Measles virus genotypes circulating in Latvia 2011 2018

Measles virus genotypes circulating in Latvia, 2011 -2018 Paper ID 23127 Oksana Savicka 1, 3, Tatjana Kolupajeva 1, Anastasia Aniscenko 1, Diana Dusacka 1 , Reinis Zeltmatis 1, Maira Petrova 1, Edite Bleidele 1, Natalija Repuscenko 1, Sanita Kuzmane 1, Larisa Firstova 1, Natalija Zamjatina 1, Jelena Storozenko 1 Jurijs Perevoscikovs 2 1 Riga East Clinical University Hospital, Infectology Centre of Latvia (ICL), National Microbiology Reference Laboratory (NRL) 2 Centre for Disease Prevention and Control of Latvia 3 RSU Infectology and Dermatology department Objectives To characterise Measles viruses (MV) circulated in Latvia in 2011 -2018. Materials and methods Conclusions Molecular studies showed introduction and circulation of 3 different Measles genotypes in Latvia in period 2011 -2018: D 4 (n=4) in 2011 and 2012, B 3 (n = 22) in 2014 and the end of 2017 / first half of 2018, and D 8 (n=5) in the second half of 2018. Laboratory confirmation of Measles cases was done by positive Measles Ig. M ELISA in sera and/or positive rt. RT-PCR in throat swab, urine, saliva or blood plasma. PCR positive samples were used for MV isolation in Vero -Slam culture. MV RNA positive samples and virus isolates (n = 54) were subjected to Sanger sequence analysis of 450 nucleotides comprising the most variable C‐terminal region of the nucleoprotein (N) gene. Results In period 2011 -2018 in Latvia were registered 63 Measles cases. One imported Measles case was confirmed in 2011 and 3, 36 and 23 laboratory confirmed cases were registered in outbreaks occurred in 2012, 2014 and 2017/2018 (by 1 st November) respectively. During this period 47 clinical samples and MV isolates from 31 persons were successfully genotyped in NRL. In 2011 and 2012 outbreaks D 4 genotype was detected. Two samples with D 4 genotypes of 2012 outbreak were confirmed by WHO Regional reference laboratory (RRL) in Robert Koch Institute, Germany, as D 4 Manchester. In 2014 and in the beginning of 2017/2018 outbreaks circulation of B 3 genotype was observed. Eight out of nine specimens of 2014 outbreak were confirmed in RRL as B 3 Harare but one sample of 2017/2018 outbreak as B 3 Dublin. Circulation of genotype B 3 Dublin in Latvia was observed from the end of 2017 till the August of 2018 (13 out of 18 successfully genotyped samples). Later D 8 genotype was introduced and detected in 5/18 samples. Figure 1. Phylogenetic tree of Measles viruses from Latvian outbreaks 2012, 2014, 2018. Genotyping was performed by Sanger sequencing (N gene 456 nt). The tree was constructed in Mega 5. 2. 2 software. 2018 Measles outbreaks in Latvia – in red Contacts and informations Oksana. Savicka@rsu. lv +371 67014217 Linezera 3, Rīga, LV-1006