Increase in invasive group A streptococcal infections and emergence of novel, rapidly expanding sub-lineage of the virulent Streptococcus pyogenes M1 clone, Denmark, 2023

Funding Information: We would like to thank Karina Kaae, Lanni Fugl Niebuhr Nielsen and Joan Nevermann Jensen for their laboratory expertise, and acknowledge the great effort by clinicians and laboratory technicians at hospitals across Denmark and at Landspítali, Reykjavik, in securing samples and data essential for WGS-based surveillance efforts, as well as the dedicated technical staff maintaining and developing the registries and epidemiological databases at the core of national surveillance in Denmark. Publisher Copyright: © 2023 European Centre for Disease Prevention and Control (ECDC). All rights reserved.A highly virulent sub-lineage of the Streptococcus pyogenes M1 clone has been rapidly expanding throughout Denmark since late 2022 and now accounts for 30% of the new invasive group A streptococcal infections. We aimed to investigate whether a shift in variant composition can account for the high incidence rates observed over winter 2022/23, or if these are better explained by the impact of COVID-19-related restrictions on population immunity and carriage of group A Streptococcus. An increase in incidence rates of invasive (iGAS) and non-invasive (nGAS) group A Streptococcus infection has been reported by several countries across Europe during the 2022/23 winter season [1-3]. Through analysis of all whole genome sequencing (WGS) data acquired for national surveillance of iGAS in Denmark since 2018, we aimed to investigate current genomic developments and the impact of emerging lineages on iGAS incidence rates in 2023. In Denmark, iGAS is not notifiable except in case of meningitis, however, test results from all 10 Departments of Clinical Microbiology (DCMs) are submitted to the Danish Microbiology Database (MiBa) [4] and can be used to monitor incidence rates. Iceland also experienced a higher iGAS incidence in early 2023, and we also present Icelandic WGS data on iGAS isolates from 2022 and 2023.Peer reviewe

Global Landscape Review of Serotype-Specific Invasive Pneumococcal Disease Surveillance among Countries Using PCV10/13: The Pneumococcal Serotype Replacement and Distribution Estimation (PSERENADE) Project.

Serotype-specific surveillance for invasive pneumococcal disease (IPD) is essential for assessing the impact of 10- and 13-valent pneumococcal conjugate vaccines (PCV10/13). The Pneumococcal Serotype Replacement and Distribution Estimation (PSERENADE) project aimed to evaluate the global evidence to estimate the impact of PCV10/13 by age, product, schedule, and syndrome. Here we systematically characterize and summarize the global landscape of routine serotype-specific IPD surveillance in PCV10/13-using countries and describe the subset that are included in PSERENADE. Of 138 countries using PCV10/13 as of 2018, we identified 109 with IPD surveillance systems, 76 of which met PSERENADE data collection eligibility criteria. PSERENADE received data from most (n = 63, 82.9%), yielding 240,639 post-PCV10/13 introduction IPD cases. Pediatric and adult surveillance was represented from all geographic regions but was limited from lower income and high-burden countries. In PSERENADE, 18 sites evaluated PCV10, 42 PCV13, and 17 both; 17 sites used a 3 + 0 schedule, 38 used 2 + 1, 13 used 3 + 1, and 9 used mixed schedules. With such a sizeable and generally representative dataset, PSERENADE will be able to conduct robust analyses to estimate PCV impact and inform policy at national and global levels regarding adult immunization, schedule, and product choice, including for higher valency PCVs on the horizon

