bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-1144. Low prevalence of neonatal sepsis due to Streptococcus agalactiae in two large Mexican NICUs: multicenter retrospective study from 2021-2023
Authors: Ballesteros-Suarez Ana , Garza-Castro Abraham P , Concha-Mora Lindsay A , Prieto-Baca Ericka Paulina , Tamez-Rivera Oscar , Salazar-Alejo Misael 
Published: January 2025

Abstract

Background
Group B Streptococcus (GBS), or S. agalactiae, is reported as a leading cause of neonatal sepsis in several regions including the United States. Although in recent years its incidence has shown a steady decline, current treatment guidelines still consider it a predominant cause of neonatal sepsis. Its prevalence varies according to geographical and racial factors; however, information regarding the epidemiology and clinical presentation of neonatal GBS infection in Mexico is scarce.

Methods
Retrospective multicenter study conducted in the NICUs of the two pediatric reference hospitals in NL, Mexico. Data of all newborns ≤28 days (d) diagnosed with blood culture-proven GBS infection from 2021-2023 were collected. Maternal premature rupture of membranes (PROM) was defined as &gt;12h. GBS infection was classified as early (&lt; 7 d) and late-onset (≥7 d). LBWIs were defined as newborns &lt; 2500 g and very LBWI (VLBWI) as &lt; 1500 g at birth, respectively. Clinical scenarios were classified as sepsis, pneumonia and meningitis. Sepsis was classified as early (≤3 d) and late-onset ( &gt;3 d). Descriptive statistical analyses were performed to determine frequencies.

Results
A total of 928 positive blood cultures were included. 28 blood cultures (3%) from 27 patients were positive for GBS. Maternal PROM was documented in 11.1%. Most patients were term infants (77%) and 92.6% of the cases were early-onset. The most common presentation was sepsis (92.6%). One patient (3.7%) had pneumonia and one (3.7%) had meningitis due to GBS. Low mortality was documented (3.7%). Table 1 shows clinical characteristics of patients with GBS infection. As expected, all isolates were susceptible to Ampicillin.

Conclusion
We report a low prevalence of culture-proven GBS infection (3%) in two large Mexican NICUs during the studied period. This is consistent with previous single-center reports from Mexico, which date back to more than two decades. Although the international epidemiology and treatment guidelines consider GBS a predominant cause of neonatal sepsis, its frequency in Mexico remains low. The vast majority of cases were early-onset infections, and the most common clinical presentation was sepsis, which is consistent with global epidemiology.

Disclosures
All Authors: No reported disclosures
P-1148. Invasive Infections by Carbapenemase-producing Enterobacterales and Pseudomonas aeruginosa in Children
Authors: Cazes Claudia Inés I , Biondi Estefania , Lanfranchi Romina , Cancellara Aldo , Procopio Adriana , Ordoñez Carolina , Ezcurra Gustavo Cesar , Aró Carolina , Juarez Ximena S , Flores Ezequiel , Cames Valeria , Dondoglio Patricia , Pereda Rosana , Granchetti Hugo , Pezzaniti Antonella , Satragno Daniela , Vazquez Miryam , López Eduardo L 
Published: January 2025

Abstract

Background
Enterobacterales and Pseudomonas aeruginosa cause invasive infections and their spread of antimicrobial resistance is of great concern in the worldwide scientific community. Carbapenemases represent the main mechanism of resistance in Enterobacterales and can spread horizontally through mobile genetic elements. Clinical evidence suggests that mortality would be related to inadequate initial empirical treatment.

Methods
A prospective observational study was carried out in three tertiary care pediatric hospitals in Argentina, since 12/1/2021 to 11/30/2022, including children between 0 to 18 years of age with a positive culture for carbapenemase-producing Enterobacterales or P. aeruginosa isolated from a sterile site and/or tracheal aspirate with pulmonary radiological confirmation.

