Clinical characteristics and risk factors of severe human parainfluenza virus infection in hospitalized children.

BACKGROUND: Human parainfluenza viruses (HPIVs) commonly cause childhood respiratory illness requiring hospitalization in Taiwan. This study aimed to investigate clinical severity and identify risk factors predisposing to severe disease in hospitalized children with HPIV infection. METHODS: We included hospitalized patients with lab-confirmed HPIV infection from 2007 to 2018 and collected their demographic and clinical characteristics. Patients with ventilator support, intravenous inotropic agents, and extracorporeal membrane oxygenation were defined as severe cases. RESULTS: There were 554 children hospitalized for HPIV infection. The median age was 1.2 years; 518 patients had non-severe HPIV infection, whereas 36 patients (6.5%) had severe HPIV infection. 266 (48%) patients had underlying diseases, and 190 patients (34.3%) had bacterial co-detection. Children with severe HPIV infection were more likely to have bacterial co-detection than those without (52.8% vs 33.0%, p = 0.02). Patients with lung patch or consolidation had more invasive bacterial co-infection or co-detection than those without patch or consolidation (43% vs 33%, p = 0.06). Patients with neurological disease (adjusted OR 4.77, 95% CI 1.94-11.68), lung consolidation/patch (adjusted OR 6.64, 95% CI 2.80-15.75), and effusion (adjusted OR 11.59, 95% CI 1.52-88.36) had significantly higher risk to have severe HPIV infection. CONCLUSION: Neurological disease and lung consolidation/patch or effusion were the most significant predictors of severe HPIV infection.

Seasonality and risk factor analysis of respiratory syncytial virus infection in children in Taiwan-A retrospective study from 1995 to 2005.

Respiratory syncytial virus (RSV) is one of the important pathogens leading to acute respiratory tract infection in infants and young children. We aimed to investigate the seasonality of RSV infection in different parts of Taiwan and to delineate the risk factors for severe RSV infections. We collected RSV-infected patients' data by retrospective chart review. A total of 1740 RSV-infected children aged under 18 years were enrolled. The infection was acquired during hospitalization in 103 (7.1%) children, while none of them required ventilator support or needed intensive care before RSV infection. The need for intensive care or ventilator support was significantly associated with congenital heart disease (CHD), chronic lung disease, and neuromuscular diseases. Age <1 year and nosocomially acquired infection are also significant predictors for the need of intensive care. Only the presence of CHD, especially acyanotic CHD, was significantly associated with a fatal outcome. RSV infection occurs all year round. Monthly distribution of RSV infections in Northern Taiwan showed a bimodal pattern, with one peak from March to May, and another from August to October. The distribution in Southern Taiwan showed a single peak from April to July. The occurrence of RSV correlates positively with temperature and rain. The bimodal seasonal distribution pattern in Northern Taiwan may be a transitional pattern shifting from a single high winter peak in temperate areas to a wider summer peak in tropical areas. Continuous surveillance is needed to explore the possible effect of global warming on the seasonality of RSV infection.

Clinical characteristics and factors associated with severe COVID-19 in hospitalized children during the SARS-CoV-2 Omicron pandemic in Taiwan.

BACKGROUND: Since April 2022, a notable increase in COVID-19 cases with the rapid spread of the SARS-CoV-2 Omicron variant has been reported in Taiwan. In the epidemic, children were one of the most vulnerable groups, so we analyzed their clinical presentations and factors associated with severe complications of COVID-19 in children. METHODS: We included hospitalized patients under 18 years old with lab-confirmed SARS-CoV-2 infection from March 1, 2022, to July 31, 2022. We collected the demographic and clinical characteristics of the patients. Patients requiring intensive care were defined as severe cases. RESULTS: Among the 339 enrolled patients, the median age was 31 months (interquartile range (IQR), 8-79.0 months); and 96 patients (28.3%) had underlying diseases. Fever was noted in 319 patients (94.1%) with a median duration of two days (IQR 2-3 days). Twenty-two patients (6.5%) were severe cases, including 10 patients (2.9%) with encephalopathy with abnormal neuroimaging and ten patients (2.9%) with shock. Two patients (0.6%) died. Patients with congenital cardiovascular disease (aOR: 21.689), duration of fever up to four days or more (aOR: 6.466), desaturation (aOR: 16.081), seizure (aOR: 20.92), and procalcitonin >0.5 ng/mL (aOR: 7.886) had a higher risk of severe COVID-19. CONCLUSIONS: Vital signs need close monitoring, early management and/or intensive care may be applied in COVID-19 patients with congenital cardiovascular diseases, fever lasting ≥4 days, seizures, desaturation and/or elevated procalcition since they are at higher risks of severe diseases.

Viral dynamics of SARS-CoV-2 Omicron infections in a previously low COVID-19 prevalence region: Effects of vaccination status, antiviral agents, and age.

BACKGROUND: In Taiwan, the prevalence of COVID-19 was low before April 2022. The low SARS-CoV-2 seroprevalence in the population of Taiwan provides an opportunity for comparison with fewer confounding factors than other populations globally. Cycle threshold (Ct) value is an easily accessible method for modeling SARS-CoV-2 dynamics. In this study, we used clinical samples collected from hospitalized patients to explore the Ct value dynamics of the Omicron variant infection. METHODS: From Jan 2022 to May 2022, we retrospectively included hospitalized patients tested positive by nasopharyngeal SARS-CoV-2 PCR. We categorized the test-positive subjects into different groups according to age, vaccination status, and use of antiviral agents. To investigate the nonlinear relationship between symptom onset days and Ct value, a fractional polynomial model was applied to draw a regression line. RESULTS: We collected 1718 SARS-CoV-2 viral samples from 812 individuals. The Ct values of unvaccinated individuals were lower than those of vaccinated persons from Day 4 to Day 10 after symptom onset. The Ct value increased more rapidly in those individuals with antiviral drug treatment from Day 2 to Day 7. In elderly individuals, the Ct values increased slowly from Day 5 to Day 10, and the increasing trend was unique compared with that in children and adults. CONCLUSION: Our study demonstrated the primary viral infection dynamics of the Omicron variant in hospitalized patients. Vaccination significantly affected viral dynamics, and antiviral agents modified viral dynamics irrespective of vaccination status. In elderly individuals, viral clearance is slower than that in adults and children.

Prolonged Streptococcus gallolyticus subsp. pasteurianus gut colonization in healthcare workers and potential transmission role in neonatal sepsis.

BACKGROUND: Streptococcus gallolyticus subsp. pasteurianus (SGSP) is a commensal in the intestinal tract and a potential pathogen of neonatal sepsis. During an 11-month period, four consecutive cases of SGSP sepsis were identified in one postnatal care unit (unit A) without evidence of vertical transmission. Therefore, we initiated this study to investigate the reservoir and mode of transmission of SGSP. METHOD: We performed cultures of stool samples from healthcare workers in unit A and unit B (another unit without SGSP sepsis). If SGSP was positive in feces, we performed isolate pulsotyping and genotyping by using pulsed-field gel electrophoresis (PFGE) and analyzing random amplified polymorphic DNA (RAPD) patterns, respectively. RESULTS: Five staff members in unit A showed positivity for SGSP. All samples from unit B were negative. We identified two major pulsogroups (groups C and D) by PFGE. In group D, the strains isolated from 3 consecutive sepsis patients (P1, P2 and P3) were closely related and clustered together as those from 2 staff members (C1/C2, C6). One staff (staff 4) had a direct contact history with patient (P1) confirmed to have the same clone. The last isolate of the patient in our study (P4) belonged to a distinct clone. CONCLUSION: We found prolonged gut colonization of SGSP in healthcare workers and its epidemiological relatedness to neonatal sepsis. Fecal-oral or contact transmission is a possible route of SGSP infection. Fecal shedding among staff may be associated with neonatal sepsis in healthcare facilities.

Differential clinical characteristics and performance of home antigen tests between parents and children after household transmission of SARS-CoV-2 during the Omicron variant pandemic.

OBJECTIVES: The SARS-CoV-2 Omicron variant pandemic struck Taiwan in April 2022. Rapid antigen tests (RATs) play an important role in providing rapid results during a pandemic. However, self-collected samples by the children's caregivers without the supervision of medical personnel raise some concerns. METHODS: This study was performed to investigate household transmission, clinical characteristics, and antigen performance in a special COVID-19 family clinic in a children's hospital. The performance of at-home RATs was evaluated based on reverse transcription-polymerase chain reaction. RESULTS: We included 627 patients in our study between May 11 and June 10, 2022. The COVID-19 full vaccination rate was significantly higher in adults (98.5%) than in children (5.9%, P <0.001). The transmission rate was significantly higher in children (91.3%) than in adults (76.6%, P <0.001). Infected children had more incidents of fever (82.4% vs 22.4%, P <0.001) and a higher peak fever than adults. Based on the reverse transcription-polymerase chain reaction, the negative predictive rate of the home RAT was only 38.7% (95% confidence interval: 31.9-46.0%) in children. The cycle threshold value of those with false-negative antigen tests was significantly lower in children. CONCLUSION: Children had a higher transmission rate, more fever, and higher peak fever than adults. Home RAT has a suboptimal negative predictive rate in children.

Clinical characteristics and outcomes of carbapenem-resistant Enterobacterales bacteremia in pediatric patients.

BACKGROUND/PURPOSE: Clinical data on carbapenem-resistant Enterobacterales (CRE) bacteremia in the pediatric population are limited. This study investigated the clinical characteristics and outcomes of pediatric CRE bacteremia. METHODS: Clinical data on bacteremia caused by carbapenem-susceptible and carbapenem-resistant Enterobacterales, including Escherichia coli, Klebsiella spp., Enterobacter spp., Serratia marcescens, Proteus mirabilis, Citrobacter spp., and Morganella spp., in pediatric patients from a children's hospital in Taiwan were retrospectively retrieved and analyzed. RESULTS: From January 2013 to December 2021, 471 clinical isolates of Enterobacterales bacteremia were identified in 451 episodes from 379 pediatric patients. Among all the isolates, the predominant species were E. coli (199/471, 42.2%), Klebsiella spp. (168/471, 35.6%), and Enterobacter spp. (59/471, 12.5%), with carbapenem-resistance rates of 1.5%, 11.9%, and 25.0%, respectively. Overall, 40 (8.4%) showed a carbapenem resistance phenotype. Patients' all-cause mortality rate at 14 days was significantly higher in CRE bacteremia episodes than non-CRE ones (12.5% vs. 3.6%, p < 0.05). The predicting factor of a CRE bacteremia episode was the causative agent of Enterobacter spp. (adjusted OR of 2.551, CI 1.073-6.066, p < 0.05) and ESBL-producing phenotype (adjusted OR 14.268, CI 5.120-39.762, p < 0.001). CONCLUSION: Bloodstream infections caused by CRE are associated with a higher mortality rate in the pediatric population. Attention must be paid to preventing and managing pediatric patients with CRE infections.

Clinical characteristics of influenza with or without Streptococcus pneumoniae co-infection in children.

BACKGROUND/PURPOSE: Influenza is frequently complicated with bacterial co-infection. This study aimed to disclose the significance of Streptococcus pneumoniae co-infection in children with influenza. METHODS: We retrospectively reviewed medical records of pediatric patients hospitalized for influenza with or without pneumococcal co-infection at the National Taiwan University Hospital from 2007 to 2019. Clinical characteristics and outcomes were compared between patients with and without S. pneumoniae co-infection. RESULTS: There were 558 children hospitalized for influenza: 494 had influenza alone whereas 64 had S. pneumoniae co-infection. Patients with S. pneumoniae co-infection had older ages, lower SpO2, higher C-Reactive Protein (CRP), lower serum sodium, lower platelet counts, more chest radiograph findings of patch and consolidation on admission, longer hospitalization, more intensive care, longer intensive care unit (ICU) stay, more mechanical ventilation, more inotropes/vasopressors use, more surgical interventions including video-assisted thoracoscopic surgery (VATS) and extracorporeal membrane oxygenation (ECMO), and higher case-fatality rate. CONCLUSION: Compared to influenza alone, patients with S. pneumoniae co-infection had more morbidities and mortalities. Pneumococcal co-infection is considered when influenza patients have lower SpO2, lower platelet counts, higher CRP, lower serum sodium, and more radiographic patches and consolidations on admission.

Clinical characteristics of recurrent pneumonia in children with or without underlying diseases.

BACKGROUND: Recurrent pneumonia is uncommon in children and few studies investigate the clinical impact of underlying diseases on this issue. This study aimed to explore the difference in clinical manifestations, pathogens, and prognosis of recurrent pneumonia in children with or without underlying diseases. METHODS: We conducted a retrospective study of pediatric recurrent pneumonia from 2007 to 2019 in National Taiwan University Hospital. Patients under the age of 18 who had two or more episodes of pneumonia in a year were included, and the minimum interval of two pneumonia episodes was more than one month. Aspiration pneumonia was excluded. Demographic and clinical characteristics of patients were collected and compared. RESULTS: Among 8508 children with pneumonia, 802 (9.4%) of them had recurrent pneumonia. Among these 802 patients, 655 (81.7%) had underlying diseases including neurological disorders (N = 252, 38.5%), allergy (N = 211, 32.2%), and cardiovascular diseases (N = 193, 29.5%). Children without underlying diseases had more viral bronchopneumonia (p < 0.001). Children with underlying diseases were more likely to acquire Staphylococcus aureus (p = 0.001), and gram-negative bacteriae, more pneumonia episodes (3 vs 2, p < 0.001), a longer hospital stay (median: 7 vs. 4 days, p < 0.001), a higher ICU rate (28.8% vs 3.59%, p < 0.001), and a higher case-fatality rate (5.19% vs 0%, p < 0.001) than those without underlying diseases. CONCLUSION: Children with underlying diseases, prone to have recurrent pneumonia and more susceptible to resistant microorganisms, had more severe diseases and poorer clinical outcomes. Therefore, more attention may be paid on clinical severity and the therapeutic plan.

RSV pneumonia with or without bacterial co-infection among healthy children.

BACKGROUND: Respiratory syncytial virus (RSV) is a common cause of childhood pneumonia, but there is limited understanding of whether bacterial co-infections affect clinical severity. METHODS: We conducted a retrospective cohort study at National Taiwan University Hospital from 2010 to 2019 to compare clinical characteristics and outcomes between RSV with and without bacterial co-infection in children without underlying diseases, including length of hospital stay, intensive care unit (ICU) admission, ventilator use, and death. RESULTS: Among 620 inpatients with RSV pneumonia, the median age was 1.33 months (interquartile range, 0.67-2 years); 239 (38.6%) under 1 year old; 366 (59.0%) males; 201 (32.4%) co-infected with bacteria. The three most common bacteria are Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae. The annually seasonal analysis showed that spring and autumn were peak seasons, and September was the peak month. Compared with single RSV infection, children with bacterial co-infection were younger (p = 0.021), had longer hospital stay (p < 0.001), needed more ICU care (p = 0.02), had higher levels of C-reactive protein (p = 0.009) and more frequent hyponatremia (p = 0.013). Overall, younger age, bacterial co-infection (especially S. aureus), thrombocytosis, and lower hemoglobin level were associated with the risk of requiring ICU care. CONCLUSION: RSV related bacterial co-infections were not uncommon and assoicated with ICU admission, especially for young children, and more attention should be given. For empirical antibacterial treatment, high-dose amoxicillin-clavulanic acid or ampicillin-sulbactam was recommended for non-severe cases; vancomycin and third-generation cephalosporins were suggested for critically ill patients requiring ICU care.

Comparisons of the clinical and mycological characteristics of pediatric candidemia.

BACKGROUND/PURPOSE: Invasive candidiasis is a severe infectious disease that could lead to mortality in critically ill children. METHODS: We collected data regarding demographics, underlying diseases, predisposing factors, outcomes for pediatric patients with candidemia at a medical centre in Taiwan from 2011 to 2017. RESULTS: Fifty-eight patients with 60 candidemia episodes were diagnosed. The 3 most common species were Candida albicans (42%), Candida parapsilosis (25%) and Candida tropicalis (23%). C. parapsilosis predominantly infected infants and neonates (median age: 0.8 years, range: 0.1-14.5). Cases with C. tropicalis had significantly higher rates of multidrug resistance (p = 0.011) and disseminated candidiasis (p = 0.025) compared with other cases. The all-cause mortality rate was 43%, and the candidemia-related mortality rate was 29%. Pediatric sequential organ failure assessment score >8 [adjusted odds ratio (aOR) 66.2, 95% CI 4.03-1088.5] and posaconazole resistance (aOR 33.57, 95% CI 1.61-700.3) were the most significant risk factors associated with candidemia-related mortality, whereas treatment with effective antifungal agents within 48 h (aOR 0.07, 95% CI 0.01-0.9) was the only significant protective factor. CONCLUSION: Candidemia-related mortality was related to azole resistance; therefore, empirical therapy with echinocandin or amphotericin B is recommended pending species and susceptibility results.

Predominant role of Haemophilus influenzae in the association of conjunctivitis, acute otitis media and acute bacterial paranasal sinusitis in children.

Haemophilus influenzae is a predominant pathogen for conjunctivitis, acute otitis media and acute bacterial paranasal sinusitis in children. We undertook this study to investigate the possible association among these diseases. Children younger than 18-year-old with a diagnosis of bacterial conjunctivitis plus acute otitis media and/or acute bacterial paranasal sinusitis during 2009-2018 were included. Sampling for bacterial cultures was obtained from the lower palpebral conjunctiva and/or ear discharge with cotton-tipped swabs. A total of 67 children were recruited and the age was 29.5 (± 22.4) months in average. Fifty-seven children had conjunctivitis-otitis media syndrome and eight of them had a concurrent diagnosis of acute paranasal sinusitis. Ten children had conjunctivitis and acute paranasal sinusitis simultaneously. Clusters in household were observed in 50.7% children. Most common isolates were Haemophilus influenzae (70%), Moraxella catarrhalis (18%), and Staphylococcus aureus (8%). Antibiotic resistance rate of H. influenzae was 80% for ampicillin, 18% for amoxicillin-clavulanate, and 11% for the second or third-generation cephalosporins. Apart from well-known conjunctivitis-otitis media syndrome, acute paranasal sinusitis may also be linked to conjunctivitis with a similar pathogenic process. Simultaneous presence of these infections may guide the choice of empiric antibiotics toward H. influenzae.

Severe Mycoplasma pneumoniae pneumonia requiring intensive care in children, 2010-2019.

BACKGROUND/PURPOSE: Despite the high prevalence of Mycoplasma pneumoniae infections, reports on severe life-threatening M. pneumoniae pneumonia (MPP) in children are limited. METHODS: We retrospectively enrolled pediatric patients with PCR-positive MPP requiring ICU admission in a children's hospital in Taipei, Taiwan from Jun 2010 to October 2019. Clinical manifestations and laboratory data of severe MPP were analyzed. Macrolide susceptibility was determined by genotyping, and its relationship with clinical manifestations was also analyzed. RESULTS: Approximately 5% (34/658) children hospitalized for MPP required ICU admission. Compared with non-ICU cases (n = 291), ICU cases (n = 34) were associated with more underlying conditions, more pleural effusion, longer fever duration, longer hospital stay, the requirement of second-line antibiotic treatment, and delayed effective and second-line antibiotic treatment. Macrolide resistance was similar in ICU and non-ICU groups (53% vs 53%; p = 0.986). In severe MPP, patients requiring endotracheal intubation were associated with more septic shock, empyema, ARDS, prolonged fever after effective antibiotic treatment, delayed second-line and effective antibiotic treatment. In 18 of the 22 patients with pleural fluid analysis, the pleural effusion was alkaline (pH > 7.7) and lymphocyte-predominant. CONCLUSION: M. pneumoniae infection can cause severe life-threatening pneumonia in children. Delayed effective and second-line antibiotic treatments are associated with severe life-threatening MPP.

