Could nonsteroidal antiinflammatory drugs (NSAIDs) enhance the progression of bacterial infections to toxic shock syndrome?

Invasive group a streptococcal disease: epidemiology, pathogenesis and management

Invasive group A streptococcal infections are uncommon, although serious, infections with high case fatality rates. Periodic resurgences in invasive group A streptococcal infections in industrialized countries have been reported from the 1980s onwards, with current estimates of incidence in these countries of approximately 3–4 per 100000 population. Infants, pregnant women and the elderly are at increased risk of invasive group A streptococcal infection. The group A streptococcus has an array of virulence factors that underpin its invasive capacity and, in approximately 10% of cases, super-antigen toxins produced by the bacteria stimulate a large proportion of T cells, leading to streptococcal toxic shock syndrome. Given the rapid clinical progression, effective management of invasive group A streptococcal infections hinges on early recognition of the disease and prompt initiation of supportive care (often intensive care) together with antibacterial therapy. In cases of toxic shock syndrome, it is often difficult to distinguish between streptococcal and staphylococcal infection before cultures become available and so antibacterial choice must include coverage of both of these organisms. In addition, clindamycin is an important adjunctive antibacterial because of its anti-toxin effects and excellent tissue penetration. Early institution of intravenous immunoglobulin therapy should be considered in cases of toxic shock syndrome and severe invasive infection, including necrotizing fasciitis. Early surgical debridement of necrotic tissue is also an important part of management in cases of necrotizing fasciitis.

Screening New Drugs for Immunotoxic Potential: I. Assessment of the Effects of Conventional Nonsteroidal Anti-Inflammatory Drugs and Selective COX-2 Inhibitors on In Vitro and In Vivo Phagocytic Activity

Although both experimental and clinical literature contain reports suggestive of associations between enhanced susceptibility to soft tissue infections and nonsteroidal anti-inflammatory drug (NSAID) use, the immunotoxicological potential of this class of therapeutic agents has not been thoroughly investigated. In consideration of the widespread clinical use of these agents, we have initiated studies of the interaction between NSAIDs (both nonselective and selective COX-2 inhibitors) and the immune system. This communication describes the conduct and results of assessments of the effects of NSAIDs on the in vitro phagocytic activity of rat macrophages and canine neutrophils and on the functional activity of the intact murine mononuclear phagocytic system. During in vitro experiments 0.1 to 10 muM concentrations of naproxen, indomethacin, and experimental selective COX-2 inhibitors, SC-236, SC-245 and SC-791, caused marginal, but statistically significant, reductions in phagocytic activity of resident rat peritoneal macrophages. The effects were consistently small and there was no evidence of concentration-response relationships. An in vitro concentration of 10 muM of either SC-236 or SC-791 was required to decrease phagocytosis by dog neutrophils. Repeated oral doses of either naproxen or SC-236 (3, 10, or 30 mg/kg twice daily for 3 days) were without effect on the intact phagocytic system of the mouse. A potential immunotoxicologic effect based on direct impairment of phagocytic processes seems an unlikely explanation for drug-induced susceptibility to infection reported earlier. However, the results of these experiments do not support an unequivocal conclusion relative to immunotoxicological potential of either conventional NSAIDs or selective COX-2 inhibitors. Further studies on other components of the immune system are needed to fully explore possible immunomodulatory effects of NSAIDs.

Invasive group a streptococcal disease: epidemiology, pathogenesis and management

Invasive group A streptococcal infections are uncommon, although serious, infections with high case fatality rates. Periodic resurgences in invasive group A streptococcal infections in industrialized countries have been reported from the 1980s onwards, with current estimates of incidence in these countries of approximately 3-4 per 100 000 population. Infants, pregnant women and the elderly are at increased risk of invasive group A streptococcal infection. The group A streptococcus has an array of virulence factors that underpin its invasive capacity and, in approximately 10% of cases, superantigen toxins produced by the bacteria stimulate a large proportion of T cells, leading to streptococcal toxic shock syndrome. Given the rapid clinical progression, effective management of invasive group A streptococcal infections hinges on early recognition of the disease and prompt initiation of supportive care (often intensive care) together with antibacterial therapy. In cases of toxic shock syndrome, it is often difficult to distinguish between streptococcal and staphylococcal infection before cultures become available and so antibacterial choice must include coverage of both of these organisms. In addition, clindamycin is an important adjunctive antibacterial because of its anti-toxin effects and excellent tissue penetration. Early institution of intravenous immunoglobulin therapy should be considered in cases of toxic shock syndrome and severe invasive infection, including necrotizing fasciitis. Early surgical debridement of necrotic tissue is also an important part of management in cases of necrotizing fasciitis.

Necrotizing fasciitis

OBJECTIVE

To describe the defining characteristics and treatment of necrotizing fasciitis (NF), emphasizing early diagnostic indications.

