摘要
Background@#We aimed to analyze the effects of an antimicrobial stewardship program (ASP) on the proportion of antimicrobial-resistant pathogens in bacteremia, antimicrobial use, and mortality in pediatric patients. @*Methods@#A retrospective single-center study was performed on pediatric inpatients under 19 years old who received systemic antimicrobial treatment from 2001 to 2019. A pediatric infectious disease attending physician started ASP in January 2008. The study period was divided into the pre-intervention (2001–2008) and the post-intervention (2009–2019) periods. The amount of antimicrobial use was defined as days of therapy per 1,000 patientdays, and the differences were compared using delta slope (= changes in slopes) between the two study periods by an interrupted time-series analysis. The proportion of resistant pathogens and the 30-day overall mortality rate were analyzed by the χ2 . @*Results@#The proportion of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae bacteremia increased from 17% (39 of 235) in the pre-intervention period to 35% (189 of 533) in the post-intervention period (P < 0.001). The total amount of antimicrobial use significantly decreased after the introduction of ASP (delta slope value = −16.5; 95% confidence interval [CI], −30.6 to −2.3; P = 0.049). The 30-day overall mortality rate in patients with bacteremia did not increase, being 10% (55 of 564) in the pre-intervention and 10% (94 of 941) in the post-intervention period (P = 0.881). @*Conclusion@#The introduction of ASP for pediatric patients reduced the delta slope of the total antimicrobial use without increasing the mortality rate despite an increased incidence of ESBL-producing gram-negative bacteremia.
摘要
Background@#The aim of this study was to capture multifaceted clinical characteristics of congenital cytomegalovirus (CMV) infection from diagnosis to treatment using a multidisciplinary approach including obstetrics, pediatrics, pathology, and otorhinolaryngology-head and neck surgery. @*Methods@#This is a retrospective study including 30 consecutive cases of congenital CMV infection that were diagnosed at a single tertiary hospital located in Seoul, Korea from January 2009 to December 2020. Congenital CMV infection was defined as a positive result by polymerase chain reaction from urine, saliva or cerebrospinal fluid or positive CMV IgM from neonatal blood sampled within 3 weeks after birth. All cases were analyzed with respect to whole clinical characteristics from diagnosis to treatment of congenital CMV by a multidisciplinary approach including prenatal sonographic findings, maternal immune status regarding CMV infection, detailed placental pathology, neonatal clinical manifestation, auditory brainstem response test, and antiviral treatment (ganciclovir or valganciclovir). Long-term outcomes including developmental delay and hearing loss were also investigated. @*Results@#The total number of births during the study period in our institution was 19,385, with the prevalence of congenital infection estimated to be 0.15%. Among 30 cases of congenital CMV, the median gestational age at delivery was 32.2 weeks [range, 22.6–40.0] and 66.7% of these infants were delivered preterm at less than 37 weeks. Suspected fetal growth restriction was the most common prenatal ultrasound finding (50%) followed by ventriculomegaly (17.9%) and abnormal placenta (17.9%), defined as thick placenta with calcification. No abnormal findings on ultrasound examination were observed in one-third of births. Maternal CMV serology tests were conducted in only 8 cases, and one case each of positive and equivocal IgM were found. The most common placental pathologic findings were chronic villitis (66.7%) and calcification (63.0%), whereas viral inclusions were identified in only 22.2%. The most common neonatal manifestations were jaundice (58.6%) followed by elevation of aspartate aminotransferase (55.2%) and thrombocytopenia (51.7%). After excluding cases for which long-term outcomes were unavailable due to death (n = 4) or subsequent follow up loss (n = 3), developmental delay was confirmed in 43.5% of infants (10/23), and hearing loss was confirmed in 42.9% (9/21) during the follow-up period. In our cohort, 56.7% (17/30) of neonates were treated for congenital CMV with ganciclovir or valganciclovir. @*Conclusion@#Our data show that prenatal findings including maternal serologic tests and ultrasound have limited ability to detect congenital CMV in Korea. Given that CMV is associated with high rates of developmental delay and hearing loss in infants, there is an urgent need to develop specific strategies for the definite diagnosis of congenital CMV infection during the perinatal period by a multidisciplinary approach to decrease the risks of neurologic impairment and hearing loss through early antiviral treatment.
