A cluster of cases of streptococcal necrotizing fasciitis in Gloucestershire

Beta-Hemolytic Streptococci and Necrotizing Soft Tissue Infections

β-hemolytic streptococci are major causes of necrotizing soft tissue infections (NSTIs), Streptococcus pyogenes (group A streptococcus; GAS) in particular. NSTIs caused by Streptococcus dysgalactiae (SD) have also been reported. In the INFECT cohort of 409 NSTIs patients, more than a third of the cases were caused by GAS (31%) or SD (7%). Risk factors of streptococcal NSTIs compared to streptococcal cellulitis have previously been largely unknown. The INFECT study confirmed blunt trauma as an important risk factor. In addition, absence of pre-existing skin lesions and a lower BMI were associated with NSTIs. The study also confirmed that septic shock is more frequent in GAS cases than in other types of NSTIs. Septic shock was also among several predictors of mortality. The role of intravenous immunoglobulin (IVIG) in streptococcal NSTIs has been unclear. In the INFECT cohort, IVIG treatment was associated with increased survival. As in other studies, a significant microbial diversity was observed, but with predominance of a few emm types. Overall, the INFECT study gives a comprehensive and contemporary picture of the clinical characteristics and the microbes involved in streptococcal NSTIs. The reported severity of disease underscores the need for new efforts aimed at identifying novel diagnostic measures and improved treatment.

Management of Contacts of Patients With Severe Invasive Group A Streptococcal Infection

BACKGROUND

Conflicting recommendations regarding antibiotic prophylaxis for contacts of patients with invasive group A streptococcal (GAS) infection exist. Close contacts of patients with such severe and rapidly progressive disease often strongly appeal to the treating clinicians for antimicrobial treatment to prevent additional cases. We aimed to use an approach based on pharyngeal culture testing of contacts and targeted antibiotic prophylaxis.

METHODS

A large throat swab survey including 105 contacts was undertaken after a fulminant and fatal case of GAS necrotizing fasciitis. GAS strains were characterized by emm typing and antimicrobial susceptibility to 7 antibiotics. The presence of 30 virulence determinants was determined by polymerase chain reaction and sequencing.

RESULTS

The GAS isolate recovered from the index patient was an M1T1 GAS clone susceptible to all antimicrobial agents tested. The same clone was present in the throat of 36% of close contacts who had exposure to the index patient (family households and classroom contacts) for >24 hours/week, whereas the strain was present in only 2% of the other contacts.

CONCLUSIONS

Although the study does not allow firm conclusions to be drawn as to whether antibiotic prophylaxis is effective, we describe a practical approach, including an educational campaign and targeted antibiotic treatment to close contacts who have been exposed to an index patient for > 24 hours/week before the initial disease onset.

Bromine, bear-claw scratch fasciotomies, and the Eagle effect: management of group A streptococcal necrotising fasciitis and its association with trauma

Necrotising fasciitis is a rare, but potentially fatal, soft-tissue infection. Historical depictions of the disease have been described since classical times and were mainly recorded in wartime reports of battle injuries. Although several different species of bacteria can cause necrotising fasciitis, perhaps the most widely known is group A streptococcus (GAS). Infection control, early surgical debridement, and antibiotic therapy are now the central tenets of the clinical management of necrotising fasciitis; these treatment approaches all originate from those used in wars in the past 150 years. We review reports from the 19th century, early 20th century, and mid-20th century onwards to show how the management of necrotising fasciitis has progressed in parallel with prevailing scientific thought and medical practice. Historically, necrotising fasciitis has often, but not exclusively, been associated with penetrating trauma. However, along with a worldwide increase in invasive GAS disease, recent reports have cited cases of necrotising fasciitis following non-combat-related injuries or in the absence of antecedent events. We also investigate the specific association between GAS necrotising fasciitis and trauma. In the 21st century, molecular biology has improved our understanding of GAS pathogenesis, but has not yet affected attributable mortality.

M-protein gene-type distribution and hyaluronic acid capsule in group AStreptococcusclinical isolates in Chile: association ofemmgene markers withcsrRalleles

Streptococcus pyogenescauses a variety of infections because of virulence factors such as capsular hyaluronic acid and M protein. The aim of this study was to determineemmtypes and capsule phenotype in 110 isolates ofS. pyogenesfrom patients with invasive (sterile sites) and non-invasive (mainly pharyngitis) infections in Chile, and the relationship between both virulence factors. The most abundant types found wereemm12,emm1,emm4andemm28and their distribution was similar to that seen in Latin America and developed countries, but very different from that in Asia and Pacific Island countries. Ten of 16emmtypes identified in pharyngeal isolates were found in sterile-site isolates, and three of nineemmtypes of sterile-site isolates occurred in pharyngeal isolates; threeemmsubtypes were novel. The amount of hyaluronic acid was significantly higher in sterile-site isolates but did not differ substantially amongemmtypes. Only three isolates were markedly capsulate and two of them had mutations in thecsrRgene that codes for a repressor of capsule synthesis genes. We found a non-random association betweenemmtypes andcsrRgene alleles suggesting that horizontal gene transfer is not freely occurring in the population.