QUALITY OF EVIDENCE

PubMed was searched using the terms necrotizing fasciitis and necrotizing soft tissue infections, paired with early diagnosis. Results were limited to human studies in English. Additional articles were obtained from references within articles. Evidence is levels II and III.

MAIN MESSAGE

Necrotizing fasciitis is classified according to its microbiology (polymicrobial or monomicrobial), anatomy, and depth of infection. Polymicrobial NF mostly occurs in immunocompromised individuals. Monomicrobial NF is less common and affects healthy individuals who often have a history of trauma (usually minor). Patients with NF can present with symptoms of sepsis, systemic toxicity, or evidence of skin inflammation, with pain that is disproportional to the degree of inflammation. However, these are also present in less serious conditions. Hyperacute cases present with sepsis and quickly progress to multiorgan failure, while subacute cases remain indolent, with festering soft-tissue infection. Because the condition is rare with minimal specific signs, it is often misdiagnosed. If NF is suspected, histology of tissue specimens is necessary. Laboratory and radiologic tests can be useful in deciding which patients require surgical consultation. Once NF is diagnosed, next steps include early wound debridement, excision of nonviable tissue, and wide spectrum cover with intravenous antibiotics.

CONCLUSION

Necrotizing fasciitis is an uncommon disease that results in gross morbidity and mortality if not treated in its early stages. At onset, however, it is difficult to differentiate from other superficial skin conditions such as cellulitis. Family physicians must have a high level of suspicion and low threshold for surgical referral when confronted with cases of pain, fever, and erythema.

A case of necrotizing fasciitis due to Streptococcus pneumoniae serotype 5 in Saskatchewan

Necrotizing fasciitis due to Streptococcus pneumoniae is a rare and grave condition, and only a few cases have been reported. Suggested risk factors include minor trauma, systemic lupus erythematosus, immunosuppression secondary to medication, use of intramuscular anti-inflammatories and alcoholism. A fatal case of pneumococcal necrotizing fasciitis that occurred in a 51-year-old woman with a history of alcohol abuse and oral anti-inflammatory use is presented. Her condition was caused by a multi-etiology outbreak of community-acquired pneumonia, from which S pneumoniae serotype 5 was also isolated. The case description outlines the subtle presentation and rapid clinical progression of this condition. Because serotype 5 antigen is included in the polysaccharide 23-valent pneumococcal vaccine, the present case highlights the importance of pneumococcal immunization programs in Canada.

Flesh-eating disease: A note on necrotizing fasciitis

There has been much media attention in the past few years to the condition dubbed 'flesh-eating disease', which refers, primarily, to a form of invasive group A beta hemolytic streptococcal (GABHS) infection that leads to fascia and muscle necrosis. In 1999, the Canadian Paediatric Society issued a statement on the state of knowledge and management of children, and close contacts of persons with all-invasive GABHS disease (1). The present note is intended to deal specifically with necrotizing fasciitis (NF) by providing an update on the limited current state of knowledge, diagnosis and management. Surveillance to establish actual national rates and epidemiology of NF through the Canadian Paediatric Society is proposed.

Ibuprofen worsens Streptococcus pyogenes soft tissue infections in mice

BACKGROUND

Group A streptococcus (GAS) is a common cause of soft tissue infection. Nonsteroidal anti-inflammatory drugs have been reported to worsen GAS soft tissue infections.

METHODS

A mouse model of GAS soft tissue infection was developed. The extent of cutaneous lesions, tissue damage, release of inflammatory cytokines, and survival rates were compared between mice with and without ibuprofen administration after GAS soft tissue infection.

RESULTS

All twelve mice without ibuprofen administration survived for at least 10 days. In contrast, mortality rate of 14 mice with ibuprofen therapy was 72.5%. Ibuprofen-treated mice exhibited more evident macrophage infiltration and tissue damage in the GAS-infected soft tissues. In GAS-infected mice, tissue levels of interleukin 6 and tumor necrosis factor alpha were significantly higher in ibuprofen-treated mice than those in the control group.

CONCLUSIONS

The results supported the concept that ibuprofen use in GAS soft tissue infections might induce the development of severe necrotizing infections and increase mortality rate.

Cyclooxygenase-2 enhances antimicrobial peptide expression and killing of Staphylococcus aureus

