title: Beta-haemolytic group A, C and G streptococcal infections in Western Norway: a 15-year retrospective survey.
abstract: Pyogenic streptococci cause significant morbidity and mortality, and the incidence of invasive group C and G streptococcal disease appears to be increasing. In this retrospective study we describe the epidemiological characteristics of invasive group A, C and G, along with non-invasive group C and G streptococcal infections in Western Norway from 1999 to 2013. A total of 512 invasive streptococcal infections were identified, of these 297 (58%) were group A (GAS), 24 (5%) group C (GCS) and 188 (37%) group G streptococci (GGS). In the non-invasive group, 4935 GCS and GGS-infections were identified. GCS and GGS were treated as one group (GCGS) for statistical purposes. All microbial categories displayed increasing incidence with age, seasonal variation and a male predominance. The incidence of invasive GCGS infections increased significantly from 1.4/100,000 inhabitants in 1999 to 6.3/100,000 in 2013 (p <0.001). Conversely, the annual rates of invasive GAS infection exhibited marked fluctuations, ranging from 2.7/100,000 (2000) to 8.3/100,000 (1999), but no significant temporal trends were observed. The incidence of non-invasive GCGS infections decreased significantly during the study period (p <0.001). The most frequently encountered emm-types among the 209 iGAS-isolates analysed were emm1 (24%), emm3 (14%) and emm28 (14%); whereas stG643 (19%), stG485 (15%) and stG6 (13%) were most prevalent among the 122 iGCGS-isolates available for typing. The increasing burden of invasive β-haemolytic streptococcal disease in our community calls for sustained attentiveness to the clinical and molecular aspects of GAS, GCS and GGS infections.
authors: Department of Medicine, Haukeland University Hospital, Bergen, Norway. Electronic address: Oddvar.Oppegaard@helse-bergen.no.
authors: O
authors: O
authors: Oppegaard
authors: Department of Microbiology, Haukeland University Hospital, Bergen, Norway.
authors: H
authors: H
authors: Mylvaganam
authors: Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Medicine, Haraldsplass Deaconess Hospital, Bergen, Norway.
authors: B R
authors: BR
authors: Kittang
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009664:Norway / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013291:Streptococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein
keywords: Epidemiology; Norway; Streptococcus dysgalactiae subspecies equisimilis; Streptococcus pyogenes; group A streptococci; group C streptococci; group G streptococci