Results
We enrolled 29 patients, 62% male. Median age: 25 months (IQR 5-127). Median length of hospitalization: 44 days (IQR 17-91). Comorbidities: 93%, oncohematological disease: 40%; 62% (18/29) were admitted to Intensive Care Unit. The most frequent isolation was Klebsiella pneumoniae: 62% (18/29), Escherichia coli 17% (5/29), Enterobacter cloacae 10% (3/29), Serratia marcescens 7% (2/29), P. aeruginosa 7% (2/29). Bacteremia: 55% (16/29). Most frequent site of infection: urinary tract 44.8%. Metallobetalactamase (MBL) was detected in 48% (14/29), KPC: 34% (10/29), OXA: 14% (4/29). Initial empirical treatment: meropenem 53% (16/29). Adjustment of initial empirical treatment at 48 hours: 79% (23/29) according to cultures and antibiogram. Ceftazidime/avibactam: 48.2%; aztreonam combined in MBL strains. Extended infusion meropenem: 24% (7/29) if MIC ≤ 8 ug/ml. Overall mortality: 20.6%, in 6.8% it was related to infection.

Conclusion
In recent years we have seen an increase in antimicrobial resistance. Metallobetalactamases were the most frequently detected in patients hospitalized in critical areas. Resistance data in Argentina showed K. pneumoniae as one of the most prevalent bacteria in multidrug-resistant infections. Carbapenemes in high doses and extended infusions plus other antibiotics were useful to treat strains with low MIC values. Ceftazidime/avibactam was a good option for KPC and some OXA infections. Aztreonam in combined use was indicated for MBL strains.

Disclosures
All Authors: No reported disclosures
P-1153. Characteristics of Invasive Group A Streptococcal Infections (iGAS) in Children during the COVID-19 Pandemic
Authors: Granberry Emma , Pinninti Swetha , Boppana Suresh 
Published: January 2025

Abstract

Background
Group A Streptococcus (GAS)/Streptococcus pyogenes is the most common cause of bacterial pharyngitis in all age groups and can also cause invasive GAS (iGAS) infections such as pneumonia, toxic shock syndrome, necrotizing fasciitis, and osteoarticular infections ± bacteremia. In the fall of 2022, the Centers for Disease Control (CDC) issued a health advisory documenting an increase in pediatric iGAS, following discontinuation of respiratory mitigation strategies (masking) during the COVID-19 pandemic. The primary objective of this study is to compare the incidence and severity of iGAS infections before and during the COVID-19 pandemic.Figure 1:Incidence of Pediatric iGAS at Children’s of Alabama

Methods
Isolation of GAS from a sterile site by culture or molecular methods was considered as iGAS. After review of electronic medical records (EMR), we identified 50 children &lt; 18 years of age who were admitted to Children’s of Alabama (COA) between 2017 and the first quarter of 2023 with iGAS were identified. The cohort was divided into 2 groups: 1) pre-COVID-19 (Jan 2017 – Feb 2020) and 2) COVID-19 (March 2020 – Feb 2023). Demographic, clinical, and laboratory characteristics were abstracted and compared between the groups. Continuous variables were compared by the Mann-Whitney test, and Chi-square/Fisher’s exact test was used to compare categorical variables. P value &lt; 0.05 was considered statistically significant.Table 1:Comparison of Laboratory Parameters between Groups

Results
Incidence of iGAS infection at COA plummeted during the COVID-19 pandemic from a peak of 16 cases in 2019 to 3 in 2021, followed by an increase in incidence but still lower than the pre-pandemic levels after the discontinuation of respiratory mitigation strategies (Figure 1). No significant difference between the two groups was observed for severity of infection (p = 1) and laboratory markers (Table 1).

Conclusion
In this single center, retrospective study of pediatric iGAS infections, the number of children with iGAS infections decreased dramatically in 2020 and 2021 with an increase in 2022. We did not observe the increase in nationwide iGAS cases reported by CDC. Also, we did not observe significant differences in the severity of iGAS infections despite the rise in cases after the discontinuation of pandemic-era masking mandates.