Antimicrobial peptides such as human β-defensins (hBDs) and cathelicidins are critical for protection against infection and can be induced by activation of TLRs, a pathway that also activates cyclooxygenase(Cox)-2 expression. We hypothesized that Cox-2 is induced by TLR activation and is necessary for optimal AMP production, and that inhibitors of Cox-2 may therefore inhibit antimicrobial action. Normal human keratinocytes (NHEKs) stimulated with a TLR2/6 ligand, macrophage-activating lipopeptide-2, or a TLR3 ligand, polyinosinic-polycytidylic acid, increased Cox-2 mRNA and protein and increased PGE(2), a product of Cox-2. Treatment with a Cox-2 selective inhibitor (SC-58125) or Cox-2 small interfering RNA attenuated hBD2 and hBD3 production in NHEKs when stimulated with macrophage-activating lipopeptide-2, polyinosinic-polycytidylic acid, or UVB (15 mJ/cm(2)), but it did not attenuate vitamin D3-induced cathelicidin. SC-58125 also inhibited TLR-dependent NF-κB activation. Conversely, treatment with Cox-derived prostanoids PGD(2) or 15-deoxy-Δ(12,14)-PGJ(2) induced hBD3 or hBD2 and hBD3, respectively. The functional significance of these observations was seen in NHEKs that showed reduced anti-staphylococcal activity when treated with a Cox-2 inhibitor. These findings demonstrate a critical role for Cox-2 in hBD production and suggest that the use of Cox-2 inhibitors may adversely influence the risk for bacterial infection.

Necrotizing soft tissue infections in the intensive care unit

Necrotizing soft tissue infection is a severe illness that is associated with significant morbidity and mortality. It is often caused by a wide spectrum of pathogens and is most frequently polymicrobial. Care for patients with necrotizing soft tissue infection requires a team approach with expertise from critical care, surgery, reconstructive surgery, and rehabilitation specialists. The early diagnosis of necrotizing soft tissue infection is challenging, but the keys to successful management of patients with necrotizing soft tissue infection are early recognition and complete surgical debridement. Early initiation of appropriate broad-spectrum antibiotic therapy must take into consideration the potential pathogens. Critical care management components such as the initial fluid resuscitation, end-organ support, pain management, nutrition support, and wound care are all important aspects of the care of patients with necrotizing soft tissue infection. Soft tissue reconstruction should take into account both functional and cosmetic outcome.

Hospitalization for severe bacterial infections in children after exposure to NSAIDs: a prospective adverse drug reaction reporting study

BACKGROUND

NSAIDs are widely used to treat fever and pain in children, but their possible role in the progression of some bacterial infections is controversial.

OBJECTIVE

This study was performed to analyse reported cases of severe bacterial infection associated with NSAID exposure in children admitted for this reason to a general paediatric department.

METHODS

This study was based on the reporting system of hospital admissions for severe bacterial infections in children after NSAID exposure, and followed the recommendations of the European Guidelines of Pharmacovigilance for medicines used in a paediatric population. Data were prospectively collected and reported by active daily surveillance in the department from November 2002 to November 2005.

RESULTS

Thirty-two cases of severe bacterial infections (cellulitis, soft tissue abscesses, parapneumonic empyema, necrotizing pneumonia, adenophlegmon [fever and a tender, warm and easily compressible neck mass] and lateral or retropharyngeal abscesses) were identified in children who had received NSAIDs, principally ibuprofen, in an exposure window of 15 days before the beginning of the signs of infection. Staphylococcus aureus, group A streptococci and Streptococcus pneumoniae were identified. Seven (22%) children required surgical treatment, and four (13%) were hospitalized in an intensive care unit.

CONCLUSIONS

The frequency of hospitalization for severe bacterial infection as a possible adverse effect of NSAID use was 0.6% (95% CI 0.4, 0.9) of all admissions during the study period. The frequency of severe bacterial infections after exposure to NSAIDs was elevated (one case per month) in the department studied. Further work is necessary to confirm these findings, given the potential for recruitment and protopathic biases in our study.

Molecular pathogenesis of necrotizing fasciitis

Necrotizing fasciitis, also known as the flesh-eating disease, is a severe invasive infection associated with very high rates of human morbidity and mortality. It is most commonly caused by group A Streptococcus(GAS), a versatile human pathogen that causes diseases ranging in severity from uncomplicated pharyngitis (or strep throat) to life-threatening infections such as necrotizing fasciitis. Herein, we review recent discoveries bearing on the molecular pathogenesis of GAS necrotizing fasciitis. Importantly, the integration of new technologies and the development of human-relevant animal models have markedly expanded our understanding of the key pathogen-host interactions underlying GAS necrotizing fasciitis. For example, we now know that GAS organisms secrete a variety of proteases that disrupt host tissue and that these proteolytic enzymes are regulated by multiple transcriptional and posttranslational processes. This pathogenesis knowledge will be crucial to supporting downstream efforts that seek to develop novel vaccines and therapeutic agents for this serious human infection.

[Prior use of anti-inflammatory and antibiotic drugs in patients hospitalized for peritonsillar abscess]

OBJECTIVE

The purpose of this study was to describe the characteristics of patients hospitalized for a peritonsillar abscess over a 1-year period and to evaluate the proportion of patients exposed to anti-inflammatory and antibiotic drugs before hospitalization.

DESIGN

Adult patients hospitalized in the ENT department at the Nantes University Hospital were included in the study during 2006. Data related to prior use of anti-inflammatory and antibiotic drugs, microbiology and treatment was analyzed.

