Approach to intrapartum fever during the COVID-19 pandemic: A New York City Hospital experience.

The yield of repeat severe acute respiratory syndrome coronovirus 2 (SARS-CoV-2) testing for intrapartum fever in patients admitted to labor and delivery negative for SARS-CoV-2 on admission testing is unknown. From October 2020 to June 2022, we performed a retrospective study of 151/3,168 (4.8%) patients who had repeat testing for intrapartum fever. One (0.7%) patient was SARS-CoV-2-positive suggesting repeat SARS-CoV-2 testing for intrapartum fever is generally not warranted nor is separating birthing dyads while awaiting test results.

Infection prevention and control and related practices in African neonatal units: The Pan-African neonatal care assessment study (PANCAS).

BACKGROUND: The burden of neonatal mortality is primarily borne by low- and middle-income countries (LMICs), including deaths due to healthcare-associated infections (HAIs). Few studies have assessed infection prevention and control (IP&C) practices in African units caring for small and/or sick newborns aimed to reduce HAIs. METHODS: We performed a mixed-methods study composed of a survey and virtual tour to assess IP&C and related practices. We created a survey composed of multiple-choice and open-ended questions delivered to site respondents via Zoom or video equivalent. Respondents provided a virtual tour of their unit via video and the study team used a checklist to evaluate specific practices. RESULTS: We recruited 45 units caring for small and sick newborns in 20 African countries. Opportunities to optimize hand hygiene, Water, Sanitation and Hygiene (WASH) practices, Kangaroo Mother Care, and IP&C training were noted. The virtual tour offered further understanding of IP&C challenges unique to individual sites. All respondents expressed the need for additional space, equipment, supplies, education, and IP&C staff and emphasized that attention to maternal comfort was important to IP&C success. DISCUSSION: This study identified opportunities to improve IP&C practices using low-cost measures including further education and peer support through learning collaboratives. Virtual tours can be used to provide site-specific assessment and feedback from peers, IP&C specialists and environmental engineering experts.

Impact of active surveillance and decolonization strategies for methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit.

OBJECTIVE: To assess the impact of active surveillance and decolonization strategies on methicillin-resistant Staphylococcus aureus (MRSA) infection rates in a NICU. STUDY DESIGN: MRSA infection rates were compared before (2014-2016) and during (2017-2022) an active surveillance program. Eligible infants were decolonized with chlorohexidine gluconate (CHG) bathing and/or topical mupirocin. Successful decolonization and rates of recolonization were assessed. RESULTS: Fifty-two (0.57%) of 9 100 hospitalized infants had invasive MRSA infections from 2014 to 2022; infection rates declined non-significantly. During the 6-year surveillance program, the risk of infection was 16.9-times [CI95 8.4, 34.1] higher in colonized infants than uncolonized infants. Those colonized with mupirocin-susceptible MRSA were more likely successfully decolonized (aOR 9.7 [CI95 4.2, 22.5]). Of 57 infants successfully decolonized who remained hospitalized, 34 (60%) became recolonized. CONCLUSIONS: MRSA infection rates did not significantly decline in association with an active surveillance and decolonization program. Alternatives to mupirocin and CHG are needed to facilitate decolonization.

Association of Pseudomonas aeruginosa incident infections with adherence to cystic fibrosis foundation care guidelines.

BACKGROUND: Care guidelines for cystic fibrosis (CF) have been developed to enhance consistent care and to improve health outcomes. We determined if adherence to CF care guidelines predicted P. aeruginosa incidence rates (Pa-IR) at U.S. CF centers in 2018. METHODS: This cross-sectional CF Foundation Patient Registry study included 82 adult and 132 pediatric centers. Adherence to 12 guidelines was defined categorically (guideline met) or as a continuous measure (proportion of patients being treated/evaluated per guideline). Association of adherence to individual guidelines with Pa-IR, accounted for center and patient characteristics relevant to Pa-IR and were modeled using random forests and weighted-least-squares (WLS) analyses. RESULTS: The mean Pa-IR was 0.2 cases/patient-years at risk (SE 0.0074) for all centers combined. Guideline adherence was lowest for ≥4 bacterial cultures/year (54% of centers) and annual oral glucose tolerance test (OGTT) (48% of centers), and highest for annual non-tuberculous mycobacteria (NTM) sputum culture (98%). The mean number of guidelines met was 6.7 and higher for pediatric (7.3) than adult (5.6) centers, (p<0.001). The number of guidelines met correlated negatively with Pa-IR (ß=-0.007, p = 0.043). Macrolide prescription and annual OGTT per guideline were associated with lower and higher Pa-IR, respectively. Centers with lower center-wide lung function, higher proportion of pwCF with low body-mass index, and location in the Southwest had higher Pa-IR. CONCLUSION: Overall adherence to guidelines was high except for performing ≥4 bacterial cultures/year and OGTT. Higher Pa-IR was associated with center characteristics and lower guideline adherence. The lower Pa-IR with greater adherence to guidelines suggests that focusing on quality care can positively impact Pa-IR.

