Assessment of blood viral load in asymptomatic and symptomatic cases of congenital cytomegalovirus infection.

This study aimed to retrospectively evaluate the baseline and follow-up viral loads and viral clearance times in cases followed for asymptomatic and symptomatic congenital cytomegalovirus (cCMV) infection between August 2010 and August 2022. Among 93 cases, they had asymptomatic (n: 55) and symptomatic (n: 38). The median baseline blood viral load detected in the symptomatic cCMV (ScCMV) infection (13 054 IU/mL) was significantly higher than that of asymptomatic cCMV (AcCMV) infection (4636 IU/mL) (p < 0.013). There was no difference in median viral clearance times (75 and 90 days, respectively) in baseline viremic cases in the ScCMV and AcCMV infection groups. There were no differences in median baseline blood viral load (6930 IU/mL and 14 268 IU/mL, respectively) and median viral clearance times (75 and 85 days, respectively) between the 6-week and 6-month antiviral treatment group. No correlation was found between baseline blood viral load, clinical severity, and the number of systems involved. However, in initial viremic cases, the viral load threshold for a symptomatic case was 8856 IU/mL, with 85.7% sensitivity and 54.5% specificity.

Management of neonates with maternal prenatal coronavirus infection and influencing factors.

The coronavirus disease 2019 (COVID-19) in pregnancy causes adverse outcomes for both the mother and the fetus. Neonates are at risk of vertical transmission and in-utero infection. Additionally, intensive care unit (ICU) admission and impairment in the organ systems of the mother are associated with neonatal outcomes, including impaired intrauterine growth, prematurity, and neonatal ICU admission. The management of neonates born from infected mothers has changed over the progress of the pandemic. At the beginning of the pandemic, cesarean section, immediate separation of mother-infant dyads, isolation of neonates, and avoiding of skin-to-skin contact, breast milk, and breastfeeding were the main practices to reduce vertical and horizontal transmission risk in the era of insufficient knowledge. The effects of antenatal steroids and delayed cord clamping on COVID-19 were also not known. As the pandemic progressed, data showed that prenatal, delivery room, and postnatal care of neonates can be performed as pre-pandemic practices. Variants and vaccines that affect clinical course and outcomes have emerged during the pandemic. The severity of the disease and the timing of infection in pregnancy also influence maternal and neonatal outcomes. The knowledge and lessons from COVID-19 will be helpful for the next pandemic if it happens. IMPACT: Prenatal infection with COVID-19 is associated with adverse maternal and neonatal outcomes. Our review includes the management of neonates with prenatal COVID-19 infection exposure, maternal-fetal, delivery room, and postnatal care of neonates, clinical features, treatment of neonates, and influencing factors such as variants, vaccination, severity of maternal disease, and timing of infection during pregnancy. There is a growing body of data and evidence about the COVID-19 pandemic. The knowledge and lessons from the pandemic will be helpful for the next pandemic if it happens.

Monitoring of adenoviremia in pediatric patients undergoing hematopoietic stem cell transplantation: Is it alone sufficient to predict adenoviral disease?

BACKGROUND: We aimed to evaluate our pediatric HSCT recipients routinely monitored for adenoviremia and to determine the adequacy of this monitoring in predicting adenoviral disease (AD). METHODS: A retrospective cohort of patients who underwent allogeneic HSCT between January 2021 and August 2022, and routinely monitored for adenoviremia by real-time PCR was included in our survey. Demographic and clinical data of the patients were recorded. Incidence rates, risk factors, and mortality rates related to adenoviremia, and AD were analyzed. RESULTS: Among 104 HSCTs performed in 94 patients adenovirus (AdV) was revealed in 27 (26%) episodes and adenoviremia in 18 (17.3%) HSCT episodes. AD without adenoviremia developed in nine episodes (8.6%). Disseminated disease was significantly more frequently detected in episodes with adenoviremia (p = .008). GVHD was independent risk factor for AdV detection (OR: 8.6, 95% CI: 2.03-33.7, p = .001). Viremia developed within a shorter time interval after HSCT in isolated episodes of adenoviremia compared to those with concomitant AD (p = .006). Initial and peak viral loads were significantly higher in adenoviremia with AD (p < .001). Mortality was higher in the AdV-detected episodes (p < .001) than in the AdV-undetected episodes. AdV-related mortality was found to be 22.2%. Adenoviremia increased the risk of mortality (OR: 1.2, 95% CI: 0.22-1.33, p = .01). CONCLUSIONS: Adenoviremia monitoring is an important process in the detection of AD. Since some patients may develop AD without accompanying by adenoviremia, monitoring for AdV in blood samples should be supported with other monitoring methods in order to evaluate the probable involvement of different organs or systems.