The silent pandemic – antimicrobial resistance

Non peer reviewe

Epidemiology of penicillin resistant pneumococci

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenPenicillin resistant and multiresistant pneumococci have become common all over the world. Pneumococci resistant to cefotaxime and ceftriaxone have only become established in the USA, Spain and South Africa, although recently such strains have been described in the UK. Resistance to cefotaxime and ceftriaxone may spread faster than penicillin resistance. With B-lactam resistant and multiresistant pneumococci, the choice of antimicrobials is reduced to a single class of antimicrobials, the glycopeptides. Penicillin resistant pneumococci were introduced in Iceland in 1988, and had gained 20% incidence in pneumococcal infections in 1993. This rapid spread was associated with serogroups 6, 19 and 23, of which serotype 6B (multiresistant) was by far the most prevalent. During this period the incidence of penicillin resistant pneumococci remained low in the other Nordic countries. Since the practice of medicine is very similar in these countries, it was important to search for epidemiological clues that would explain the difference. The following risk factors have been shown to be important in epidemiological studies conducted in Iceland: most Icelandic children attend day-care centres, where they have numerous contacts with children with respiratory tract infections during the long winter months. Antimicrobial usage was high in children attending day care centres. The popularity of the sulpha-trimethoprim combination in Iceland may also be important, as it was shown to be an independent risk factor. Total use of antimicrobial agents declined in Iceland in the years 1991-1993 following a propaganda campaign against misuse and legislative changes that increased the cost of the antimicrobials for patients. The antimicrobial use in day-care centres was significantly reduced from 1992 to 1995. In 1994 the incidence of penicillin resistant pneumococci decreased to 17% (from 20% in 1993). Hopefully reduction in antimicrobial use will continue and contribute to further lowering of resistance levels.Penicillin ónæmir og fjölónæmir pneumókokkar hafa náð að breiðast út um allan heim, og hafa náð mikilli útbreiðslu á sumum stöðum. Cefótaxím og ceftríaxón ónæmi hjá pneumókokkum hefur til þessa aðeins náð fótfestu í Bandaríkjunum, Spáni og Suður Afríku, en nýlega var þannig stofnum þó lýst í Bretlandi. Hætta er á því að það kunni að breiðast hraðar út en penicillin ónæmið. Þegar pneumókokkar eru bæði fjölónæmir og ónæmir fyrir öllum (3-laktamlyfjunum er aðeins einn lyfjaflokkur eftir með góða verkun, glýkópeptíð (vankómýcín). Penicillin ónæmir pneumókokkar komu fyrst fram á Íslandi í desember 1988, og höfðu þeir náð 20% nýgengi í pneumókokkasýkingum árið 1993. Þessi hraða útbreiðsla tengdist aðeins þremur hjúpgerðum, 6, 19 og 23, en af þeim var hjúpgerð 6B (fjölónæm) langalgengust. Á sama tíma hélst nýgengi penicillin ónæmra pneumókokka lágt á hinum Norðurlöndunum. Þar sem lækningar eru iðkaðar nánast á sama hátt á Norðurlöndunum, skipti miklu máli að kanna hvaða þættir ættu mestan þátt í þessari hröðu útbreiðslu á Íslandi. Innlendar rannsóknir hafa sýnt að ákveðnir áhættuþættir vega þungt, en þeir helstu eru: a) Dagvistun á leikskólum, þar sem börnin dvelja lengi innan dyra í stórum barnahópi með háa tíðni öndunarfærasýkinga. b) Mikil sýklalyfjanotkun er í yngstu aldurshópunum, þar á meðal á leikskólum. c) Miklar vinsældir trímetóprímsúlfa lyfjablöndunnar, en hún virtist vera sjálfstæður áhættuþáttur. Heildar sýklalyfjanotkun Íslendinga minnkaði á árunum 1991-1993 eftir áróður gegn ofnotkun sýklalyfja og breytingar á reglugerð um kostnaðarhlutdeild sjúklinga í sýklalyfjum. Sýklalyfjanotkun minnkaði marktækt á leikskólum frá 1992 til 1995. Nýgengi penicillin ónæmra pneumókokka lækkaði niður í 17% árið 1994 (úr 20% árið 1993). Vonandi mun sýklalyfjanotkunin minnka enn frekar og stuðla að minna ónæmi í framtíðinni

