Postpartum invasive group A streptococcal disease in the modern era

Antimicrobial stewardship and targeted therapies in the changing landscape of maternal sepsis

Pregnant and postnatal women are a high-risk population particularly prone to rapid progression to sepsis with significant morbidity and mortality worldwide. Moreover, severe maternal infections can have a serious detrimental impact on neonates with almost 1 million neonatal deaths annually attributed to maternal infection or sepsis. In this review we discuss the susceptibility of pregnant women and their specific physiological and immunological adaptations that contribute to their vulnerability to sepsis, the implications for the neonate, as well as the issues with antimicrobial stewardship and the challenges this poses when attempting to reach a balance between clinical care and urgent treatment. Finally, we review advancements in the development of pregnancy-specific diagnostic and therapeutic approaches and how these can be used to optimize the care of pregnant women and neonates.

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.

Alterations in Toll-Like Receptor 7 and -9 mRNA Levels in Lungs after Ovariohysterectomy in a Pyometra Mouse Model

BACKGROUND

Pyometra (P) leads to sepsis and multiple organ dysfunction syndrome. Toll-like receptors (TLRs) recognize pathogens which can cause P. The aim of this study was to investigate TLR-7 and -9 via the MYD88 pathway and the nuclear factor kappa B (NFκB) response in the uterus of a P mouse model before and after ovariohysterectomy (RP) as well as potential lung injury.

MATERIALS AND METHODS

200 female C57BL/6J mice were randomly divided into groups (N = 10/subgroup; sham 1, 2, 3, 7; P1, 2, 3, 7; 1RP1, 2, 3, 7; 2RP1, 2, 3, 7; 3RP1, 2, 3, 7) according to the day of euthanasia. Pathogens were administrated in the groups P and RP in order to induce P.

RESULTS

Alterations in blood chemistry, histopathology, and RT-qPCT analysis before (P) and after RP were observed. Significant correlations were also found between MYD88, NFκB, and TLR9 in P and RP groups in the lungs and in RP groups in the uterus, suggesting that the immune system responded via the TLR9-MYD88 pathway.

CONCLUSIONS

This is the first report of immunohistochemical TLR-7 and -9 localization and of TLR-7, -9, MYD88, and NFκB mRNA expression in the uterus causing lung injury in a P mouse model.

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.

A Case Study of Puerperal Group A Streptococcal Infection Complicated by Toxic Shock Syndrome

Puerperal infection with group A streptococcus (GAS), Streptococcus pyogenes , is associated significant morbidity and mortality. When associated with toxic shock syndrome (TSS), mortality rates rise to approximately 50%. We present the case of a 32-year-old Para 2 reporting severe left distal lower extremity pain, fevers, and chills at 1 week following an uncomplicated vaginal delivery. The patient's clinical status rapidly decompensated to septic shock requiring transfer to the intensive care unit. She underwent anterior and lateral compartment fasciotomy of the left lower extremity for concerns of possible necrotizing soft tissue infection. Final blood cultures confirmed GAS infection with unclear primary source, though endometritis was favored. She required additional orthopaedic procedures including an arthroscopy with washout for contralateral septic arthritis and myositis before her discharge on hospital day 19. She obtained a near-full recovery complicated by poor wound healing and permanent left foot drop. While GAS remains a rare puerperal event, obstetricians should recall there is a 20-fold increased incidence among postpartum women. Progression to TSS is associated with very poor prognosis and hysterectomy is often necessary. Favorable outcomes in GAS with or without TTS hinge on astute clinical suspicion, aggressive fluid resuscitation, early antibiotic therapy, and source control.

Puerperal septic shock and necrotizing fasciitis caused by staphylococcus caprae and Escherichia coli

Puerperal sepsis is one of the leading causes of maternal morbidity and mortality worldwide. Postpartum pelvic infections can cause various complications, including wound infections and necrotizing fasciitis. Several microorganisms are known to cause such infections; however, no study has reported on staphylococcus caprae, a coagulase-negative staphylococcus that is isolated frequently from animals and infrequently from human specimens, as a causative agent. Here, we report a rare case of septic shock complicated by necrotizing fasciitis after a cesarean section. This is the first report of a human isolate of S. caprae in association with puerperal sepsis and necrotizing fasciitis.

