Subdural Empyema from Streptococcus suis Infection, South Korea.

In Jeju Island, South Korea, a patient who consumed raw pig products had subdural empyema, which led to meningitis, sepsis, and status epilepticus. We identified Streptococcus suis from blood and the subdural empyema. This case illustrates the importance of considering dietary habits in similar clinical assessments to prevent misdiagnosis.

Effect of directive laboratory comments on prescribing response to positive throat swab cultures.

BACKGROUND: In patients without ethnicity risk factors for acute rheumatic fever (ARF), our local guidelines recommend limiting antibiotic use following a positive throat swab culture (TSC). If symptoms are severe, a 5-7 day course is recommended. Despite this, most local patients with a positive TSC for group A Streptococcus (GAS) or Streptococcus dysgalactiae subsp. equisimilis (SDSE) were being prescribed 10 days of antibiotics. In response, we added comments to positive TSC reports recommending shorter treatment durations in those without ARF risk factors. No other antimicrobial stewardship initiatives were implemented. OBJECTIVES: To assess the effect of these comments on antibiotic course duration after positive TSC. METHODS: All community TSC results from 1 October 2021 to 31 March 2023 (1 year pre- to 6 months post-change) were matched to antibiotic dispensing data. Patients who had been empirically dispensed an antibiotic prior to the culture report were excluded. The outcome of interest was the antibiotic duration dispensed in the 5 day period after the TSC report. RESULTS: Following introduction of the comments, median course duration reduced from 10 (IQR 5-10) to 7 days (IQR 0-10; P < 0.01) and from 7 (IQR 0-10) to 0 days (IQR 0-5; P < 0.01) following GAS- and SDSE-positive TSC, respectively, in those without ARF risk factors. The percentage of people receiving 10 days of antibiotics decreased from 63.0% to 37.0% (P < 0.01) and 41.2% to 14.6% (P < 0.01) for GAS and SDSE, respectively. CONCLUSIONS: The introduction of comments providing direct prescribing advice to requestors appears to have been highly effective at improving guideline-compliant prescribing following positive TSC report.

A pharmacy-led sore throat test and treat (STTT) service: antigen testing and antibiotic supply rates during the period of heightened public awareness of Group A Streptococcus infections.

BACKGROUND: Community pharmacies in Wales delivered an NHS-funded sore throat test and treat (STTT) service during the period of increased invasive Group A Streptococcus (iGAS) incidents in winter 2022-23. Service users were screened using FeverPAIN/CENTOR scores, offered GAS rapid antigen detection tests (RADT) if appropriate, and antibiotics if indicated. OBJECTIVES: To evaluate the service's response to a substantial rise in sore throat presentations during a period of heightened public anxiety. METHODS: Cross-sectional study with anonymized individual-level data from electronic pharmacy records of all eligible STTT service users, between January 2022 and March 2023. RESULTS: Antibiotics were supplied to 24% (95% CI: 23-24) of people who used the STTT service and 31% (95% CI: 31-32) of those who met the threshold for an RADT. Of 27 441 STTT consultations, 9308 (33.9%) occurred during December 2022. In the week commencing 2 December 2022, following the announcements of increased iGAS incidents, we observed a statistically significant increase of 1700 consultations (95% CI: 924-2476) and a statistically significant decrease in supply rate of 13.9 antibiotics per 100 RADT (95% CI: -18.40 to -9.40). Antibiotic supply rates increased thereafter to those observed before the announcements of iGAS incidents. Referral rates to other primary care or emergency settings remained below 10% throughout the study period. CONCLUSIONS: Our findings suggest that, despite a dramatic increase in sore throat consultation rates in response to media reports, the pre-specified pathway followed by pharmacists ensured appropriate use of antibiotics, and absorbed a substantial workload that would otherwise end up in other healthcare settings.

Loop-mediated isothermal amplification (LAMP) assay for early on-site detection of Group B Streptococcus infection in neonatal sepsis blood sample.