Diagnosis, Treatment, and Prevention Resources for Infectious Diseases in Sub-Saharan African Hospitals Caring for Children.

Objective. The Children's Hospitals in Africa Mapping Project survey was developed and implemented to assess the readiness of hospitals in sub-Saharan African to respond to emergencies, epidemics, and pandemics affecting children. Methods. This sub-study analyzed 56 survey questions that characterized the hospitals and assessed resources for diagnosis, treatment, and prevention of community-acquired infections and healthcare-associated infections (HAIs). Results. Twenty-four sites were recruited and 20 (from 15 countries) completed the survey in 2018 to 2019. Overall, 90% to 100% of sites reported that diagnostic assays were available for malaria, tuberculosis, and HIV. Periodic shortages of antibiotics, antimalarial drugs, and vaccines were reported by 45%, 25%, and 20% of sites, respectively. Sites reported formal programs for infection prevention and control (79%), monitoring HAIs (17%), and antimicrobial stewardship (53%). Conclusions. Opportunities to improve care for hospitalized African children were identified. These included resources for HAI surveillance and antimicrobial stewardship which can facilitate epidemic and pandemic preparedness.

Epidemiology, risk factors, and applicability of CDC definitions for healthcare-associated bloodstream infections at a level IV neonatal ICU.

OBJECTIVES: We studied the epidemiology of primary bloodstream infections (BSIs), secondary BSIs, and central line-associated BSIs (CLABSIs) and applicability of CDC definitions for primary sources of infection causing secondary BSIs in patients in the neonatal ICU. STUDY DESIGN: We classified healthcare-associated BSIs (HABSIs) as primary BSIs, secondary BSIs, and CLABSIs using CDC surveillance definitions and determined their overall incidence and incidence among different gestational age strata. We assessed the applicability of CDC definitions for infection sources causing secondary BSIs. RESULTS: From 2010 to 2019, 141 (32.7%), 202 (46.9%), and 88 (20.4%) HABSIs were classified as primary BSIs, secondary BSIs, and CLABSIs, respectively; all declined during the study period (all p < 0.001). Gestational age <28 weeks was associated with increased incidence of all HABSI types. CDC criteria for site-specific primary sources were met in 137/202 (68%) secondary BSIs. CONCLUSIONS: Primary and secondary BSIs were more common than CLABSIs and should be prioritized for prevention.

Next Steps for Health Care-Associated Infections in the Neonatal Intensive Care Unit.

We discuss the burden of health care-associated infections (HAIs) in the neonatal ICU and the role of quality improvement (QI) in infection prevention and control. We examine specific QI opportunities and approaches to prevent HAIs caused by Staphylococcus aureus , multidrug-resistant gram-negative pathogens, Candida species, and respiratory viruses, and to prevent central line-associated bloodstream infections (CLABSIs) and surgical site infections. We explore the emerging recognition that many hospital-onset bacteremia episodes are not CLABSIs. Finally, we describe the core tenets of QI, including engagement with multidisciplinary teams and families, data transparency, accountability, and the impact of larger collaborative efforts to reduce HAIs.

Healthcare-Associated Respiratory Syncytial Virus in Children's Hospitals.