Toxic Shock Syndrome within 24 H of an Office Hysteroscopy

Office hysteroscopy is now a common procedure performed to look at the endometrial cavity and is relatively free of serious complications. A 68-year-old lady, previously fit and well, presented with abdominal pain, rigors, sweats, and vomiting within 24 h of an outpatient hysteroscopy for postmenopausal bleeding. She was diagnosed with streptococcal toxic shock syndrome (STSS) due to Group A beta-hemolytic streptococci. She was managed in the Intensive Care Unit, with inotropic and antibiotic support. She recovered eventually and was discharged home with oral antibiotics. Toxic shock syndrome due to Streptococci is an unusual occurrence, whose incidence has been slowly increasing over the years. However, this appears to be the first case of STSS manifesting within 24 h following an outpatient hysteroscopy.

Virulence factors of Streptococcus pyogenes strains from women in peri-labor with invasive infections

Invasive group A streptococcal (GAS) infections constitute an important epidemiological problem. Many cases occur in women during the postnatal period. The objective of this study was to evaluate the presence of the genes responsible for production of iron-chelating protein (perR) and superantigens (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, and ssa) in S. pyogenes strains isolated from invasive infections in women after delivery. Furthermore, this study sought to verify whether S. pyogenes strains show special phenotypic and genotypic (sla, spy1325) characteristics that may play a decisive role in adherence to the genital tract epithelium. Moreover, the emm-types and antibiotic susceptibility were determined. We tested 30 invasive S. pyogenes strains isolated from postpartum invasive infection and 37 GAS control strains isolated from the genital tracts of asymptomatic multiparous women. The majority of the tested strains were shown to express two types of emm genes (1 and 28), though emm -12, -28, -75 and -89 were uniquely expressed in the group of strains isolated from invasive infections. A significantly higher prevalence of perR in the strains from puerperal fever was shown. Significant differences were also found between the two groups with respect to the incidence of the genes related to adherence; GAS strains originating from women with sepsis/puerperal fever showed presence of these genes less frequently than those of the control group. Although differences in frequencies of the gene coding for various superantigens were noted between the compared groups of GAS strains, they were not significant.

Unexplained persistent postpartum palpitations and tachycardia due to Group A Streptococcus

Background

Group A Streptococcus is one of the most morbid infections in modern obstetric practice. Pregnant women are known to have a 20-fold increased risk of invasive Group A Streptococcus with greatest risk in the first 4 days postpartum. The overwhelming majority of these infections will present with fever, uterine tenderness, or vaginal discharge. A much smaller subset may present to the Emergency Room after initial hospital discharge with much less obvious symptoms. In our case, persistent palpitations with unexplained tachycardia led to improper diagnosis in multiple Emergency Rooms.

Case presentation

A 37 year-old Caucasian female presents with four post-partum days of unexplained sinus tachycardia and absence of fever, uterine tenderness, or vaginal discharge, which elicits an extensive cardiac and pulmonary workup in multiple Emergency Rooms. Consequent late diagnosis of invasive Group A Streptococcus infection lead to significantly increased morbidity including toxic shock syndrome, acute renal failure, total abdominal hysterectomy and bilateral salpingo-oophorectomy, multiple laparotomies, fasciotomy, intubation, continuous renal replacement therapy, and extensive hospital course and recovery.

Conclusion

Persistent palpitations with unexplained tachycardia in the post-partum patient in the Emergency Room setting is a potential early warning of Group A Streptococcus infection. Even in the absence of reported clinical fever, uterine tenderness, or vaginal discharge, an early speculum and pelvic exam, with or without consultation with the obstetrics service, is prudent due to the potentially high morbidity or even fatality of Group A Streptococcus infection.