Intravenous fosfomycin indications and treatment outcomes in pediatric usage: analysis from a single center in Turkey.

Current data on fosfomycin usage in children are limited. We present data on the clinical use of intravenous (IV) fosfomycin in children. Hospitalized patients who received ≥3 days of IV fosfomycin between April 2021 and March 2023 were analyzed retrospectively. Forty-three episodes of infection in 39 patients were evaluated. The mean age of the patients was 5.35 (10 days to 17.5 years) years, and 54% were male. Infections were hospital-acquired in 79% of the episodes. Indications for fosfomycin were urinary tract infection (35%), bacteremia (32.6%), catheter-related bloodstream infection (16.3%), soft tissue infection (4.7%), sepsis (4.7%), surgical site infection (2.3%), burn infection (2.3%), and pneumonia (2.3%). Klebsiella pneumoniae was identified in 46.5% of the episodes, and a pan-drug or extensive drug resistance was detected in 75% of them. Carbapenem was used before fosfomycin at significantly higher rates in K. pneumoniae episodes (P = .006). Most (88.5%) patients received fosfomycin as a combination therapy. Culture negativity was achieved in 80% of episodes within a median treatment period of 3 (2-22) days, which was significantly shorter in K. pneumoniae episodes (P < .001). Treatment-related side effects were seen in 9.3% of the episodes. Side effects were significant after 3 weeks of treatment (P = .013). The unresponsivity rate to fosfomycin was 23.3%. Nine (21%) of the patients who were followed up in the intensive care units mainly died because of sepsis (56%). IV fosfomycin is an effective agent in treating severe pediatric infections caused by resistant microorganisms. Fosfomycin can be used in various indications and is generally safe for children.

Antibiotic associated diarrhea in outpatient pediatric antibiotic therapy.

BACKGROUND: Antibiotic-associated diarrhea is one of the most frequent side effects of antimicrobial therapy. We assessed the epidemiological data of antibiotic-associated diarrhea in pediatric patients in our region. METHODS: The prospective multi-center study included pediatric patients who were initiated an oral antibiotic course in outpatient clinics and followed in a well-established surveillance system. This follow-up system constituded inclusion of patient by the primary physician, supply of family follow-up charts to the family, passing the demographics and clinical information of patient to the Primary Investigator Centre, and a close telephone follow-up of patients for a period of eight weeks by the Primary Investigator Centre. RESULTS: A result of 758 cases were recruited in the analysis which had a frequency of 10.4% antibiotic-associated diarrhea. Among the cases treated with amoxicillin-clavulanate 10.4%, and cephalosporins 14.4% presented with antibiotic-associated diarrhea. In the analysis of antibiotic-associated diarrhea occurrence according to different geographical regions of Turkey, antibiotic-associated diarrhea episodes differed significantly (p = 0.014), particularly higher in The Eastern Anatolia and Southeastern Anatolia. Though most commonly encountered with cephalosporin use, antibiotic-associated diarrhea is not a frequent side effect. CONCLUSION: This study on pediatric antibiotic-associated diarrhea displayed epidemiological data and the differences geographically in our region.

Should a third booster dose be scheduled after two doses of CoronaVac? A single-center experience.

In the 10th month of the pandemic, coronavirus disease 2019 (COVID-19) vaccination was given first to healthcare workers in Turkey after receiving emergency use approval from the Ministry of Health. This study, which was performed at the COVID-19 reference center in Ankara (the capital of Turkey) aimed to evaluate the seroconversion rate of the CoronaVac vaccine. The anti-spike immunoglobulin G response to the two-dose vaccination was retrospectively examined in healthcare workers who had no previous history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The postvaccine seroconversion rate was investigated by measuring the antibody levels of healthcare workers who had received CoronaVac. Vaccination was administered as 600 SU in 28-day intervals. The healthcare workers' anti-SARS-CoV-2 immunoglobulin G levels were used to determine the seroconversion rate 2 months after the second dose of the vaccine. Of the healthcare workers, 22.9% (n = 155) were seronegative. The younger the age of the participant, the higher the level of anti-SARS-CoV-2 immunoglobulin G. Furthermore, anti-SARS-CoV-2 immunoglobulin G levels were much higher in women than men.