BACKGROUND: Neonatal sepsis, often attributed to Group B Streptococcus (GBS) infection, poses a critical health risk to infants, demanding rapid and accurate diagnostic approaches. Existing diagnostic approaches are dependent on traditional culture methods, a process that requires substantial time and has the potential to delay crucial therapeutic assessments. METHODS: This study introduces an innovative Loop-Mediated Isothermal Amplification (LAMP) assay for the early on-site detection of GBS infection from neonatal sepsis blood samples. To develop a LAMP assay, the primers are designed for the selective targeting of a highly conserved segment within the cfb gene encoding the CAMP factor in Streptococcus agalactiae ensuring high specificity. RESULTS: Rigorous optimization of reaction conditions, including temperature and incubation time, enhances the efficiency of the LAMP assay, enabling rapid and reliable GBS detection within a short timeframe. The diagnostic efficacy of the LAMP assay was evaluated using spiked blood samples by eliminating the DNA extraction step. The simplified colorimetric LAMP assay has the capability to detect S. agalactiae in a neonatal blood sample containing 2 CFU/mL during sepsis. Additionally, the LAMP assay effectively detected S. agalactiae in both the standard and spiked blood samples, with no detectable interference with blood. CONCLUSION: This optimised LAMP assay emerges as a promising tool for early GBS detection, offering a rapid and accurate on-site solution that has the potential to inform timely interventions and improve outcomes in neonatal sepsis cases.

Performances of two rapid LAMP-based techniques for the intrapartum detection of Group B Streptococcus vaginal colonization.

PURPOSE: Group B Streptococcus (GBS) is the leading cause of invasive infections in newborns. The prevention of GBS neonatal disease relies on the administration of an intrapartum antibiotic prophylaxis to GBS-colonized women. In recent years, rapid intrapartum detection of GBS vaginal colonization using real-time nucleic acid amplification tests (NAATs) emerged as an alternative to antenatal culture screening methods. METHODS: We compared the performances of two loop-mediated isothermal amplification (LAMP) tests, the Ampliflash® GBS and the PlusLife® GBS tests, to standard culture for GBS detection in vaginal specimens from pregnant women. The study was conducted from April to July 2023 in a French hospital of the Paris area. RESULTS: A total of 303 samples were analyzed, including 85 culture-positive samples (28.1%). The Ampliflash® GBS test and the PlusLife® GBS tests gave a result for 100% and 96.3% tests, respectively. The performances of the tests were as follows: sensitivity 87.1% (95% confidence interval (CI) 78.3-92.6) and 98.7% (95% CI 93.0-99.8), specificity 99.1% (95% CI 96.7-99.8), and 91.9% (95% CI 87.3-95.0), respectively. False negative results of the Ampliflash® GBS test correlated with low-density GBS cultures. Time-to-results correlated with GBS culture density only for the PlusLife® GBS test (p < 0.001). CONCLUSION: Both techniques provide excellent analytical performances with high sensitivity and specificity together with a short turnaround time and results available in 10 to 35 min. Their potential to further reduce the burden of GBS neonatal disease compared with antenatal culture screening needs to be assessed in future clinical studies.

To evaluate the performance of simultaneous amplification and testing assay for group B Streptococcus detection: comparison with real-time PCR and ddPCR assays.

BACKGROUND: To evaluate the performance of simultaneous amplification and testing (SAT) assay for the detection of group B Streptococcus (GBS) in maternal vaginal and perianal swabs compared with real-time polymerase chain reaction (RT-PCR). METHODS: We obtained vaginal and perianal swabs from 1474 pregnant women at the Obstetrics and Gynecology Hospital of Fudan University (Shanghai, China) between April 2023 and June 2023. Vaginal and perianal swabs were collected at 35-37 weeks of gestation. Swabs were tested for GBS simultaneously by using the SAT assay and RT-PCR, and a comparative analysis (kappa coefficient) was performed. Furthermore, we conducted additional droplet digital PCR (ddPCR) tests to confirm the results when there were controversial results between SAT and RT-PCR. In addition, we compared the limit of detection, technical specificity, repeatability and reproducibility of SAT-GBS with those of routine RT-PCR assays. RESULTS: In our study, the detection rate of clinical GBS according to the SAT assay was 11.5% (169/1471). The SAT assay showed a sensitivity of 91.8%, a specificity of 99.9%, a diagnostic accuracy of 98.9%, a positive predictive value (PPV) of 99.4% and a negative predictive value (NPV) of 98.8%. The kappa value between RT-PCR and SAT was 0.917. CONCLUSIONS: This SAT assay for the detection of group B Streptococcus is not only easy to perform but can also detect GBS sensitively and specifically and may be used in the regular molecular diagnosis of GBS infection among pregnancies.