Life-threatening necrotizing myometritis, due to Group A streptococcus - still a life-threatening condition

Puerperal infection with Group A streptococcus (GAS) can present with few symptoms and rapidly progress to a life-threatening condition. Often, the infection can be treated with antibiotics. Delay in diagnosis increases risk of sepsis, multiorgan failure, and death. GAS infection is a differential diagnose for all postpartum women with unexplained symptoms.

Necrotizing Fasciitis Associated with Pregnancy: a Population-Based Cohort Study

Introduction

Necrotizing fasciitis (NF) is a rare complication in pregnant women. There have been no population-level data reported to date on its epidemiology, clinical features, resource utilization, and outcomes.

Methods

This was a retrospective, population-based cohort study, using the Texas Inpatient Public Use Data File to identify pregnancy-associated hospitalizations for the years 2001–2010. Hospitalizations with a diagnosis of NF were then identified using the International Classification of Diseases, Ninth Revision, Clinical Modification code 728.86. Denominator data for incidence estimates were derived from the Texas Center for Health Statistics reports of live births, abortions and fetal deaths, and previously reported population-based, age-specific linkage data on miscarriage, and were used to estimate the annual total number of pregnancies (TEP). The incidence of pregnancy-associated NF (PANF), hospitalization type, clinical features, resource utilization and outcomes were examined.

Results

There were 4,060,201 pregnancy-associated hospitalizations and 148 PANF hospitalizations during study period. Postpartum hospitalizations accounted for 82.4% of all PANF events, and intensive care unit care was required in 61.5%. The key trends noted between 2001–2002 and 2009–2010 included rising incidence of PANF from 1.1 vs. 3.8 per 100,000 TEP-years (P = 0.0001), chronic comorbidities 0% vs. 31.7% (P = 0.0777), and development of organ failure in 9.1% vs. 31.7% (P = 0.0302). There was no significant change in total hospital charges or hospital length of stay. Three patients (2%) died in the hospital and 55% of survivors had routine home discharge.

Conclusions

The present cohort of PANF is the largest reported to date. The incidence of PANF rose nearly 3.5-fold over the past decade, with most events developing following delivery hospitalization. Chronic illness has been increasingly present, along with rising severity of illness. The majority of patients required ICU care. Hospital mortality was lower than that reported for NF in the general population. The sources of the observed findings require further study.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-014-0031-0) contains supplementary material, which is available to authorized users.

The IL-8 protease SpyCEP is detrimental for Group A Streptococcus host-cells interaction and biofilm formation

SpyCEP-mediated chemokine degradation translates into more efficient spreading and increased severity of invasive Group A Streptococcus (GAS) infections, due to impaired neutrophil recruitment to the site of infection. SpyCEP is markedly up-regulated in invasive as compared to colonizing GAS isolates raising the question whether SpyCEP expression hinders bacterial attachment and thus colonization of the host. To address this question we used a molecular approach involving the use of homologous GAS strains either expressing or not SpyCEP or expressing an enzymatically inactive variant of SpyCEP. We found that expression of enzymatically functional SpyCEP lowered GAS adherence and invasion potential toward various epithelial and endothelial cells. SpyCEP also blunted biofilm formation capacity. Our data indicate that expression of SpyCEP decreases colonization and thus might be detrimental for the spreading of GAS.

Intrauterine group A streptococcal infections are exacerbated by prostaglandin E2