Epidemic of severe Streptococcus pyogenes infections in injecting drug users in the UK, 2003-2004

During the late 1990s, increases in referrals to the national reference laboratory of Streptococcus pyogenes isolates from injecting drug users (IDUs) with severe soft tissue infection indicated an emerging problem in the UK, later confirmed during the 2003-2004 European enhanced surveillance (Strep-EURO) programme. In light of these findings, further analyses were undertaken in an attempt to understand the reasons behind this increase in referrals. Single and multivariable analyses were undertaken to compare clinical, microbiological and demographic characteristics of IDUs diagnosed with severe S. pyogenes infection during the 2003-2004 enhanced surveillance study with those of other cases arising during this same period. Temporal and spatial analyses were undertaken for IDUs to identify clustering, as a means of understanding the transmission dynamics underpinning this increase. Infections in IDUs were spread across the UK, with some concentration in northern England and London. IDUs presented with a wide range of clinical manifestations, including pneumonia, which was found to be significantly more common in IDUs (OR 3.00) than in other cases. Marked differences in type distributions were found between IDUs and other cases, in particular the concentration of emm/M83 (22% of IDUs, 2% of non-IDUs). These findings indicate that an epidemic of severe S. pyogenes infections in IDUs occurred in the UK, peaking in 2003. The explanation for this rise remains unclear.

Provider knowledge, attitudes, and practices regarding obstetric and postsurgical gynecologic infections due to group A Streptococcus and other infectious agents

Background. Knowledge, attitudes, and practices of obstetricians and gynecologists regarding the Centers for Disease Control and Prevention (CDC) recommendations for prevention of healthcare-associated group A streptococcal (GAS) infections as well as general management of pregnancy-related and postpartum infections are unknown. Methods. Questionnaires were sent to 1300 members of the American College of Obstetricians and Gynecologists. Results. Overall, 53% of providers responded. Postpartum and postsurgical infections occurred in 3% and 7% of patients, respectively. Only 14% of clinicians routinely obtain diagnostic specimens for postpartum infections; providers collecting specimens determined the microbial etiology in 28%. Microbiologic diagnoses were confirmed in 20% of postsurgical cases. Approximately 13% and 15% of postpartum and postsurgical infections for which diagnoses were confirmed were attributed to GAS, respectively. Over 70% of clinicians were unaware of CDC recommendations. Conclusions. Postpartum and postsurgical infections are common. Providing empiric treatment without attaining diagnostic cultures represents a missed opportunity for potential prevention of diseases such as severe GAS infections.

Epidemiology of invasive Streptococcus pyogenes infections in Germany, 1996–2002: results from a voluntary laboratory surveillance system

A nationwide voluntary laboratory-based surveillance study of invasive Streptococcus pyogenes (group A streptococcus; GAS) infections was conducted in Germany between 1996 and 2002. Demographical and clinical information concerning the patients was obtained from the medical files. Multiple logistic regression analysis was used to determine risk-factors for fatal outcome. Invasive isolates were obtained from 475 patients, with 251 (52.8%) of the isolates cultured from blood. The most frequent emm types were emm1 (36.4%), emm28 (8.8%) and emm3 (8%). The speA, speC and ssa genes were present at variable frequencies in different emm types. The highest frequencies of speA and speC were found in emm1 (speA, 93.6%) and emm4 (speC, 94.7%), respectively. The estimated annual incidence of invasive GAS disease for 1997-2002 was 0.1 cases/100 000 individuals. This apparently low incidence rate might be explained by the voluntary nature of the surveillance system, resulting in relatively few cases being referred to the laboratory. Complete clinical information was available for 165 cases. The overall case fatality rate was 40.6%, and was highest (65.2%) in the group aged 60-69 years. Shock, an age of >or=30 years and adult respiratory distress syndrome were predictors of a fatal outcome in a multiple logistic regression analysis. Overall, 6.7% of the cases were considered to be nosocomial, and nine cases of puerperal sepsis were observed. The study underscores the importance of invasive S. pyogenes disease in Germany.

emm Types, virulence factors, and antibiotic resistance of invasive Streptococcus pyogenes isolates from Italy: What has changed in 11 years?

To investigate the epidemiology and characteristics of invasive group A streptococcal (GAS) disease over 11 years in Italy, this study compared the emm types and the superantigen toxin genes speA and speC as well as the erythromycin, clindamycin, and tetracycline susceptibilities of 207 invasive GAS strains collected during two national enhanced surveillance periods (1994 to 1996 and 2003 to 2005) and the time between each set of surveillance periods. The present study demonstrated that emm1 strains were consistently responsible for about 20% of invasive GAS infections, while variations in the frequencies of the other types were noted, although the causes of most cases of invasive infections were restricted to emm1, emm3, emm4, emm6, emm12, and emm18. During the 1994 to 1996 surveillance period, an emm89 epidemic clone spread across the northern part of Italy. A restricted macrolide resistance phenotype-type distribution of the bacteriophage-encoded speA toxin as well as of macrolide resistance genes was noted over time. Indeed, the recent acquisition of macrolide resistance in previously susceptible emm types was observed.