RESULTS

Thirty-four patients were included in the study, 20 (59%) and 21 (62%) patients had been previously exposed to anti-inflammatory and antibiotic drugs, respectively. Half of the patients had received antibiotics despite the negativity of the rapid screening test. All diagnoses were made on pus examination after aspiration. Tonsillectomy was performed only in two cases. A total of 21 bacterial isolates (13 anaerobic and 9 aerobic) were identified. Single bacterial isolates were recovered in 8 infections. The most frequent bacteria were Streptococcus, Fusobacterium, and Prevotella.

CONCLUSIONS

Many patients were exposed to both anti-inflammatory and antibiotic drugs, which did not prevent the peritonsillar abscess.

A multicentre case-control study of nonsteroidal anti-inflammatory drugs as a risk factor for severe sepsis and septic shock

INTRODUCTION

We aimed to establish whether the use of nonsteroidal anti-inflammatory drugs (NSAIDs) during evolving bacterial community-acquired infection in adults is associated with severe sepsis or septic shock.

METHODS

We conducted a multicentre case-control study in eight intensive care units. Cases were all adult patients admitted for severe sepsis or septic shock due to a bacterial community-acquired infection. Control individuals were patients hospitalized with a mild community-acquired infection. Each case was matched to one control for age, presence of diabetes and site of infection.

RESULTS

The main outcome measures were the proportions of cases and controls exposed to NSAIDs or aspirin during the period of observation. In all, 152 matched pairs were analyzed. The use of NSAIDs or aspirin during the observation period did not differ between cases and controls (27% versus 28; odds ratio = 0.93, 95% confidence interval [CI] = 0.52 to 1.64). If aspirin was not considered or if a distinction was made between acute and chronic drug treatment, there remained no difference between groups. However, the median time to prescription of effective antibiotic therapy was longer for NSAID users (6 days, 95% CI = 3 to 7 days) than for nonusers (3 days, 95% CI = 2 to 3 days; P = 0.02).

CONCLUSIONS

In this study, the use of NSAIDs or aspirin during evolving bacterial infection was frequent and occurred in one-quarter of the patients with such infection. Although the use of NSAIDs by patients with severe sepsis or septic shock did not differ from their use by those with mild infection at the same infected site, we observed a longer median time to prescription of effective antibiotic therapy in NSAID users.

Predictors of mortality in beta-hemolytic streptococcal bacteremia: a population-based study

OBJECTIVES

Several factors associated with mortality in Lancefield group A beta-hemolytic streptococcal bacteremia have been described in population-based surveillance studies, whereas such reports on group B, C, and G streptococcal are scant.

METHODS

In this population-based study all 314 episodes of beta-hemolytic streptococcal bacteremia in adult patients in the Pirkanmaa area, Finland, during the 10-year period 1995-2004 were retrospectively reviewed.

RESULTS

The 30-day case-fatality rate was 13%, being highest in group C (22%); in group A it was 15%, in group B 7%, and in group G 15%. Confusion, unconsciousness and dyspnea as the first sign or symptom were associated with increased case-fatality, while fever seemed to be a protecting factor for death. Alcoholism and ultimately or rapidly fatal underlying disease were significantly associated with increased case-fatality. Among infections of the skin and soft-tissues, necrotizing fasciitis had the highest risk of death (38%), while patients with cellulitis had a case-fatality of 8%. A history of previous cellulitis seemed to protect against death (case-fatality of 3% as compared to 16% among those without such a history (p=0.014)).

CONCLUSION

A history of previous cellulitis seemed to be a protecting factor against death. Fever was also associated with a good prognosis.

Muscle injury, vimentin expression, and nonsteroidal anti-inflammatory drugs predispose to cryptic group A streptococcal necrotizing infection

BACKGROUND

Myonecrosis due to group A streptococci (GAS) often develops at sites of nonpenetrating muscle injury, and nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the severity of these cryptic infections. We have previously shown that GAS bind to vimentin on injured skeletal muscles in vitro. The present study investigated whether vimentin up-regulation in injured muscles in vivo is associated with homing of circulating GAS to the injured site and whether NSAIDs facilitate this process.

METHODS

M type 3 GAS were delivered intravenously 48 h after eccentric contraction (EC)-induced injury of murine hind-limb muscles. Vimentin gene expression and homing of GAS were followed by real-time reverse-transcriptase polymerase chain reaction and quantitative bacteriology of muscle homogenates, respectively. In separate experiments, ketorolac tromethamine (Toradol) was given 1 h before GAS infusion.

RESULTS

Vimentin was up-regulated approximately 8-fold 48 h after EC. Significantly more GAS were found in moderately injured muscles than in noninjured controls. NSAIDs greatly augmented the number of GAS in injured muscles.

CONCLUSIONS

Vimentin may tether circulating GAS to injured muscle, and NSAIDs enhance this process. Strategies targeting the vimentin-GAS interaction may prevent or attenuate GAS myonecrosis. Use of NSAIDs should increase suspicion of cryptic GAS infection in patients with increasing pain at sites of nonpenetrating muscle injury.

