Community-Acquired Methicillin-Resistant Staphylococcus aureus Among Patients With Puerperal Mastitis Requiring Hospitalization

The prevalence and risk factors of methicillin-resistant Staphylococcus aureus among pediatric populations: a systematic review and meta-analysis

There is scarcity in the data about MRSA prevalence and risk factors among the pediatric population. This research explores the global prevalence and risk factors of MRSA among the pediatric population. PubMed, Scopus, Web of Sciences, and the Cochrane Central Register of Controlled Trials were systematically searched. Our primary goal was to assess the prevalence of MRSA colonization and its related risk factors in the general pediatric population. A total of 124 studies encompassing 44 million participants were included in this meta-analysis, and the overall pooled estimated global prevalence of MRSA colonization in pediatric was 5% [95% CI 4-5%]. Female sex (OR = 4.17; 95% CI, 3.31-5.27), recent surgery (OR = 3.79; 95% CI, 2.20-6.52), recent hospitalization (OR = 2.63; 95% CI, 1.78-3.86), and antibiotic use (OR = 2.42; 95% CI, 1.58-3.72) were significantly associated with higher odds of MRSA colonization.

CONCLUSION

Future research should build on these findings by emphasizing ongoing efforts to combat MRSA in pediatric settings and implementing targeted interventions.

WHAT IS KNOWN

• Methicillin-resistant Staphylococcus aureus (MRSA) is considered a threat to public health. It is noteworthy to mention that the prevalence of MRSA strains has not been adequately quantified in many countries, especially in the pediatric population. The pediatric population is a pivotal source of MRSA and may play a central role in its distribution in both community and healthcare settings. A notable study underscores the gravity of the situation, estimating a tenfold increase in the incidence of MRSA infection among children in the USA between 1999 and 2008.

WHAT IS NEW

• Here we present the first global systematic review and meta-analysis to investigate the prevalence and risk factors of MRSA among the pediatric population. A total of 124 studies encompassing 44 million participants were included in this analysis. The overall pooled estimated global prevalence of MRSA colonization in the pediatric population was 5% [95% CI 4-5%]. The prevalence was the highest in Asia and lowest in Europe. Female sex, recent surgery, recent hospitalization, and antibiotic use were significantly associated with higher odds of MRSA colonization.

Puerperal mastitis caused by limited community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clones

Objective

To outline the epidemiology of puerperal mastitis caused by methicillin-resistant Staphylococcus aureus (MRSA) and evaluate the effect of an infection control bundle on its incidence.

Methods

A surge in MRSA puerperal mastitis was noted in a community hospital in September 2009. MRSA samples from mastitis cases and the environment underwent typing using multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec), gene encoding surface protein A (spa), accessory gene regulator (agr), and pulsed-field gel electrophoresis (PFGE). The phenotypic characteristics, including superantigen toxin profiles, gene encoding Panton-Valentine leucocidin (pvl), and minimal inhibitory concentration (MIC) against vancomycin, were ascertained. Subsequently, an infection control bundle emphasizing contact precautions was introduced, and mastitis incidence rates pre- and post-intervention were compared.

Results

The majority of cases occurred within 6 weeks post-delivery in first-time mothers. Of the 42 S. aureus isolates (27 from mastitis and 15 from colonized staff and environmental sources), 25 (92.6%) clinical and 3 (20%) colonized MRSA were identified as ST59-SCCmecVT-spa t437-agr group I with a vancomycin MIC of 1 mg/L, pvl-positive, and predominantly with a consistent toxin profile (seb-selk-selr). PFGE revealed 13 patterns; pulsotype B exhibited clonal relatedness between two clinical and three colonized MRSA samples. Post-intervention, the incidence of both mastitis and MRSA mastitis notably decreased from 13.01 to 1.78 and from 3.70 to 0.99 episodes per 100 deliveries, respectively.

Conclusion

Distinct community-associated MRSA (CA-MRSA) clones were detected among puerperal mastitis patients and colonized staff. The outbreak was effectively controlled following the implementation of a targeted infection control bundle.

Red Cabbage: A Novel Treatment for Periductal Lactational Mastitis

Lactational mastitis is a common condition in breastfeeding women that manifests as painful, swollen, and erythematous breasts. Customary treatment guidelines include antibiotics, cold compression, and continued breastfeeding. This report highlights a unique case in which the symptomatic progression of lactational mastitis was alleviated with the utilization of red cabbage and warm compresses. The study further investigates the potential benefits and role of red cabbage in treating mastitis infections to prevent unnecessary overuse of antibiotics and promote antibiotic stewardship practices.

Risk factors and prognosis of acute lactation mastitis developing into a breast abscess: A retrospective longitudinal study in China

Background

Breast abscess is developed on the basis of acute mastitis, which will cause damage to the physical and mental health of lactating women and is an important factor affecting the rate of breastfeeding. This study examined the risk factors for mastitis to develop into breast abscess, and analyzed the distribution of pathogenic bacteria, bacterial resistance, and treatment outcome.

Methods

The medical records of 316 cases of mastitis and 219 cases of breast abscess were retrospectively collected. We analyzed the bacterial distribution of mastitis and breast abscess, and compared the differences of bacterial drug resistance. Univariate analysis and binary logistic regression were used to analyze the following aspects: age, primiparity or not, history of breast surgery, body temperature, puerperium or not, onset time, located in the nipple/areolar complexe area or not, history of massage by non-professionals, staphylococcus aureus/methicillin-resistant staphylococcus aureus (MRSA) infection or not, diabetes and white blood cell count.

Results

Of the 535 patients, 203 (37.9%) were positive for staphylococcus aureus. There were 133 (65.5%) cases of methicillin-sensitive staphylococcus aureus (MSSA) and 70 (34.5%) cases of MRSA. Concerning bacterial drug resistance, a statistical analysis showed that MSSA had high resistance rate to penicillin (96.2%), ampicillin (91%), clindamycin (42.9%) and erythromycin (45.9%). MRSA had a high resistance rate to penicillin (100%), ampicillin (98.6%), oxacillin (95.7%), erythromycin (81.4%), clindamycin (80%), and amoxicillin (31.7%). Risk factors for progression of mastitis to breast abscess include a body temperature<38.5°C, a postpartum time ≥ 42 days, an onset time ≥ 2 days, lesions in the nipple/areolar complex area, a history of massage by non-medical staff and bacterial cultures for milk or pus that test positive for staphylococcus aureus or MRSA (P < 0.001).

Conclusions

The most common pathogenic bacteria of mastitis and breast abscess is staphylococcus aureus. There are many risk factors for mastitis to develop into breast abscess. We should take effective measures for its risk factors and select sensitive antibiotics according to the results of bacterial culture to reduce the formation of breast abscess.

Inflammatory diseases of the breast

Inflammatory disorders of the breast are common benign breast conditions. Lactational mastitis occurs in breastfeeding women and may be associated with breast abscess in severe cases. Non-lactational inflammatory disorders are less common and include idiopathic granulomatous mastitis, periductal mastitis, and tuberculous mastitis. While these disorders have some similarities in their presentation, each disorder requires a specific treatment regimen for resolution, and correct diagnosis is crucial for appropriate treatment. In this chapter, we will review the presentation, diagnosis, and management of each of these distinct clinical entities.

Clinical characteristics of lactational breast abscess caused by methicillin-resistant Staphylococcus aureus: hospital-based study in China

Background

This study aimed to identify the differences in clinical characteristics, puncture efficacy, antibiotic use, treatment duration, breastfeeding post-illness, and recurrence of patients with breast abscesses caused by methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-susceptible Staphylococcus aureus (MSSA) infection during lactation.

Methods

The clinical data of patients with breast abscesses during lactation who were treated from January 2014 to February 2017 at Haidian Maternal and Child Health Hospital, Beijing, were reviewed. According to bacterial culture results, they were divided into MRSA (n = 260) and MSSA (n = 962) groups. Hospitalization (whether or not the patients were hospitalized), postpartum period, maternal age, location of abscess cavities, number of abscess cavities, amount of pus, frequency of needle aspiration, failure of needle aspiration, antibiotic use, treatment duration, cessation of breastfeeding and recurrence were compared between the two groups using a t-test and a chi-squared test.

Results

We noted that only the cessation of breastfeeding was statistically significantly different between the two groups (P = 0.018). Hospitalization, postpartum period, maternal age, location of abscess cavities, number of abscess cavities, amount of pus, number of needle aspiration, failure of needle aspiration, antibiotic use, treatment duration and recurrence showed no statistically significant differences (P = 0.488, P = 0.328, P = 0.494, P = 0.218, P = 0.088, P = 0.102, P = 0.712, P = 0.336, P = 0.512, P = 0.386 and P = 0.359, respectively).

Conclusions

There was no difference in clinical characteristics between breast abscesses infected by MRSA and those infected by MSSA. Ultrasound-guided needle aspiration could be the first choice for MRSA-infected breast abscess treatment. There is no need to increase antibiotic use because of MRSA infection, unless it is necessary. The reason why more patients with MRSA infected breast abscesses terminated breastfeeding is unclear from this study.

