Abstract
Background
In Uruguay varicella is mandatory notification disease since 1963. Universal vaccination starts in 1999 (OKA strain 1 dose) when incidence was 105/100.000 inhab; in 2014 2nd dose was added (5 years) to prevent outbreaks. Objective: describe epidemiology and variations of the cases notified in Uruguay between 1.1.2008 and 12.31.2021 according vaccine strain.
Methods
Observational, descriptive, retrospective study. All cases reported to the Department of Health Surveillance (DEVISA)-Epidemiology Division-Ministry of Health in period: 1.1.08 to 12.31.21. Data source: DEVISA and Honorary Commission-Fight Against TB-Prevalent Diseases. Variables: notified cases, average annual incidence, age, sex, outbreaks. Vaccine: doses, OKA or MAV/06 strain Statistical analysis: frequency distribution, summary measures and statistical significance tests (significant: p value ≤ 0.05) 4 periods according vaccine strain in nation immunization program were defined: 2008 and 2009 (Oka), 2010 to 2012 (Oka and MAV06); 2013 to 2018 (MAV) and 2019 to 2021 (OKA)
Results
Accumulated cases: 13,896 (annual average: 992). Women: 6639 (48%) Vaccine coverage was around 95-97%. Incidence: 32.2/100,000/inhabitants (95%CI:30-34) in 2008-2009, the rate decrease in 2010-2012 to 21.5 (19-13), in 2013-2018 increased 35,78 (35-36), in this period in 2013, 1968 cases was reported. Rate in 2019-2021: 12 (11-12) [2019: 24, 2020: 7 and 2021: 4,6], with 2 doses of vaccine. There wasn’t a significant difference in annual average cases (AANC) 2008-2013 (AANC: 1025) vs 2014-2018 (AANC: 1293) p=0,345. The AANC in 2019-2021 were 424. [rate in 2019: 24, in 2020: 7 and 2021: 4,6]. There was a significant increase in the annual average of outbreaks 30/2012-2013 vs. 90/2014-2018. In 2019:81, 2020:10 and 2021:7 outbreaks. Between 2008-2018 most cases were reported in the group 10 to 14 years of age (median 187.5m); 2019-2021, 678/1,272 cases were older than 12
Conclusion
Incidence dropped from 105 in 1999 to 24 in 2019. There was a displacement to older ages. The 2nd dose didn’t change incidence and outbreaks frequency. The incidence decreased in 2019-2021. Surely the great decrease in the incidence and outbreaks in 2020 and 2021 was influenced by COVID-19 pandemic. Since 2010 to 2018, the most widely used vaccine contained MAV/06
Disclosures
Marcos Delfino, Pediatrician, pediatric infectologist, Adjunct Professor of pediatric clinic, Pfizer: Finnancial support to travel to IDWeek 2023 Ignacio Olivera, Medical Doctor, Master in Health Economics and Pharmaceutical Economics, Pfizer: Grant/Research Support|Roche: Expert Testimony|Sanofis Pasteur: Grant/Research Support María Catalina Pírez, Pediatrician, Pediatric infectologist, microbiologist Professor of pediatric, Degree V, Merck, Pfizer: Expert Testimony|Merck, Pfizer: Honoraria