BACKGROUND: Outbreaks of healthcare-associated respiratory syncytial virus (HA-RSV) infections in children are well described, but less is known about sporadic HA-RSV infections. We assessed the epidemiology and clinical outcomes associated with sporadic HA-RSV infections. METHODS: We retrospectively identified hospitalized children ≤18 years old with HA-RSV infections in six children's hospitals in the United States during the respiratory viral seasons October-April in 2016-2017, 2017-2018, and 2018-2019 and prospectively from October 2020 through November 2021. We evaluated outcomes temporally associated with HA-RSV infections including escalation of respiratory support, transfer to the pediatric intensive care unit (PICU), and in-hospital mortality. We assessed demographic characteristics and comorbid conditions associated with escalation of respiratory support. RESULTS: We identified 122 children (median age 16.0 months [IQR 6, 60 months]) with HA-RSV. The median onset of HA-RSV infections was hospital day 14 (IQR 7, 34 days). Overall, 78 (63.9%) children had two or more comorbid conditions; cardiovascular, gastrointestinal, neurologic/neuromuscular, respiratory, and premature/ neonatal comorbidities were most common. Fifty-five (45.1%) children required escalation of respiratory support and 18 (14.8%) were transferred to the PICU. Five (4.1%) died during hospitalization. In the multivariable analysis, respiratory comorbidities (aOR: 3.36 [CI95 1.41, 8.01]) were associated with increased odds of escalation of respiratory support. CONCLUSIONS: HA-RSV infections cause preventable morbidity and increase healthcare resource utilization. Further study of effective mitigation strategies for HA-respiratory viral infections should be prioritized; this priority is further supported by the impact of the COVID-19 pandemic on seasonal viral infections.

Strategies to prevent surgical site infections in acute-care hospitals: 2022 Update.

The intent of this document is to highlight practical recommendations in a concise format designed to assist acute-care hospitals in implementing and prioritizing their surgical-site infection (SSI) prevention efforts. This document updates the Strategies to Prevent Surgical Site Infections in Acute Care Hospitals published in 2014. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA). It is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the Association for Professionals in Infection Control and Epidemiology (APIC), the American Hospital Association (AHA), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.

Acceptability, Feasibility, and Validity of Detecting Respiratory Pathogens During Acute Respiratory Illness in Participant-Collected Swabs in a Low-Income, Community Sample.

Background: Community surveillance for acute respiratory illness (ARI) can include unsupervised participant-collected nasal swabs. Little is known about use of self-swabs in low-income populations or among households including extended family members and the validity of self-collected swabs. We assessed the acceptability, feasibility, and validity of unsupervised participant-collected nasal swabs in a low-income, community sample. Methods: This was a substudy of a larger prospective community-based ARI surveillance study in 405 households in New York City. Participating household members self-collected swabs on the day of a research home visit for an index case, and for 3-6 subsequent days. Demographics associated with agreement to participate and swab collection were assessed, and index case self-collected versus research staff-collected swab results were compared. Results: Most households (n = 292 [89.6%]) agreed to participate, including 1310 members. Being <18 years old, female, and the household reporter or member of the nuclear family (parents and children) were associated with both agreement to participate and self-swab collection. Being born in the United States or immigrating ≥10 years ago was associated with participation, and being Spanish-speaking and having less than a high school education were associated with swab collection. In all, 84.4% collected at least 1 self-swabbed specimen; self-swabbing rates were highest during the first 4 collection days. Concordance between research staff-collected swabs and self-swabs was 88.4% for negative swabs, 75.0% for influenza, and 69.4% for noninfluenza pathogens. Conclusions: Self-swabbing was acceptable, feasible, and valid in this low-income, minoritized population. Some differences in participation and swab collection were identified that could be noted by future researchers and modelers.

Antimicrobial use and opportunities for antimicrobial stewardship in pediatric postacute and long-term care settings.

We performed a point-prevalence study of antimicrobial prescriptions in 9 pediatric postacute and long-term care (pPALTC) settings. Antimicrobials were prescribed for 5%-7% of residents including infectious (41%), noninfectious (24%), prophylaxis (24%), and unknown (11%) indications. Macrolides were often prescribed for noninfectious indications. Developing treatment guidelines are antimicrobial stewardship opportunities for pPALTC.

Successful diagnostic stewardship for Clostridioides difficile testing in pediatrics.

OBJECTIVE: To reduce both inappropriate testing for and diagnosis of healthcare-onset (HO) Clostridioides difficile infections (CDIs). DESIGN: We performed a retrospective analysis of C. difficile testing from hospitalized children before (October 2017-October 2018) and after (November 2018-October 2020) implementing restrictive computerized provider order entry (CPOE). SETTING: Study sites included hospital A (a ∼250-bed freestanding children's hospital) and hospital B (a ∼100-bed children's hospital within a larger hospital) that are part of the same multicampus institution. METHODS: In October 2018, we implemented CPOE. No testing was allowed for infants aged ≤12 months, approval of the infectious disease team was required to test children aged 13-23 months, and pathology residents' approval was required to test all patients aged ≥24 months with recent laxative, stool softener, or enema use. Interrupted time series analysis and Mann-Whitney U test were used for analysis. RESULTS: An interrupted time series analysis revealed that from October 2017 to October 2020, the numbers of tests ordered and samples sent significantly decreased in all age groups (P < .05). The monthly median number of HO-CDI cases significantly decreased after implementation of the restrictive CPOE in children aged 13-23 months (P < .001) and all ages combined (P = .003). CONCLUSION: Restrictive CPOE for CDI in pediatrics was successfully implemented and sustained. Diagnostic stewardship for CDI is likely cost-saving and could decrease misdiagnosis, unnecessary antibiotic therapy, and overestimation of HO-CDI rates.