Mastitis, Breast Abscess, and Granulomatous Mastitis

Breastfeeding is immunoprotective and World Health Organization recommends exclusive breastfeeding for about six months with continuation of breastfeeding for one year or longer as mutually desired by mother and infant. But the target for duration of exclusive breastfeeding has not been reached in a significant number of women. It may be due to inflammatory breast disease such as milk stasis or lactational mastitis.In this chapter we discuss the most common complications of breastfeeding including milk stasis, mastitis, and breast abscess. Also idiopathic granulomatous mastitis, a less common condition, is discussed due to its confusing characteristics and not universally-accepted treatment strategies .Breastfeeding mastitis is inflammation of the breast that can be infectious or non-infectious. With proper diagnosis and treatment of this condition, more severe complications like breast abscess could be avoided, so that breastfeeding could be continued in some circumstances.

Identification of Key Determinants of Staphylococcus aureus Vaginal Colonization

Staphylococcus aureus is an important pathogen responsible for nosocomial and community-acquired infections in humans, and methicillin-resistant S. aureus (MRSA) infections have continued to increase despite widespread preventative measures. S. aureus can colonize the female vaginal tract, and reports have suggested an increase in MRSA infections in pregnant and postpartum women as well as outbreaks in newborn nurseries. Currently, little is known about specific factors that promote MRSA vaginal colonization and subsequent infection. To study S. aureus colonization of the female reproductive tract in a mammalian system, we developed a mouse model of S. aureus vaginal carriage and demonstrated that both hospital-associated and community-associated MRSA isolates can colonize the murine vaginal tract. Immunohistochemical analysis revealed an increase in neutrophils in the vaginal lumen during MRSA colonization. Additionally, we observed that a mutant lacking fibrinogen binding adhesins exhibited decreased persistence within the mouse vagina. To further identify novel factors that promote vaginal colonization, we performed RNA sequencing to determine the transcriptome of MRSA growing in vivo during vaginal carriage at 5 h, 1 day, and 3 days postinoculation. Over 25% of the bacterial genes were differentially regulated at all time points during colonization compared to laboratory cultures. The most highly induced genes were those involved in iron acquisition, including the Isd system and siderophore transport systems. Mutants deficient in these pathways did not persist as well during in vivo colonization. These results reveal that fibrinogen binding and the capacity to overcome host nutritional limitation are important determinants of MRSA vaginal colonization.IMPORTANCE Staphylococcus aureus is an opportunistic pathogen able to cause a wide variety of infections in humans. Recent reports have suggested an increasing prevalence of MRSA in pregnant and postpartum women, coinciding with the increased incidence of MRSA infections in neonatal intensive care units (NICUs) and newborn nurseries. Vertical transmission from mothers to infants at delivery is a likely route of MRSA acquisition by the newborn; however, essentially nothing is known about host and bacterial factors that influence MRSA carriage in the vagina. Here, we established a mouse model of vaginal colonization and observed that multiple MRSA strains can persist in the vaginal tract. Additionally, we determined that MRSA interactions with fibrinogen and iron uptake can promote vaginal persistence. This study is the first to identify molecular mechanisms which govern vaginal colonization by MRSA, the critical initial step preceding infection and neonatal transmission.

Clinical relevance of colonization with antimicrobial-resistant bacteria (AMRB) and methicillin susceptible Staphylococcus aureus (MSSA) for mothers during pregnancy

PURPOSE

The impact of colonization with antimicrobial-resistant bacteria (AMRB) and methicillin-sensitive Staphylococcus aureus (MSSA) of healthy pregnant women is not described in detail in Germany. In this study, we screened for MSSA and AMRB, especially for methicillin-resistant S. aureus (MRSA) as well as extended-spectrum beta-lactamase (ESBL)-producing E. coli. Potential risk factors for colonization with AMRB/MSSA and the potential effects of colonization with these on the obstetric population were investigated.

METHODS

From October 2013 until December 2015 pregnant women were screened before birth for colonization with AMRB/MSSA from the mammillae, nose, perianal and vaginal area. Before birth, the expectant mother was administered a standardized interview questionnaire by a trained interviewer. Data from the hospital admission records were also included.

RESULTS

Samples from 651 pregnant women were analyzed. Colonization with MSSA was detected in 14.3% (n = 93), AMRB in 3.5% [(n = 23); MRSA: n = 3/ESBL: n = 20]. Significantly more colonization of AMRB/MSSA could be detected in women who had previously given birth compared to women who were nulliparous (p < 0.05). MSSA colonization was significantly associated with self-reported respiratory diseases during pregnancy (p < 0.05), but AMRB/MSSA colonization was not statistically associated with other types of infection.

