Pregnancy-related group a streptococcal infections: temporal relationships between bacterial acquisition, infection onset, clinical findings, and outcome

A model for predicting bacteremia species based on host immune response

Introduction

Clinicians encounter significant challenges in quickly and accurately identifying the bacterial species responsible for patient bacteremia and in selecting appropriate antibiotics for timely treatment. This study introduces a novel approach that combines immune response data from routine blood counts with assessments of immune cell activation, specifically through quantitative measurements of Rho family GTPase activity. The combined data were used to develop a machine-learning model capable of distinguishing specific classes of bacteria and their associations.

Methods

We aimed to determine whether different classes of bacteria elicit distinct patterns of host immune responses, as indicated by quantitative differences in leukocyte populations from routine complete blood counts with differential. Concurrently, we conducted quantitative measurements of activated Rac1 (Rac1•GTP) levels using a novel 'G-Trap assay' we developed. With the G-Trap, we measured Rac1•GTP in peripheral blood monocytes (PBMC) and polymorphonuclear (PMN) cells from blood samples collected from 28 culture-positive patients and over 80 non-infected patients used as controls.

Results

Our findings indicated that 18 of the 28 patients with bacteremia showed an increase of ≥ 3-fold in Rac1•GTP levels compared to the controls. The remaining ten patients with bacteremia exhibited either neutrophilia or pancytopenia and displayed normal to below-normal Rac1 GTPase activity, which is consistent with bacteria-induced immunosuppression. To analyze the data, we employed partial least squares discriminant analysis (PLS-DA), a supervised method that optimizes group separation and aids in building a novel machine-learning model for pathogen identification.

Discussion

The results demonstrated that PLS-DA effectively differentiates between specific pathogen groups, and external validation confirmed the predictive model's utility. Given that bacterial culture confirmation may take several days, our study underscores the potential of combining routine assays with a machine-learning model as a valuable clinical decision-support tool. This approach could enable prompt and accurate treatment on the same day that patients present to the clinic.

Streptococcal toxic shock syndrome in the immediate postpartum period

In the puerperal phase, streptococcal toxic shock syndrome is a relatively uncommon occurrence. However, there has been a rise in the prevalence of more aggressive strains of Group A Streptococcus (GAS), leading to significant maternal morbidity and mortality. In this report, we present a case of a postpartum patient who developed streptococcal toxic shock syndrome with substantial inflammation shortly after delivery. The patient presented on the second postpartum day with hypotension, high fever, hypogastric tenderness and anaemia. After timely workup and appropriate antibiotic therapy, the patient fully recovered. Culture studies confirmed Gram-positive septicaemia with the presence of Streptococcus pyogenes in both the patient's blood and a previously inserted intrauterine device (IUD). This case underscores the importance of maintaining a high index of suspicion for GAS as the cause of puerperal infections despite its rarity. This results in prompt administration of antibiotics and source control, preventing consequences and avoiding mortality.

A Death From Necrotizing Wound Infection After Cesarean Section: Resurgence of Group A Streptococcal Puerperal Sepsis

ABSTRACT

Necrotizing wound infections are potentially lethal complications of surgeries, including cesarean deliveries. A 32-year-old female with obesity and hidradenitis suppurativa (HS) underwent uncomplicated cesarean section. Four days later, she developed abdominal pain and imaging showed ascites; she was treated with antibiotics. She progressed to septic shock and expired the following day from cardiopulmonary arrest. Hospital blood cultures grew no microorganisms. Autopsy revealed soft tissue purulence around the incision and copious purulent ascites without evidence of tubo-ovarian abscess, retained products of conception, or emboli. Microscopic examination of the tissues demonstrated inflammatory debris with neutrophils and gram-positive cocciform bacteria. Postmortem bacterial cultures had no growth. Paraffin blocks submitted to the Centers for Disease Control Infectious Disease Pathology Branch revealed Streptococcus pyogenes. Historically, group A streptococcus (GAS) was a major cause of peripartum mortality, and the prevalence of puerperal sepsis-associated deaths declined with antibiotic usage. Although the rates of mortality have remained stable in the United States, GAS has made a resurgence over recent decades. Additionally, there is some evidence in the literature of cutaneous bacterial biofilms associated with HS. Theoretically, this could have increased the risk of perioperative infection due to colonization or secondary infection of HS lesions.

The intricate pathogenicity of Group A Streptococcus: A comprehensive update

Group A Streptococcus (GAS) is a versatile pathogen that targets human lymphoid, decidual, skin, and soft tissues. Recent advancements have shed light on its airborne transmission, lymphatic spread, and interactions with neuronal systems. GAS promotes severe inflammation through mechanisms involving inflammasomes, IL-1β, and T-cell hyperactivation. Additionally, it secretes factors that directly induce skin necrosis via Gasdermin activation and sustains survival and replication in human blood through sophisticated immune evasion strategies. These include lysis of erythrocytes, using red cell membranes for camouflage, resisting antimicrobial peptides, evading phagocytosis, escaping from neutrophil extracellular traps (NETs), inactivating chemokines, and cleaving targeted antibodies. GAS also employs molecular mimicry to traverse connective tissues undetected and exploits the host's fibrinolytic system, which contributes to its stealth and potential for causing autoimmune conditions after repeated infections. Secreted toxins disrupt host cell membranes, enhancing intracellular survival and directly activating nociceptor neurons to induce pain. Remarkably, GAS possesses mechanisms for precise genome editing to defend against phages, and its fibrinolytic capabilities have found applications in medicine. Immune responses to GAS are paradoxical: robust responses to its virulence factors correlate with more severe disease, whereas recurrent infections often show diminished immune reactions. This review focuses on the multifaceted virulence of GAS and introduces novel concepts in understanding its pathogenicity.