Intestinal microbiota composition of children with infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and multisystem inflammatory syndrome (MIS-C).

Microbiota composition may play a role in the development, prognosis, or post-infection of COVID-19. There are studies evaluating the microbiota composition at the time of diagnosis and during the course of COVID-19, especially in adults, while studies in children are limited and no study available in children with multisystem inflammatory syndrome in children (MIS-C). This study was planned to compare intestinal microbiota composition in children diagnosed with MIS-C and acute COVID-19 infection with healthy children. In this prospective multicenter study, 25 children diagnosed with MIS-C, 20 with COVID-19 infection, and 19 healthy children were included. Intestinal microbiota composition was evaluated by 16 s rRNA gene sequencing. We observed changes of diversity, richness, and composition of intestinal microbiota in MIS-C cases compared to COVID-19 cases and in the healthy controls. The Shannon index was higher in the MIS-C group than the healthy controls (p < 0.01). At phylum level, in the MIS-C group, a significantly higher relative abundance of Bacteroidetes and lower abundance of Firmicutes was found compared to the control group. Intestinal microbiota composition changed in MIS-C cases compared to COVID-19 and healthy controls, and Faecalibacterium prausnitzii decreased; Bacteroides uniformis, Bacteroides plebeius, Clostridium ramosum, Eubacterium dolichum, Eggerthella lenta, Bacillus thermoamylovorans, Prevotella tannerae, and Bacteroides coprophilus were dominant in children with MIS-C. At species level, we observed decreased Faecalibacterium prausnitzii, and increased Eubacterium dolichum, Eggerthella lenta, and Bacillus thermoamylovorans in children with MIS-C and increased Bifidobacterium adolescentis and Dorea formicigenerasus in the COVID-19 group. Our study is the first to evaluate the microbiota composition in MIS-C cases. There is a substantial change in the composition of the gut microbiota: (1) reduction of F. prausnitzii in children with MIS-C and COVID-19; (2) an increase of Eggerthella lenta which is related with autoimmunity; and (3) the predominance of E. dolichum is associated with metabolic dysfunctions and obesity in children with MIS-C. CONCLUSIONS:  Alterations of the intestinal microbiota might be part of pathogenesis of predisposing factor for MIS-C. It would be beneficial to conduct more extensive studies on the cause-effect relationship of these changes in microbiota composition and their effects on long-term prognosis. WHAT IS KNOWN: • Microbiota composition may play a role in the development, prognosis, or post-infection of COVID-19.  • However, the number of studies on children is limited, and no study on multisystem inflammatory syndrome in children is currently available (MIS-C). WHAT IS NEW: • In individuals with MIS-C, the composition of the gut microbiota changed dramatically. • Decreased Faecalibacterium prausnitzii have been observed, increased Eggerthella lenta, which was previously linked to autoimmunity, and predominance of Eubacterium dolichum which was linked to metabolic dysfunction and obesity.

Potential and promising marker for serious bacterial infections in children: Delta neutrophil index.

AIM: This study aimed to evaluate the usefulness and accuracy of the delta neutrophil index (DNI), an index expressing the number of immature granulocytes as a proportion of the total, as an inflammatory marker in predicting serious bacterial infections (SBIs). METHODS: Paediatric patients admitted to our hospital with fever were divided into four groups: SBI, non-SBI, COVID-19 and control group. White blood cell count, absolute neutrophil count, C-reactive protein and the DNI were recorded, and their accuracy in predicting SBI was evaluated. RESULTS: Mean DNI was 4.96 ± 8.38 in the SBI group (150 patients), 0.67 ± 1.68 in the non-SBI group (397 patients), 0.29 ± 0.99 in the COVID-19 group (112 patients) and 0.14 ± 0.21 in the control group (102 patients). The DNI was significantly higher in the SBI group compared with the non-SBI (P < 0.001); the non-SBI group also had higher levels than the COVID-19 group (P = 0.005). One percent increase in the DNI increased the SBI rate 1.36 times (odds ratio 1.36 (95% confidence interval 1.23-1.49), P < 0.001). Based on the determined cut-off value (>2.5%), the DNI (odds ratio 6.27 (95% confidence interval 3.85-10.21), P < 0.001) significantly predicted SBIs with 90.4% specificity and 47.7% sensitivity. CONCLUSIONS: SBIs in childrenare associated with an increase in DNI levels. Compared to other biomarkers, the DNI had higher specificity in predicting SBIs. The DNI may also be usefulin differentiating bacterial and non-bacterial infections in individualclinical syndromes. Currently, there is no evidence that serum DNI aids indifferentiating COVID-19 and upper respiratory tract infection.