CONCLUSION

Our results demonstrate a low overall rate of colonization with AMRB/MSSA, as well as a low percentage of colonized pregnant women who developed infections. Multiparous women are at higher risk for colonization with MSSA/MRSA or ESBL. Because the prevalence of AMRB/MSSA is low, this study suggests that general screening of pregnant women without risk factors is not recommended.

Breast infections - Microbiology and treatment in an era of antibiotic resistance

INTRODUCTION

Primary breast abscesses occur in <1% of non-lactating women, rising to 11% in women with lactational mastitis. In patients undergoing breast cancer surgery, the inflammatory response to post-operative surgical site infection (SSI) has been implicated in recurrence. Anti-microbial resistance increasingly hampers treatment in each group.

AIMS

Describe the demographic and predisposing characteristics of patients with primary breast abscesses and secondary infections, identify the microbial and antimicrobial patterns and formulate an evidence-based protocol for treating breast infections.

METHODS

Retrospective cohort study of all breast infections (primary and post-operative) treated at UHL from 2014 to 2017. Data collected from microbiology databases and patient records was analysed using Minitab V18.

RESULTS

537 cultures from 108 patients were analysed. 47 (43.5%) had primary abscesses, 12 (11.1%) were lactational and 49 (45.4%) were post-operative SSI. For primary infections, the mean age was 41.9 (±12.2) and reinfection rate 33%. For SSIs the mean age was 51.8 (±14.52) and reinfection rate 11.8%. Overall, 29.3% were smokers, 6.4% diabetic and 2.9% pregnant. 60 (43%) patients required radiological drainage and 2 (1%) surgical drainage. 57.5% had mixed growth. The most common isolate was Staphylococcus aureus; cultured in 16.7% of primary abscesses and 24% of SSIs. 13 empiric antibiotic regimes were prescribed before 26.4% of patients changed to 12 different targeted regimes.

CONCLUSION

Breast infections are frequently polymicrobial with a wide variety of organisms isolated, suggesting the need for broad spectrum coverage until culture results become available. Based on our local culture results, the addition of clindamycin to flucloxacillin would provide excellent empiric coverage for all categories of breast infection. An evidence-based treatment guideline is required and should be formulated in close collaboration with microbiology specialists.

Staphylococcus aureus-Associated Skin and Soft Tissue Infections: Anatomical Localization, Epidemiology, Therapy and Potential Prophylaxis

Skin and soft tissue infections (SSTIs) are among the most common infections worldwide. They range in severity from minor, self-limiting, superficial infections to life-threatening diseases requiring all the resources of modern medicine. Community (CA) and healthcare (HA) acquired SSTIs are most commonly caused by Staphylococcus aureus . They have variable presentations ranging from impetigo and folliculitis to surgical site infections (SSIs). Superficial SSTIs may lead to even more invasive infections such as bacteraemia and osteomyelitis. Here we describe the anatomical localization of the different SSTI associated with S. aureus, the virulence factors known to play a role in these infections, and their current epidemiology. Current prevention and treatment strategies are also discussed. Global epidemiological data show increasing incidence and severity of SSTIs in association with methicillin-resistant S. aureus strains (MRSA). CA-SSTIs are usually less morbid compared to other invasive infections caused by S. aureus, but they have become the most prevalent, requiring a great number of medical interventions, extensive antibiotic use, and therefore a high cost burden. Recurrence of SSTIs is common after initial successful treatment, and decolonization strategies have not been effective in reducing recurrence. Furthermore, decolonization approaches may be contributing to the selection and maintenance of multi-drug resistant strains. Clinical studies from the early 1900s and novel autovaccination approaches suggest an alternative strategy with potential effectiveness: using vaccines to control S. aureus cutaneous infections.

Metagenomic Analysis of Milk of Healthy and Mastitis-Suffering Women

BACKGROUND

Some studies have been conducted to assess the composition of the bacterial communities inhabiting human milk, but they did not evaluate the presence of other microorganisms, such as fungi, archaea, protozoa, or viruses.

OBJECTIVE

This study aimed to compare the metagenome of human milk samples provided by healthy and mastitis-suffering women.

METHODS

DNA was isolated from human milk samples collected from 10 healthy women and 10 women with symptoms of lactational mastitis. Shotgun libraries from total extracted DNA were constructed and the libraries were sequenced by 454 pyrosequencing.