Invasive group A Streptococcus infection (Streptococcus pyogenes): Current situation in Spain

Group A ß-hemolytic Streptococcus (S. pyogenes), also known as GAS, is a Gram-positive bacterium. It can be easily identified in the microbiology laboratory by its ability to hemolyse blood in culture media. This bacterium is highly virulent due to its production of enzymes and toxins, and its ability to cause immunologically mediated diseases such as rheumatic fever and post-streptococcal glomerulonephritis. GAS is the primary cause of bacterial pharyngotonsillitis, although it is typically a benign and non-invasive disease. However, it also has the potential to cause severe skin and soft tissue infections, necrotising fasciitis, bacteraemia and endocarditis, pneumonia and empyema, and streptococcal toxic shock syndrome, without any age or predisposition limits. The term invasive GAS disease (iGAS) is used to refer to this group of conditions. In more developed countries, iGAS disease has declined thanks to improved hygiene and the availability of antibiotics. For example, rheumatic fever has practically disappeared in countries such as Spain. However, recent data suggests a potential increase in some iGAS diseases, although the accuracy of this data is not consistent. Because of this, the COVID and Emerging Pathogens Committee of the Illustrious Official College of Physicians of Madrid (ICOMEM) has posed several questions about invasive GAS infection, especially its current situation in Spain. The committee has enlisted the help of several experts in the field to answer these questions. The following lines contain the answers that we have collaboratively produced, aiming to assist not only the members of ICOMEM but also anyone interested in this topic.

Sepsis in obstetric care for the emergency clinician: A review

Sepsis remains a leading cause of mortality among pregnant and recently pregnant patients, rendering it a subject of vital importance to emergency clinicians in the US. However, death by sepsis has been found to be largely preventable with prompt and appropriate intervention. This narrative review provides a summary of the physiologic, epidemiologic, and systemic factors specific to obstetric sepsis that contribute to delays in diagnosis and treatment. Additionally, it provides a framework for emergency department providers to approach infection identification, antimicrobial selection, and appropriate resuscitation prior to disposition.

Maternal Sepsis

Sepsis is the second leading cause of pregnancy-related mortality in the United States. Early recognition, treatment, and escalation of care for the obstetric patient affected by sepsis mitigate the risk of mortality and improve patient outcomes. In this article, we provide an overview of maternal sepsis and address topics of maternal pathophysiology, early warning signs, diagnostic criteria, early goal-directed therapy, and contemporary critical care practices. We also present an overview of common etiologies of maternal sepsis and suggested treatment approaches.

Surviving Postpartum Group A Streptococcus Sepsis Complicated by Multiorgan System Failure: A Complex Case Presentation

Postpartum group A streptococcal (GAS) sepsis is a rare obstetric complication with severe clinical implications and high morbidity and mortality, presenting diagnostic and management challenges. This report analyzes a complex case of postpartum GAS sepsis, highlighting the importance of understanding the pathophysiology and clinical trajectories of this often fatal pathogen. A comprehensive analysis was conducted on a patient with postpartum GAS sepsis. Literature review and case comparisons informed the study's context. Medical history, clinical presentation, diagnostic procedures, interventions, and outcomes were reviewed and documented. The patient presented on postpartum day 5 with abdominal pain and vaginal bleeding. Her condition rapidly deteriorated, requiring aggressive interventions and systemic support. Blood cultures confirmed GAS bacteremia. She developed toxic shock syndrome, cardiomyopathy with acute cardiac failure, and seizures secondary to subdural empyema. Multidisciplinary care facilitated eventual clinical recovery. Obstacles in achieving treatment balance were evident, underscoring the systemic nature of GAS infection and the significance of interdisciplinary collaboration. This case underscores the complex pathophysiology of postpartum GAS sepsis and the importance of prompt treatment initiation, aggressive intervention, and a multidisciplinary approach to management. The study contributes to the understanding of disease progression and clinical management in severe peripartum infections, reaffirming the need for further research to improve outcomes.

Estimating predictors of severity of group A Streptococcus infection in pregnancy

OBJECTIVE

To identify the clinical characteristics of pregnancy associated group A streptococcus (GAS) infection and predictors for intensive care unit (ICU) admission.

METHODS

A retrospective cohort study of culture-proven pregnancy-related GAS infections in tertiary hospital Electronic medical records were reviewed, for cases of cultures positive GAS that were identified between January 2008 and July 2021. A GAS infection was defined by the isolation of the pathogen from a sterile liquid or tissue site. Blood and urine cultures were obtained from all patients with peripartum hyperpyrexia (fever >38 °C). Medical Personnel screening included cultures of the throat, rectum, and skin lesions (if present). In cases of hemodynamic instability patients were transferred ad hoc to ICU, according to the obstetrician and intensivist judgment.

RESULTS

Of the 143,750 who delivered during the study period, 66 (0.04%) were diagnosed as having a pregnancy associated GAS infection. Of these, 57 patients presented postpartum, and represented the study cohort. The most common presenting signs and symptoms among puerperal GAS, were postpartum pyrexia (72%), abdominal pain (33%), and tachycardia (>100 bpm, 22%). 12 women (21.0%) developed streptococcal toxic shock syndrome (STSS. Predictors for STSS and ICU admission were: antibiotic administration >24 h from presentation postpartum, tachycardia, and a C-reactive protein level >200 mg/L. Women that received antibiotic prophylaxis during labor had a significantly lower rate of STSS (0 vs 10, 22.7%; p = .04).

CONCLUSION

Deferral of medical intervention >24 h from the first registered abnormal sign had the most important impact on deterioration of women with invasive puerperal GAS. Antibiotic prophylaxis during labor in women with GAS may reduce associated complications.

Group A Streptococcal Endometritis and Toxic Shock causing Septic Pelvic Thrombophlebitis and Septic Pulmonary Emboli

Group A Streptococcus (GAS) in the setting of postpartum endometritis can have severe and life-threatening complications. We report a rare case of septic pulmonary emboli that we surmised to have originated from septic pelvic thrombosis in the setting of GAS toxic shock syndrome (TSS) secondary to postpartum endometritis and intrauterine demise. Although the patient had source control with hysterectomy, she continued to have new septic emboli to the lungs seen on CT scans. CT scan of the pelvis demonstrated several filling defects in the renal and pelvic veins. The patient eventually responded well to anticoagulation in addition to antibiotics, which is similar to cases of Lemierre's syndrome. Additionally, we would like to bring attention to how important radiological findings can be missed if there is lack of interspecialty communication about the patient's clinical situation.

Pathogenesis, epidemiology and control of Group A Streptococcus infection

Streptococcus pyogenes (Group A Streptococcus; GAS) is exquisitely adapted to the human host, resulting in asymptomatic infection, pharyngitis, pyoderma, scarlet fever or invasive diseases, with potential for triggering post-infection immune sequelae. GAS deploys a range of virulence determinants to allow colonization, dissemination within the host and transmission, disrupting both innate and adaptive immune responses to infection. Fluctuating global GAS epidemiology is characterized by the emergence of new GAS clones, often associated with the acquisition of new virulence or antimicrobial determinants that are better adapted to the infection niche or averting host immunity. The recent identification of clinical GAS isolates with reduced penicillin sensitivity and increasing macrolide resistance threatens both frontline and penicillin-adjunctive antibiotic treatment. The World Health Organization (WHO) has developed a GAS research and technology road map and has outlined preferred vaccine characteristics, stimulating renewed interest in the development of safe and effective GAS vaccines.

Outcomes and management of pregnancy and puerperal group A streptococcal infections: A systematic review

INTRODUCTION

Group A streptococcus (Streptococcus pyogenes) is one of the most lethal bacterial pathogens of humans, with increased risk of progression to septic shock and multiorgan failure in the pregnant population. The objective of this study is to systematically review the outcomes and management strategies for pregnancy and puerperal group A streptococcus infections in an effort to provide further guidance for prevention and treatment of a rare but lethal infection worldwide.

MATERIAL AND METHODS

A comprehensive search using puerperium and streptococcus pyogenes terms was completed across several registered databases. A total of 902 articles investigating pregnancy and puerperal group A streptococcus infection were identified, with 40 studies fulfilling inclusion criteria of original research articles in humans published from 1990 onwards reporting four or more unique cases of group A streptococcus in pregnancy or postpartum. This study was registered in PROSPERO: CRD42020198983.

RESULTS

A total of 1160 patients with pregnancy and puerperal group A streptococcus infection were identified. Most infections occurred postpartum (91.9%), with 4.7% reported antepartum and 0.6% intrapartum. Bacteremia was present in 49.0% of patients and endometritis in 45.9%. Puerperal sepsis was described in 28.2% of cases and progressed to streptococcal toxic shock syndrome in one-third of such cases. Overall, the case fatality ratio was 2.0%, with one-third of the deaths from antenatal cases including 3/22 (13.6%) cases of septic abortion and 10/46 (21.7%) antenatal cases of group A streptococcus infection.

CONCLUSIONS

Group A streptococcus infection remains an important contributor to pregnancy and puerperal morbidity and mortality. Early recognition, diagnosis and aggressive management are important for favorable outcomes given the serious risk of sepsis and streptococcal toxic shock syndrome.

Standardization of Epidemiological Surveillance of Invasive Group A Streptococcal Infections

Invasive group A streptococcal (Strep A) infections occur when Streptococcus pyogenes, also known as beta-hemolytic group A Streptococcus, invades a normally sterile site in the body. This article provides guidelines for establishing surveillance for invasive Strep A infections. The primary objective of invasive Strep A surveillance is to monitor trends in rates of infection and determine the demographic and clinical characteristics of patients with laboratory-confirmed invasive Strep A infection, the age- and sex-specific incidence in the population of a defined geographic area, trends in risk factors, and the mortality rates and rates of nonfatal sequelae caused by invasive Strep A infections.

This article includes clinical descriptions followed by case definitions, based on clinical and laboratory evidence, and case classifications (confirmed or probable, if applicable) for invasive Strep A infections and for 3 Strep A syndromes: streptococcal toxic shock syndrome, necrotizing fasciitis, and pregnancy-associated Strep A infection.

Considerations of the type of surveillance are also presented, noting that most people who have invasive Strep A infections will present to hospital and that invasive Strep A is a notifiable disease in some countries. Minimal surveillance necessary for invasive Strep A infection is facility-based, passive surveillance. A resource-intensive but more informative approach is active case finding of laboratory-confirmed Strep A invasive infections among a large (eg, state-wide) and well defined population.

Participant eligibility, surveillance population, and additional surveillance components such as the use of International Classification of Disease diagnosis codes, follow-up, period of surveillance, seasonality, and sample size are discussed. Finally, the core data elements to be collected on case report forms are presented.

Case report: An unusual presentation of puerperal sepsis

Group A Streptococcus (GAS; Streptococcus pyogenes) is a facultative gram-positive coccus, uncommonly colonizing parturient genitalia, where its presence can potentially lead to a life-threatening invasive infection after delivery. GAS infection typically occurs within the first 4 days post-partum and is characterized by high fever, chills, flashing, abdominal pain, and uterine tenderness. Nonetheless, patients with GAS puerperal sepsis may have an unusual presentation, when fever is absent, and the symptoms and signs can be mild, non-specific, and not indicative of the severity of infection. This unusual presentation may lead to a delayed diagnosis and increase the risk for severe puerperal sepsis. Therefore, in these cases, a high index of suspicion and prompt early antibiotic and surgical treatment is crucial to saving the parturient’s life.

Group B Streptococcus colonization at delivery is associated with maternal peripartum infection

Background

Group B Streptococcus (GBS) is a major cause of serious neonatal infection but its role in maternal morbidity has received little investigation. The aim of this study was to determine whether GBS colonization at delivery is associated with increased risk of maternal peripartum infection.

Methods

In this prospective cohort study, 1746 unselected women had a vaginal-rectal culture taken at the onset of labor. Diagnosis of maternal peripartum infection was based on a combination of two or more signs or symptoms including fever, breast pain, severe wound or pelvic pain, purulent discharge and abnormal laboratory tests including C-reactive protein and white blood cell count occurring from labor until 2 weeks postpartum. The main outcome measure was the proportion of women with maternal peripartum infection according to GBS colonization status.

Results

A total of 25.9% (452/1746) women were colonized with GBS. The rate of peripartum infection was almost twice as high in colonized women (49/452 [10.8%]) vs. non-colonized women (81/1294 [6.3%]); OR 1.82 [1.26–2.64], p = 0.002). This association was confirmed in a multivariable model (OR 1.99 [1.35–2.95], p = 0.001). Women diagnosed with peripartum infection had a significantly longer hospital stay compared to women without peripartum infection (4 days (median) vs. 3 days, p < 0.001). Length of hospital stay did not differ between colonized and non-colonized women. Serotype IV GBS was more frequent in colonized women with peripartum infection than in women without peripartum infection (29.3% vs. 12.5%, p = 0.003).

Conclusions

GBS colonization at delivery is associated with increased risk of peripartum infection. Whether this increase is due directly to invasion by GBS or whether GBS colonization is associated with a more general vulnerability to infection remains to be determined.

Severe acute otitis media and mastoiditis caused by group A beta-hemolytic streptococcus

OBJECTIVE

To describe the characteristics, diagnostics, treatment, and outcome of severe acute otitis media (AOM) and acute mastoiditis (AM) caused by group A beta-hemolytic streptococcus (GAS).

STUDY DESIGN

A retrospective cohort study.

METHODS

The yearly incidence of inpatient care-needing GAS AOM/AM patients in our hospital catchment area between 2002 and 2018 was investigated. A detailed analysis was performed for cases treated during the last GAS epidemic in 2017-2018. Anamnesis, signs and symptoms, pure-tone audiometry results, treatment, complications, and outcome were collected from medical charts. Patients responded to an otology-specific health-related quality of life survey (EOS-16) 1.5 to 3 years after their treatment.

RESULTS

The number of GAS infections peaks at approximately 7-year intervals. During 2017 and 2018, altogether 37 patients (29 adults and 8 children) were hospitalized due to GAS AOM/AM. AM was diagnosed in 14 (38%) patients. The disease progression was typically very rapid. At presentation, all patients had severe ear pain, 68% tympanic membrane perforation and discharge, 43% fever, and 43% vertigo. In pure-tone audiometry, there was usually a marked mixed hearing loss at presentation. There was a significant recovery in both air and bone conduction thresholds; the pure tone average improvement from presentation was 32.3 ± 14.8 dB. Rapid strep tests (RST) proved to be more sensitive than bacterial culture in identifying GAS as a cause of AOM/AM.

CONCLUSION

GAS AOM/AM has a rapid onset. Hearing loss usually includes a sensorineural component, which is usually reversible with adequate treatment. RST seems to be useful in detecting GAS from middle ear discharge.

LEVEL OF EVIDENCE

4.

The RD2 Pathogenicity Island Modifies the Disease Potential of the Group A Streptococcus

Serotype M28 isolates of the group A Streptococcus (GAS; Streptococcus pyogenes) are nonrandomly associated with cases of puerperal sepsis, a potentially life-threatening infection that can occur in women following childbirth. Previously, we discovered that the 36.3-kb RD2 pathogenicity island, which is present in serotype M28 isolates but lacking from most other isolates, promotes the ability of M28 GAS to colonize the female reproductive tract. Here, we performed a gain-of-function study in which we introduced RD2 into representative serotype M1, M49, and M59 isolates and assessed the phenotypic consequences of RD2 acquisition. All RD2-containing derivatives colonized a higher percentage of mice, and at higher CFU levels, than did the parental isolates in a mouse vaginal colonization model. However, for two additional phenotypes, survival in heparinized whole human blood and adherence to two human vaginal epithelial cell lines, there were serotype-specific differences from RD2 acquisition. Using transcriptomic comparisons, we identified that such differences may be a consequence of RD2 altering the abundance of transcripts from select core genome genes along serotype-specific lines. Our study is the first that interrogates RD2 function in GAS serotypes other than M28 isolates, shedding light on variability in the phenotypic consequences of RD2 acquisition and informing on why this mobile genetic element is not ubiquitous in the GAS population.

Diseases and complications of the puerperium

BACKGROUND

In terms of maternal morbidity and mortality, the puerperium is just as significant as pregnancy and childbirth. Nearly half of all maternal deaths occur in the time after delivery.

METHODS

This review is based on pertinent articles in English and German from the years 2000- 2020 that were retrieved by a selective search in MEDLINE and EMBASE, as well as on the available guidelines in English and German and on German-language textbooks of obstetrics.

RESULTS

The most common and severe complications are, in the post-placental phase, bleeding and disturbances of uterine involution; in the first seven days after delivery, infection (e.g., endomyometritis, which occurs after 1.6% [0.9; 2.5] of all births) and hypertension-related conditions. Thromboembolism, incontinence and disorders of the pelvic floor, mental disease, and endocrine disturbances can arise at any time during the puerperium. In an Australian study, the incidence of embolism was 0.45 per 1000 births, with 61.3% arising exclusively after delivery.

CONCLUSION

Basic familiarity with the most common and severe diseases in the puerperium is important for non-gynecologists as well, among other things because highly acute, lifethreatening complications can arise that demand urgent intervention.

Invasive Streptococcus pyogenes disease in Spain: a microbiological and epidemiological study covering the period 2007-2019

The aim of this study is to present the first nationwide microbiological and epidemiological study of invasive group A Streptococcus (iGAS) disease in Spain. One thousand eight hundred ninety-three iGAS isolates were analyzed over 2007-2019. emm typing was performed by sequencing the gene's variable 5' end, exotoxin genes were identified by PCR, and antimicrobial susceptibility explored via the E test and disk diffusion. Five hundred twenty-three isolates were associated with sepsis, 292 with cellulitis, 232 with scarlet fever, 153 with pneumonia, 141 with streptococcal toxic shock syndrome, and 94 with necrotizing fasciitis. The most prevalent emm types were emm1 (449/1893 isolates), emm89 (210/1893), emm3 (208/1893), emm4 (150/1893), emm12 (112/1893) emm6 (107/1893), emm87 (89/1893), emm28 (88/1893), emm75 (78/1893), emm77 (78/1893), emm11 (58/1893), and emm22 (35/1893). emm1, emm3, emm4, and emm6 were the predominant types affecting children (mostly respiratory infections), while emm11, emm77, and emm89 prevailed in the elderly (mostly skin infections). Each emm type was associated with one or more exotoxin gene (spe, sme, and ssa) profiles. speA was detected in 660 isolates, speB in 1829, speC in 1014, speF in 1826, speG in 1651, speJ in 716, speH in 331, smeZ in 720, and ssa in 512. Isolates with speA were associated with the most severe infections. Penicillin susceptibility was universal. Two hundred twenty-four isolates were resistant to tetracycline, 169 to erythromycin, and 81 to clindamycin. Tetracycline, erythromycin, and clindamycin resistance rates declined over the study period. The above information could serve as the basis for continued surveillance efforts designed to control disease cause by this bacterium.

Native Hip Septic Arthritis in the Setting of Postpartum Gynecologic Infection: A Case Report

CASE

A 34-year-old healthy G3P3 woman, 1.5 weeks postpartum, presented with hip pain, fever, and a rash. Clinical examination, laboratory testing, and microbiologic cultures identified bacterial arthritis of the right hip; obstetric/gynecologic examination and cultures identified endometrial, vaginal, and urinary tract infections caused by the same pathogen, group A streptococcus, likely contracted from her 5-year-old son who had streptococcal pharyngitis. She underwent successful surgical decompression of the hip with concurrent medical management of toxic shock syndrome (TSS).

CONCLUSIONS

Hematogenously spread septic arthritis may occur in the absence of positive blood cultures during the postpartum period, increasing the risk of developing TSS.

Genital Tract GAS Infection ISIDOG Guidelines

There has been an increasing worldwide incidence of invasive group A streptococcal (GAS) disease in pregnancy and in the puerperal period over the past 30 years. Postpartum Group A streptococci infection, and in particular streptococcal toxic shock syndrome (TSS) and necrotizing fasciitis, can be life threatening and difficult to treat. Despite antibiotics and supportive therapy, and in some cases advanced extensive surgery, mortality associated with invasive group A streptococcal postpartum endometritis, necrotizing fasciitis, and toxic shock syndrome remains high, up to 40% of postpartum septic deaths. It now accounts for more than 75,000 deaths worldwide every year. Postpartum women have a 20-fold increased incidence of GAS disease compared to non-pregnant women. Despite the high incidence, many invasive GAS infections are not diagnosed in a timely manner, resulting in potentially preventable maternal and neonatal deaths. In this paper the specific characteristics of GAS infection in the field of Ob/Gyn are brought to our attention, resulting in guidelines to improve our awareness, early recognition and timely treatment of the disease. New European prevalence data of vaginal GAS colonization are presented, alongside two original case histories. Additionally, aerobic vaginitis is proposed as a supplementary risk factor for invasive GAS diseases.

A Review of Streptococcus pyogenes: Public Health Risk Factors, Prevention and Control

Streptococcus pyogenes, (colloquially named "group A streptococcus" (GAS)), is a pathogen of public health significance, infecting 18.1 million people worldwide and resulting in 500,000 deaths each year. This review identified published articles on the risk factors and public health prevention and control strategies for mitigating GAS diseases. The pathogen causing GAS diseases is commonly transmitted via respiratory droplets, touching skin sores caused by GAS or through contact with contaminated material or equipment. Foodborne transmission is also possible, although there is need for further research to quantify this route of infection. It was found that GAS diseases are highly prevalent in developing countries, and among indigenous populations and low socioeconomic areas in developed countries. Children, the immunocompromised and the elderly are at the greatest risk of S. pyogenes infections and the associated sequelae, with transmission rates being higher in schools, kindergartens, hospitals and residential care homes. This was attributed to overcrowding and the higher level of social contact in these settings. Prevention and control measures should target the improvement of living conditions, and personal and hand hygiene. Adherence to infection prevention and control practices should be emphasized in high-risk settings. Resource distribution by governments, especially in developed countries, should also be considered.

Streptococcus pyogenes infects human endometrium by limiting the innate immune response

Group A Streptococcus (GAS), a Gram-positive human-specific pathogen, yields 517,000 deaths annually worldwide, including 163,000 due to invasive infections and among them puerperal fever. Before efficient prophylactic measures were introduced, the mortality rate for mothers during childbirth was approximately 10%; puerperal fever still accounts for over 75,000 maternal deaths annually. Yet, little is known regarding the factors and mechanisms of GAS invasion and establishment in postpartum infection. We characterized the early steps of infection in an ex vivo infection model of the human decidua, the puerperal fever portal of entry. Coordinate analysis of GAS behavior and the immune response led us to demonstrate that (a) GAS growth was stimulated by tissue products; (b) GAS invaded tissue and killed approximately 50% of host cells within 2 hours, and these processes required SpeB protease and streptolysin O (SLO) activities, respectively; and (c) GAS impaired the tissue immune response. Immune impairment occurred both at the RNA level, with only partial induction of the innate immune response, and protein level, in an SLO- and SpeB-dependent manner. Our study indicates that efficient GAS invasion of the decidua and the restricted host immune response favored its propensity to develop rapid invasive infections in a gynecological-obstetrical context.

Nationwide study of mortality and survival in pregnancy-related streptococcal toxic shock syndrome

AIM

Streptococcal toxic shock syndrome is associated with the highest infection-related maternal mortality rates. We conducted a comparative analysis of the background factors and treatment course between survivors and nonsurvivors to improve our understanding concerning the optimal initial treatment approach for this fulminant disease.

METHODS

This retrospective observational study was conducted based on clinical data collected from two national organizations. Clinical data of patients who died or survived (i.e. background information, clinical course and treatment administered) were collected.

RESULTS

Records of 13 dead and 15 surviving patients were collected and analyzed. No statistically significant differences were found between the groups regarding age, parity, season, gestational age or the patients' location at the onset of symptoms. After the initial symptom onset, the survivors received antibiotics more systematically during their first visit to a clinic (P = 0.006). More survivors had received treatment within 1 h of onset of fulminant disease (P = 0.069). The number of fetal deaths was significantly higher in the mortality group (P = 0.003), while the fetal survival number was higher in the group of maternal survivors (P = 0.055). Maternal survivors with nonspecific initial symptoms received early intervention when there was a family history of group A streptococcal infection or a positive rapid antigen test result.