Surveillance for Acute Respiratory Illnesses in Pediatric Chronic Care Facilities.

Overall, 119 (33%) of 364 pediatric chronic care facility residents experienced 182 acute respiratory illnesses (ARIs) that met the surveillance definition which led to 31 (17%) emergency room visits, 34 (19%) acute care hospitalizations, and/or 25 (14%) ICU admissions. Continued PCR-positivity was observed in 35% of ARIs during follow-up testing.

Clinical impact of healthcare-associated respiratory syncytial virus in hospitalized adults.

OBJECTIVE: To describe the clinical impact of healthcare-associated (HA) respiratory syncytial virus (RSV) in hospitalized adults. DESIGN: Retrospective cohort study within a prospective, population-based, surveillance study of RSV-infected hospitalized adults during 3 respiratory seasons: October 2017-April 2018, October 2018-April 2019, and October 2019-March 2020. SETTING: The study was conducted in 2 academically affiliated medical centers. PATIENTS: Each HA-RSV patient (in whom RSV was detected by PCR test ≥4 days after hospital admission) was matched (age, sex, season) with 2 community-onset (CO) RSV patients (in whom RSV was detected ≤3 days of admission). METHODS: Risk factors and outcomes were compared among HA-RSV versus CO-RSV patients using conditional logistic regression. Escalation of respiratory support associated with RSV detection (day 0) from day -2 to day +4 was explored among HA-RSV patients. RESULTS: In total, 84 HA-RSV patients were matched to 160 CO-RSV patients. In HA-RSV patients, chronic kidney disease was more common, while chronic respiratory conditions and obesity were less common. HA-RSV patients were not more likely to be admitted to an ICU or require mechanical ventilation, but they more often required a higher level of care at discharge compared with CO-RSV patients (44% vs 14%, respectively). Also, 29% of evaluable HA-RSV patients required respiratory support escalation; these patients were older and more likely to have respiratory comorbidities, to have been admitted to intensive care, and to die during hospitalization. CONCLUSIONS: HA-RSV in adults may be associated with escalation in respiratory support and an increased level of support in living situation at discharge. Infection prevention and control strategies and RSV vaccination of high-risk adults could mitigate the risk of HA-RSV.

Genomic and Epidemiological Features of Two Dominant Methicillin-Susceptible Staphylococcus aureus Clones from a Neonatal Intensive Care Unit Surveillance Effort.

Methicillin-susceptible Staphylococcus aureus (MSSA) is a more prevalent neonatal intensive care unit (NICU) pathogen than methicillin-resistant S. aureus (MRSA). However, the introduction and spread of MSSA, the role of systematic decolonization, and optimal infection prevention and control strategies remain incompletely understood. We previously screened infants hospitalized in a university-affiliated level III to IV NICU twice monthly over 18 months for S. aureus colonization and identified several prevalent staphylococcal protein A (spa) types. Here, we performed whole-genome sequencing (WGS) and phylogenetic comparisons of 140 isolates from predominant spa types t279, t1451, and t571 to examine possible transmission routes and identify genomic and epidemiologic features associated with the spread of dominant clones. We identified two major MSSA clones: sequence type 398 (ST398), common in the local community, and ST1898, not previously encountered in the region. ST398 NICU isolates formed distinct clusters with closely related community isolates from previously published data sets, suggesting multiple sources of acquisition, such as family members or staff, including residents of the local community. In contrast, ST1898 isolates were nearly identical, pointing to clonal expansion within the NICU. Almost all ST1898 isolates harbored plasmids encoding mupirocin resistance (mupA), suggesting an association between the proliferation of this clone and decolonization efforts with mupirocin. Comparative genomics indicated genotype-specific pathways of introduction and spread of MSSA via community-associated (ST398) or health care-associated (ST1898) sources and the potential role of mupirocin resistance in dissemination of ST1898. Future surveillance efforts could benefit from routine genotyping to inform clone-specific infection prevention strategies. IMPORTANCE Methicillin-susceptible Staphylococcus aureus (MSSA) is a significant pathogen in neonates. However, surveillance efforts in neonatal intensive care units (NICUs) have focused primarily on methicillin-resistant S. aureus (MRSA), limiting our understanding of colonizing and infectious MSSA clones which are prevalent in the NICU. Here, we identify two dominant colonizing MSSA clones during an 18-month surveillance effort in a level III to IV NICU, ST398 and ST1898. Using genomic surveillance and phylogenetic analysis, coupled with epidemiological investigation, we found that these two sequence types had distinct modes of spread, namely the suggested exchange with community reservoirs for ST398 and the contribution of antibiotic resistance to dissemination of ST1898 in the health care setting. This study highlights the additional benefits of whole-genome surveillance for colonizing pathogens, beyond routine species identification and genotyping, to inform targeted infection prevention strategies.