Development of a prototypic, field-usable diagnostic tool for the detection of gram-positive cocci-induced mastitis in cattle.

BACKGROUND: Bovine mastitis is one of the most widespread diseases affecting cattle, leading to significant losses for the dairy industry. Currently, the so-called gold standard in mastitis diagnosis involves determining the somatic cell count (SCC). Apart from a number of advantages, this method has one serious flaw: It does not identify the etiological factor causing a particular infection, making it impossible to introduce targeted antimicrobial therapy. This can contribute to multidrug-resistance in bacterial species. The diagnostic market lacks a test that has the advantages of SCC and also recognizes the species of pathogen causing the inflammation. Therefore, the aim of our study was to develop a lateral flow immunoassay (LFIA) based on elongation factor Tu for identifying most prevalent Gram-positive cocci responsible for causing mastitis including Streptococcus uberis, Streptococcus agalactiae and Staphylococcus aureus. RESULTS: As a result, we showed that the assay for S. uberis detection demonstrated a specificity of 89.02%, a sensitivity of 43.59%, and an accuracy of 80.3%. In turn, the second variant - assay for Gram-positive cocci reached a specificity of 95.59%, a sensitivity of 43.28%, and an accuracy of 78.33%. CONCLUSIONS: Our study shows that EF-Tu is a promising target for LFIA and we have delivered evidence that further evaluation could improve test parameters and fill the gap in the mastitis diagnostics market.

Mediastinitis secondary to invasive infection by group A Streptococcus in Spain.

This study describes 5 mediastinitis cases secondary to invasive group A Streptococcus (iGAS) disease in a recent outbreak in Spain. Among 398 iGAS cases between January 2019-March 2023, 5 (1.3%) were mediastinitis, 4 occurring in December 2022, all secondary to pneumonia or deep neck infection. We outline the clinical outcome with a review of the scarce pediatric literature.  Conclusion: mediastinistis is a rare but severe complication of iGAS and a high level of suspicion is required to diagnose it. What is Known: • Group A Streptococcus can cause invasive and severe infections in children. • Mediastinitis is a severe complication from some bacterial infections, mainly secondary due to deep-neck abscesses. What is New: • Mediastinitis is an unrecognized complication due to an invasive group A Streptococcus (iGAS) infection. • In cases of a deep-neck abscess or complicated pneumonia a high clinical suspicion of iGAS mediastinitis is required, especially when the clinical course is not favorable.

Revising the value of Antistreptolysin O titre in childhood and its interpretation in the diagnostic approach of rheumatic diseases.

The burden of group A streptococcus (GAS) infection and its rheumatic sequelae remains dramatically high, especially in low-income countries. Recently, an increased number of Acute Rheumatic Fever (ARF) cases was documented in many regions of Italy. The diagnosis of rheumatic sequelae relies on clinical signs and on the evaluation of the Antistreptolysin O titre (ASO), whose variations are globally reported. To re-examine the standard reference value of ASO titre, by measuring either its upper limit of normal (ULN) in a population of healthy children (HC) or comparing these values with streptococcal antibodies registered in a cohort of patients affected by the rheumatic sequelae of GAS infection. We performed a multicenter retrospective study. We enrolled 125 HC, aged 2-17 years, and a total of 181 patients affected by ARF, acute streptococcal pharyngitis, post-streptococcal arthritis, Henoch-Schönlein purpura and erythema nodosum, divided into four groups. The levels of ASO and anti-deoxyribonuclease B (anti-DNase B) titres were analyzed and compared among the various groups. Moreover, the 80th percentile value was calculated and established as the ULN for ASO titre in HC group. The ULN for ASO titre in overall HC group was 515 IU/mL, resulting in higher than used in the routine investigation. The ASO titre was significantly higher in patients with rheumatic sequelae compared with HC group, with a peak in the age between 5 and 15 years.    Conclusion: Our study established a new ULN normal value of streptococcal serology in a childhood and adolescent population of Italy, suggesting the need to extend this revaluation to the critical areas, in order to avoid underestimating ARF diagnosis. The correct interpretation of ASO and anti-DNase B values in the context of rheumatic diseases has been discussed. What is Known: • The global burden of disease caused by group A streptococcus is not known and remains an important cause of morbidity and mortality. Acute rheumatic fever continues to be a serious worldwide public health problem and a recent recurrence of group A streptococcus infection cases is observed. • The streptococcal sequelae requires evidence of preceding streptococcal infection, commonly elevated streptococcal antibody titre, but the upper limit for these titres varies considerably based on age group, region, and origin. What is New: • This study provides population-specific values for streptococcal antibody titres in Italy. • Interpret the results of group A streptococcal antibody tests within the clinical context.