CONCLUSION

Intensive care, including systemic antibiotic administration, may contribute to maternal survival when administered immediately (within 1 h) after the fulminant streptococcal toxic shock syndrome onset. Eliciting a family history of streptococcal infection and conducting a rapid antigen test can identify the patients needing early intervention.

Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections occur after traumatic injuries, minor skin lesions, nonpenetrating injuries, natural childbirth, and in postsurgical and immunocompromised patients. Infections can be severe, rapidly progressive, and life threatening. Survivors often endure multiple surgeries and prolonged hospitalization and rehabilitation. Despite subtle nuances that may distinguish one entity from another, clinical approaches to diagnosis and treatment are highly similar. This review describes the clinical and laboratory features of necrotizing soft tissue infections and addresses recommended diagnostic and treatment modalities. It discusses the impact of delays in surgical debridement, antibiotic use, and resuscitation on mortality, and summarizes key pathogenic mechanisms.

How could we suspect life-threatening perinatal group A streptococcal infection?

AIM

Perinatal group A streptococcal infection is a rare but life-threatening condition. Few reports have focused on its clinical characteristics and how to prevent deterioration. We report our experience with two antenatal fatal cases and reviewed 96 cases in the literature to assess the clinical characteristics of group A streptococcal infection.

METHODS

English-language clinical reports of antenatal and postnatal group A streptococcal infection in 1974-2019 were retrieved and examined. Relationships between clinical characteristics and maternal outcomes were assessed.

RESULTS

Univariate analysis revealed that antenatal group A streptococcal infection was significantly associated with an age of ≤19 or ≥ 35 years, cesarean section, sore throat as an initial symptom, positive throat culture, maternal death and fetal death. Multivariate analysis revealed that antenatal onset (odds ratio = 7.922, 95% confidence interval = 1.297-48.374; P = 0.025) and a quick sepsis-related organ-failure assessment score (qSOFA; low blood pressure, high respiratory rate or altered mental status) of ≥2 (odds ratio = 6.166, 95% confidence interval = 1.066-35.670; P = 0.042) were significantly related to maternal death.

CONCLUSION

Per our findings, antenatal group A streptococcal infection was significantly associated with maternal and fetal death. Further, the antenatal infection was revealed as a more critical risk factor. We suggest that the presence of any sign related to the qSOFA is a potential clue suspecting perinatal group A streptococcal infection in primary obstetric facilities.

Global genomic epidemiology of Streptococcus pyogenes

Streptococcus pyogenes is one of the Top 10 human infectious disease killers worldwide causing a range of clinical manifestations in humans. Colonizing a range of ecological niches within its sole host, the human, is key to the ability of this opportunistic pathogen to cause direct and post-infectious manifestations. The expansion of genome sequencing capabilities and data availability over the last decade has led to an improved understanding of the evolutionary dynamics of this pathogen within a global framework where epidemiological relationships and evolutionary mechanisms may not be universal. This review uses the recent publication by Davies et al., 2019 as an updated global framework to address S. pyogenes population genomics, highlighting how genomics is being used to gain new insights into evolutionary processes, transmission pathways, and vaccine design.

Management of an outbreak of postpartum Streptococcus pyogenes emm75 infections

BACKGROUND

Streptococcus pyogenes is a well-known cause of postpartum infections and is causing significant morbidity and mortality.

AIM

To describe measures taken to control an outbreak of postpartum infections caused by S. pyogenes emm75 on a maternity ward.

METHODS

Patients presenting postpartum with signs and symptoms of infection were cultured for β-haemolytic streptococci with cervical swabs and blood cultures, and bacterial isolates were species-determined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and emm-typed. Pharyngeal swabs were taken from healthcare workers (HCWs) at the ward. Bacterial isolates were subjected to whole-genome sequencing (WGS). The multi-locus sequence type and the number of single nucleotide polymorphisms (SNPs) compared to an index genome were determined.

FINDINGS

During a three-month period, six cases of postpartum infection with S. pyogenes emm75 were identified on the maternity ward. By comparing delivery dates with duty rotas, one HCW was identified as a possible source of infection in five cases. After repeated pharyngeal swabs from this individual, an S. pyogenes emm75 was isolated. The five isolates from patients epidemiologically linked to the HCW and the two isolates of the family members had an identical sequence type (ST49) and 0-2 SNPs difference compared to the HCW isolate, whereas the sixth patient had an unrelated isolate. Eradication antibiotic therapy with clindamycin and rifampicin was given to the carrier. All patients received intravenous antibiotic treatment and recovered.

CONCLUSION

A three-month outbreak was stopped when a carrier was identified and treated. Source identification and WGS proved vital for outbreak control.

A rare case of group A streptococcal toxic-shock syndrome in a postpartum adolescent leading to multi-organ failure

Teenage pregnancy is not uncommon, but given the age of the patient, experience, and competency among medical providers varies. While toxic-shock syndrome from group A streptococcus is rare in teenage pregnancy, observed is a gap in care of bridging.

Genetic evolution of invasive emm28 Streptococcus pyogenes strains and significant association with puerperal infections in young women in Finland

OBJECTIVES

Streptococcus pyogenes or group A streptococcus (GAS) is a human specific pathogen that annually infects over 700 million individuals. GAS strains of type emm28 are an abundant cause of invasive infections in Europe and North America.

METHODS

We conducted a population-based study on bacteraemic emm28 GAS cases in Finland, from 1995 to 2015. Whole-genome sequencing (WGS) was used to genetically characterize the bacterial isolates. Bayesian analysis of the population structure was used to define genetic clades. Register-linkage analysis was performed to test for association of emm28 GAS with delivery- or postpartum-related infections. A genome-wide association study was used to search for DNA sequences associated with delivery or puerperal infections.

RESULTS

Among 3060 bacteraemic cases reported during the study period, 714 were caused by emm28. Women comprised a majority of cases (59 %, 422/714), and were significantly over-represented (84.4 %, 162/192, p < 0.0001) among cases in the childbearing age group (20-40 years). Register-linkage analysis revealed strong association (p < 0.0001) of emm28 bacteraemias with delivery and puerperium. In this register-linkage analysis, 120 women with GAS bacteraemia were identified and linked to delivery, infections during delivery or puerperium time. Among these the proportion of cases caused by emm28 was significantly higher than any other emm type (55.8%, 67/120, p < 0.0001). Among the four genetic subclades identified, SC1B has dominated among the bacteraemic cases since 2000. Altogether 620 of 653 (94.9%) isolates belonged to SC1B. No specific sequence or genetic clade was found nonrandomly associated with delivery or puerperal infections.