摘要
Chronic recurrent multifocal osteomyelitis (CRMO) is an inflammatory bone disorder presenting with sterile osteomyelitis, most often presenting in childhood. Although the etiology is understood incompletely, its association with other auto-inflammatory diseases including inflammatory bowel disease (IBD); psoriasis; Wegener’s disease; arthritis; and synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome suggests that dysregulated innate immunity may play an important role in the pathogenesis. We report a case of a 13-year-old boy with CRMO associated with Crohn’s disease (CD) successfully treated with infliximab after failure of non-steroidal anti-inflammatory drug (NSAID) treatment. He initially was diagnosed with CRMO based on symmetric and aseptic bone lesions with no fever, lack of response to antibiotic treatment, vertebral involvement, and normal blood cell counts. Despite five months of NSAID treatment, his musculoskeletal symptoms were aggravated, and he developed gastrointestinal symptoms. Finally, he was diagnosed with CRMO associated with CD. Due to the severity of symptoms, infliximab was initiated and produced symptom improvement. This case supports infliximab as another choice for treatment of bowel symptoms in addition to the bone and joint symptoms of CRMO when other first-line treatments are ineffective.
摘要
Background@#Acinetobacter baumannii infections cause high morbidity and mortality in intensive care unit (ICU) patients. However, there are limited data on the changes of longterm epidemiology of imipenem resistance in A. baumannii bacteremia among pediatric ICU (PICU) patients. @*Methods@#A retrospective review was performed on patients with A. baumannii bacteremia in PICU of a tertiary teaching hospital from 2000 to 2016. Antimicrobial susceptibility tests, multilocus sequence typing (MLST), and polymerase chain reaction for antimicrobial resistance genes were performed for available isolates. @*Results@#A. baumannii bacteremia occurred in 27 patients; imipenem-sensitive A. baumannii (ISAB, n = 10, 37%) and imipenem-resistant A. baumannii (IRAB, n = 17, 63%). There was a clear shift in the antibiogram of A. baumannii during the study period. From 2000 to 2003, all isolates were ISAB (n = 6). From 2005 to 2008, both IRAB (n = 5) and ISAB (n = 4) were isolated. However, from 2009, all isolates were IRAB (n = 12). Ten isolates were available for additional test and confirmed as IRAB. MLST analysis showed that among 10 isolates, sequence type 138 was predominant (n = 7). All 10 isolates were positive for OXA-23-like and OXA-51-like carbapenemase. Of 27 bacteremia patients, 11 were male (41%), the median age at bacteremia onset was 5.2 years (range, 0–18.6 years). In 33% (9/27) of patients, A. baumannii was isolated from tracheal aspirate prior to development of bacteremia (median, 8 days; range, 5–124 days). The overall case-fatality rate was 63% (17/27) within 28 days. There was no statistical difference in the case fatality rate between ISAB and IRAB groups (50% vs. 71%; P = 0.422). @*Conclusion@#IRAB bacteremia causes serious threat in patients in PICU. Proactive infection control measures and antimicrobial stewardship are crucial for managing IRAB infection in PICU.
摘要
Background@#Limited data exist on children's utilization of the emergency department (ED) in the ongoing coronavirus disease 2019 (COVID-19) pandemic. Thus, we aimed to examine ED utilization among pediatric patients and the impact of COVID-19 in one large city affected by the outbreak. @*Methods@#This retrospective study included data from six EDs in Daegu, Korea. We compared the demographic and clinical data of patients presenting to the ED during the COVID-19 pandemic (February 1st–June 30th 2020) with those of patients who visited the ED in this period during 2018 and 2019. @*Results@#Fewer patients, particularly children visited the EDs during the study period in 2020 than those in the previous (2018/2019) year period: the number of adult patient decreased by 46.4% and children by 76.9%. Although the number of patients increased from the lowest point of the decrease in March 2020, the number of pediatric patients visiting the ED remained less than half (45.2%) in June 2020 compared with that of previous years. The proportion of patients with severe conditions increased in adults, infants, and school-aged children, and consequently resulted in increased ambulance use and higher hospitalization rates. Fewer infants and young children but more school-aged children visited the ED with febrile illnesses in 2020 than in 2018/2019. @*Conclusion@#The COVID-19 pandemic has led to a substantial decrease in pediatric ED utilization. These findings can help reallocate human and material resources in the EDs during infectious disease outbreaks.
摘要
To the Editor:The authors regret that there were errors in the text. This notice corrects the numbers in the result of the Abstract. We changed the percentages indicating the decrease in the number of patients (adults and children) who visited the emergency department (EDs) during the study period.Content of correction:Before:“ Fewer patients, particularly children visited the EDs during the study period in 2020 than those in the previous (2018/2019) year period: the number of adult patient decreased by 46.4% and children by 76.9%.”After:“ Fewer patients, particularly children visited the EDs during the study period in 2020 than those in the previous (2018/2019) year period: the number of adult patient decreased by 26.0% and children by 62.0%.”
摘要
Invasive fungal infection (IFI) is a serious threat to pediatric patients with cancer given high morbidity and mortality. We present an 18-year-old male with precursor T-cell lymphoblastic leukemia who developed Pancoast syndrome, presented with paresthesia and numbness in the right shoulder and arm during a neutropenic fever period. He was diagnosed with pneumonia in the right upper lung field. He was later found to have an invasive pulmonary fungal infection caused by multiple fungi species, including Rhizomucor, confirmed by histology and polymerase chain reaction (PCR) (proven infection), Penicillium decumbens diagnosed by PCR, and Aspergillus suspected from galactomannan assay (probable infection). Unfortunately, the patient's condition further worsened owing to the aggravation of leukemia, chemotherapy-induced neutropenia, and bacterial coinfection, leading to multiorgan failure and death. Here, we report a case of IFI caused by multiple fungal species that presented as Pancoast syndrome.
摘要
Invasive fungal infection (IFI) is a serious threat to pediatric patients with cancer given high morbidity and mortality. We present an 18-year-old male with precursor T-cell lymphoblastic leukemia who developed Pancoast syndrome, presented with paresthesia and numbness in the right shoulder and arm during a neutropenic fever period. He was diagnosed with pneumonia in the right upper lung field. He was later found to have an invasive pulmonary fungal infection caused by multiple fungi species, including Rhizomucor, confirmed by histology and polymerase chain reaction (PCR) (proven infection), Penicillium decumbens diagnosed by PCR, and Aspergillus suspected from galactomannan assay (probable infection). Unfortunately, the patient's condition further worsened owing to the aggravation of leukemia, chemotherapy-induced neutropenia, and bacterial coinfection, leading to multiorgan failure and death. Here, we report a case of IFI caused by multiple fungal species that presented as Pancoast syndrome.
摘要
Activated phosphoinositide 3-kinase δ syndrome (APDS)1 is caused by gain-of-function mutations in PIK3CD, which encodes the catalytic p110δ subunit of phosphoinositide 3 kinase. We describe three patients with APDS1, the first thereof in Korea. Therein, we investigated clinical manifestations of APDS1 and collected data on the efficacy and safety profile of sirolimus, a mammalian target of rapamycin inhibitor and pathway-specific targeted medicine. The same heterozygous PIK3CD mutation was detected in all three patients (E1021K). After genetic diagnosis, all patients received sirolimus and experienced an excellent response, including amelioration of lymphoproliferation and improvement of nodular mucosal lymphoid hyperplasia in the gastrointestinal tract. The median trough level of sirolimus was 5.5 ng/mL (range, 2.8–7.5) at a dose of 2.6–3.6 mg/m2. Two patients who needed highdose, short-interval, immunoglobulin-replacement treatment (IGRT) had a reduced requirement for IGRT after initiating sirolimus, and the dosing interval was extended from 2 and 3 weeks to 4 weeks. The IgG trough level after sirolimus treatment (median, 594 mg/dL; range, 332–799 mg/dL) was significantly higher than that before sirolimus treatment (median, 290 mg/dL; range, 163–346 mg/dL) (p<0.001). One episode of elevated serum creatinine with a surge of sirolimus (Patient 2) and episodes of neutropenia and oral stomatitis (Patient 1) were observed. We diagnosed the first three patients with APDS1 in Korea. Low-dose sirolimus may alleviate clinical manifestations thereof, including hypogammaglobulinemia.
摘要
The musculoskeletal system can be involved as an extra-intestinal manifestation of inflammatory bowel disease. Among these, myositis in ulcerative colitis (UC) is very rare. A 14-year-old girl was admitted due to severe shoulder tenderness. She had complained of left jaw pain and swelling for the past 10 days. Inflammatory markers were elevated with no evidence of infectious etiology. Myositis was suspected by shoulder magnetic resonance imaging. Three days after admission, she developed hematochezia. Muscle biopsy and colonoscopy was performed due to worsening left mandibular area pain and persistent hematochezia. Colonoscopy showed consistent findings with UC. She was finally diagnosed with UC with myositis as an extra-intestinal manifestation. She showed a dramatic response to UC treatment. Gastrointestinal symptoms were well-controlled. After 14 months, UC symptoms and muscle pain were aggravated, which were relieved after steroid and cyclosporin treatment. We report a unique case of UC initially presented with myositis, preceding gastrointestinal symptoms.
