1.Resurgence of measles virus infection in an eliminated country, Sri Lanka
Merennage Anusha Yasanthi Fernando ; Gankandage Prabhath Chathuranga ; Kaanthaka Gunaradha Abeygunasekara
Asian Pacific Journal of Tropical Medicine 2024;17(5):208-213
Objective: To describe the situation of measles in Sri Lanka from
May to November, 2023 and to define the role of virology laboratory
towards case confirmation and epidemiological and genetic
characterization of the outbreak.
Methods: This retrospective study analyzed all samples tested for
measles from 1st of May to 30th of November, 2023 at National
Measles Rubella Laboratory, Sri Lanka. According to the World
Health Organization (WHO) algorithm, serum and oropharyngeal/
nasopharyngeal swabs were tested with WHO recommended kits
for anti-measles IgM and measles virus specific RNA, respectively.
Selected RNA positive samples were sequenced at reference
laboratory, India. Analysis of sequencing data and construction of
phylogenetic tree were carried out at National Measles Rubella
Laboratory. Data was analyzed using descriptive statistics.
Results: Of the total 1 132 serum samples and 497 oropharyngeal/
nasopharyngeal swabs from 1 326 patients, 657 (49.5%) patients
were confirmed as measles by anti-measles IgM, measles virus
specific RNA or both. Males (55.6%, n=365) and the age group from
>20 to ≤30 years (33.0%, n=217) predominated positive patients. All
provinces reported measles positive cases. All samples sequenced
(100%, n=42) were genotype D8 with 95.2% (n=40) bearing
Victoria.Australia origin.
Conclusions: We described resurgence of measles in an eliminated
country, confirming the genotype to be D8, one of the two genotypes
currently circulating globally. Further, the study strongly convinced
the importance of a strengthened virological surveillance system in
an eliminated country, despite its eliminated status.