Postpartum invasive group A streptococcal disease in the modern era

To describe the clinical features of individuals hospitalized for postpartum invasive group A Streptococcus (GAS) infection, a retrospective, population-based study of hospitalized patients in the state of Florida was conducted. Cases of postpartum invasive GAS infection (occurring within 42 days of delivery) were compared to women with other manifestations of invasive GAS disease with respect to their age at the time of admission. Four cases of postpartum invasive GAS infection were detected in this population, yielding a prevalence of 1.6% (4/257) of postpartum disease in this invasive GAS infection database. Patients presented a median of 4 days (mean of 9 days) after delivery with signs and symptoms of infection. Three cases were complicated by bacteremia and one patient had streptococcal toxic shock syndrome. Each patient received multiple antibiotics and survived. No patients received intravenous immunoglobulin. For comparison, a secondary retrospective investigation of a large hospital discharge dataset obtained from the Florida Agency for Health Care Administration was assessed for patients with puerperal GAS infections. This method yielded an additional three cases, whose clinical and demographic characteristics were summarized. These data highlight that postpartum invasive GAS infection continues to complicate pregnancy, though the frequency has decreased markedly over the past century.

Epidemiology and outcome of necrotizing fasciitis in children: an active surveillance study of the Canadian Paediatric Surveillance Program

OBJECTIVE

To describe the epidemiology, management, and outcome of pediatric necrotizing fasciitis (NF) in Canada before full implementation of varicella immunization programs.

STUDY DESIGN

This was a prospective cohort study of all children under age 16 years identified by the Canadian Paediatric Surveillance Program (CPSP).

RESULTS

Between November 1, 2001 and October 31, 2003, 36 NF cases were identified (mean age, 5.9 +/- 5 years). Group A streptococcus (GAS)-related and non-GAS-related NF accounted for 2.12 and 0.81 cases per million children, respectively. The annual incidence was substantially higher in children under age 5 years (5.9 vs 1.8 per million; P = .0002). Males over age 1 year had the highest disease burden, with 12 cases per million, versus 3.2 cases per million for females under age 1 year (P < .0001). Most (15/26; 58%) GAS-related cases were associated with varicella. Complications occurred in 29 children (78%), and 2 children (5.4%) died.

CONCLUSION

In the prevaccine era, NF occurred most commonly in Canadian children under age 5 years, with a peak incidence in males under age 1 year. There is substantial associated morbidity and about 5% mortality. The data provide baseline incidence of disease and a surveillance mechanism for NF after the implementation of publicly funded varicella immunization programs in Canada.

[Ibuprofen in childhood: evidence-based review of efficacy and safety]

Ibuprofen is the non-steroidal anti-inflammatory drug most prescribed for the treatment of fever and moderate pain in childhood. Its analgesic and antipyretic efficacy is now well documented: at equal doses ibuprofen appears slightly more effective than acetaminophen in the treatment of fever and is equivalent for analgesia. However, adverse effects should be taken into account in the choice between ibuprofen and acetaminophen. Lot of studies (case reports, cohort studies, case-control studies and one multicenter double-blind randomized control trial) have reported ibuprofen adverse effects at therapeutics doses. These data suggest there is an increased risk of invasive group A streptococcal infection after chickenpox and of acute renal failure in case of hypovolemia after a treatment by ibuprofen. Gastroduodenal and hemorrhagic adverse events could also happen, but the causality with ibuprofen is not demonstrated. Therefore, ibuprofen is not recommended for the treatment of fever or moderate pain during chickenpox or during a disease with a risk of dehydration, until other pharmacoepidemiology studies more accurately quantify the risk of adverse events of ibuprofen in children.

Life-threatening necrotizing fasciitis

Necrotizing fasciitis is characterized by a rapidly progressing necrosis of subcutaneous fat and fascia, which can be life-threatening without prompt recognition, surgical intervention, and immediate antibiotic therapy. Necrotizing fasciitis has been subdivided into type 1, or polymicrobial necrotizing fasciitis, and type 2, or group A streptococcal necrotizing fasciitis. In addition, synonyms, such as streptococcal gangrene and "flesh-eating bacteria syndrome," have been used in the literature.

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.

Risk factors for pediatric invasive group A streptococcal disease

Invasive group A Streptococcus (GAS) infections can be fatal and can occur in healthy children. A case-control study identified factors associated with pediatric disease. Case-patients were identified when Streptococcus pyogenes was isolated from a normally sterile site, and matched controls (≥2) were identified by using sequential-digit dialing. All participants were noninstitutionalized surveillance-area residents <18 years of age. Conditional regression identified factors associated with invasive disease: other children living in the home (odds ratio [OR] = 16.85, p = 0.0002) and new use of nonsteroidal antiinflammatory drugs (OR = 10.64, p = 0.005) were associated with increased risk. More rooms in the home (OR = 0.67, p = 0.03) and household member(s) with runny nose (OR = 0.09, p = 0.002) were associated with decreased risk. Among children, household-level characteristics that influence exposure to GAS most affect development of invasive disease.