Epidemiology of penicillin resistant pneumococci

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenPenicillin resistant and multiresistant pneumococci have become common all over the world. Pneumococci resistant to cefotaxime and ceftriaxone have only become established in the USA, Spain and South Africa, although recently such strains have been described in the UK. Resistance to cefotaxime and ceftriaxone may spread faster than penicillin resistance. With B-lactam resistant and multiresistant pneumococci, the choice of antimicrobials is reduced to a single class of antimicrobials, the glycopeptides. Penicillin resistant pneumococci were introduced in Iceland in 1988, and had gained 20% incidence in pneumococcal infections in 1993. This rapid spread was associated with serogroups 6, 19 and 23, of which serotype 6B (multiresistant) was by far the most prevalent. During this period the incidence of penicillin resistant pneumococci remained low in the other Nordic countries. Since the practice of medicine is very similar in these countries, it was important to search for epidemiological clues that would explain the difference. The following risk factors have been shown to be important in epidemiological studies conducted in Iceland: most Icelandic children attend day-care centres, where they have numerous contacts with children with respiratory tract infections during the long winter months. Antimicrobial usage was high in children attending day care centres. The popularity of the sulpha-trimethoprim combination in Iceland may also be important, as it was shown to be an independent risk factor. Total use of antimicrobial agents declined in Iceland in the years 1991-1993 following a propaganda campaign against misuse and legislative changes that increased the cost of the antimicrobials for patients. The antimicrobial use in day-care centres was significantly reduced from 1992 to 1995. In 1994 the incidence of penicillin resistant pneumococci decreased to 17% (from 20% in 1993). Hopefully reduction in antimicrobial use will continue and contribute to further lowering of resistance levels.Penicillin ónæmir og fjölónæmir pneumókokkar hafa náð að breiðast út um allan heim, og hafa náð mikilli útbreiðslu á sumum stöðum. Cefótaxím og ceftríaxón ónæmi hjá pneumókokkum hefur til þessa aðeins náð fótfestu í Bandaríkjunum, Spáni og Suður Afríku, en nýlega var þannig stofnum þó lýst í Bretlandi. Hætta er á því að það kunni að breiðast hraðar út en penicillin ónæmið. Þegar pneumókokkar eru bæði fjölónæmir og ónæmir fyrir öllum (3-laktamlyfjunum er aðeins einn lyfjaflokkur eftir með góða verkun, glýkópeptíð (vankómýcín). Penicillin ónæmir pneumókokkar komu fyrst fram á Íslandi í desember 1988, og höfðu þeir náð 20% nýgengi í pneumókokkasýkingum árið 1993. Þessi hraða útbreiðsla tengdist aðeins þremur hjúpgerðum, 6, 19 og 23, en af þeim var hjúpgerð 6B (fjölónæm) langalgengust. Á sama tíma hélst nýgengi penicillin ónæmra pneumókokka lágt á hinum Norðurlöndunum. Þar sem lækningar eru iðkaðar nánast á sama hátt á Norðurlöndunum, skipti miklu máli að kanna hvaða þættir ættu mestan þátt í þessari hröðu útbreiðslu á Íslandi. Innlendar rannsóknir hafa sýnt að ákveðnir áhættuþættir vega þungt, en þeir helstu eru: a) Dagvistun á leikskólum, þar sem börnin dvelja lengi innan dyra í stórum barnahópi með háa tíðni öndunarfærasýkinga. b) Mikil sýklalyfjanotkun er í yngstu aldurshópunum, þar á meðal á leikskólum. c) Miklar vinsældir trímetóprímsúlfa lyfjablöndunnar, en hún virtist vera sjálfstæður áhættuþáttur. Heildar sýklalyfjanotkun Íslendinga minnkaði á árunum 1991-1993 eftir áróður gegn ofnotkun sýklalyfja og breytingar á reglugerð um kostnaðarhlutdeild sjúklinga í sýklalyfjum. Sýklalyfjanotkun minnkaði marktækt á leikskólum frá 1992 til 1995. Nýgengi penicillin ónæmra pneumókokka lækkaði niður í 17% árið 1994 (úr 20% árið 1993). Vonandi mun sýklalyfjanotkunin minnka enn frekar og stuðla að minna ónæmi í framtíðinni