RESULTS

The amount of human DNA sequences was ≥ 90% in all the samples. Among the bacterial sequences, the predominant phyla were Proteobacteria, Firmicutes, and Bacteroidetes. The healthy core microbiome included the genera Staphylococcus, Streptococcus, Bacteroides, Faecalibacterium, Ruminococcus, Lactobacillus, and Propionibacterium. At the species level, a high degree of inter-individual variability was observed among healthy women. In contrast, Staphylococcus aureus clearly dominated the microbiome in the samples from the women with acute mastitis whereas high increases in Staphylococcus epidermidis-related reads were observed in the milk of those suffering from subacute mastitis. Fungal and protozoa-related reads were identified in most of the samples, whereas Archaea reads were absent in samples from women with mastitis. Some viral-related sequence reads were also detected.

CONCLUSION

Human milk contains a complex microbial metagenome constituted by the genomes of bacteria, archaea, viruses, fungi, and protozoa. In mastitis cases, the milk microbiome reflects a loss of bacterial diversity and a high increase of the sequences related to the presumptive etiological agents.

ABM clinical protocol #4: Mastitis, revised March 2014

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

Role of sortase A in the pathogenesis of Staphylococcus aureus-induced mastitis in mice

Sortase A (SrtA), a transpeptidase, anchors surface proteins with an LPXTG-motif sorting signal to the cell envelope. To determine the role of SrtA in the pathogenesis of Staphylococcus aureus, we constructed a mutant strain, ∆SrtA, by genetic techniques and identified its functions in a S. aureus-induced mastitis mouse model. The histological and myeloperoxidase (MPO) level results showed that the ∆SrtA strain attenuated the inflammatory reaction in the mammary tissue of mice compared with wild-type S. aureus challenge. Additionally, the ELISA results showed that the ∆SrtA strain impaired the induction of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and the Western blot results showed that the mutant strain blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) by attenuating the degradation and phosphorylation of signaling pathway molecules such as IκBα, p65 and p38. These results suggest that SrtA is a key virulence factor in the pathogenesis of S. aureus-induced mastitis in mice. It appears that the srtA mutant affected the attachment of S. aureus to host cells, thus attenuating the activation of the NF-κB and MAPK signaling pathways, which regulated the expression of pro-inflammatory cytokines and decreased the susceptibility to mastitis.

Maternal sepsis

Maternal sepsis is relatively common. Most of these infections are the result of tissue damage during labor and delivery and physiologic changes normally occurring during pregnancy. These infections, whether directly pregnancy-related or simply aggravated by normal pregnancy physiology, ultimately have the potential to progress to severe sepsis and septic shock. This article discusses commonly encountered entities and septic shock. The expeditious recognition of common maternal sepsis and meticulous attention to appropriate management to prevent the progression to severe sepsis and septic shock are emphasized. Also discussed are principles and new approaches for the management of septic shock.

Health and economic burden of post-partum Staphylococcus aureus breast abscess

Objectives

To determine the health and economic burdens of post-partum Staphylococcus aureus breast abscess.

Study design

We conducted a matched cohort study (N = 216) in a population of pregnant women (N = 32,770) who delivered at our center during the study period from 10/1/03–9/30/10. Data were extracted from hospital databases, or via chart review if unavailable electronically. We compared cases of S. aureus breast abscess to controls matched by delivery date to compare health services utilization and mean attributable medical costs in 2012 United States dollars using Medicare and hospital-based estimates. We also evaluated whether resource utilization and health care costs differed between cases with methicillin-resistant and -susceptible S. aureus isolates.

Results

Fifty-four cases of culture-confirmed post-partum S. aureus breast abscess were identified. Breastfeeding cessation (41%), milk fistula (11.1%) and hospital readmission (50%) occurred frequently among case patients. Breast abscess case patients had high rates of health services utilization compared to controls, including high rates of imaging and drainage procedures. The mean attributable cost of post-partum S. aureus breast abscess ranged from $2,340–$4,012, depending on the methods and data sources used. Mean attributable costs were not significantly higher among methicillin-resistant vs. –susceptible S. aureus cases.

Conclusions

Post-partum S. aureus breast abscess is associated with worse health and economic outcomes for women and their infants, including high rates of breastfeeding cessation. Future study is needed to determine the optimal treatment and prevention of these infections.

Puerperal mastitis: a reproductive event of importance affecting anti-mucin antibody levels and ovarian cancer risk

PURPOSE

Test the hypothesis that puerperal mastitis may alter immunity related to the mucin (MUC) family of glycoproteins and lower risk of ovarian cancer.