Risk factors for pediatric invasive group A streptococcal disease

Invasive group A Streptococcus (GAS) infections can be fatal and can occur in healthy children. A case-control study identified factors associated with pediatric disease. Case-patients were identified when Streptococcus pyogenes was isolated from a normally sterile site, and matched controls (>or=2) were identified by using sequential-digit dialing. All participants were noninstitutionalized surveillance-area residents <18 years of age. Conditional regression identified factors associated with invasive disease: other children living in the home (odds ratio [OR]=16.85, p=0.0002) and new use of nonsteroidal antiinflammatory drugs (OR=10.64, p=0.005) were associated with increased risk. More rooms in the home (OR=0.67, p=0.03) and household member(s) with runny nose (OR=0.09, p=0.002) were associated with decreased risk. Among children, household-level characteristics that influence exposure to GAS most affect development of invasive disease.

Treatment options in the management of necrotising fasciitis caused by Group A Streptococcus

Invasive Group A Streptococcus (GAS) disease is a serious condition that has multiple manifestations. A particularly severe form of invasive GAS disease is necrotising fasciitis (NF). The case-fatality rate of GAS NF is approximately 20%. Penicillin remains the antibiotic of choice when treating invasive GAS infections. Epidemiological studies have shown that clindamycin is effective in the treatment of deep infections that are caused by GAS. Clinicians should consider adding clindamycin to the beta-lactam antibiotic regimen when NF or myositis is present. Intravenous immunoglobulin appears to be a promising adjunctive therapy in the management of GAS NF. Consultations with surgeons and infectious disease specialists are imperative.

Toxic shock syndrome in children: epidemiology, pathogenesis, and management

Toxic shock syndrome (TSS) is an acute, toxin-mediated illness, like endotoxic shock, and is characterized by fever, rash, hypotension, multiorgan involvement, and desquamation. TSS reflects the most severe form of the disease caused by Staphylococcus aureus and Streptococcus pyogenes. A case definition for staphylococcal TSS was well established in the early 1980s and helped in defining the epidemiology. Since the late 1980s, a resurgence of highly invasive streptococcal infections, including a toxic shock-like syndrome, was noted worldwide and a consensus case definition for streptococcal TSS was subsequently proposed in 1993. Both TSS and the toxic shock-like syndrome occur at a lower incidence in children than in adults. Changes in the manufacturing and use of tampons led to a decline in staphylococcal TSS over the past decade, while the incidence of nonmenstrual staphylococcal TSS increased. Nonmenstrual TSS and menstrual TSS are now reported with almost equal frequency. The incidence of streptococcal TSS remains constant after its resurgence, but varies with geographic location. Streptococcal TSS occurs most commonly following varicella or during the use of NSAIDs. Sites of infection in streptococcal TSS are much deeper than in staphylococcal TSS, such as infection caused by blunt trauma, and necrotizing fasciitis. Bacteremia is more common in streptococcal TSS than in staphylococcal TSS. Mortality associated with streptococcal TSS is 5-10% in children, much lower than in adults (30-80%), and is 3-5% for staphylococcal TSS in children.TSS is thought to be a superantigen-mediated disease. Toxins produced by staphylococci and streptococci act as superantigens that can activate the immune system by bypassing the usual antigen-mediated immune-response sequence. The host-pathogen interaction, virulence factors, and the absence or presence of host immunity determines the epidemiology, clinical syndrome, and outcome. Early recognition of this disease is important, because the clinical course is fulminant and the outcome depends on the prompt institution of therapy. Management of a child with TSS includes hemodynamic stabilization and appropriate antimicrobial therapy to eradicate the bacteria. Supportive therapy, aggressive fluid resuscitation, and vasopressors remain the main elements. An adjuvant therapeutic strategy may include agents that can block superantigens, such as intravenous immunoglobulin that contains superantigen neutralizing antibodies.

Life-threatening eruptions due to infectious agents

Some infectious diseases may cause rapidly fatal eruptions that need to be diagnosed and treated in an early phase for patient survival. The main life-threatening eruptions of infectious etiology include Rocky Mountain spotted fever, meningococcemia, toxic shock syndrome, streptococcal toxic shock syndrome, and staphylococcal scalded skin syndrome.

