Mumps Resurgence in Gipuzkoa (Basque Country, Spain)
Total Page:16
File Type:pdf, Size:1020Kb
P2433 Abstract (poster session) Mumps resurgence in Gipuzkoa (Basque country, Spain). Major outbreaks in 2007 and 2012 M.S. Zapico*, J. Artieda, L. Piñeiro, M. Montes, L. Arriola, G. Cilla, E. Pérez-Trallero (San Sebastian, ES) Objectives: The measles, mumps, rubella (MMR) vaccine was included in the vaccination schedule of the Basque Country in 1982. The mumps vaccine mainly contained the Jeryl-Linn strain. The coverage for cohorts born in 1986-2005 was 94% (first dose) and 90,7% (second dose). As a result, the large mumps epidemics occurring every 3-5 years in the prevaccine era disappeared after 1990 (annual incidence 233 cases/100000 inhabitants in the 80s vs 2.3/100000 during 1996-2006). Nonetheless, since 2007 major mumps outbreaks had occurred. In this study those outbreaks are described as well as the genetic analysis of involved mumps virus (MuV) strains. Methods: Mumps is an individually notifiable disease in our region, including confirmed (virollogically or epidemiologically linked to a confirmed case) or suspected cases. MuV RNA was amplified from oral fluid (saliva), pharyngeal swabs or cerebrospinal fluid (CSF) samples by RT-PCR against SH gene (Wu et al, Vaccine 1998;16:281). Genotyping was performed by sequencing of the SH gene (ABIPRISM 3100, Applied Biosystems) and the results compared with mumps reference strains in BLAST web. Detection of IgM was performed by ELISA (Enzygnostâ Anti-Parotitis virus IgM, Siemens, Germany). In major mumps outbreak years, detection of MuV RNA was investigated in CSF of patients with aseptic meningitis. Results: Two major mumps outbreaks occurred in 2007 (1074 cases) and 2012 (1013 cases until September), with an incidence of 159 and 150 cases/100000 population respectively (male/female ratio 1.60). In 2007 and 2012, 726 and 783 cases were virologically confirmed respectively. Most of the cases (76%) had received two doses of MMR vaccine. The average age of vaccinated cases was similar in the two outbreaks (16 years old), and lower than that found in non-vaccinated cases (35 years old in 2007 and 40 years old in 2012). MuV RNA was detected in 4 patients with aseptic meningitis in 2007 and 2012, 0,2% (4/2087) of the notified cases. MuVs circulating between 2007 and 2012 belonged to subgenotype G5, showing a nucleotide sequence similarity >99% in the SH gene. Conclusion: After a long period (1993-2006) in which mumps epidemic waves were suppressed in Gipuzkoa, mumps have re-emerged causing major outbreaks affecting mostly vaccinated teenagers and young adults. Meningitis, usually considered as a frequent complication of mumps, was rare. Waning of vaccine induced immunity has possibly contributed to the origin of these outbreaks..