METHODS

In two case-control studies conducted in New England between 1998 and 2008, we examined the association between self-reported mastitis and ovarian cancer in 1,483 women with epithelial ovarian cancer and 1,578 controls. IgG1 antibodies against (MUC1) CA15.3 and (MUC16) CA125 were measured using electrochemiluminescence assays in a subset of controls (n = 200). Preoperative CA125 was recorded in 649 cases. The association between ovarian cancer and mastitis was assessed using unconditional logistic regression to calculate adjusted odds ratios, OR, and 95 % confidence intervals (CI). Associations between mastitis and anti-CA15.3 and anti-CA125 antibodies and preoperative CA125 levels were evaluated using adjusted linear regression models.

RESULTS

Prior mastitis was associated with a significantly lower risk of ovarian cancer: OR (and 95 % CI) of 0.67 (0.48, 0.94) adjusted for parity, breastfeeding, and other potential confounders. The association was strongest with 2 or more episodes of mastitis, and risk declined progressively with increasing number of children and episodes of mastitis. Among controls, prior mastitis was associated with significantly higher anti-CA15.3 and anti-CA125 antibody levels and, among cases, with significantly lower preoperative CA125 levels.

CONCLUSION

Puerperal mastitis may produce long-lasting anti-mucin antibodies that may lower the risk of ovarian cancer, plausibly through enhanced immune surveillance. Studying immune reactions related to MUC1 and MUC16 in the 10-20 % of breastfeeding women who develop mastitis may suggest ways to duplicate its effects through vaccines based on both antigens.

Breast diseases during pregnancy and lactation

Breast is a typical female sexual physiologic organ that is influenced by steroid hormone from menarche until menopause. Therefore various diseases can be developed by continuous action of estrogen and progesterone. Breast diseases are mainly categorized as benign and malignant. It is very important to distinguish the malignancy from breast diseases. However, it is very difficult to diagnose malignancy in pregnant and lactating women even though the same breast diseases took place. Therefore, we will review breast diseases such as breast carcinoma during pregnancy and lactation.

Managing the risks of sepsis in pregnancy

Sepsis is a major cause of maternal mortality and morbidity worldwide. In the UK, sepsis is now the leading cause of direct maternal deaths. Raising awareness among healthcare professionals about the risks of maternal sepsis and the importance of early management is urgently needed. The challenge in the management of maternal sepsis is the translation of the vast knowledge gained from sequential confidential enquiries into maternal death and research findings, into clinical practice, to ensure an improvement in patient quality of care and maternal mortality and morbidity. In this chapter, I give an overview of the management of the risks of sepsis, and discuss implementation strategies that may reduce these risks.

Extremely large breast abscess in a breastfeeding mother

Puerperal mastitis often occurs in younger primiparous women. Most cases occur between 3 and 8 weeks postpartum. If mastitis results in the formation of a breast abscess, surgical drainage or needle aspiration is most commonly performed. We report a case of an extremely large breast abscess in a primiparous 20-year-old woman, which presented 6 weeks postpartum. Surgical incision and evacuation of 2 liters of exudate were performed, and intravenous antibiotics therapy was administered. On the sixth day after incision, we secondarily closed the wound. Examination after 3 months showed symmetrical breasts with a small scar in the incision area of the right breast. A high degree of suspicion and adequate diagnostic procedures are essential to avoid delay in the treatment of mastitis and breast abscess and thereby prevent unnecessary surgical treatment.

An outbreak of post-partum breast abscesses in Mumbai, India caused by ST22-MRSA-IV: genetic characteristics and epidemiological implications

A cluster of methicillin-resistant Staphylococcus aureus (MRSA) breast abscesses in women who had given birth at a hospital in Mumbai, India was investigated retrospectively. Nineteen of 20 cases were caused by a single clone: pvl-positive, spa type 648 (Ridom t852), ccrB:dru subtype 3:0, ST22-MRSA-IV. Despite the presence of pvl and SCCmec type IV, which are common genetic markers in community-associated MRSA, this outbreak was caused by a healthcare-associated, community-onset MRSA that was common in the hospital environment. Thus, infection control practices may have an important role in limiting the spread of this virulent clone.

Mastitis therapy and antimicrobial susceptibility: a multispecies review with a focus on antibiotic treatment of mastitis in dairy cattle

Mastitis occurs in numerous species. Antimicrobial agents are used for treatment of infectious mastitis in dairy cattle, other livestock, companion animals, and humans. Mastitis is an economically important disease of dairy cattle and most mastitis research has focused on epidemiology and control of bovine mastitis. Antibiotic treatment of clinical and subclinical mastitis in dairy cattle is an established component of mastitis control programs. Research on the treatment of clinical and subclinical mastitis in other dairy species such as sheep and goats has been less frequent, although the general principles of mastitis therapy in small ruminants are similar to those of dairy cattle. Research on treatment of clinical mastitis in humans is limited and as for other species empirical treatment of mastitis appears to be common. While antimicrobial susceptibility testing is recommended to direct treatment decisions in many clinical settings, the use of susceptibility testing for antibiotic selection for mastitis treatments of dairy cattle has been challenged in a number of publications. The principle objective of this review is to summarize the literature evaluating the question, "Does antimicrobial susceptibility predict treatment outcome for intramammary infections caused by common bacterial pathogens?" This review also addresses current issues related to antimicrobial use and treatment decisions for mastitis in dairy cattle. Information on treatment of mastitis in other species, including humans, is included although research appears to be limited. Issues related to study design, gaps in current knowledge and opportunities for future research are identified for bovine mastitis therapy.