Treatment of staphylococcal scalded skin syndrome

Humans are a natural reservoir for Staphylococcal aureus. Colonization begins soon after birth and predisposes to infection. S. aureus is one of the most common causes of skin infection, giving rise to folliculitis, furunculosis, carbuncles, ecthyma, impetigo, cellulitis and abscesses. In addition, S. aureus may cause a number of toxin-mediated life-threatening diseases, including staphylococcal scalded skin syndrome (SSSS). Epidermolytic toxins released by certain S. aureus strains cause SSSS by cleaving the epidermal cell adhesion molecule, desmogelin-1, resulting in superficial skin erosion. Recent experiments have revealed similarities in the pathophysiology of SSSS and pemphigus foliaceus, an autoimmune disorder that is characterized by antibodies targeting the same epidermal attachment protein. SSSS typically affects neonates and infants but may also occur in predisposed adults. It is painful and distressing for the patient and parents, although most cases respond to antibiotic treatment. Mortality is low in infants but can be as high as 67% in adults, and is dependent on the extent of skin involvement and the comorbid state. Thus, the management of adults who develop SSSS remains a major therapeutic challenge. The antibody response against the toxins neutralizes their effect and prevents recurrence or limits the effects to the area of infection, which is known as bullous impetigo.

Effect of water extract of Turkish propolis on tuberculosis infection in guinea-pigs

Mycobacterium tuberculosis (H(37)R(v))-infected guinea-pig model was used to investigate the effect of water extract of propolis (WEP). After subcutaneous inoculation of tubercle bacilli, each animal received oral WEP (n=9), isoniazid (n=5) or saline (n=6) as placebo and were sacrificed 30 days later. Formation of necrosis was less prominent in the group treated with WEP, but was not statistically significant (P>0.05). The granuloma formation in the same group was more prominent than the placebo and isoniazid groups; however, this finding failed to reach statistical significance by the Kruskal-Wallis test (P>0.05). These findings suggest that Turkish WEP may have a limited effect on the development of tuberculosis infection in this guinea-pig model.

Pneumococcal necrotizing fasciitis in a patient with Type 2 diabetes

Necrotizing fasciitis (NF) is a rare and often fatal soft-tissue infection involving the superficial fascial layers of the extremities, abdomen or perineum. Progression to septic shock can occur very rapidly with its associated high morbidity and mortality. NF is usually caused by beta haemolytic streptococci; less often a poly-microbial isolate is the cause. It typically occurs in patients with some degree of immune dysfunction. We present a case of severe pneumococcal necrotizing fasciitis in an obese patient with Type 2 diabetes. There was no history of trauma or evidence of diabetes-related complications. The initial presentation was with features of septic arthritis of the left knee, which subsequently progressed to NF. Differentiation from cellulitis is often difficult in the early stages. Invasive pneumococcal infections are extremely rare, with only a few reported in the literature. Moreover, our case highlights the need to consider other differential diagnoses (and to look out for complications) in patients with diabetes, especially if there is little clinical response to the initial treatment.

Group A Streptococcal Infections in Sweden: A Comparative Study of Invasive and Noninvasive Infections and Analysis of Dominant T28 emm28 Isolates

Surveillance of group A streptococcus (GAS) infections in Sweden during 1996-1997 indicated that T28 isolates were dominant, whereas T1M1 infections were uncommon. Circulating T28 isolates were nearly all emm28, MLST52, and these clones had also been prevalent 10 years earlier. Isolates from invasive and noninvasive infections were of similar types and prevalences. The average national incidence of invasive episodes was 2.9/100,000 population but varied between 0 and 8.3/100,000 population in different counties. It increased markedly with age, reaching 22.9 episodes/100,000 among people aged > or =90 years. The incidence of puerperal sepsis was higher than expected (22.4/100,000 of those at risk), with 1 death. Overall mortality was 16% and was associated with preexisting chronic disease (P=.002). Streptococcal toxic shock syndrome (STSS) developed in approximately 15% of patients with invasive episodes, with a mortality rate of 45%. The use of nonsteroidal anti-inflammatory drugs was not found to be associated with the development of STSS.

Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections are characterized by necrosis of skin and associated structures. Despite advances in the diagnosis and treatment of these infections, the mortality remains high. There have been increasing reports of necrotizing fasciitis caused by group A Streptococcus over the past decade. Recent information supports the role of superantigens in the pathogenesis of this infection. The approach to management requires expeditious evaluation with early surgery and appropriate antimicrobial agents. Limited data suggest that surgical debridement may be delayed in selected patients until the patient is stable by the use of intravenous immunoglobulin, which can neutralize superantigens.

Invasive group A streptococcal disease: risk factors for adults

We conducted a case-control study to identify risk factors for invasive group A streptococcal (GAS) infections, which can be fatal. Case-patients were identified when Streptococcus pyogenes was isolated from a normally sterile site and control subjects (two or more) were identified and matched to case-patients by using sequential-digit telephone dialing. All participants were noninstitutionalized surveillance area residents, >18 years of age. Conditional logistic regression identified the risk factors for invasive GAS infection: in adults 18 to 44 years of age, exposure to one or more children with sore throats (relative risk [RR]=4.93, p=0.02), HIV infection (RR=15.01, p=0.04), and history of injecting drug use (RR=14.71, p=0.003); in adults >45 years of age, number of persons in the home (RR=2.68, p=0.004), diabetes (RR=2.27, p=0.03), cardiac disease (RR=3.24, p=0.006), cancer (RR=3.54, p=0.006), and corticosteroid use (RR=5.18, p=0.03). Thus, host and environmental factors increased the risk for invasive GAS disease.