Prevalence of genital chlamydia trachomatis infections in college students

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenSexually transmitted Chlamydia infection is the most common venereal disease in Iceland. Although considerable information is available on the epidemiology of these infections, the true prevalence of C. trachomatis infections in Iceland is unknown because all the studies have been conducted on selected populations. The purpose of the present study was twofold: To investigate the prevalence of Chlamydia infection in an unselected group of people in the age group at high risk, and to investigate the usefulness of collecting urine samples from college students as a screening method for Chlamydia. All students, aged 18-21, in the senior classes in a college in Reykjavik were requested to submit a first void urine (FVU) specimen taken in the morning and asked to fill out a short questionnaire. The urine samples were tested with a polymerase chain reaction assay, the Amplicor® PCR. One hundred eighty three students received urine collection kits. One hundred sixty (87.4%) delivered specimens. Seventy three males and 110 females received the containers. Sixty males (82%) and 100 (91%) females returned the samples. Three samples turned out to be positive (2%), all of them from females. For those who were sexually active (one or more partners for the last six months) the prevalence was 2.6% (117/160). In conclusion: The prevalence of asymptomatic Chlamydia infection in college students in this school was low, probably too low for screening to be cost effective. The procedure was not satisfactory because of the low percentage that enquired about their tests. It is therefore unsuitable in a screening program

Human listeriosis diagnosed in Iceland 1978-1994

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenListeriosis has been recognised in Iceland, as a distinct disease entity in sheep called silage disease (votheysveiki), since 1910. The use of silage was introduced in Iceland in the latter part of the 19th century. Because of the climatic conditions it came into widespread use and the connection between silage and listeriosis was first demonstrated in Iceland by Pálsson et al. The first case of human listeriosis was diagnosed in 1961. The diease was not diagnosed again untill 1978 when four cases were identified. In the period between 1978 and 1994 L. monocytogenes was isolated from 36 patients, 11 males and 25 females. During this period the population of Iceland grew from 224.384 to 264.919. If mother and child are counted as one the incidence is approximately 8.3 per million per year. There were nine cases of neonatal infections, nine cases involving pregnant women, 13 cases of immunosuppressed patients and five patients were previously healthy. There were four miscarriages. The patients received conventional treatment of ampicillin and aminoglycoside or in one case chloramphenicol. All neonates but two survived. One older patient with meningitis died and 3 severely immunocompromised patients died. All of the strains were of the most common serotypes, 4b, l/2a and l/2b. The different serotypes were not evenly distributed during the study period. During the years 1978-1984 only one of 13 isolates was serotype l/2a and the rest was 4b. On the other hand all but three strains isolated since 1985 were either 172a or l/2b. During the first part of the study period the majority of cases involved neonates or pregnant women but during the second part most of the patients were old or immunocompromised. Nothing is known about the source of the infection in any of the patients except in one neonate which was considered to be nosocomially infected.Listeriosis er þekktur sjúkdómur í sauðfé á Íslandi frá því snemma á þessari öld. Fyrstu sýkingu í mönnum hér á landi var lýst 1961, en frá árinu 1978 hafa mörg tilfelli greinst. Markmið þessarar rannsóknar var að meta tíðni sjúkdómsins á Íslandi og kanna afdrif sjúklinganna. Á þeim 17 árum sem rannsóknin náði til, var Listeria monocytogenes einangruð frá 36 einstaklingum, sem teljast 34 tilfelli ef nýfætt barn og móðir eru talin sem eitt. Samkvæmt því telst nýgengi tæplega 8,3 á hverja milljón íbúa á ári. Karlar voru 11 en konur 25. Níu sýkingar voru í nýburum (sex fyrirburar), níu á meðgöngu og 11 í ónæmisbældum sjúklingum. Fimm sjúklinganna höfðu áður verið hraustir. Árangur meðferðar þeirra, sem ekki höfðu alvarlega ónæmisbælingu, var góður, dánartíðni var lág og aðeins tveir nýburanna dóu. Þrír sjúklingar með ónæmisbælingu og einn aldraður sjúklingur með heilahimnubólgu af völdum L. monocytogenes létust. Allir L. monocytogenes stofnar nema einn, sem ræktuðust á Íslandi á árunum 1978-1993, voru stofngreindir í Sviss. Þeir voru af þeim þremur stofngerðum sem eru algengastar: 4b, l/2a og l/2b. Ekki er enn vitað hvaða stofngerðir greindust 1994. Athyglisvert er hve mikil breyting varð á stofngerðum á tímabilinu sem rannsóknin náði til. Á árunum 1985-1993 voru aðeins þrír stofnar af 15 af stofngerð 4b en hinir ýmist l/2a eða l/2b. Á fyrri hluta tímabilsins eða fram til ársins 1985 var aðeins einn af 13 stofnum af stofngerð l/2a en allir hinir 4b. Astæður þessara breytinga eru óþekktar. Tíðni sjúkdómsins á Íslandi var há á því tímabili sem rannsóknin náði til. Brýnt er aö kanna faraldsfræði sjúkdómsins og útbreiðslu sýkilsins nánar hér á landi