Mastitis: comparative etiology and epidemiology

Mastitis is broadly defined as the inflammation of the mammary gland; however, the concept of mastitis is customized to address its social and clinical impact in the case of humans and the health, welfare, and economic consequences for other mammals. There are many microbial, host, and environmental factors that influence the development of mastitis. Some are common to all mammals as well as inherent to each species. Together these factors influence the most prevalent etiological agents for each species and might determine the possibility of interspecies transmission with its consequences to public health. The present review will summarize and compare reports on mastitis etiology and its epidemiology in humans and food animal species.

Risk factors for Staphylococcus aureus postpartum breast abscess

BACKGROUND

Staphylococcus aureus (SA) breast abscesses are a complication of the postpartum period. Risk factors for postpartum SA breast abscesses are poorly defined, and literature is conflicting. Whether risk factors for methicillin-resistant SA (MRSA) and methicillin-susceptible SA (MSSA) infections differ is unknown. We describe novel risk factors associated with postpartum breast abscesses and the changing epidemiology of this infection.

METHODS

We conducted a cohort study with a nested case-control study (n = 216) involving all patients with culture-confirmed SA breast abscess among >30 000 deliveries at our academic tertiary care center from 2003 through 2010. Data were collected from hospital databases and through abstraction from medical records. All SA cases were compared with both nested controls and full cohort controls. A subanalysis was completed to determine whether risk factors for MSSA and MRSA breast abscess differ. Univariate analysis was completed using Student's t test, Wilcoxon rank-sum test, and analysis of variance, as appropriate. A multivariable stepwise logistic regression was used to determine final adjusted results for both the case-control and the cohort analyses.

RESULTS

Fifty-four cases of culture-confirmed abscess were identified: 30 MRSA and 24 MSSA. Risk factors for postpartum SA breast abscess in multivariable analysis include in-hospital identification of a mother having difficulty breastfeeding (odds ratio, 5.00) and being a mother employed outside the home (odds ratio, 2.74). Risk factors did not differ between patients who developed MRSA and MSSA infections.

CONCLUSIONS

MRSA is an increasingly important pathogen in postpartum women; risk factors for postpartum SA breast abscess have not changed with the advent of community-associated MRSA.

Puerperal mastitis requiring hospitalization during a nine-year period

OBJECTIVES

To review the clinical and microbiologic features of isolates among patients with puerperal mastitis requiring hospitalization.

STUDY DESIGN

Between January 2000 and December 2008, postpartum patients who were hospitalized for mastitis were enrolled. The clinical characteristics, microbiologic results, management, and outcomes were reviewed.

RESULTS

One hundred twenty-seven cases were enrolled. Seventy-six patients (59.9%) underwent incision and drainage for abscess drainage, all of whom discontinued breastfeeding. Staphylococcus aureus and coagulase-negative staphylococci were the most common isolates. Among 81 isolates of S aureus, 52 (64.2%) were resistant to oxacillin. Patients undergoing incision and drainage were more likely to discontinue breastfeeding, had a longer duration of symptoms, a longer hospitalization, a higher platelet count and higher rates of infection caused by S aureus and oxacillin-resistant S aureus.

CONCLUSION

Oxacillin-resistant S aureus has emerged in patients with puerperal mastitis during the past decade, and often necessitates incision and drainage, which results in discontinuation of breastfeeding.

Benign breast disease

Benign breast diseases are among the most common diagnoses that the busy obstetrician-gynecologist will see in practice. Moreover, breast cancer will undoubtedly be diagnosed numerous times in an obstetrician-gynecologist's career. An ability to accurately and promptly diagnose both benign and malignant breast diseases is within the purview of the generalist obstetrician-gynecologist. A thorough understanding of benign breast diseases, including appropriate diagnostic techniques, is vitally important in well-women care. In addition, a working knowledge of breast cancer risk factors with the ability to identify women at high risk and either refer or initiate risk reduction methods is equally important. This review outlines common benign breast diseases stratified by future risk of breast cancer and discusses appropriate management after diagnosis.