Assessing the relationship between the use of nonsteroidal antiinflammatory drugs and necrotizing fasciitis caused by group A streptococcus

Group A streptococcal (GAS) necrotizing fasciitis is a rapidly progressive soft tissue infection. Elderly and chronically ill individuals are at greatest risk, particularly when skin breakdown is present. Reports suggest that nonsteroidal antiinflammatory drugs (NSAIDs) increase the risk of developing GAS necrotizing fasciitis, impede its timely recognition and management, and accelerate the course of infection. We present a literature review conducted to examine these hypotheses and present a case of GAS necrotizing fasciitis associated with rofecoxib use. Initial symptoms of fasciitis may be nondescript, mimicking more benign conditions such as cellulitis, arthritis, or musculoskeletal pain. Case reports and retrospective studies suggest that the application of NSAIDs to relieve these nonspecific symptoms can delay diagnosis and treatment of GAS necrotizing fasciitis. However, prospective studies do not support a risk of developing GAS necrotizing fasciitis as a result of NSAID therapy, or a worsening of established streptococcal infection. To avoid the application of NSAIDs in lieu of aggressive medical and surgical management of streptococcal fasciitis, clinicians must understand the early symptoms of GAS necrotizing fasciitis that precede visible soft tissue necrosis. A rational approach to patients presenting with localized soft tissue pain will enhance detection and therapy of this rapidly progressive, life-threatening disease.

Streptococcal toxic shock syndrome

Perhaps more noteworthy than the emergence of Streptococcal toxic shock syndrome (StrepTSS) is its persistence for a period of more than 15 years in most geographical areas and an actual increase in incidence in some regions. Early diagnosis remains a problem, and aggressive surgery often cannot be avoided. The continuing rates of mortality and morbidity indicate the need for novel approaches to diagnosis and treatment.

Streptococcal toxic shock syndrome: a description of 14 cases from North Yorkshire, UK

OBJECTIVE

To analyze the clinical and laboratory features of patients diagnosed with streptococcal toxic shock syndrome (TSS) in North Yorkshire from 1986 to 1999.

METHODS

Records of patients with features satisfying the published criteria for streptococcal TSS were reviewed from laboratory and clinical records made at the time and from the hospital case notes. Isolates of streptococci were analyzed for serotype and genes encoding for the production of streptococcal pyrogenic exotoxins.

RESULTS

Fourteen patients satisfied the entry criteria. In one district, where the data were complete, the annual incidence of detected streptococcal TSS rose from 1.1 to 9.5 cases per million population in the 1990s. TSS was associated with various M serotypes of group A streptococci and various exotoxin genotypes. Two cases (14% of the series) were associated with severe group G streptococcal infection. The fatality rate was 64%, and the mode of time to death was 4 days. Local tissue necrosis occurred in 71% of cases, including necrotizing fasciitis, intrathoracic and intra-abdominal forms. Non-steroidal anti-inflammatory drugs (NSAIDs) had been taken around the time of onset of disease by 92% of the patients with TSS.

CONCLUSIONS

There has been a dramatic increase in the number of detected cases of streptococcal TSS over the 14 years since the first case was recognized here. There was a wide range of invasive forms of infection, a high fatality rate even in fit young adults, and a rapid course from onset to death. There was a high association of TSS with aggressive streptococcal infection producing local tissue necrosis.

Streptococcus pyogenes pyomyositis

Group A beta-hemolytic Streptococcus pyomyositis continues to be an uncommon disease. We present a case of a 7-year-old boy with an M protein type 1, streptococcal pyrogenic exotoxin A and B, Streptococcus pyogenes pyomyositis and streptococcal toxic shock syndrome.

Toxic shock syndrome and bacterial superantigens: an update

Toxic shock syndrome (TSS) is an acute onset illness characterized by fever, rash formation, and hypotension that can lead to multiple organ failure and lethal shock, as well as desquamation in patients that recover. The disease is caused by bacterial superantigens (SAGs) secreted from Staphylococcus aureus and group A streptococci. SAGs bypass normal antigen presentation by binding to class II major histocompatibility complex molecules on antigen-presenting cells and to specific variable regions on the beta-chain of the T-cell antigen receptor. Through this interaction, SAGs activate T cells at orders of magnitude above antigen-specific activation, resulting in massive cytokine release that is believed to be responsible for the most severe features of TSS. This review focuses on clinical and epidemiological aspects of TSS, as well as important developments in the genetics, biochemistry, immunology, and structural biology of SAGs. From the evolutionary relationships between these important toxins, we propose that there are five distinct groups of SAGs.