Prevalence of genital chlamydia trachomatis infections in college students

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenSexually transmitted Chlamydia infection is the most common venereal disease in Iceland. Although considerable information is available on the epidemiology of these infections, the true prevalence of C. trachomatis infections in Iceland is unknown because all the studies have been conducted on selected populations. The purpose of the present study was twofold: To investigate the prevalence of Chlamydia infection in an unselected group of people in the age group at high risk, and to investigate the usefulness of collecting urine samples from college students as a screening method for Chlamydia. All students, aged 18-21, in the senior classes in a college in Reykjavik were requested to submit a first void urine (FVU) specimen taken in the morning and asked to fill out a short questionnaire. The urine samples were tested with a polymerase chain reaction assay, the Amplicor® PCR. One hundred eighty three students received urine collection kits. One hundred sixty (87.4%) delivered specimens. Seventy three males and 110 females received the containers. Sixty males (82%) and 100 (91%) females returned the samples. Three samples turned out to be positive (2%), all of them from females. For those who were sexually active (one or more partners for the last six months) the prevalence was 2.6% (117/160). In conclusion: The prevalence of asymptomatic Chlamydia infection in college students in this school was low, probably too low for screening to be cost effective. The procedure was not satisfactory because of the low percentage that enquired about their tests. It is therefore unsuitable in a screening program