Clinical features and risk factors associated with bacteremia of nontyphoidal salmonellosis in pediatric patients, 2010-2018.

BACKGROUND/PURPOSE(S): This study aimed to investigate clinical features and antimicrobial susceptibility of inpatient children with nontyphoidal salmonellosis from 2010 to 2018. METHODS: We retrospectively collected pediatric patients with nontyphoidal Salmonella infection confirmed by positive cultures in a tertiary medical center in Taiwan from 2010 to 2018. Patients' characteristics, clinical manifestations, and laboratory data were collected. Serogroup category and antimicrobial susceptibility were also analyzed. RESULTS: Of total 569 isolates, ampicillin resistant rate was 53% in average, third-generation cephalosporin resistant rate was 6.7%, ciprofloxacin resistant rate was 9% and trimethoprim-sulfamethoxazole resistant rate was 30%. Compared to the resistant rates in 2010, the resistance rate of third generation cephalosporin was significantly higher (3.4% vs. 11%, p = 0.003) but that of ciprofloxacin was significantly lower (20% vs. 11%, p < 0.001) in 2018. Among 297 inpatients with nontyphoidal salmonellosis, Group D (38%) was the most common in the bacteremia patients whereas Group B (48%) was the most common in the non-bacteremia patients. Among 244 immunocompetent inpatients with community-acquired salmonellosis, the bacteremia patients had significantly longer fever duration and diarrhea duration before hospitalization (p < 0.001), and significant higher rate of anemia (p = 0.028) due to either thalassemia trait or prolonged disease course than the non-bacteremia patients. CONCLUSION: Third-generation cephalosporin was still the drug of choice for nontyphoidal Salmonella infection in children though the resistant rate increased progressively. Significant risk factors associated with bacteremia were longer fever and diarrhea duration and anemia due to either thalassemia trait or prolonged disease course in immunocompetent children.

Clustering of Streptococcus gallolyticus subspecies pasteurianus bacteremia and meningitis in neonates.

BACKGROUND/PURPOSE: Although Streptococcus gallolyticus subspecies pasteurianus (SGSP) is a rare pathogen in children, it can cause invasive infections among neonates and infants. Herein, we report bacteremia/meningitis caused by SGSP in three neonates and review the literature on bacteremia and/or meningitis caused by this organism. METHODS: Three neonates, referred from an obstetrics clinic within a 2-month period, presented with invasive SGSP infections. The bacterial isolates were analyzed using Bruker Biotyper MALDI-TOF, sequencing of 16S rRNA and sodA genes (encoding manganese dependent superoxide dismutase), and PCR restriction fragment length polymorphism assay of groESL gene. Molecular typing was performed to evaluate the genetic relatedness. RESULTS: The median onset age of infection in the three neonates was 3 days (range 2-5 days). They were delivered through cesarean section in the same operation room under different doctors, and were cared for by different nurses. Patient A presented with bacteremia, patient B with bacteremia and meningitis, and patient C with meningitis. Four isolates were identified as SGSP and were susceptible to penicillin G, cefotaxime, and vancomycin. All patients were treated with ampicillin plus cefotaxime for 14 days, and no complications were observed. The molecular typing results suggested that all isolates belonged to a single clone, which indicated the possibility of an outbreak in the obstetrics clinic. CONCLUSION: Infection by a rare pathogen such as SGSP in multiple patients belonging to a single healthcare unit indicates that detailed investigation and stringent infection control policy are necessary for preventing further outbreaks of such diseases.