Disclosures
Swetha Pinninti, MD, Moderna: Grant/Research Support|Pfizer: Grant/Research Support Suresh Boppana, MD, GSK: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support
420. Immunization Impact on Serotype Distribution of Invasive Pneumococcal Disease - Playing the Serotype Whack-A-Mole!
Authors: Nieves Delma J , Osborne Stephanie , Cheung Michele , Zahn Matt , Arrieta Antonio C 
Published: January 2025

Abstract

Background
Implementation of 7-valent pneumococcal vaccine (PCV7) resulted in significant reduction of invasive pneumococcal disease (IPD) followed by a subsequent increase in IPD by non-vaccine (n-Vac) serotypes (ser) (19A, 7F, 3) with increased severity and antimicrobial resistance. Approved following immunogenicity data, 13-valent PCV (PCV13) adoption reduced IPD again. Surveillance was strongly recommended by the CDC. We present 13 years of countywide (Orange County, CA) surveillance of IPD and serotypes.
Serotype distribution of IPD by Year

Methods
Prospective (1/2010 - 12/2023) countywide study of patients &lt; 18 years old with culture proven IPD. Demographic, clinical course and immunization data were collected. Serotyping was by Quelung method. Antibiotic susceptibilities were obtained.

Results
During the study period 261 patients were identified; 42% female, median age 3.7 years, 52% &lt; 5 years old. IPD rate per 10,000 decreased by 70% (0.408 – &gt; 0.123) from 2010 - 2014 and increased steadily from 2015 to 2019 (peaking at 0.403). As COVID19 pandemic social distancing measures were adopted, IPD rate decreased by 86% (0.057 in 2021); it has since rapidly increased again (0.285) after lifting social distancing measures. Ser was known for 86%; 15B and 22F were the most common nVac ser seen (8% and10% respectively). Ser distributions by year are seen in Figure 1. Table 1 shows the distribution of IPD with immunization status and where the pneumonias and meningitis occurred. Pneumonia (102 [39%]) remains the most common IPD (30% with empyema); we saw a rise of meningitis cases after 2018, 1 was ser3, 13 were n-Vac ser and 3 unknown. IPD attributed mortality occurred in 8 (3%) patients; 4 were due to PCV13 ser. Penicillin resistance (meningitis) increased from 21% to 31%; penicillin non-susceptible (MIC &gt;1) remained unchanged. New 15 and 20 valent ser include 12% and 19% of emerging n-Vac serotypes.

Conclusion
Similar to PCV-7, PCV-13 implementation resulted in an initial significant decrease in IPD, mainly due to 5 of the 6 additional ser included in PCV-13, ser 3 was not significantly affected. This was followed by resurgence of IPD, mainly to n-VAC serotypes. Of our IPD since 2010, 65% are from ser now included in 20-valent PCV. IPD attributable mortality remains high. Active surveillance following higher valent PCVs remains important.

Disclosures
All Authors: No reported disclosures
P-1160. Surge of Pediatric Streptococcus pneumoniae Infections at a Tertiary Healthcare Center after Introduction of 15 and 20 Valent Pneumococcal Conjugate Vaccines: Early Evidence of Serotype Replacement?
Authors: Burkhart Kyle , Aluru Ujwal , Abolhassani Ali , Topping Bradley , Giraldez Ediza M , Hampton Laura L , Samra Hasan , Neshangi Srilatha , Camelo Ingrid 
Published: January 2025

Abstract

Background
Routine pneumococcal vaccination has contributed to the overall decrease in pediatric cases of invasive pneumococcal disease (IPD). However, there has been an increase in non-vaccine serotypes (NVT) causing IPD in North America, Europe, and Australia. We describe hospital admissions of Streptococcus pneumoniae-related illness at a tertiary health care center from 2022-2024.