Antimicrobial Stewardship in Cystic Fibrosis.

The chronic airway infection and inflammation characteristic of cystic fibrosis (CF) ultimately leads to progressive lung disease, the primary cause of death in persons with CF (pwCF). Despite many recent advances in CF clinical care, efforts to preserve lung function in many pwCF still necessitate frequent antimicrobial use. Incorporating antimicrobial stewardship (AMS) principles into management of pulmonary exacerbations (PEx) would facilitate development of best practices for antimicrobial utilization at CF care centers. However, AMS can be challenging in CF given the unique aspects of chronic, polymicrobial infection in the CF airways, lack of evidence-based guidelines for managing PEx, limited utility for antimicrobial susceptibility testing, and increased frequency of adverse drug events in pwCF. This article describes current evidence-based antimicrobial treatment strategies for pwCF, highlights the potential for AMS to beneficially impact CF care, and provides practical strategies for integrating AMS programs into the management of PEx in pwCF.

Change in functional status associated with respiratory syncytial virus infection in hospitalized older adults.

BACKGROUND: Respiratory syncytial virus (RSV) causes severe respiratory illnesses in infants and older adults. Older adults are frequently hospitalized with RSV illness and may experience loss of function. This study evaluated longitudinal changes in function associated with RSV hospitalization in older adults. METHODS: Adults ≥60 years hospitalized with laboratory-confirmed RSV were enrolled (N = 302). Demographics and comorbidities were collected. Functional status was assessed 2 weeks pre-hospitalization by recall, at enrollment, hospital discharge and 2, 4, and 6 months post-discharge using the Lawton-Brody Instrumental Activities of Daily Living (IADL) (scale 0-8) and Barthel ADL Index (scale 0-100). RESULTS: RSV-associated hospitalization resulted in acute functional loss. Median IADL (5 vs. 3, p < 0.0001) and ADL (90 vs. 70, p < 0.0001) scores decreased significantly from pre-hospitalization to admission and remained decreased at discharge. There were no statistically significant differences between pre-hospitalization and 2-, 4-, or 6-month scores. However, 33% and 32% of subjects experienced decreased 6-month IADL and ADL scores, respectively. Additionally, 14% required a higher level of care at discharge. When stratified by pre-hospitalization living situation, 6-month IADL scores declined significantly for those admitted from a skilled nursing facility (3 vs. 1, p = 0.001). In multivariate analysis, male sex and diabetes were associated with a 6-month decline in ADL score of ≥10. CONCLUSIONS: Older adults hospitalized with RSV demonstrate acute functional decline that may become prolonged. Pre-hospitalization living situation may predict patient outcomes. Further study is needed with hospitalized age-matched controls and refined measurement tools to better define the specific impact of RSV on function.

Predicting risk-adjusted incidence rates of methicillin-resistant Staphylococcus Aureus and Pseudomonas Aeruginosa in cystic fibrosis programs in the United States.

BACKGROUND: Healthcare-associated transmission of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa occurs for people with cystic fibrosis (CF), but CF programs lack a process to monitor incidence rates (IRs). We assessed predictors of incident infections and created a model to determine risk-adjusted IRs for CF programs. METHODS: Using the CF Foundation Patient Registry data for all patients from 2012 to 2015, coefficients for variables that predicted IRs were estimated. Hazard functions were then used to predict IRs of MRSA and P. aeruginosa for CF programs based on their patient and program characteristics. Predicted IRs were compared with observed IRs over multiple time intervals. RESULTS: Multiple patient and program characteristics were identified as predictors of observed IRs. Our model's predicted IRs closely aligned with observed IRs for most CF programs. Alarm values (defined as observed IR > 95% confidence interval of predicted IR) were found at 5.9%, 5.9%, 6.0% (adult, pediatric, affiliate) of programs for MRSA and 3.0%, 1.7%, 0.0% (adult, pediatric, affiliate) of programs for P. aeruginosa. CONCLUSIONS: We found patient and program characteristics that predicted MRSA and P. aeruginosa IRs. Our model accurately predicted risk-adjusted IRs of MRSA and P. aeruginosa. CF programs could use our model to monitor their IRs and potentially improve infection prevention and control.