Pediatric parapneumonic effusion before and after national pneumococcal vaccination programs in Taiwan.

BACKGROUND: Reports on the effectiveness of pneumococcal conjugate vaccines (PCVs) on pediatric parapneumonic effusion are limited. We report the changes in cases and etiologies of pediatric parapneumonic effusion in a children's hospital before and after national PCV13 vaccination programs. METHODS: We screened medical records of children 0-18 years admitted to the National Taiwan University Hospital with diagnoses of lobar pneumonia and parapneumonic effusion between 2008 and 2017. Patients with effusion analyses were included. Results of blood, pleural fluid, and respiratory specimens surveyed as standard care were analyzed. RESULTS: Diagnostic testing revealed at least a pathogen in 85% of 202 children with lobar pneumonia and parapneumonic effusion. After national PCV13 immunization, pneumococcal empyema decreased by 72% among 2- to 5-year olds. Mycoplasma pneumoniae was the second most common etiology. There were marked differences in effusion characteristics, metabolic, and respiratory parameters between children infected with pneumococcus and M. pneumoniae. CONCLUSION: The effectiveness of the national PCV13 immunization programs on pneumococcal empyema was evident and remained substantial after 4 years in Taiwan. Continuous surveillance is important to monitor the emergence of other pathogens including non-PCV serotypes and M. pneumoniae.

Applicability of an in-house saponin-based extraction method in Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for identifying bacterial and fungal species in positively flagged pediatric VersaTREK blood cultures.

BACKGROUND/PURPOSE: Early identification of pathogens causing bloodstream infection (BSI) is critical for prompt administration of appropriate antimicrobial therapy. METHODS: We used an in-house saponin-based extraction method to evaluate the performance of Bruker Biotyper MALDI-TOF MS system (MALDI Biotyper) for bacterial and fungal identification in 2013 positively-flagged VersaTREK blood culture bottles. RESULTS: A total of 180 monomicrobial and 23 polymicrobial positive blood cultures were investigated. Among monomicrobial positive blood cultures, the MALDI Biotyper recognized 90.6% and 81.7% of organisms directly from the flagged blood culture bottles to the genus and species levels, respectively. The MALDI Biotyper also correctly characterized one of the polymicrobial organisms to the species level in 20 (87%) bottles and to the genus level in 21 (91.3%) bottles. The overall identification rate using our protocol was 90.6% (184/203) and 82.3% (167/203) for genus and species levels, respectively. Identification accuracy was higher for Gram-positive than Gram-negative organisms and was the lowest for yeasts. Score values of identification were ≥1.500 for 200 (98.5%) bottles, ≥1.700 for 195 (96.1%) bottles and ≥2.000 for 182 (89.7%) bottles. Moreover, 83.5% and 92% of the isolates were identified precisely to species and genus level with the lower cutoff score of 1.500. Using our protocol also helped identifying BSI pathogens 18-24 h earlier compared to the sub-cultured colonies. CONCLUSION: Using Bruker MALDI Biotyper for identification of isolates directly from positive VersaTREK blood culture bottles, our in-house saponin-based protocol provided a more rapid turn-around time for correct identification of BSI pathogens than the conventional methods.

Increased age and proton pump inhibitors are associated with severe Clostridium difficile infections in children.