Clinical Characteristics of Lung Abscess Caused by Streptococcus Constellatus Infection.

BACKGROUND: This study aimed to understand the clinical characteristics of pulmonary abscess caused by Streptococcus constellatus infection. METHODS: The clinical manifestations, laboratory examination, drug sensitivity, chest CT manifestations, and treatment and prognosis of patients with pulmonary abscess caused by Streptococcus constellatus infection were retrospectively collected and analyzed. RESULTS: A total of 9 cases of pulmonary abscess caused by Streptococcus constellatus infection were confirmed; one case was confirmed by traditional cultures, while metagenomic next-generation sequencing (mNGS) confirmed the other 8 cases. All of the 9 patients had different degrees of cough, sputum, fever, chest pain, and/or dyspnea, and the physical examination showed fast breathing, reduced respiratory sound, or moist rales on the affected side. In laboratory tests, 8 patients had elevated white blood cells and hypoproteinemia upon admission. Blood gas analysis showed an oxygenation index < 300. The antimicrobial susceptibility testing results in 1 patient with culture-confirmed pathogen diagnosis showed that Streptococcus constellatus was susceptible to ampicillin, penicillin G, cefotaxime, ceftriaxone, cefepime, meropenem, chloramphenicol, linezolid, levofloxacin, and vancomycin and resistant to tetracycline and clindamycin. Relevant antibiotic resistance genes were not detected by mNGS in the 8 patients with negative culture and positive mNGS results. A chest CT showed lung consolidation or cavity formation in 9 patients admitted to the hospital, and 5 patients had pleural effusion. 3 cases were admitted to the respiratory intensive care unit (RICU) and 6 cases were admitted to the general ward. There were 3 cases of nasal catheter oxygen inhalation, 1 case of mask oxygen inhalation, and 5 cases of non-invasive ventilator assisted ventilation. All patients received penicillin or respiratory quinolones anti-infection therapy, and 3 cases were treated with a thoracic closed drainage tube. All patients were discharged from the hospital after improvement, and the hospital stay was 15 - 23 days. CONCLUSIONS: Patients with pulmonary abscess caused by Streptococcus constellatus infection have an urgent condition and rapid progression. It is helpful to use mNGS combined with traditional culture as soon as possible to identify the pathogenic bacteria. Penicillin antibiotics should be the first choice for pulmonary abscess caused by a suspected Streptococcus constellatus infection. If a patient´s condition worsens during the treatment, especially for patients who have lesions involving the interlobar fissure or pleura, compressive atelectasis caused by pleural fluid formation or an increase in the amount of pleural effusion needs to be highly suspected.

Analysis of Differences in Neonatal Sepsis Caused by Streptococcus Agalactiae and Escherichia Coli.

BACKGROUND: Streptococcus agalactiae (GBS) and Escherichia coli (E. coli) are the main pathogenic bacteria in neonatal sepsis. Therefore, the clinical characteristics, nonspecific indicators, and drug susceptibilities of these two bacteria were studied. METHODS: In total, 81 and 80 children with sepsis caused by GBS and E. coli infection, respectively, admitted to the neonatal department of our hospital between May 2012 and July 2023, were selected, and the clinical characteris-tics of the two groups were analyzed. Nonspecific indicators and drug sensitivity test results were analyzed retrospectively. RESULTS: Birth weight, tachypnea, groan, tachycardia or bradycardia, and the incidence of complications, such as pneumonia, respiratory failure, and purulent meningitis, were higher in the GBS group than in the E. coli group. The children were born prematurely, and the mother had a premature rupture of membranes. The incidence of jaundice, abdominal distension, atypical clinical manifestations, and complications of necrotizing enterocolitis was lower than of the E. coli group, and the differences were statistically significant (p < 0.05). The WBC, NE#, NE#/LY#, hs-CRP, and PCT of the GBS group were higher than those of the E. coli group, whereas the MPV, D-D, and FDP levels were lower than those in the E. coli group. The differences were all statistically significant (p < 0.05). The 81-bead GBS had high resistance rates against tetracycline (95%), erythromycin (48.8%), and clindamycin (40%), and no strains resistant to vancomycin, linezolid, penicillin, or ampicillin appeared, whereas 80 strains of E. coli were more resistant to penicillin and third-generation cephalosporins, with the higher resistance rates to ampicillin (68.30%), trimethoprim/sulfamethoxazole (53.6%), and ciprofloxacin (42.90%). Resistance rates to carbapenems and aminoglycosides were extremely low. CONCLUSIONS: Both GBS and E. coli neonatal sepsis have specific clinical characteristics, especially in terms of clinical manifestations, complications, non-specific indicators, and drug resistance. Early identification is important for clinical diagnosis and treatment.

Sexual activity, vaginal symptoms, maternal perineal hygiene behavior, and constipation on ano-vaginal colonization of group B streptococcus in near term pregnancy.

BACKGROUND: Maternal Group B Streptococcus (GBS) colonization is influenced by many factors but results are inconsistent. Consideration of antenatal risk factors may help inform decision making on GBS microbiological culture screening where universal screening is not standard of care. We sought to identify independent predictors of GBS colonization at 34-37 weeks gestation incorporating vaginal symptoms, perineal hygiene measures, sexual activity, and a potential novel factor, constipation. METHODS: In this prospective cross-sectional study, 573 women at 34-37 weeks gestation had an ano-vaginal swab taken and sent for selective culture for GBS. Women were asked about vaginal bleeding, discharge, irritation and candidiasis, antibiotic use during pregnancy, ano-vaginal hygiene practices such as douching and perineal cleansing after toileting, sexual intercourse related activities, and a potential novel factor for GBS carriage, constipation. Maternal basic demographics and obstetric-related characteristics were also collected. Bivariate analyses were performed to identify associates of GBS colonization. All variables with p < 0.05 found on bivariate analysis were then included into a model for multivariable binary logistic regression analysis to identify independent risk factors for GBS colonization. RESULTS: GBS colonization was found in 235/573 (41.0%) of participants. Twenty six independent variables were considered for bivariate analysis. Eight were found to have p < 0.05. Following adjusted analysis, six independent predictors of GBS colonization were identified: ethnicity, previous neonatal GBS prophylaxis, antenatal vaginal irritation, antibiotic use, recent panty liner use, and frequency of sexual intercourse. Vaginal discharge and perineal cleansing were not associated after adjustment. Recent douching and constipation were not associated on bivariate analysis. CONCLUSION: The identification of independent predictors of GBS colonization in late pregnancy may inform the woman and care provider in their shared decision making for microbiological screening at 35-38 weeks gestation in locations where universal GBS screening is not standard of care. ETHICS OVERSIGHT: This study was approved by the Medical Ethics Committee of University Malaya Medical Centre (UMMC) on August 9, 2022, reference number 2022328-11120.

Novel Insights on Group B Streptococcus in Pregnancy.

Group B Streptococcus (GBS) is a frequent colonizer of the human genital and gastrointestinal tract. In pregnant or postpartum persons, colonization is often asymptomatic and can contribute to infectious morbidity in both the parturient and the newborn. The prevalence of invasive GBS disease has dramatically decreased over the past 3 decades. However, despite standardized clinical algorithms, GBS disease remains a public health concern. Our review summarizes the GBS bacteria pathophysiology, morbidity, management guidelines, and summarizes ongoing research. While novel testing and parturient vaccination are being explored, barriers exist, preventing guideline updates and widespread implementation.