Invasive group A streptococcal disease: should close contacts routinely receive antibiotic prophylaxis?

Group A streptococci (Streptococcus pyogenes) causes a wide range of illnesses from non-invasive disease--eg, pharyngitis--to more severe invasive infections--eg, necrotising fasciitis and toxic shock-like syndrome. There remains uncertainty about the risk of secondary cases of invasive disease occurring among close contacts of an index case and how best to manage that risk. We do not consider that currently available evidence justifies the routine administration of chemoprophylaxis to close contacts. We suggest that the appropriate response should be to routinely inform all household contacts of a patient with invasive group A streptococcal disease about the clinical manifestations of invasive disease and to seek immediate medical attention if they develop such symptoms.

Streptococcal infection and necrotizing fasciitis—implications for rehabilitation: a report of 5 cases and review of the literature

Five cases are presented of patients who were diagnosed with necrotizing fasciitis secondary to (1) hip disarticulation (in a paraplegic patient); (2) tooth abscess with extensive neck dissection, complicated by sepsis and hypotension with resultant dysphagia and ischemic encephalopathy; (3) below-knee amputation, anoxia, and severe debility; (4) emergent above-knee amputation; and (5) percutaneous endoscopic gastrostomy placement. The latter patient developed abdominal and chest wall necrotizing fasciitis that required skin grafting. Four patients were treated in an acute rehabilitation setting and returned home, and the fifth was rehabilitated in a subacute facility. This report emphasizes the importance of carefully monitoring rehabilitation patients, especially those with impaired sensation.

[Necrotizing soft tissue infections: nomenclature and classification]

Terminology used to refer to necrotizing infections is extensive because of the absence of clear definitions and the use of classification systems based on a variety of criteria, including etiologic, microbiologic, anatomic, and clinical aspects. This situation has led to some confusion. In the attempt to unify terminology, it might be more appropriate to use only the terms necrotizing fasciitis and myonecrosis, in which differentiation is mainly anatomical. Another option would be to use only the expression necrotizing soft tissue infections, a non-specific term, since these constitute a group of clinical processes having similar pathophysiologic characteristics and therapeutic principles.

Recurrent inflammation in a site of previous necrotising fasciitis during intravenous CMF chemotherapy

We present the case history of a patient with breast carcinoma who developed repeated inflammation at the site of previous necrotising fasciitis following each cycle of intravenous CMF chemotherapy. This complication has not previously been reported.

Streptococcus pyogenes hospital-acquired infection within a dermatological ward

Seventeen strains of Streptococcus pyogenes were isolated from 17 patients in the Dermatological Ward of Gunma University Hospital in Japan between June 1994 and March 1995. Of these 17 strains, 14 were isolated from the pus of skin infections, two from blood, and one from ascitic fluid. The strains showed the same minimum inhibitory concentrations; 4 mg/L of minomycin, 4 mg/L of ofloxacin and 16 mg/L of fosfomycin. T-antigen typing of the strains indicated they were T11 type. The restriction endonuclease digestion patterns of chromosomal DNA from the 17 strains were all identical. The vinyl sheet covering the bed on which the patients were treated was found to be contaminated with S. pyogenes. This strain showed identical characteristics to the strains derived from the patients. These results suggest that S. pyogenes was transmitted to patients in the Dermatological Ward from the surface of the vinyl sheet covering the bed.

Antibiotic resistance among clinically important gram-positive bacteria in the UK

The resistance of bacteria to antibiotics, particularly those used for first-line therapy, is an increasing cause for concern. In the UK, the prevalence of resistance to methicillin and mupirocin in Staphylococcus aureus, and to penicillin and macrolides in Streptococcus pneumoniae, appear to be increasing. There has also been an increase in the number of hospitals where glycopeptide-resistant enterococci are known to have been isolated. The increases in methicillin-resistant S. aureus and glycopeptide-resistant enterococci are due, in part, to the inter-hospital spread of epidemic strains. Although new quinolones and streptogramins with activity against Gram-positive bacteria (including strains resistant to currently available agents) are under development, there is no reason to believe that resistance to these agents will not emerge. The control of resistance in Gram-positive bacteria will require a multi-faceted approach, including continued and improved surveillance, a reduction in the unnecessary use of antibiotics, and the application of other strategies such as vaccination.

Streptococcus pyogenes bacteraemia: a 27-year study in a London teaching hospital

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.

Necrotizing fasciitis. The changing spectrum

Necrotizing fasciitis, by nature of its high inoculum of aggressive bacteria and the depth of the fascial involvement, is one of the most serious infections known to humans. Rapid tissue destruction of skin and fascia, along with bacteremia, is common. The mortality for this disease is much higher than that for cellulitis. Unfortunately, delay in diagnosis occurs commonly. The emergence of toxic shock strains of Streptococcus leading to fasciitis with organ dysfunction makes it necessary to make a rapid diagnosis and institute early antibiotic and surgical interventions.