccination.