Temporal Association of the Appearance of Mucoid Strains ofStreptococcus PyogenesWith a Continuing High Incidence of Rheumatic Fever in Utah

Abstract

ABSTRACT. Objective. Our objective was to confirm an observed temporal association of increased numbers of rheumatic fever cases concomitant with the appearance of an increased prevalence of mucoid strains of Streptococcus pyogenes. During the resurgence of rheumatic fever (RF) that has occurred in the Intermountain area surrounding Salt Lake City, Utah, since 1985, the largest number of cases occurred in 1985 and 1986 and 12 years later in 1997 and 1998. During the initial outbreak and the later exacerbation of the resurgence, an increased number of mucoid strains of S pyogenes were present in the community.Methods. The referred cases of RF that fulfilled Jones criteria have been systematically reviewed by the medical staff at Primary Children's Medical Center yearly since 1985. Before the resurgence of RF, a program was initiated by the microbiology laboratory at Primary Children's Medical Center to store frozen isolates of S pyogenes. All frozen specimens were randomly selected and entered into a log; the coded entry allowed for comments regarding the origin of the isolate and whether the isolate had a mucoid appearance on the blood agar culture plate. This log was reviewed in October 2002 to determine whether the percentage of frozen mucoid isolates stored during the resurgence of RF would support the clinical and epidemiologic suspicion that mucoid isolates seemed to be present with a higher frequency during the 2 periods of high incidence of RF. The percentage of mucoid isolates was compared with the yearly number of cases of RF. A Pearson r correlation analysis was completed to determine whether there was a significant association between the percentage of mucoid isolates and the number of cases of RF.Results. The highest number of cases of RF was temporally associated with the highest percentage of mucoid isolates. There was statistically significant correlation between percentage of mucoid strains and the number of RF cases.Conclusions. The Utah experience with the resurgence of RF in a civilian population during the last decade and a half of the 20th century confirmed the temporal association of mucoid strains of S pyogenes, primarily M-type 18, with a high incidence of RF. (PCMC) in Salt Lake City, Utah, like the rest of the United States, witnessed a striking decline in the number of cases of rheumatic fever (RF) compared with the numbers encountered during the mid 1950s and early 1960s. In 1985, a sudden and unanticipated resurgence of RF occurred when 61 cases were referred to the staff at PCMC. 1 An additional 41 cases were evaluated in 1986. This initial 2-year experience represented a 10-fold increase in the number of cases seen per year during the previous decade (average 5 cases per year).After our initial report of this resurgence, isolated outbreaks of RF were reported from 3 children's hospitals 2-4 ; 2 military installations 5,6 ; and communities in Texas, 7 West Virginia, 8,9 Tennessee, 10,11 New York, 12 and Alabama. 13 Although probably an increase did occur during the late 1980s and...

Identification of a Streptococcal Octapeptide Motif Involved in Acute Rheumatic Fever

“…GAS strains of serotype M18 were temporally associated with repeated outbreaks of ARF in Utah (34). Such strains were highly encapsulated by HA that, because of its ability to bind collagen (15), could also be a rheumatogenic factor.…”

Evolution of Transcription Regulatory Genes Is Linked to Niche Specialization in the Bacterial Pathogen Streptococcus pyogenes

“…However, 8 of the 12 possible genotypes are observed among this set of 114 strains. Rare genotypes can be associated with highly prevalent clones, such as the pattern A-C/mga-1/ nra and pattern A-C/mga-2/nra combinations found in the emm3-ST15/ST16 and emm18-ST62 clones, respectively (see Table S1 in the supplemental material) (41,56,64). Highly prevalent clones having a rare genotype may owe their success to compensatory mutations.…”

Sequence Type and emm Type Diversity in Streptococcus pyogenes Isolates Causing Invasive Disease in Norway between 1988 and 2003

“…Different M-protein types are epidemiologically associated with particular syndromes; e.g., M-protein type 1 (M-1) and M-3 are associated with higher frequencies of severe invasive disease and increased rates of case fatality (21,23,27). Introduction of penicillin virtually eliminated GAS in developed countries until the 1980s.…”