Haemophilus influenzae invasive disease in Portugal, 2017-2018 - what have been changing after Hib vaccine implementation?

Bettencourt, Célia; Bajanca Lavado, Maria Paula; The Portuguese Group for the “Study of Haemophilus influenzae invasive infection”

Publication

Haemophilus influenzae invasive disease in Portugal, 2017-2018 - what have been changing after Hib vaccine implementation?

2019-05-28Conference object

dc.contributor.author	Bettencourt, Célia
dc.contributor.author	Bajanca Lavado, Maria Paula
dc.contributor.author	The Portuguese Group for the “Study of Haemophilus influenzae invasive infection”
dc.date.accessioned	2020-05-23T15:01:24Z
dc.date.available	2020-05-23T15:01:24Z
dc.date.issued	2019-05-28
dc.description.abstract	Introduction and Aims: Haemophilus influenzae is a frequent colonizer of the upper airways that can easily spread through respiratory tract leading to invasive infections in both children and adults. H. influenzae serotype b (Hib) has been prevented by vaccination, in Portugal, since 2000, but the emergence of non-typeable isolates (NTHi), as well as non-b serotypes responsible for invasive disease have been documented.1,2 We aim to characterize H. influenzae invasive isolates recovered in Portugal, during the last two years and compare results from previous studies. 1,2 Materials and Methods: As part of a laboratory-based surveillance system, 108 invasive H. influenzae were received at the National Reference Laboratory for Haemophilus influenzae for characterization. Capsular status was identified by PCR with primers and conditions described in the literature.3 Antibiotic susceptibility was determined by microdilution, according to EUCAST guidelines. 4 β-lactamase production was assessed with nitrocefin. Genetic relatedness among the isolates was examined by MLST as previously described.5 Sequences were analysed and submitted to the MLST website (https://pubmlst.org/hinfluenzae/) for assignment of the sequence type (ST). goeBURST analysis was performed using the PHYLOViZ platform.6 Results: Among 108 H. influenzae isolates, 90% were from blood, and 66% were from adults. Serotyping revealed that 74% were NTHi (80/108) and 26% (28/108) were capsulated isolates. Among capsulated isolates, 10.7% were Hia, 60.7% Hib, 10.7% Hie and 7.1% Hif. Most of the isolates were susceptible to the antibiotics studied, with the exception of 12.9% (14/108) ampicillin resistant by β-lactamase producing and 9.6% (9/94) that correlates with BLNAR phenotype (MIC≥1 to ampicillin and co-amoxiclave). MLST profiles revealed, as expected, high genetic variability (74.1%), with 23 different STs among 31 NTHi isolates tested. In opposition, encapsulated isolates were clonal with all Hia assigned to CC23, Hib assigned to CC6, (ST6 and ST1231), Hie to CC18, and Hif to CC124. Conclusion: After vaccine implementation and the great decline observed in Hib invasive disease (from 81% in 1989-2001 to 13% in 2002-2010),1,2 we are now concerned about Hib isolates (16%) that still in circulation in our country, affecting mostly children (88%), and accounting for 47% of vaccine failures. In addition, Hia increased, from 2% in the last period of five years (2012-2016) to 3% in this two years period (2017-2018), with all isolates from infants, up to two years old. It is important to continue the surveillance of H. influenzae invasive disease to monitor the true magnitude of these problems and develop public health prevention strategies.	pt_PT
dc.description.version	info:eu-repo/semantics/publishedVersion	pt_PT
dc.identifier.uri	http://hdl.handle.net/10400.18/6788
dc.language.iso	eng	pt_PT
dc.peerreviewed	yes	pt_PT
dc.rights.uri	http://creativecommons.org/licenses/by-nc/4.0/	pt_PT
dc.subject	H. influenzae	pt_PT
dc.subject	Serotype	pt_PT
dc.subject	Invasive Disease Epidemiology	pt_PT
dc.subject	Hib Vaccine	pt_PT
dc.subject	MLST	pt_PT
dc.subject	Infecções Respiratórias	pt_PT
dc.subject	Portugal
dc.subject	2017-2018
dc.title	Haemophilus influenzae invasive disease in Portugal, 2017-2018 - what have been changing after Hib vaccine implementation?	pt_PT
dc.type	conference object
dspace.entity.type	Publication
oaire.citation.conferencePlace	Lisboa, Portugal	pt_PT
oaire.citation.title	15th EMGM Congress of the EMGM, European Meningococcal and Haemophilus Disease Society, 27-30 May 2019	pt_PT
person.familyName	Bajanca Lavado
person.givenName	Maria Paula
person.identifier.ciencia-id	2B11-E245-3D39
person.identifier.orcid	0000-0002-1453-0315
person.identifier.scopus-author-id	6506614938
rcaap.rights	restrictedAccess	pt_PT
rcaap.type	conferenceObject	pt_PT
relation.isAuthorOfPublication	31093b71-e0a5-4796-8b01-12f4eccfc57a
relation.isAuthorOfPublication.latestForDiscovery	31093b71-e0a5-4796-8b01-12f4eccfc57a