Risk factors for complicated community-acquired pneumonia in children.

BACKGROUND: Community-acquired pneumonia (CAP) in children continues to be one of the prominent causes of pediatric morbidity and mortality worldwide. By determining the risk factors associated with the development of complicated CAP (CCAP), new approaches for early diagnosis and effective treatment can be identified. METHODS: This retrospective cohort study enrolled patients with CAP and CCAP who visited the pediatric ward of the study hospital between January 1, 2017 and December 31, 2017. For patients with CCAP, data regarding medical procedures performed, surgical intervention, and hospitalization duration were collected. RESULTS: A total of 111 patients, 93 (83.7%) with CAP and 18 (16.3%) with CCAP, aged between 3 months and 18 years were hospitalized because of severe pneumonia. The mean age of the patients was 3.6 ± 1.2 years and 60 (54%) of them were female. The mean age of patients with CCAP was higher than that of patients with CAP (4.2 ± 3.3 vs. 2.8 ± 2.1 years respectively); however, the difference was not significant (p = 0.012). Patients with CCAP exhibited a significantly higher C-reactive protein level than those with CAP (10.06 ± 7.55 vs. 4.43 ± 3.37 g/L respectively; p = 0.007). Hypoxia upon admission was noted more commonly in the CCAP group than in the CAP group (p < 0.001). CONCLUSION: Findings related to hypoxia, respiratory distress, and pleural effusion on imaging are important distinguishing factors associated with the development of complications in patients hospitalized with CAP. Therefore, CCAP etiology, diagnosis, and treatment approaches should be established and protective measures adopted.

Loneliness, internalizing symptoms, and inflammatory markers in adolescent COVID-19 survivors.

BACKGROUND: Concerns about the psychiatric sequelae after COVID-19 infection have increased as the pandemic spreads worldwide. The increase in self-isolation during this pandemic period has also revealed the importance of feelings of loneliness. This study aimed to examine the relationship between baseline inflammation levels, internalizing symptoms, and feelings of loneliness in adolescent COVID-19 survivors in the long term. METHODS: A total of 74 adolescents (41 girls, 55.4%, mean age 14.88) and their parents were included in the study. This cross-sectional study assessed internalizing symptoms via Revised Children's Anxiety and Depression Scale (RCADS) and feelings of loneliness using the UCLA-loneliness scale. Baseline inflammatory markers at COVID-19 diagnosis were collected. Logistic regression analysis was used to determine predictors for depression in adolescents. RESULTS: The most common disorder was Major Depressive Disorder (MDD) (25.7%), and 33.8% of the adolescents were in the clinical range in at least one internalizing domain. Baseline C-Reactive Protein (CRP) levels correlated weakly with MDD scores. Loneliness scores correlated with all internalizing symptoms, strong association with MDD scores. Loneliness, anxiety, and parental anxiety were associated with an increased likelihood of MDD. Baseline CRP positivity did not predict MDD in adolescent COVID-19 survivors. CONCLUSIONS: This study indicates that anxiety, loneliness, and parental anxiety play an important role in adolescents' experience of depressive symptoms after COVID-19 infection. Thus, screening parental psychopathology and loneliness in COVID-19 survivors seems to be preventive for adolescent mental health problems.

Do parents vaccinated against COVID-19 protect their children from hospitalization due to COVID-19?

OBJECTIVE: This study aimed to determine whether parental vaccination against coronavirus disease 2019 (COVID-19) prevents hospitalization of COVID-19-infected children. METHODS: This study was based on data obtained from the records of pediatric patients that were followed up for virologically proven COVID-19 infection between August and October 2021, during which time the delta variant was dominant in Turkey and the children were isolating at home. RESULTS: There were 151 patients in the inpatient group and 218 in the outpatient group; the mean age was 172.5 and 145.5 months in the groups, respectively. The rates of obesity (22.5% and 6.4%, respectively, p < 0.001) and neurological-neurodevelopmental disorders (8.6% and 1.4%, respectively, p < 0.001) were significantly higher in the inpatient group than in the outpatient group. Of the outpatients' parents, 67.4% (n = 147) were fully vaccinated vs. 38.4% (n = 58) in the inpatient group. In all, 39.7% (n = 60) of the inpatients' parents were unvaccinated vs. 18.3% (n = 40) in the outpatient group. There was a significant correlation between the vaccination status and the patient groups (p < 0.001); it was determined that the COVID-19 infection would be mild in children if both parents were fully vaccinated. When both parents were fully vaccinated against COVID-19, the hospitalization rate decreased and the outpatient follow-up rate increased. CONCLUSION: Having both parents fully vaccinated against COVID-19 can indirectly protect their subsequently infected children from hospitalization and the long-term effects of infection. Nonetheless, more comprehensive research on delta and non-delta variants is needed.