Methods
Retrospective chart review was conducted of IPD and non-IPD cases admitted to the Children’s Hospital of Georgia from April 2022-April 2023 and April 2023-April 2024. We used the Centers for Disease Control and Prevention (CDC) definition of IPD. IPD and non-IPD disease cases were analyzed for site of infection, concomitant viral infections, vaccination status, Pediatric Intensive Care Unit (PICU) admission, and death.

Results
From 2023-2024, there were 12 cases of IPD, 8 had bacteremia, 3 had meningitis and bacteremia, and 1 had meningitis compared to only 3 IPD cases in 2022-2023, all with bacteremia. 7 of the 12 cases (58%) of IPD cases in 2023-2024 were fully PCV13 vaccinated compared to 1 of the 3 cases (33%) in 2022-2023. Only RSV and rhino/enterovirus were found concomitantly. 7 patients required PICU admission in 2023-2024, 1 on 2022-2023. 1 patient died during 2023-2024. 2 cases had serotyping during 2023-2024; one had serotype 38 and the other had serotype 10A. PCV20 includes serotype 10A. None of the above serotypes are included in the PCV 13 or PCV 15 vaccines.
From 2023-2024, there were 9 cases of non-IPD infection compared to 13 cases in 2022-2023, all of which had pneumonia as the site of infection. Only 5 cases were fully immunized in 2023-2024 while 8 were vaccinated in 2022-2023. Concurrent viruses included parainfluenza, human metapneumovirus, SARS-CoV-2, coronavirus OC43, adenovirus, and rhinovirus. 4 patients required PICU admission in 2023-2024 and 5 in 2022-2023. 1 case died during 2023-2024, and 1 died during 2022-2023.

Conclusion
The recent surge in IPD cases at our institution could be related to early serotype replacement following vaccine-expanded serotypes since more children with IPD were immunized during the 2023-2024 period. Increased surveillance and serotyping will guide decisions about increased IPD infections. Immunization efforts need to be reinforced in our community.

Disclosures
All Authors: No reported disclosures
P-1187. Comparative Evaluation of Clinical Characteristics in Pediatric Patients Hospitalized in Taiwan with RSV and hMPV Infections
Authors: chiu Yu-Ting , Wei Hsiu-Mei , Hsu Yu-Lung , Chang Yu-Chang , Hsiao Chiung-Tzu , Lai Huan-Cheng , Chen Jiun-An , Low Yan-Yi , Lin Hsiao-Chuan , Hwang Kao-Pin 
Published: January 2025

Abstract

Background
Respiratory Syncytial Virus (RSV) and Human Metapneumovirus (hMPV) are prevalent pathogens responsible for respiratory tract infections in infants and young children. This study aims to conduct a comprehensive analysis of the clinical presentations and outcomes among hospitalized infants and young children with RSV and hMPV infections.

Methods
This retrospective observational study was conducted at China Medical University Children's Hospital (CMUCH) from January 2020 to December 2021. The study enrolled patients under 5 years old admitted due to respiratory tract infections, with RSV or hMPV detection confirmed using a commercial respiratory panel employing real-time polymerase chain reaction. Demographic details, clinical manifestations, and outcomes were gathered and analyzed to facilitate comparative assessments.

Results
A total of 145 pediatric patients were included in the study. Among them, 82 patients tested positive for RSV, while 63 patients tested positive for hMPV. There were no significant differences in age and gender distribution between the two groups. Common symptoms such as fever, cough, and rhinorrhea were observed in both groups without notable disparities. No significant differences were found in laboratory parameters between the groups. Pneumonia patches were more frequently observed in the hMPV group and less frequently observed in the RSV group (28.3% vs. 8.3%, p=0.001). Medical interventions did not significantly differ between the two groups. However, the hMPV group exhibited a notably higher rate of antibiotic usage compared to the RSV group (90.5% vs. 57.3%, p&lt;0.001). Moreover, there were no significant discrepancies in the duration of hospitalization (5 vs. 5 days, p=0.110), requirement for oxygen (36.6% vs. 25.4%, p=0.151), and admission to the intensive care unit (ICU) (14.6% vs. 9.5%, p=0.355) between the two groups. Only one RSV patient required intubation, and there were no reported fatalities in either group during the study period.