CONCLUSIONS

Women of childbearing age were significantly overrepresented among bacteraemic emm28 GAS cases, and in particular were strongly associated with delivery and puerperium cases over the 21 years studied. The molecular mechanisms behind these associations are unclear and warrant further investigation.

Group A Streptococcal Infection During Pregnancy and the Postpartum Period

Group A Streptococcus, the causative organism for "childbed fever," continues to pose a threat to women during pregnancy and the postpartum period, despite advances in hygiene and the development of antibiotic therapy. This resilient bacterium has resurfaced with intensified virulence, and, for reasons not entirely clear, causes severe disease in some women. Sepsis and toxic shock syndrome caused by Group A Streptococcus contribute to the alarming rates of maternal morbidity and mortality in the United States. Early recognition of the subtle signs and symptoms of sepsis is critical to decrease the risk for mortality; however, early signs can be elusive during the perinatal period because of the physiologic changes of pregnancy. Care management requires a coordinated, collaborative, multidisciplinary team approach. Sepsis is a clinical emergency, and health care providers need to respond as a well-prepared team.

Screening asymptomatic households for Streptococcus pyogenes pharyngeal carriage as a part of in-hospital investigation of puerperal sepsis

BACKGROUND

Invasive group A streptococcal (iGAS) infection in the peripartum setting is a rare but devastating disease occasionally occurring as a health care-associated infection (HAI). Current guidelines suggest enhanced surveillance and streptococcal isolate storage after a single case of iGAS, as well as a full epidemiological investigation that includes screening health care workers (HCWs) from several sites after 2 cases. Current guidelines do not recommend routine screening of household members of a patient with iGAS.

METHODS

We conducted studies of 3 patients with iGAS puerperal sepsis and related epidemiologic and molecular investigations.

RESULTS

Identical GAS emm gene types were found in pharyngeal cultures of 3 asymptomatic spouses of patients with iGAS puerperal sepsis. HCWs screened negative for GAS, and emm typing indicated that other iGAS cases from this hospital were sporadic and not related to the puerperal cases.

CONCLUSIONS

The concurrent presence of the same emm type in a household member practically excludes the option of an inadvertent HAI or facility outbreak. Hence, we suggest that screening close family members for asymptomatic GAS carriage should be performed early as a part of infection prevention measures, as doing so would have significant utility in saving time and resources related to a full epidemiological inquiry.

A Mobile Genetic Element Promotes the Association Between Serotype M28 Group A Streptococcus Isolates and Cases of Puerperal Sepsis

BACKGROUND

Bacterial infections following childbirth-so-called puerperal infections-cause morbidity in 5%-10% of all new mothers. At low frequency, the infection can spread to the blood, resulting in life-threatening sepsis known as puerperal sepsis. Pathogens causing puerperal sepsis include group A Streptococcus (GAS), and epidemiological analyses have identified isolates of a single serotype, M28, as being nonrandomly associated with cases of puerperal sepsis. The genomes of serotype M28 GAS isolates harbor a 36.3-kb mobile genetic element of apparent group B Streptococcus origin, termed region of difference 2 (RD2).

METHODS

The phenotypic (determined via tissue culture and a vaginal colonization model) and regulatory (determined via RNA sequencing analysis) contributions of RD2 were assessed by comparing parental, RD2 deletion mutant, and complemented mutant serotype M28 GAS strains.

RESULTS

RD2 affords serotype M28 isolates an enhanced ability to adhere to human vaginal epithelial cells and to colonize the female reproductive tract in a mouse model of infection. In addition, RD2 influences the abundance of messenger RNAs from >100 core chromosomal GAS genes.

CONCLUSIONS

The data are consistent with RD2 directly, via encoded virulence factors, and indirectly, via encoded regulatory proteins, modifying the virulence potential of GAS and contributing to the decades-old association of serotype M28 isolates with cases of puerperal sepsis.

Integrated analysis of population genomics, transcriptomics and virulence provides novel insights into Streptococcus pyogenes pathogenesis

Streptococcus pyogenes causes 700 million human infections annually worldwide, yet, despite a century of intensive effort, there is no licensed vaccine against this bacterium. Although a number of large-scale genomic studies of bacterial pathogens have been published, the relationships among the genome, transcriptome, and virulence in large bacterial populations remain poorly understood. We sequenced the genomes of 2,101 emm28 S. pyogenes invasive strains, from which we selected 492 phylogenetically diverse strains for transcriptome analysis and 50 strains for virulence assessment. Data integration provided a novel understanding of the virulence mechanisms of this model organism. Genome-wide association study, expression quantitative trait loci analysis, machine learning, and isogenic mutant strains identified and confirmed a one-nucleotide indel in an intergenic region that significantly alters global transcript profiles and ultimately virulence. The integrative strategy that we used is generally applicable to any microbe and may lead to new therapeutics for many human pathogens.

Risk factors, clinical course and outcomes of pregnancy-related group A streptococcal infections: retrospective 13-year cohort study

OBJECTIVES

To investigate the incidence, risk factors, clinical course and outcomes of pregnancy-related group A streptococcus (GAS) infection.

METHODS

A retrospective 13-year cohort study of culture-proven pregnancy-related GAS infection was performed at two university hospitals serving heterogeneous, multicultural, urban and rural populations.

RESULTS

Of 124 women diagnosed with pregnancy-related GAS infection, 115 (93%) were in the puerperium, an incidence of 0.8 cases per 1000 live births (95% confidence interval, 0.7-0.9). A multivariate analysis showed primiparity and cesarean delivery to be independent protective factors against puerperal GAS infection (adjusted odds ratios (95% confidence interval), 0.60 (0.38, 0.97) and 0.44 (0.23, 0.81), respectively). Of the nine remaining patients, eight were diagnosed after first trimester abortions and one had an infected ectopic pregnancy. Among the entire cohort (n = 124), the predominant manifestations were fever and abdominal tenderness. Twenty-eight patients (23%) had severe GAS infections. All were treated with β-lactams, and most (n = 104, 84%) received clindamycin. Only four (3%) required surgical intervention; the rest fully recovered with conservative medical treatment including antibiotics. No recurrences, maternal deaths or neonatal complications were noted.