Human listeriosis diagnosed in Iceland 1978-1994

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenListeriosis has been recognised in Iceland, as a distinct disease entity in sheep called silage disease (votheysveiki), since 1910. The use of silage was introduced in Iceland in the latter part of the 19th century. Because of the climatic conditions it came into widespread use and the connection between silage and listeriosis was first demonstrated in Iceland by Pálsson et al. The first case of human listeriosis was diagnosed in 1961. The diease was not diagnosed again untill 1978 when four cases were identified. In the period between 1978 and 1994 L. monocytogenes was isolated from 36 patients, 11 males and 25 females. During this period the population of Iceland grew from 224.384 to 264.919. If mother and child are counted as one the incidence is approximately 8.3 per million per year. There were nine cases of neonatal infections, nine cases involving pregnant women, 13 cases of immunosuppressed patients and five patients were previously healthy. There were four miscarriages. The patients received conventional treatment of ampicillin and aminoglycoside or in one case chloramphenicol. All neonates but two survived. One older patient with meningitis died and 3 severely immunocompromised patients died. All of the strains were of the most common serotypes, 4b, l/2a and l/2b. The different serotypes were not evenly distributed during the study period. During the years 1978-1984 only one of 13 isolates was serotype l/2a and the rest was 4b. On the other hand all but three strains isolated since 1985 were either 172a or l/2b. During the first part of the study period the majority of cases involved neonates or pregnant women but during the second part most of the patients were old or immunocompromised. Nothing is known about the source of the infection in any of the patients except in one neonate which was considered to be nosocomially infected.Listeriosis er þekktur sjúkdómur í sauðfé á Íslandi frá því snemma á þessari öld. Fyrstu sýkingu í mönnum hér á landi var lýst 1961, en frá árinu 1978 hafa mörg tilfelli greinst. Markmið þessarar rannsóknar var að meta tíðni sjúkdómsins á Íslandi og kanna afdrif sjúklinganna. Á þeim 17 árum sem rannsóknin náði til, var Listeria monocytogenes einangruð frá 36 einstaklingum, sem teljast 34 tilfelli ef nýfætt barn og móðir eru talin sem eitt. Samkvæmt því telst nýgengi tæplega 8,3 á hverja milljón íbúa á ári. Karlar voru 11 en konur 25. Níu sýkingar voru í nýburum (sex fyrirburar), níu á meðgöngu og 11 í ónæmisbældum sjúklingum. Fimm sjúklinganna höfðu áður verið hraustir. Árangur meðferðar þeirra, sem ekki höfðu alvarlega ónæmisbælingu, var góður, dánartíðni var lág og aðeins tveir nýburanna dóu. Þrír sjúklingar með ónæmisbælingu og einn aldraður sjúklingur með heilahimnubólgu af völdum L. monocytogenes létust. Allir L. monocytogenes stofnar nema einn, sem ræktuðust á Íslandi á árunum 1978-1993, voru stofngreindir í Sviss. Þeir voru af þeim þremur stofngerðum sem eru algengastar: 4b, l/2a og l/2b. Ekki er enn vitað hvaða stofngerðir greindust 1994. Athyglisvert er hve mikil breyting varð á stofngerðum á tímabilinu sem rannsóknin náði til. Á árunum 1985-1993 voru aðeins þrír stofnar af 15 af stofngerð 4b en hinir ýmist l/2a eða l/2b. Á fyrri hluta tímabilsins eða fram til ársins 1985 var aðeins einn af 13 stofnum af stofngerð l/2a en allir hinir 4b. Astæður þessara breytinga eru óþekktar. Tíðni sjúkdómsins á Íslandi var há á því tímabili sem rannsóknin náði til. Brýnt er aö kanna faraldsfræði sjúkdómsins og útbreiðslu sýkilsins nánar hér á landi

Diagnostic efforts for the detection of chlamydia trachomatis infections in Iceland 1982-1994

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenThe results of diagnostic testing for the detection of Chlamydial infections in Iceland during the years 1982 to 1994 were reviewed. During those 13 years 123,461 laboratory tests were performed in 101,574 examinations. These examinations were positive in 14,462 instances. The first diagnostic test to be introduced was cell culture in 1982. From then on the number of examinations and the number of positive examinations increased steadily until 1988, when positive examinations reached a peak at approximately 570 cases per 100,000 inhabitants. In 1990 a sharp decline in both the total number of examinations and positive results was observed. The percentage of positive examinations declined during the study period. In 1991 and 1992 the number of examinations, the number of positive examinations and the percentage of positive examinations increased but the number of positive tests declined again in 1993. In 1994 the polymerase chain reaction assay (PCR) replaced the much less sensitive Chlamydiazyme® assay and the number of positive examinations rose again although the number of tests declined. The dramatic reduction in prevalence experienced in Sweden does not seem to have taken place in Iceland. In Sweden a substantial effort was made to screen asymptomatic populations. In Iceland the screening of asymptomatic patients increased from the beginning of the study period until 1988 but declined thereafter. Screening of asymptomatic populations as well as contact tracing may be important for bringing about a significant reduction of the prevalence of sexually transmitted infections caused by Chlamydia trachomatis