Conclusion
The findings indicate that RSV and hMPV infections have similar clinical presentations, highlighting diagnostic challenges in the absence of molecular methods. Patients with hMPV are more likely to develop pneumonia patches and receive antibiotic therapy.

Disclosures
All Authors: No reported disclosures
P-1191. Maternal Antibodies Against Parechovirus-A3 Before and During the Coronavirus Disease 2019 Pandemic
Authors: Tachikawa Jun , Aizawa Yuta , Watanabe Kanako , Haino Kazufumi , Nishijima Koji , Saitoh Akihiko 
Published: January 2025

Abstract

Background
Parechovirus-A3 (PeV-A3) is an important emerging virus that causes severe disease in neonates and young infants. The coronavirus disease 2019 (COVID-19) pandemic greatly affected the incidence of infectious diseases, including PeV-A3 infection. Before the pandemic, we reported that maternal neutralizing antibody response against PeV-A3 was important in protecting neonates and young infants from PeV-A3 and that neutralizing antibody titers (NATs) were higher in younger mothers (Emerg Infect Dis. 2015;21:1966-1972). Because the impact of the COVID-19 pandemic on maternal NATs against PeV-A3 is unclear, we investigated NATs against PeV-A3 during the COVID-19 pandemic and compared our findings with previous data.

Methods
Cord blood (CB) samples for healthy newborns born at full-term were collected from June through December 2023 at Niigata University Hospital in Niigata, Japan. Maternal clinical data were collected, and NATs measured using LLC-MK2 cells were compared with the pre-pandemic data, classified by age group, ie, 16–24 years, 25–34 years, and 35–44 years.

Results
In total, 102 CB samples were collected. Median maternal age was 34.5 years (range: 30–37 years), and the geometric mean titer (GMT) of antibodies against PeV-A3 was 98.4 (95% CI: 61.7–156.8). The GMT values for age 25–34 years during the pandemic (184.6, n = 45) and age 16–24 years before the pandemic (336.5, n = 11) did not significantly differ (P = 0.84). Similarly, the GMT for age 35–44 years during the pandemic (56.3, n = 51) did not significantly differ from that for the matching age group, 25–34 years, before the pandemic (31.9, n = 107) (P = 0.14). Notably, the GMT was significantly higher for age 25–34 years during the pandemic than for age 25–34 years and age 35–44 years before the pandemic (P &lt; 0.001), which is consistent with our finding that the pre-pandemic age group 16–24 years had the highest GMT.

Conclusion
Maternal NATs against PeV-A3 in CB before and during the COVID-19 pandemic were similar, which suggests that humoral immunity to PeV-A3 was not substantially altered even after 3 years of limited PeV-A3 infections during the COVID-19 pandemic.

Disclosures
All Authors: No reported disclosures
P-1195. Incidence and Diagnosis of Neonatal Herpes Simplex Virus (HSV) Following Transition to In-House Serum Testing
Authors: Patt Elizabeth , Ribes Julie A , Howard Joel I , Olney Katie B 
Published: January 2025

Abstract

Background
Neonatal Herpes simplex virus (HSV) infection is associated with significant morbidity and mortality, and previously estimated to account for 0.2-0.9% of hospitalizations in infants admitted with sepsis nationally. Recently, our institution transitioned the performance of serum HSV PCR testing in-house to expedite evaluation in neonates admitted with concerns for sepsis. This study was conducted to internally review the impact of in-house testing on neonatal HSV diagnosis and incidence.Table 1:Baseline Characteristics, Diagnosis, and Disease Classification in Infants with Positive Diagnostics

Methods
All infants ≤2 months of age admitted to our institution in the pre-implementation (8/2021-1/2022) or post-implementation (8/2022-5/2023) periods who had at least one HSV PCR obtained were included. Patient demographics and results of HSV testing were collected retrospectively. A complete evaluation was defined as the performance of HSV PCRs from blood, cerebrospinal fluid (CSF), and all surface sites (mouth, both eyes, nasopharynx, and rectum). The diagnosis of neonatal HSV was made by positive diagnostic(s) in conjunction with clinical presentation.