Group B Streptococcus and Intraamniotic Inflammation and Infection.

Intraamniotic inflammation and infection complicate 2% to 5% of term deliveries. Group B Streptococcus (GBS) is a common cause of intraamniotic infection associated with invasive neonatal disease and maternal morbidity. Universal vaginal-rectal screening for GBS colonization is recommended between 36 and 37 weeks. Intrapartum antibiotic prophylaxis is recommended for individuals with positive GBS screens and other risk factors. Intravenous penicillin is the preferred antimicrobial agent. Individuals with penicillin allergies may receive cefazolin for low-risk allergies and either clindamycin or vancomycin for high-risk allergies, depending on their antimicrobial susceptibilities. Clinical trials are underway to evaluate the safety and immunogenicity of maternal anti-GBS vaccine candidates.

Toxic Shock Syndrome (TSS) Caused by Group A Streptococcus: Novel Insights Within the Context of a Familiar Clinical Syndrome.

The emergence of invasive infections attributed to group A Streptococcus (GAS) infections, has resurged since the 1980s. The recent surge in reports of toxic shock syndrome due to GAS in Japan in 2024, while sensationalized in the media, does not represent a novel infectious disease per se, as its diagnosis, treatment, and prevention are already well-established. However, due to signs of increasing incidence since 2011, further research is needed. Health authorities in neighboring countries like The Republic of Korea should not only issue travel advisories but also establish meticulous surveillance systems and initiate epidemiological studies on the genotypic variations of this disease while awaiting various epidemiological research findings from Japan.

Streptococcal Pharyngitis: Rapid Evidence Review.

Group A beta-hemolytic streptococcal pharyngitis is a common infection responsible for more than 6 million office visits in the United States annually. Only 10% of adults seeking care for a sore throat have group A beta-hemolytic streptococcal pharyngitis; however, 60% or more are prescribed antibiotics. Guidelines recommend using clinical decision rules to assess the risk of group A beta-hemolytic streptococcal infection, followed by rapid antigen testing if a diagnosis is unclear, before prescribing antibiotics. Fever, tonsillar exudate, cervical lymphadenitis, and patient ages of 3 to 15 years increase clinical suspicion. A cough is more suggestive of a viral etiology. The limited history used in these decision rules is amenable to virtual visits. After a negative rapid antigen test result, a throat culture is recommended in children and adolescents. Penicillin and amoxicillin are first-line antibiotics, with a recommended course of 10 days; first-generation cephalosporins are recommended for patients with nonanaphylactic allergies to penicillin. There is significant resistance to azithromycin and clarithromycin in some parts of the United States. Steroids are not recommended for symptomatic treatment. Patients with worsening symptoms after appropriate antibiotic initiation or with symptoms lasting 5 days after the start of treatment should be reevaluated. Tonsillectomy is rarely recommended as a preventive measure: seven episodes of streptococcal pharyngitis in 1 year, five episodes in each of the past 2 years, or three episodes in each of the past 3 years are commonly used thresholds for considering surgery.

Increase in invasive group A streptococcal infections (iGAS) in children and older adults, Norway, 2022 to 2024.

At the end of 2022 and most notably during the first half of 2023, the number of invasive group A streptococcus (iGAS) notifications increased in Norway, largely affecting children younger than 10 years, as observed in several other countries. Following this atypical season, a new surge in the number of iGAS notifications began in December 2023 and peaked between January and February 2024, now particularly affecting both children younger than 10 years and older adults (70 years and above).

The current status of Group B Streptococcus infection in the reproductive tract of late-pregnancy women and its impact on pregnancy outcomes.

OBJECTIVE: Analyze Group B Streptococcus (GBS) infection in late-pregnancy pregnant women in Shanghai, the risk factors of GBS infection, and its impact on pregnancy outcomes, providing guidance for early prevention and treatment in clinical practice. METHODS: We selected 12,132 late-pregnancy pregnant women admitted from January 2022 to December 2022 as the research subjects. Based on the GBS test results of reproductive tract secretion samples from pregnant women, 210 cases of GBS positive pregnant women were randomly selected as the observation group, and 200 cases of GBS negative pregnant women were selected as the control group. The risk factors of infection and the impact on pregnancy outcomes were compared between the two groups. RESULTS: The GBS colonization rate of pregnant women in this study was 6.52%; the incidence of Vaginal delivery and Neonatal infection in GBS positive group was significantly higher than that in GBS negative group (P < 0.05); with Neonatal infection as the dependent variable, and the GBS infection, Vaginal delivery and GDM of the elderly and women in late pregnancy as independent variables, the results showed that GBS infection of women in late pregnancy was an independent risk factor for Neonatal infection. CONCLUSION: Clinical practice should attach great importance to GBS infection in late pregnancy, strengthen GBS screening in late pregnancy, and actively implement the strategy of intrapartum antibiotic intervention (IAP), which is of great significance in reducing the vertical infection rate of maternal and infant GBS and improving the quality of newborn birth.

To ASLO or Not to ASLO: Utility of the ASLO Test in Dermatology.

BACKGROUND: Group A Streptococcus (GAS) causes a wide spectrum of acute infections and immune-related diseases, most of which include a dermatological presentation. However, dermatological findings have a wide range of other possible etiologies. The diagnosis of GAS-related disease requires an indication of preceding GAS infection by direct culture or by measuring antistreptolysin O (ASLO) titer. OBJECTIVES: To explore the correlation between ASLO positivity and dermatological diseases. METHODS: We analyzed clinical data from all cases of patients over 18 years of age who underwent ASLO testing between the years 2016 and 2020 in the Department of Dermatology at Rambam Health Care Campus. RESULTS: Of 152 adult patients with ASLO tests, 100 had diagnoses that were potentially related to streptococcal infection. Vasculitis and psoriasis were the most suspected diagnoses. Positive ASLO test was found in 44 (29%) patients. The diagnoses showing the highest ratio of positive ASLO were psoriasis (60%), erythema nodosum (46%), skin infections (43%), Sweet syndrome (33%), and vasculitis (15%). Psoriasis types included plaque psoriasis (8 patients), guttate psoriasis (3 patients), and palmoplantar pustulosis and erythroderma (2 patients each). CONCLUSIONS: Although the applicability of ASLO for the spectrum of dermatological diseases remains unclear, our results enhance the practical relevance of the test. We showed a higher prevalence of positive ASLO tests in psoriasis and erythema nodosum cases and a lower prevalence in vasculitis. Notably, ASLO was positive in all psoriasis subtypes, suggesting high utility of the test for psoriasis.

Machine Learning for Clinical Decision Support of Acute Streptococcal Pharyngitis: A Pilot Study.

BACKGROUND: Group A Streptococcus (GAS) is the predominant bacterial pathogen of pharyngitis in children. However, distinguishing GAS from viral pharyngitis is sometimes difficult. Unnecessary antibiotic use contributes to unwanted side effects, such as allergic reactions and diarrhea. It also may increase antibiotic resistance. OBJECTIVES: To evaluate the effect of a machine learning algorithm on the clinical evaluation of bacterial pharyngitis in children. METHODS: We assessed 54 children aged 2-17 years who presented to a primary healthcare clinic with a sore throat and fever over 38°C from 1 November 2021 to 30 April 2022. All children were tested with a streptococcal rapid antigen detection test (RADT). If negative, a throat culture was performed. Children with a positive RADT or throat culture were considered GAS-positive and treated antibiotically for 10 days, as per guidelines. Children with negative RADT tests throat cultures were considered positive for viral pharyngitis. The children were allocated into two groups: Group A streptococcal pharyngitis (GAS-P) (n=36) and viral pharyngitis (n=18). All patients underwent a McIsaac score evaluation. A linear support vector machine algorithm was used for classification. RESULTS: The machine learning algorithm resulted in a positive predictive value of 80.6 % (27 of 36) for GAS-P infection. The false discovery rates for GAS-P infection were 19.4 % (7 of 36). CONCLUSIONS: Applying the machine-learning strategy resulted in a high positive predictive value for the detection of streptococcal pharyngitis and can contribute as a medical decision aid in the diagnosis and treatment of GAS-P.