Streptococcus pyogenes bacteraemia: a 27-year study in a London teaching hospital.
ABSTRACT The clinical and epidemiological features of 120 episodes of Streptococcus pyogenes bacteraemia in St. Thomas' Hospital between 1970 and 1997 were analysed. One-third of episodes were nosocomial. M1 was the most common serotype, and 29% of strains were non-typable. There was a variety of presenting features, but nearly half of the patients had cellulitis, 15% were shocked, and 6% had necrotic infections. There was no focus of infection in 13%. 54% of patients had an underlying disease, and 23% of infections were associated with a medical procedure or device. The mortality rate was 19%, and was associated with shock, coma, no focus of infection, and underlying disease. Since 1989, the annual incidence has more than doubled, and M1 strains and necrotic infections have increased, but the mortality rate and the proportion of patients presenting with shock have decreased, and the increase in cases involved many different M-types.
- SourceAvailable from: unirioja.esRevista Española de Quimioterapia, ISSN 0214-3429, Vol. 19, Nº. 4, 2006, pags. 367-375. 01/2006;
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ABSTRACT: To evaluate the efficacy of on-line hemoperfusion for the removal of circulating superantigens in a rat model of streptococcal shock. In vitro and experimental animal studies. University research laboratories. Chemically modified polystyrene-based composite fiber reinforced with polypropylene was formulated in discs and used to evaluate the removal of superantigenic toxins from culture supernatants in vitro, and from blood in vivo. Incubation of streptococcal supernatant with a single disc reduced the concentration of the superantigen streptococcal pyrogenic exotoxin A from 90.9 +/- 12.7 ng/mL with the control fiber to 32.5 +/- 3.6 ng/mL with active fiber (p <.001). The active discs also brought about a dose-dependent reduction in mitogenic activity that was highly significant (counts reduced from 82,133 +/- 2747 using three control discs to 26,307 +/- 3547 with three active discs [p <.001]). Beginning 6 hrs after infection, animals were hemoperfused for 3 hrs over columns containing control or active fiber. At the end of the treatment period, there was a significant decrease in the number of circulating bacteria in the active group (3.5 x 10(4) vs. 3.1 x 10(3) colony-forming units/mL, p<.05). However, bacterial counts subsequently increased and by 15 hrs and at all subsequent time points, the number of circulating bacteria was no different between the two groups. There was a highly significant and sustained difference in circulating streptococcal pyrogenic exotoxin A levels between the groups. Streptococcal pyrogenic exotoxin A levels at 9 hrs were 19.9 ng/mL in the controls vs. 2.1 ng/mL in the active group (p =.05). Animals perfused over active fibers had a highly significant survival advantage compared with control or nonperfused groups (p <.01). Hemoperfusion and on-line removal of superantigens merits further study as a possible treatment strategy for streptococcal shock syndromes. The mechanism by which the fibers are operating requires further investigation.Critical Care Medicine 01/2003; 31(1):171-8. · 6.12 Impact Factor
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ABSTRACT: A significant proportion of invasive group A streptococcal infections are hospital acquired. No large, prospective studies have characterized this subgroup of cases and evaluated the risk of transmission in hospitals. We conducted prospective, population-based surveillance of invasive group A streptococcal infections in Ontario, Canada, from 1992 to 2000. Epidemiologic and microbiologic investigations were conducted to identify cross-transmission. We identified 291 hospital-acquired cases (12.4%) among 2351 cases of invasive group A streptococcal disease. Hospital-acquired invasive group A streptococcal infections are heterogeneous, including surgical site (96 cases), postpartum (86 cases), and nonsurgical, nonobstetrical infections (109 cases). Surgical site infections affected 1 of 100,000 surgical procedures and involved all organ systems. Postpartum infections occurred at a rate of 0.7 cases per 10,000 live births and exhibited an excellent prognosis. Nonsurgical, nonobstetrical infections encompassed a broad range of infectious syndromes (case-fatality rate, 37%). Nine percent of cases were associated with in-hospital transmission. Transmission occurred from 3 of 142 patients with community-acquired cases of necrotizing fasciitis requiring intensive care unit (ICU) admission, compared with 1 of 367 patients with community-acquired cases without necrotizing fasciitis admitted to the ICU and 1 of 1551 patients with other cases (P<.001). Fifteen outbreaks were identified; 9 (60%) involved only 2 cases. Hospital staff were infected in 1 of 15 outbreaks, but colonized staff were identified in 6 (60%) of 10 investigations in which staff were screened. Presentation of hospital-associated invasive group A streptococcal infections is diverse. Cross-transmission is common; illness occurs in patients but rarely in staff. Isolation of new cases of necrotizing fasciitis and intervention after a single nosocomial case may also prevent transmission.Clinical Infectious Diseases 09/2005; 41(3):334-42. · 9.37 Impact Factor