Potential opportunities and challenges for infection prevention and control for cystic fibrosis in the modern era.

PURPOSE OF REVIEW: We describe recent changes in care for people with cystic fibrosis (PwCF) that could impact infection prevention and control (IP&C) practices. RECENT FINDINGS: Current IP&C guidelines primarily aim to prevent acquisition and transmission of pathogens in PwCF utilizing evidence-based recommendations for healthcare settings. Currently, highly effective modulator therapy (HEMT) is dramatically improving the clinical manifestations of cystic fibrosis and reducing pulmonary exacerbations and hospitalizations. Thus, it is feasible that long-term, sustained improvements in pulmonary manifestations of cystic fibrosis could favorably alter cystic fibrosis microbiology. The COVID-19 pandemic increased the use of virtual care, enabling PwCF to spend less time in healthcare settings and potentially reduce the risk of acquiring cystic fibrosis pathogens. The increasing use of whole genome sequencing (WGS) shows great promise in elucidating sources of cystic fibrosis pathogens, shared strains, and epidemic strains and ultimately could allow the cystic fibrosis community to monitor the safety of changed IP&C practices, if deemed appropriate. Finally, given the nonhealthcare environmental reservoirs for cystic fibrosis pathogens, practical guidance can inform PwCF and their families about potential risks and mitigation strategies. SUMMARY: New developments in the treatment of PwCF, a shift toward virtual care delivery of care, and use of WGS could change future IP&C practices.

Perioperative Antibiotics and Other Factors Associated with Postcesarean Infections: A Case-Control Study.

OBJECTIVE: Our objective was to determine modifiable risk factors associated with surgical site infection (SSI) and postpartum endometritis. We hypothesized that inappropriate surgical antibiotic prophylaxis would be a risk factor for both types of infections. STUDY DESIGN: This was a single-center case-control study of SSI and endometritis after cesarean delivery over a 2-year period from 2016 to 2017. Cases were identified by International Classification of Diseases, 10th Revision diagnosis codes, infection control surveillance, and electronic medical records search and were subsequently confirmed by chart review. Three controls were randomly selected for each case from all cesareans ± 48 hours from case delivery. Demographic, pregnancy, and delivery characteristics were abstracted. Separate multivariable logistic regression models were used to assess factors associated with SSI and endometritis. Postpartum outcomes, including length of stay and readmission, were also compared. RESULTS: We identified 141 cases of SSI and endometritis with an overall postpartum infection rate of 4.0% among all cesarean deliveries. In adjusted analysis, factors associated with both SSI and endometritis were intrapartum delivery, classical or other (non-low-transverse) uterine incision, and blood transfusion. Factors associated with SSI only included inadequate antibiotic prophylaxis, public insurance, hypertensive disorder of pregnancy, and nonchlorhexidine abdominal preparation; factors only associated with endometritis included ß-lactam allergy, anticoagulation therapy, and chorioamnionitis. Among cases, 34% of those with SSI and 25% of those with endometritis did not receive adequate antibiotic prophylaxis, compared with 12.9 and 13.5% in control groups, respectively. Failure to receive appropriate antibiotic prophylaxis was associated with an increased risk of SSI (adjusted odds ratio [aOR]: 4.4, 95% confidence interval [CI]: 1.3-15.6) but not endometritis (aOR 0.9, 95% CI 0.4-2.0). CONCLUSION: Inadequate surgical antibiotic prophylaxis was associated with an increased risk of SSI but not postpartum endometritis, highlighting the different mechanisms of these infections and the importance of prioritizing adequate surgical prophylaxis. Additional potentially modifiable factors which emerged included blood transfusion and chlorhexidine skin preparation. KEY POINTS: · Inadequate antibiotic prophylaxis is associated with a four-fold risk in surgical site infections.. · The most common cause for failure to achieve adequate surgical prophylaxis was inappropriate timing of antibiotics at or after skin incision.. · Blood transfusions are strongly associated (>10-fold risk) with both SSI and endometritis..