摘要
Purpose@#Epstein-Barr virus (EBV) infection is related to infectious mononucleosis or nasopharyngeal cancer, and its epidemiology may change according to the socioeconomic development of communities. This study aimed to evaluate the recent epidemiology of EBV seropositive rate in Korea. @*Methods@#We retrospectively reviewed EBV serology test results obtained from a part of clinical care at Samsung Medical Center, Seoul, South Korea, from January 2000 to December 2017. @*Results@#The EBV seropositive rate in 26,527 subjects during the study period was 81.0% (21,485/26,527): 44.4% (2,716/6,122) in subjects aged 0–9 years, 75.8% (2,077/2,739) in those aged 10–19 years, and 94.5% (16,692/17,666) in those aged ≥20 years. The EBV seropositive rate decreased from 89.4% (8,592/9,616) in 2000–2008 to 76.2% (12,893/16,911) in 2009– 2017 (P<0.001). Especially, the EBV seropositive rate in subjects aged 0–19 years significantly decreased from 2000–2008 to 2009–2017 (0–9 years, 62.8% [1,172/1,866] in 2000–2008 and 36.3% [1,544/4,256] in 2009–2017; 10–19 years, 83.8% [745/858] in 2000–2008 and 70.8% (1,332/1,881) in 2009–2017) (P<0.001). @*Conclusions@#The EBV seropositive rate in children has decreased in the last 20 years. As the age of patients with primary EBV infection increased, there is a need for interest in clinical manifestation, such as infectious mononucleosis, in adolescents and young adults.
摘要
Purpose@#Group A streptococcus (GAS) is a common pathogen in pediatric patients and often causes acute pharyngotonsillitis and skin and soft tissue infections. In addition, bacteremia with significant morbidity and mortality can also occur. This study was conducted to describe the clinical manifestations and treatment outcomes of pediatric GAS bacteremia patients in Korea. @*Methods@#This was a single-center, retrospective study. From January 2000 to December 2016, pediatric patients aged ≤18 years with GAS bacteremia were studied. Clinical manifestations, underlying diseases, intensive care unit stay, and antibiotic susceptibility were evaluated. @*Results@#During the study period, 19 patients had GAS bacteremia. Ten (53%) were male, and the median age was 7.4 years (range, 0.3–17.4 years). Fourteen (74%) had chronic underlying diseases. Five (26%) were immunocompromised (leukemia and chronic kidney disease).Eight (42%) had lymphatic or vascular malformations, of which seven had lesions with signs of inflammation. Three (16%) developed pneumonia, and two of them received ventilator care. The 30-day mortality rate was 6% (1/19), and the cause of death was bacteremic pneumonia. All GAS isolates were sensitive to penicillin. Fifteen (79%) were sensitive to both erythromycin and clindamycin. @*Conclusions@#This study identified various clinical manifestations of GAS bacteremia. GAS should be considered as a potential pathogen that can cause bacteremia and result in a serious clinical course.
摘要
KCNQ2 mutations induce a neonatal-onset epileptic encephalopathy of widely varying severity, ranging from benign familial neonatal epilepsy to severe refractory epileptic encephalopathy. Refractory seizures with KCNQ2 mutations have a positive response to sodium-channel blockers. Recently, a distinctive ictal pattern has been reported during amplitude-integrated electroencephalographic (aEEG) monitoring in infants with KCNQ2 encephalopathy. Herein, we describe a case of KCNQ2 encephalopathy with this distinctive ictal aEEG pattern, which was confirmed using conventional electroencephalography (EEG). A 3-day-old female infant presented with neonatal seizures accompanied by cyanosis and desaturation. Her seizure semiology was tonic and focal clonic. Her ictal aEEG demonstrated a sudden rise in amplitude followed by a suppressed background pattern. This pattern was also confirmed on conventional EEG. Her seizures were refractory despite the administration of multiple conventional antiepileptic drugs. Finally, c.794C>T; p. (Ala265Val) mutation was observed in the KCNQ2 gene on genetic testing, and she was diagnosed with KCNQ2 encephalopathy. Identifying this distinctive ictal pattern on aEEG monitoring facilitates the early detection of KCNQ2 encephalopathy and timely targeted treatment in patients with refractory seizures.
摘要
KCNQ2 mutations induce a neonatal-onset epileptic encephalopathy of widely varying severity, ranging from benign familial neonatal epilepsy to severe refractory epileptic encephalopathy. Refractory seizures with KCNQ2 mutations have a positive response to sodium-channel blockers. Recently, a distinctive ictal pattern has been reported during amplitude-integrated electroencephalographic (aEEG) monitoring in infants with KCNQ2 encephalopathy. Herein, we describe a case of KCNQ2 encephalopathy with this distinctive ictal aEEG pattern, which was confirmed using conventional electroencephalography (EEG). A 3-day-old female infant presented with neonatal seizures accompanied by cyanosis and desaturation. Her seizure semiology was tonic and focal clonic. Her ictal aEEG demonstrated a sudden rise in amplitude followed by a suppressed background pattern. This pattern was also confirmed on conventional EEG. Her seizures were refractory despite the administration of multiple conventional antiepileptic drugs. Finally, c.794C>T; p. (Ala265Val) mutation was observed in the KCNQ2 gene on genetic testing, and she was diagnosed with KCNQ2 encephalopathy. Identifying this distinctive ictal pattern on aEEG monitoring facilitates the early detection of KCNQ2 encephalopathy and timely targeted treatment in patients with refractory seizures.
摘要
Background@#Teicoplanin is used to treat serious gram-positive infections. Optimal teicoplanin trough levels are considered to be ≥ 10 μg/mL. Despite its wide use in various clinical settings, data on teicoplanin trough level in pediatric patients are limited. Therefore, the aim of this study was to investigate the therapeutic drug level monitoring of teicoplanin in Korean pediatric patients, including those with impaired renal function. @*Methods@#A retrospective study was performed in pediatric patients (age ≤ 18 years old) who received teicoplanin from September 2014 to April 2018. The regimen included a loading dose of 10 mg/kg/dose at 12 hours' interval three times in a row, and a maintenance dose of 10 mg/kg/dose commenced at 24 hours of interval after the loading dose, with a maximum of 400 mg/dose, respectively. The first therapeutic drug levels were measured. Distribution and characteristics of trough levels in patients with decreased renal function and those with bacteremia were also assessed. @*Results@#A total of 187 trough levels were collected from 143 patients. Hematologic and oncologic diseases were the most common underlying diseases (83.2%, n = 119). One hundred eighty trough levels were first measured, and their median value was 16.2 μg/mL (range, 2.3–100 μg/mL) and the median interval between initial teicoplanin injection and 1st trough level was 96.5 hours (range 47.6–179.3 hours). Lower steady-state levels were observed in younger age group (median, 13.5 vs. 18.0 μg/mL, P = 0.038). Median trough levels were higher in patients with decreased renal functions (P < 0.001). In addition, among eight with gram-positive bacteremia, seven of them had a favorable outcome. @*Conclusion@#This study provides additive information on trough level monitoring of teicoplanin in children with impaired renal function and treatment effect in patients with gram-positive bacteremia. Careful monitoring for steady state trough levels of teicoplanin is warranted.
摘要
PURPOSE: There is limited data on the use of perampanel in children under 12 years of age. We evaluated the efficacy and tolerability of adjunctive perampanel treatment in children under 12 years of age with refractory epilepsy. METHODS: This retrospective observational study was performed in Kyungpook National University Hospital from July 2016 to March 2018. A responder was defined as a patient with ≥50% reduction in monthly seizure frequency compared with the baseline. Adverse events and discontinuation data were obtained to evaluate tolerability. RESULTS: Twenty-two patients (8 males, 14 females) aged 3.1–11.4 years (mean, 8.0±2.5 years) were included in this study. After an average of 9.2 months (range, 0.5–19 months) of follow-up, 15 patients (68%) showed a reduction in seizure frequency, including 5 patients (23%) with seizure freedom. The age at epilepsy onset was significantly lower (P=0.048), and the duration of epilepsy was significantly longer (P=0.019) in responders than in nonresponders. Nine patients (41%) experienced adverse events, including somnolence (23%), respiratory depression (9%), violence (4.5%), and seizure aggravation (4.5%). The most serious adverse event was respiratory depression, which required mechanical ventilation in 2 patients (9%). Eight patients (36%) discontinued perampanel due to lack of efficacy or adverse events. Three out of 4 patients (75%) who discontinued perampanel due to adverse events had an underlying medical condition. CONCLUSION: Perampanel offers a treatment option for refractory epilepsy in children. Adjunctive treatment with perampanel requires special consideration in those with underlying medical conditions to prevent serious adverse events.