Streptococcus pyogenes (Group A Streptococcus; GAS) is a major cause of severe postpartum sepsis, a re-emerging cause of maternal morbidity and mortality worldwide. Immunological alterations occur during pregnancy to promote maternofetal tolerance, which may increase the risk for puerperal infection. PGE2 is an immunomodulatory lipid that regulates maternofetal tolerance, parturition, and innate immunity. The extent to which PGE2 regulates host immune responses to GAS infections in the context of endometritis is unknown. To address this, both an in vivo mouse intrauterine (i.u.) GAS infection model and an in vitro human macrophage-GAS interaction model were used. In C57BL/6 mice, i.u. GAS inoculation resulted in local and systemic inflammatory responses and triggered extensive changes in the expression of eicosanoid pathway genes. The i.u. administration of PGE2 increased the mortality of infected mice, suppressed local IL-6 and IL-17A levels, enhanced neutrophilic inflammation, reduced uterine macrophage populations, and increased bacterial dissemination. A role for endogenous PGE2 in the modulation of antistreptococcal host defense was suggested, because mice lacking the genes encoding the microsomal PGE2 synthase-1 or the EP2 receptor were protected from death, as were mice treated with the EP4 receptor antagonist, GW627368X. PGE2 also regulated GAS-macrophage interactions. In GAS-infected human THP-1 (macrophage-like) cells, PGE2 inhibited the production of MCP-1 and TNF-α while augmenting IL-10 expression. PGE2 also impaired the phagocytic ability of human placental macrophages, THP-1 cells, and mouse peritoneal macrophages in vitro. Exploring the targeted disruption of PGE2 synthesis and signaling to optimize existing antimicrobial therapies against GAS may be warranted.

Puerperal group a streptococcal infections: a case series and discussion

Puerperal group A streptococcal infections, a major postpartum killer during the late 19th and early 20th centuries, have become (fortunately) rare. We describe a cluster of 4 serious peripartum group A streptococcal infections occurring within the past five years at a single medical center. These cases were not epidemiologically linked and serve to illustrate the continuing risk of these potentially fulminant infections.

Leukotriene B4 enhances innate immune defense against the puerperal sepsis agent Streptococcus pyogenes

Puerperal sepsis is a leading cause of maternal mortality worldwide. Streptococcus pyogenes [group A Streptococcus; (GAS)] is a major etiologic agent of severe postpartum sepsis, yet little is known regarding the pathogenesis of these infections. Tissue macrophages provide innate defense against GAS, and their actions are highly regulated. The intracellular second messenger cAMP can negatively regulate macrophage actions against GAS. Because leukotriene (LT) B(4) has been shown to suppress intracellular cAMP in macrophages, we hypothesized that it could enhance innate defenses against GAS. We assessed the capacity of LTB(4) to modulate antistreptococcal actions of human macrophages, including placental and decidual macrophages and used a novel intrauterine infection model of GAS in mice lacking the 5-lipoxygenase enzyme to determine the role of endogenous LTs in host defense against this pathogen. Animals lacking 5-lipoxygenase were significantly more vulnerable to intrauterine GAS infection than were wild-type mice and showed enhanced dissemination of bacteria out of the uterus and a more robust inflammatory response than did wild-type mice. In addition, LTB(4) reduced intracellular cAMP levels via the BLT1 receptor and was a potent stimulant of macrophage phagocytosis and NADPH oxidase-dependent intracellular killing of GAS. Importantly, interference was observed between the macrophage immunomodulatory actions of LTB(4) and the cAMP-inducing lipid PGE(2), suggesting that interplay between pro- and anti-inflammatory compounds may be important in vivo. This work underscores the potential for pharmacological targeting of lipid mediator signaling cascades in the treatment of invasive GAS infections.

Postpartum group a Streptococcus sepsis and maternal immunology

Group A Streptococcus (GAS) is an historically important agent of puerperal infections and sepsis. The inception of hand-washing and improved hospital hygiene drastically reduced the incidence of puerperal sepsis, but recently the incidence and severity of postpartum GAS infections has been rising for uncertain reasons. Several epidemiological, host, and microbial factors contribute to the risk for GAS infection and mortality in postpartum women. These include the mode of delivery (vaginal versus cesarean section), the location where labor and delivery occurred, exposure to GAS carriers, the altered immune status associated with pregnancy, the genetic background of the host, the virulence of the infecting GAS strain, and highly specialized immune responses associated with female reproductive tract tissues and organs. This review will discuss the complicated factors that contribute to the increased susceptibility to GAS after delivery and potential reasons for the recent increase observed in morbidity and mortality.