Trends in methicillin-resistant Staphylococcus aureus anovaginal colonization in pregnant women in 2005 versus 2009

In 2005, the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) anovaginal colonization in pregnant women at our center (Columbia University Medical Center) was 0.5%, and MRSA-colonized women were less likely to carry group B streptococcus (GBS). In this study, our objectives were to identify changing trends in the prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) anovaginal colonization in pregnant women, to assess the association between MRSA and GBS colonization, and to characterize the MRSA strains. From February to July 2009, Lim broths from GBS surveillance samples were cultured for S. aureus. MRSA strains were identified by resistance to cefoxitin and characterized by MicroScan, staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), spa typing, and Panton-Valentine leukocidin PCR. A total of 2,921 specimens from different patients were analyzed. The prevalences of MSSA, MRSA, and GBS colonization were 11.8%, 0.6% and 23.3%, respectively. GBS colonization was associated with S. aureus colonization (odds ratio [OR], 1.9; 95% confidence interval [95% CI], 1.5 to 2.4). The frequencies of GBS colonization were similar in MRSA-positive (34.2%) versus MRSA-negative patients (21.8%) (P = 0.4). All MRSA isolates from 2009 and 13/14 isolates from 2005 were SCCmec type IV or V, consistent with community-associated MRSA; 12/18 (2009) and 0/14 (2005) isolates were the USA300 clone. Levofloxacin resistance increased from 14.3% (2005) to 55.6% (2009) (P = 0.028). In conclusion, the prevalence of MRSA anovaginal colonization in pregnant women in New York City, NY, remained stable from 2005 to 2009, and USA300 emerged as the predominant clone with a significant increase in levofloxacin-resistant isolates.

Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic

Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.

MRSA as a cause of postpartum breast abscess in infant and mother

This report describes the unusual occurrence of mastitis and breast abscess in both mother and infant, both caused by methicillin-resistant Staphylococcus aureus (MRSA). Mother and child were both immunocompetent, and their only risk factor was routine confinement. The case highlights the importance of considering MRSA as a cause for mastitis in mothers and infants. MRSA is increasingly common, and failure to consider it as a cause for mastitis will lead to delays in treatment (as it did in this case). The case also demonstrates the role of Hospital in the Home in the treatment of postnatal infections, where hospitalization can be extremely disruptive.

Community-associated meticillin-resistant Staphylococcus aureus infections: epidemiology, recognition and management

Meticillin-resistant Staphylococcus aureus (MRSA) is an important cause of infection, particularly in hospitalized patients and those with significant healthcare exposure. In recent years, epidemic community-associated MRSA (CA-MRSA) infections occurring in patients without healthcare risk factors have become more frequent. The most common manifestation of CA-MRSA infection is skin and soft tissue infection, although necrotizing pneumonia, sepsis and osteoarticular infections can occur. CA-MRSA strains have become endemic in many communities and are genetically distinct from previously identified MRSA strains. CA-MRSA may be more capable colonizers of humans and more virulent than other S. aureus strains. Specific mechanisms of pathogenicity have not been elucidated, but several factors have been proposed as responsible for the virulence of CA-MRSA, including the Panton-Valentine leukocidin, phenol-soluble modulins and type I arginine catabolic mobile element. The movement of CA-MRSA strains into the nosocomial setting limits the utility of using clinical risk factors alone to designate community- or healthcare-associated status. Identification of unique genetic characteristics and genotyping are valuable tools for MRSA epidemiological studies. Although the optimum pharmacological therapy for CA-MRSA infections has not been determined, many CA-MRSA strains remain broadly susceptible to several non-beta-lactam antibacterial agents. Empirical antibacterial therapy should include an MRSA-active agent, particularly in areas where CA-MRSA is endemic.

Pharmacologic advances in canine and feline reproduction

Substantial improvements in therapeutic options for companion animal reproduction and gynecologic emergencies have been made over the last decade. New, alternative drug treatments, with fewer side effects and improved efficacy, are available. This has widened the spectrum of therapeutic possibilities for diseases that were previously treated only by surgical intervention. New drugs are available for estrus induction and pregnancy termination, as well as for the treatment of pyometra. This review summarizes the pharmacology and toxicology of reproductive agents currently in use for contraception, pyometra, dystocia, eclampsia, premature labor, agalactia, mastitis, metritis, and prostatic disorders, and compares their efficacy and safety with newer agents. Drug use and exposure during pregnancy and lactation, and subsequent risks to the fetuses, are also explored, with emphasis on antimicrobials, antifungals, anthelminthics, anesthetics, and vaccinations.