Severe Group A Streptococcal Soft-Tissue Infections in Ontario: 1992–1996

Abstract

A prospective, population-based, surveillance study of invasive soft-tissue infections due to group A streptococci was conducted in Ontario, Canada, from 1992 through 1996. Demographic and clinical information was obtained by patient interview and chart review. Isolates were characterized by M protein and T agglutination typing. The incidence of necrotizing fasciitis (NF) increased from 0.08 cases per 100,000 population in 1992 to 0.49 cases per 100,000 population in 1995. The case-fatality rate was 13% (68 of 520 patients died). Hypotension and multiorgan dysfunction complicated 64 cases (12%), and NF complicated 119 cases (23%). Underlying diabetes, alcohol abuse, cancer, and cardiac and pulmonary disease increased the risk of disease. Prior use of nonsteroidal anti-inflammatory agents did not influence disease severity. All 197 patients without NF, underlying illness, and hypotension at presentation survived, as did 95 (99%) of 96 normotensive patients who were <65 years old but who had underlying chronic illness. Previously healthy patients without hypotension or NF may be considered for outpatient treatment.

Genome-wide molecular dissection of serotype M3 group A Streptococcus strains causing two epidemics of invasive infections

“…Between 1992 and 2002, populationbased surveillance identified 255 invasive infections caused by serotype M3 isolates (9)(10)(11)16). The frequency of occurrence of invasive episodes in the 2000 peak (i.e., years 1998-2002) was twice that of the 1995 peak (i.e., years 1993-1997) (Fig.…”

“…To gain new insight into the molecular genetic basis of subclone emergence and disease epidemics and to study the relationship between bacterial strain genotype and patient disease phenotype on a genome-wide level, we analyzed 255 serotype M3 invasive isolates collected in an 11-year population-based surveillance study conducted in Ontario, Canada (9)(10)(11)16). The results provided understanding of the molecular events underlying bacterial epidemics.…”

Evolutionary pathway to increased virulence and epidemic group A Streptococcus disease derived from 3,615 genome sequences

“…Group A Streptococcus (GAS, also known as Streptococcus pyogenes), a Gram-positive bacterial pathogen, causes human infections worldwide (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). For example, GAS is responsible for more than 600 million infections globally each year, including a conservative estimate of 10,000-15,000 severe invasive infections annually in the United States (4).…”

“…This organism has a longrecognized proclivity to cause epidemic waves, the reasons for which are largely unknown. After several decades of declining incidence, a striking resurgence of severe invasive infections caused by serotype Emm protein 1 (M1) GAS was reported in many countries in the late 1980s and early 1990s (1)(2)(3)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). The resurgence received widespread public interest in part because of the untimely death of Jim Henson, the Muppeteer, of invasive GAS, and because of severe infections occurring in other notable public figures in Canada and elsewhere (21).…”

Molecular genetic anatomy of inter- and intraserotype variation in the human bacterial pathogen group A Streptococcus

“…Serotype M3 strains cause a disproportionate number of invasive disease cases, including necrotizing fasciitis, bacteremia, and streptococcal toxic shock syndrome (5-9). Importantly, serotype M3 strains cause a higher rate of lethal infections than strains of other M types (7)(8)(9). In addition, serotype M3 and other GAS strains can undergo rapid shifts in disease frequency and display epidemic behavior (5).…”