Results
A total of 335 infants (pre-transition=131, post-transition=204) were included. Demographics were similar overall between time periods. Diagnosis of neonatal HSV was made in 2 (1.5%) infants evaluated in the pre-transition and 17 (8.3%) infants evaluated in the post-transition period. Following transition to in-house performance of serum HSV PCR testing, infants were more likely to have a complete evaluation performed (82% vs. 0%; p=0.012). Both patients in the pre-cohort had isolated HSV-2 disease while 4 (23.5%) patients in the post-cohort had co-infection with HSV-1 and HSV-2 (Table 1). Overall, 5 (29%) patients in in the post-transition period had only a serum HSV PCR positive at diagnosis.

Conclusion
Incidence of neonatal HSV within our institution was higher than previous national estimates and incidence increased following transition to in-house serum testing, possibly due in part to improved rates of complete evaluation. The nonspecific clinical presentation and frequency for which only a single PCR was positive reinforces the importance of collecting all surface, blood, and CSF PCRs in neonates undergoing a sepsis evaluation.

Disclosures
All Authors: No reported disclosures
P-1206. Dengue Epidemic Outbreak 2023-2024: is it here for good? Experience in a Tertiary Care Pediatric Hospital in Buenos Aires, Argentina
Authors: Carril Sofia S , Tineo Soledad , Sanz Antonella Antonelli , Denardi Agustina , Marin Andrea , Mistchenko Alicia S , López Eduardo L 
Published: January 2025

Abstract

Background
Between epidemiological weeks (EW) 1 and 13 of 2024, the Region of the Americas reported 4,820,955 suspected dengue cases, triple the count from 2023. Argentina ranked second with 379,341 cases, a fourfold increase from the previous season. Our aim is to describe the behavior of dengue in a pediatric population during 2023 and 2024 and compare the characteristics of the latest two dengue outbreaks in Argentina.

Methods
Two cross-sectional studies were conducted in a children’s hospital in Buenos Aires City. Clinical, epidemiological, laboratory, and follow-up data were recorded for patients &lt; 18 years with confirmed dengue, according to PAHO definitions. The first season period included from March to May 2023 (EW 11 to 20) and the second from January to April 2024 (EW 2 to 15).

Results
A total of 1145 suspected cases were attended. 565 (49%) patients with confirmed dengue were included. Median age: 11 years (IQR 9-14), 308 (54%) being male. Most common symptoms: fever (100%), median duration of 4 days (IQR 3-5); headache/retro-orbital pain (88%); myalgias (75%). 188 patients (33%) exhibited warning signs, the most common: mucosal bleeding, persistent vomiting and severe abdominal pain. 396 patients had leukopenia (71%) and 346 had elevated liver enzymes (62%). Thrombocytopenia (&lt; 100,000/mm3) was found in 131 patients (24%). Significant differences were observed when comparing warning signs: more mucosal bleeding in 2024 (p&lt; 0,001), and more abdominal pain in 2023 (p=0,023). Regarding diagnosis, 495 (88%) patients were confirmed by detectable RT-qPCR, serotype 2 predominated (57%) and was significantly most frequent in 2023 (p&lt; 0,001). 70 (12%) patients had positive NS1 antigen enzyme immunoassay. 86 patients (15%) required hospitalization. 5 cases (0,8%) of severe dengue. No deaths occurred.

Conclusion
Timely and precise diagnosis, along with proper categorization of severity criteria, are crucial during dengue infection. One third of patients had warning signs. Despite serotype 2 being the most common during the 2023 outbreak, which is often linked with severe dengue, the hospitalization rate was the same in both periods. The new quadrivalent vaccine available could be an important tool to decrease the number of patients in our region.

Disclosures
All Authors: No reported disclosures