CONCLUSIONS

Pregnancy-related GAS infection is not rare; it lacks specific signs and still carries significant morbidity. Primiparity, a presumable surrogate for diminished exposure to children and thus less GAS carriage, and cesarean delivery in which perioperative antibiotic prophylaxis was uniformly provided, appear as protective factors against puerperal GAS infection. This hints to the importance of community-acquired GAS and may support shifting efforts from infection-control-oriented nosocomial investigations to screening and prevention-driven policies.

Operative vaginal delivery and post-partum infection

During the past decade, there has been an increase in the awareness of infections associated with pregnancy and delivery. The most significant cause of post-partum infection is caesarean section; 20-25% of operations are followed by wound infections, endometritis or urinary tract infections. Approximately 13% of women in the UK undergo operative vaginal delivery (OVD) with forceps or vacuum, which is also associated with an increased risk of infection, estimated at 0.7%-16% of these deliveries. Despite this, previous reviews have identified only one small trial of antibiotic prophylaxis in 393 women and concluded that there was insufficient evidence to support the routine use of prophylactic antibiotics after OVD. The ANODE trial, a multicentre, blinded, placebo-controlled trial from the UK, is due to report findings from more than 3400 women in 2019 and will be the largest study to date of antibiotic prophylaxis following OVD.

Postpartum Invasive Group A Streptococcus Infection: Case Report and Mini-review

The overall incidence of postpartum invasive group A streptococcal (GAS) disease is low in the United States. However, postpartum women are much more likely to develop GAS disease than nonpregnant women. Additionally, postpartum GAS has the potential to develop into a severe disease and a delay in diagnosis can have deadly consequences. This case describes a patient with invasive postpartum endometritis in the setting of diastases of the pubic symphysis. Sepsis secondary to the endometritis develops along with bilateral pneumonia. This case characterizes some of the typical and atypical symptoms a patient with invasive postpartum GAS can present with. Further, it outlines the timely identification of the disease and its appropriate treatment to prevent a potentially disastrous outcome.

Sepsis in pregnancy and the puerperium

Sepsis remains a leading cause of maternal morbidity and mortality. Recognition and treatment of maternal sepsis are often delayed due to the physiological adaptations of pregnancy and vague or absent signs and symptoms during its initial presentation. Over the past decade, our understanding of sepsis has evolved and maternal early warning systems have been developed in an effort to help providers promptly identify and stratify parturients who are at risk. In addition, new consensus definitions and care bundles have recently been published by the World Health Organization and the Surviving Sepsis Campaign to facilitate earlier recognition and timely management of sepsis. In this narrative review, we summarize the available evidence about sepsis and provide an overview of the research efforts focused on maternal sepsis to date. Controversies and challenges surrounding the anesthetic management of parturients with sepsis or at risk of developing sepsis during pregnancy or the puerperium will be highlighted.

Clinical Variables Associated With Adverse Maternal Outcomes in Puerperal Group A Streptococci Infection

OBJECTIVE

To identify clinical variables associated with increased risk of composite adverse outcome in a cohort of women with puerperal group A streptococci infection.

METHODS

Our prospective case registry enrolled patients between 1991 and 2017. Chart abstraction was conducted for admission demographic and clinical data in patients with culture-proven puerperal group A streptococci infection. We created a composite variable of signs of capillary leakage including pulmonary edema, pleural effusion, ascites, and abdominal distention. The composite adverse outcome included death, hysterectomy, intensive care unit admission, mechanical ventilation, and blood transfusion. Clinical characteristics were compared between those with a composite adverse outcome and those without. We fit unadjusted log-linear models with robust error variance to measure the relative risk of a composite adverse outcome associated with clinical and demographic variables among patients with group A streptococci.

RESULTS

Thirty-five of 71 (49%) patients had an adverse outcome. Women who had adverse outcomes had higher admission heart rates (126±19 vs 112±22 beats per minute, P=.008) and respiratory rates (26±10 vs 20±5 breaths per minute, P=.01), lower systolic blood pressure (98±24 vs 114±19 mm Hg, P=.004), and were more likely to have signs of capillary leakage (77% vs 20%, P<.001) and symptoms of capillary leakage (dyspnea, cough, shoulder pain, abdominal bloating, and chest pain) (40% vs 17%, P=.03) compared with those without adverse outcomes. Log-linear models indicated that these clinical variables were individually associated with increased risk of a composite adverse outcome. The relative risk of an adverse outcome was 3.5 times higher among women with signs of capillary leakage (relative risk 3.67, 95% CI 1.94-6.94, P<.001).

CONCLUSION

Vital sign parameters consistent with severe infection correlate with adverse outcomes in women with puerperal group A streptococci infection. Signs of capillary leakage are most strongly associated with a composite adverse outcome. These clinical characteristics, particularly signs of capillary leakage, are potentially useful to guide clinical care.

Severe maternal morbidity due to sepsis: The burden and preventability of disease in New Zealand

BACKGROUND

Sepsis is a life-threatening systemic condition that appears to be increasing in the obstetric population. Clinical detection can be difficult and may result in increased morbidity via delays in the continuum of patient care.

AIMS

To describe the burden of severe maternal morbidity (SMM) caused by sepsis in New Zealand and investigate the potential preventability.

METHODS

A multidisciplinary expert review panel was established to review cases of obstetric sepsis admitted to intensive care or high-dependency units over an 18 month span in New Zealand. Cases were then analysed for the characteristics of infection and their preventability.

RESULTS

Fifty cases met the inclusion criteria, most commonly due to uterine, respiratory or kidney infection. Fifty per cent (25) of these cases were deemed potentially preventable, predominantly due to delays in diagnosis and treatment.

CONCLUSIONS

A high index of suspicion, development of early recognition systems and multi-disciplinary training are recommended to decrease preventable cases of maternal sepsis.