BACKGROUND: Clostridium difficile infection (CDI) is increasing in children. We aimed to compare the clinical characteristics between CDI and colonization and to identify the risk factors for severe diseases of CDI in children. METHOD: We retrospectively reviewed 124 children (1-18 years old) from 2011 to 2018. CDI was defined as diarrhea (≥3 loose stool in the past 24 h) with confirmed toxigenic strain. Colonization was defined as presence of C. difficile without clinical symptoms. Severe diseases included ileus, acute kidney injury, gastrointestinal bleeding or mortality. Patients younger than 1 year old and coinfections with other enteric pathogens were excluded. RESULTS: Among 124 patients with C. difficile identified, 49 of them fulfilled CDI definition and 75 had C. difficile colonization. Children with CDI were more likely to present with watery (74% vs. 1%, p < 0.01) and mucoid stool (25% vs. 7%, p < 0.01) and occult blood in stool (67% vs. 33%, p < 0.01) than children with colonization. In CDI cases, elevated age-adjusted creatinine (18% vs. 0%, p = 0.03) and hyponatremia (134 mEq/L vs. 137 mEq/L, p = 0.04) were found. Also, they had more complicated diseases (27% vs. 0%, p < 0.01). On multivariate analysis, age older than 4 years (adjusted odds ratio: 5.83; 95% confidence interval: 1.05-32.27) and proton pump inhibitor use (PPI) (adjusted odds ratio: 7.25; 95% confidence interval: 1.07-49.07) were the independent factors for severe diseases. CONCLUSIONS: Watery diarrhea, mucoid stool and occult blood in stool could differentiate CDI from colonization. Patients with increased age and previous PPI use were the independent risk factors for severe diseases in children.

Resurgence of pertussis in Taiwan during 2009-2015 and its impact on infants.

BACKGROUND/PURPOSE: Pertussis incidence markedly decreased due to universal vaccination, but outbreaks had been noted worldwide in recent decade. This study was conducted to know the epidemiology of pertussis and its impact on infants in Taiwan. METHODS: Epidemiologic parameters for confirmed pertussis cases were collected from the Taiwan Centers for Disease Control. The incidence of each age group over years was calculated using population data. We also did retrospective reviews of laboratory-confirmed pertussis cases in NTUH to analyze clinical characteristics and disease severity. RESULTS: A total of 668 confirmed pertussis cases were obtained from the Taiwan CDC open database between 2003 and 2017. There was higher incidence during the period 2009-2015, with a mean incidence of 0.27 cases per 100,000 population, about 2-fold increase compared with mean incidence of 0.12 cases per 100,000 population during the period 2003-2008. Infants accounted for the highest proportion of all cases (49.8%), with mean incidence of 16.1 cases per 100,000 people per year during 2009-2015, and a trend of increase was found from 2003 to 2015. In NTUH, a total of 17 laboratory-confirmed pertussis cases were diagnosed during 2012-2016, and 14 cases were young infants. Among them, 9 infants had been admitted to intensive care unit and 2 infant needed invasive ventilator support. CONCLUSION: There was a resurgence of pertussis during 2009-2015 and it had significant impact on infants. Young infants with pertussis may be severe and need intensive care, so preventive strategy may be advocated for them.

Human parvovirus B19 infection in patients with or without underlying diseases.

BACKGROUND/PURPOSE: The clinical presentations of parvovirus B19 in patients with underlying diseases have greater diversity than previously healthy patients. We retrospectively identified patients with polymerase chain reaction (PCR)-confirmed parvovirus B19 infection in attempt to describe its clinical features especially in these populations. METHODS: From 2009 to 2018, patients with real-time PCR-confirmed parvovirus B19 infection were collected. Comparisons were done between previously healthy patients and patients with preexisting diseases, as well as patients with high (>5.5 × 105 copies/mL sera) and low viral loads. RESULTS: Parvovirus B19 DNA was detected in 31 patients. Fourteen (45%) patients had underlying diseases, including six (19%) with immunologic diseases, five (16%) with hematologic diseases, and three (10%) with cardiopulmonary diseases. Only seven (23%) patients received an initial impression of erythema infectiosum prior to positive PCR. A higher proportion of patients with underlying diseases presented with fatigue and pallor, and suffered from tachycardia and hepatosplenomegaly compared to previously healthy patients. Among patients with a high viral load, a substantial proportion were of older age, suffered fatigue, and anemia. There was a trend of patients with immunologic comorbidity having a higher viral load. CONCLUSION: The classical parvovirus B19 manifestations were less frequently observed in patients with a preexisting disease compared with previously healthy patients. Depending on host factors, the symptoms of parvovirus B19 infection can be multifaceted.