Therapeutic plasma exchange: A potential management strategy for critically ill MIS-C patients in the pediatric intensive care unit.

This study aimed to evaluate the effectiveness and the role of therapeutic plasma exchange (TPE) in treatment of children with severe MIS-C. In addition, we assessed demographic data, clinical features, laboratory abnormalities, underlying conditions, treatments, and outcomes. Patients with severe MIS-C who were admitted to the pediatric intensive care unit (PICU) between September 01 and October 05, 2020 were included in this observational, descriptive, retrospective study. The data collected included the patients' demographic data, presenting symptoms, clinical features, laboratory parameters, diagnostic investigations, and medications. Of 27 children with MIS-C, 63 % were male. The median age of the patients was nine years. Intravenous immunoglobulin and corticosteroids were used for treatment in 100 % of the patients, anakinra in 51.8 %, vasopressors in 85.1 %, noninvasive mechanical ventilation in 25.9 %, and invasive mechanical ventilation in 18.5 %. Ten of the 27 patients (37 %) underwent TPE. In the patients who underwent TPE, the median PELOD score was 21 (IQR: 11-30.25) before TPE and 10 (IQR: 10-11) after TPE (p < 0.001). Moreover, their median left ventricular ejection fraction (LVEF) was 52 % (IQR: 49.25 %-55 %) before TPE and median LVEF was 66.5 (IQR: 58 %-68.5 %) after TPE (p = 0.012). The median number of TPE sessions was three (IQR: 2-4.75). The mortality rate of the patients with severe MIS-C admitted to the PICU was 7.4 %. We suggest that TPE should be considered as a therapeutic option in children with severe MIS-C. Early initiation of TPE followed by immunomodulatory therapy in critically ill children with MIS-C may help improve clinical and laboratory outcomes.

Algorithm for the diagnosis and management of the multisystem inflammatory syndrome in children associated with COVID-19.

OBJECTIVE: Although the initial reports of COVID-19 cases in children described that children were largely protected from severe manifestations, clusters of paediatric cases of severe systemic hyperinflammation and shock related to severe acute respiratory syndrome coronavirus 2 infection began to be reported in the latter half of April 2020. A novel syndrome called "multisystem inflammatory syndrome in children" (MIS-C) shares common clinical features with other well-defined syndromes, including Kawasaki disease, toxic shock syndrome and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. Our objective was to develop a protocol for the evaluation, treatment and follow-up of patients with MIS-C. METHODS: The protocol was developed by a multidisciplinary team. We convened a multidisciplinary working group with representation from the departments of paediatric critical care, cardiology, rheumatology, surgery, gastroenterology, haematology, immunology, infectious disease and neurology. Our protocol and recommendations were based on the literature and our experiences with multisystem inflammatory syndrome in children. After an agreement was reached and the protocol was implemented, revisions were made on the basis of expert feedback. CONCLUSION: Children may experience acute cardiac decompensation or other organ system failure due to this severe inflammatory condition. Therefore, patients with severe symptoms of MIS-C should be managed in a paediatric intensive care setting, as rapid clinical deterioration may occur. Therapeutic approaches for MIS-C should be tailored depending on the patients' phenotypes. Plasmapheresis may be useful as a standard treatment to control hypercytokinemia in cases of MIS-C with severe symptoms. Long-term follow-up of patients with cardiac involvement is required to identify any sequelae of MIS-C.

A purely quantitative form of partial recessive IFN-γR2 deficiency caused by mutations of the initiation or second codon.

Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by clinical disease caused by weakly virulent mycobacteria, such as environmental mycobacteria and Bacillus Calmette-Guérin vaccines, in otherwise healthy individuals. All known genetic etiologies disrupt interferon (IFN)-γ immunity. Germline bi-allelic mutations of IFNGR2 can underlie partial or complete forms of IFN-γ receptor 2 (IFN-γR2) deficiency. Patients with partial IFN-γR2 deficiency express a dysfunctional molecule on the cell surface. We studied three patients with MSMD from two unrelated kindreds from Turkey (P1, P2) and India (P3), by whole-exome sequencing. P1 and P2 are homozygous for a mutation of the initiation codon(c.1A>G) of IFNGR2, whereas P3 is homozygous for a mutation of the second codon (c.4delC). Overexpressed mutant alleles produce small amounts of full-length IFN-γR2 resulting in an impaired, but not abolished, response to IFN-γ. Moreover, SV40-fibroblasts of P1 and P2 responded weakly to IFN-γ, and Epstein Barr virus-transformed B cells had a barely detectable response to IFN-γ. Studies in patients' primary T cells and monocyte-derived macrophages yielded similar results. The residual expression of IFN-γR2 protein of normal molecular weight and function is due to the initiation of translation between the second and ninth non-AUG codons. We thus describe mutations of the first and second codons of IFNGR2, which define a new form of partial recessive IFN-γR2 deficiency. Residual levels of IFN-γ signaling were very low, accounting for the more severe clinical phenotype of these patients with residual expression levels of normally functional surface receptors than of patients with partial recessive IFN-γR2 deficiency due to surface-expressed dysfunctional receptors, whose residual levels of IFN-γ signaling were higher.

Monitoring Crimean-Congo haemorrhagic fever virus RNA shedding in body secretions and serological status in hospitalised patients, Turkey, 2015.

IntroductionCrimean-Congo haemorrhagic fever (CCHF) is a tick-borne disease in Africa, Asia, the Balkan peninsula, the south-east of Europe and the Middle East, with mortality rates of 3-30%. Transmission can also occur through contact with infected animals or humans.AimThis observational, prospective case series aimed to investigate detectable viral genomic RNA in whole-body fluids and antibody dynamics in consecutive daily samples of patients diagnosed with CCHF until discharge from hospital.MethodsWe tested 18 patients and 824 swabs and sera with RT-PCR and 125 serum samples serologically.ResultsThe longest duration until clearance of viral RNA was 18 days from serum collection and 18, 15, 13, 19 and 17 days, respectively, from nasal, oral, genital (urethral or vaginal) and faecal swab, and urine. In seven patients, viral load decreased in serum at the same time as it increased in urine or persisted at the same logarithmic values. Despite clearance in serum, viral RNA was detected in faeces and genital swabs in two and three patients, respectively. Viral clearance from body fluids occurred earlier than from serum in eight patients on ribavirin treatment. The shortest seroconversion time was 3 days after symptom onset for IgM and IgG. Seroconversion of IgG occurred until Day 14 of symptoms.ConclusionWe report persistence of viral RNA in urine, faeces and genital swabs despite serum clearance. This may indicate a need for extending isolation precautions, re-evaluating discharge criteria and transmission risk after discharge, and considering oral swabs as a less invasive diagnostic alternative.

Incidence of Antibiotic-Related Rash in Children with Epstein-Barr Virus Infection and Evaluation of the Frequency of Confirmed Antibiotic Hypersensitivity.

BACKGROUND: The incidence of rash after aminopenicillin treatment in children with Epstein-Barr Virus (EBV) infection was reported to be 80-100%. A few recent studies suggested that the incidence may be much lower during EBV infection. There are no clear data on the incidence of true drug hypersensitivity among these patients. The aim of this study is to determine the incidence of rash and antibiotic allergy after antibiotic treatment in children with EBV infection. METHODS: Drug hypersensitivity was investigated in antibiotic-treated patients with a positive EBV IgM who developed a rash between 2013 and 2016. RESULTS: During the study period, 221 children were diagnosed with EBV infection, and 120 (54.3%) patients were treated with antibiotics during disease. Rash developed in 41 (41/221, 18.6%) patients, and 20 of them (total 120; 16.6%) were treated with antibiotics (most frequently aminopenicillins: 72.5%), and 21 of them (total 101, 20.8%) were not treated with antibiotics (p = 0.43). For 10 of the 20 antibiotic-treated patients with a rash, parents did not consent to an allergy workup. Three of the 10 patients who were tested for drug allergy were proven to have amoxicillin-clavulanate hypersensitivity (30%). Five of the patients without workup reacted after reuse of the suspected drug for infection treatment. CONCLUSION: In this study, the incidence of drug hyper-sensitivity was much lower than previously reported. Some of the reactions that occur during infectious mononucleosis are transient, and some are true drug hypersensitivity reactions. Thus, these patients should be evaluated with allergy tests before these drugs are used again after EBV infection.