Subject(s)
Child , Humans , Male , Epilepsy , Follow-Up Studies , Freedom , Observational Study , Respiration, Artificial , Respiratory Insufficiency , Retrospective Studies , Seizures , Violence摘要
Scabies is a highly contagious skin infestation caused by the mite, Sarcoptes scabiei var. hominis. Complex responses to scabies mites in the innate, humoral, and cellular immune systems can cause skin inflammation and pruritus. Diagnosis can be challenging because scabies resembles other common skin conditions. We report the first Korean case of scabies in a hematopoietic cell transplant (HCT) recipient, initially suspected of skin graft versus host disease (GVHD). A T-cell acute lymphocytic leukemia patient underwent a sibling-matched allogeneic HCT and developed pruritus after cell engraftment. Treatment for GVHD did not improve the symptoms. He was diagnosed with scabies 30 days after the onset of symptoms.
Subject(s)
Humans , Diagnosis , Graft vs Host Disease , Immune System , Inflammation , Mites , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma , Pruritus , Sarcoptes scabiei , Scabies , Skin , Transplants摘要
PURPOSE: Tuberculosis (TB) is one of the most important diseases that cause significant mortality and morbidity in young children. Data on TB transmission from an infected child are limited. Herein, we report a case of disseminated TB in a child and conducted a contact investigation among exposed individuals. METHODS: A 4-year-old child without Bacille Calmette-Guérin vaccination was diagnosed as having culture-proven disseminated TB. The child initially presented with symptoms of inflammatory bowel disease, and nosocomial and kindergarten exposures were reported. The exposed individuals to the index case were divided into 3 groups, namely household, nosocomial, or kindergarten contacts. Evaluation was performed following the Korean guidelines for TB. Kindergarten contacts were further divided into close or casual contacts. Chest radiography and tuberculin skin test or interferon-gamma-releasing assay were performed for the contacts. RESULTS: We examined 327 individuals (3 household, 10 nosocomial, and 314 kindergarten contacts), of whom 18 (5.5%), the brother of the index patient, and 17 kindergarten children were diagnosed as having latent TB infection (LTBI). LTBI diagnosis was more frequent in the children who had close kindergarten contact with the index case (17.1% vs. 4.4%, P=0.007). None of the cases had active TB. CONCLUSION: This is the first reported case of TB transmission among young children from a pediatric patient with disseminated TB in Korea. TB should be emphasized as a possible cause of chronic diarrhea and failure to thrive in children. A national TB control policy has been actively applied to identify Korean children with LTBI.
Subject(s)
Child , Child, Preschool , Humans , Diagnosis , Diarrhea , Failure to Thrive , Family Characteristics , Inflammatory Bowel Diseases , Korea , Mortality , Radiography , Siblings , Skin Tests , Thorax , Tuberculin , Tuberculosis , Vaccination摘要
BACKGROUND: Pneumocystis is difficult to culture or detect in laboratory environments. Its ecology including the timing and method of transmission as well as environmental sources and communicability remain unclear. METHODS: We retrospectively evaluated the pattern and treatment outcome of Pneumocystis jirovecii pneumonia (PCP) in children with acute lymphoblastic leukemia (ALL) who received chemotherapy. RESULTS: A total of 56 patients with ALL were evaluated. While on chemotherapy, all patients received PCP prophylaxis. PCP were found in a total of 6 patients, including definite PCP in 2, probable PCP in 2, and possible PCP in 2 patients. There were no significant differences in sex, age group, National Cancer Institute risk group, or pneumocystis prophylaxis type between PCP and non-PCP groups. However, there was a significant statistical difference in the times of ALL diagnosis. Regarding recent chemotherapy at the time of PCP diagnosis, there were one induction, one consolidation, and four maintenance cases. All PCP patients were treated with high-dose sulfamethoxazole (100 mg/kg/day) and trimethoprim (20 mg/kg/day) intravenously. Five patients survived, while one patient with endotracheal mechanical ventilation therapy died due to respiratory failure in spite of aggressive treatment. CONCLUSION: Pediatric PCP became extremely rare due to routine prophylaxis in clinical practice of pediatric malignancy. Nevertheless, we analyzed patients with acute lymphoblastic leukemia who had received PCP prophylaxis for 14 years, and analyzed the clustered outbreaks of PCP. It is still important to emphasize the need for prophylaxis and to increase the level of attention and isolation under environmental and personal risk factors.