A nationwide survey of human metapneumovirus-associated encephalitis/encephalopathy in Japan.

BACKGROUND: As there have been no comprehensive reports of human metapneumovirus-associated encephalopathy (hMPVE), this study examined the clinical features of hMPVE in children in Japan. METHOD: A nationwide survey of children with hMPVE was conducted using a structured research form. An initial survey asked pediatricians about children with hMPVE treated between 2014 and 2018. A second survey obtained patient information from hospitals that responded to the initial survey and those identified as having treated cases from a literature search. We collected demographic data, symptoms of hMPV infection, neurological symptoms, laboratory data, treatment, and outcomes. Outcomes were determined using the Pediatric Cerebral Performance Category Score. RESULT: Clinical information was available for 16 children. Their median age was 37 months. Six had preexisting neurological disorders. The interval between the onsets of infection and hMPVE was 4 days. Outcomes were good in 11 patients and poor in 5. There were no significant differences in demographic data, neurological symptoms, or laboratory data between the patients with good and poor outcomes. The encephalopathy subtypes were acute encephalopathy with biphasic seizures and late reduced diffusion in 3, clinically mild encephalitis/encephalopathy with a reversible splenial lesion in 3, hemorrhagic shock and encephalopathy syndrome in 2, and others in 8. CONCLUSION: The outcomes of children with hMPVE were not very different from those of acute encephalopathy due to other viruses. We found no factors associated with poor outcomes.

Performance of Nanopore and Illumina Metagenomic Sequencing for Pathogen Detection and Transcriptome Analysis in Infantile Central Nervous System Infections.

Background: Infantile central nervous system infections (CNSIs) can be life-threatening and cause severe sequelae. However, the causative microorganism remains unknown in >40% of patients with aseptic infections. This study aimed to analyze the metagenome for detection of pathogens and the transcriptome for host immune responses during infection in a single cerebrospinal fluid (CSF) sample using 2 different next-generation sequencing (NGS) platforms, Nanopore and Illumina. Methods: Twenty-eight CNSIs patients (<12 months) were enrolled, and 49 clinical samples (28 CSF and 21 blood) were collected. The DNA extracted from all 49 samples was sequenced using the Illumina sequencer for the detection of pathogens. Extracted RNA was obtained in sufficient quantities from 23 CSF samples and subjected to sequencing on both Nanopore and Illumina platforms. Human-derived reads subtracted during pathogen detection were used for host transcriptomic analysis from both Nanopore and Illumina sequencing. Results: RNA metagenomic sequencing using both sequencing platforms revealed putative viral pathogens in 10 cases. DNA sequencing using the Illumina sequencer detected 2 pathogens. The results of Nanopore and Illumina RNA sequencing were consistent; however, the mapping coverage and depth to the detected pathogen genome of Nanopore RNA sequencing were greater than those of Illumina. Host transcriptomic analysis of Nanopore sequencing revealed highly expressed genes related to the antiviral roles of innate immunity from pathogen-identified cases. Conclusions: The use of Nanopore RNA sequencing for metagenomic diagnostics of CSF samples should help to elucidate both pathogens and host immune responses of CNSI and could shed light on the pathogenesis of these infections.

Diagnosis of Peripheral Facial Palsy Associated with Parvovirus B19 Infection by Polymerase Chain Reaction.

Human parvovirus B19 (PVB19) infection causes neurological manifestations, including encephalitis, meningitis, and neuropathy, but facial nerve palsy is rare. Moreover, no case of facial nerve palsy related to PVB19 infection that was diagnosed by PCR and serology has been reported. A 19-month-old boy without the medical history developed facial nerve palsy and was treated with prednisolone and valacyclovir. On the 19th day, erythema appeared on his body, and the PVB19-specific IgM and PVB19 DNA were detected in the serum, leading to the diagnosis of infectious erythema associated with PVB19 infection. This case indicates that PVB19 may be one of the causative agents of facial nerve palsy.

Pediatric sepsis cases diagnosed with group B streptococcal meningitis using next-generation sequencing: a report of two cases.

BACKGROUND: Group B Streptococcus (GBS) is an important cause of invasive infection in neonates and infants. Cerebrospinal fluid (CSF) findings and culture may not show evidence of infection early in GBS meningitis. Next-generation sequencing (NGS) has the potential to detect microbial genetic material in patients with infectious diseases. We report two cases of infantile sepsis of GBS meningitis with negative results for CSF culture tests, but positive results for NGS analysis. CASE PRESENTATION: Patient 1 was a 22-day-old male infant diagnosed with sepsis and meningitis. His CSF findings showed pleocytosis, decreased glucose, and increased protein levels. However, CSF and blood culture results at admission were negative. He received a total of 3 weeks of treatment with ampicillin and cefotaxime, and showed clinical improvement. GBS was detected through NGS analysis of CSF collected at admission. Patient 2 was a 51-day-old male infant with sepsis. CSF findings on admission were normal, and blood and CSF cultures were also negative. Intravenous ampicillin and cefotaxime treatment were initiated. Treatment was de-escalated to ampicillin alone because Enterococcus faecalis was cultured from urine. He was discharged after a total of 1 week of antibiotic treatment. Six days after discharge, he was re-hospitalized for sepsis. Blood and CSF cultures were negative, and E. faecalis was again cultured from urine. He received a total of 3 weeks of ampicillin treatment for enterococcal-induced nephritis and did not relapse thereafter. NGS pathogen searches were retrospectively performed on both blood and CSF collected at the first and second admission. GBS was detected in the CSF collected at the first admission, but no significant pathogen was detected in the other samples. Inadequate treatment for GBS meningitis at the first admission may have caused the recurrence of the disease. CONCLUSION: Infantile sepsis may present bacterial meningitis that is not diagnosed by either culture testing or CSF findings. NGS analysis for CSF may be useful for confirming the diagnosis of bacterial meningitis.

The eldest case of MICPCH with CASK mutation exhibiting gross motor regression.

BACKGROUND: MICPCH is manifested as microcephaly associated with pontocerebellar hypoplasia and global developmental delay but developmental regression has never been reported. We describe the detailed clinical history of a woman with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH) with a CASK mutation who exhibited gross motor regression after adolescence. CASE: The patient experienced severe motor and intellectual developmental delay with microcephaly from infancy. The initial diagnosis was Rett syndrome based on her clinical features, including hand stereotypes and the absence of structural abnormality on magnetic resonance imaging (MRI) performed at the age of 5 years. Although gross motor abilities developed slowly and she could walk independently, she never acquired speech or understanding of languages. After adolescence, her motor ability gradually regressed so that she was unable to stand without support and moved with a wheelchair. At the age of 31 years, because of her atypical clinical course for Rett syndrome, whole exome sequencing was performed, which revealed a de novo heterozygous c.2068 + 1G > A mutation in the CASK gene (NM_001126055). Brain MRI revealed mild pontocerebellar hypoplasia compatible with the clinical phenotype of MICPCH. DISCUSSION: This case suggests that MICPCH with a CASK mutation might cause developmental regression after adolescence and might be regarded as a neurodegenerative disorder.

Nutcracker syndrome complicated with intestinal malrotation.

Nutcracker syndrome (NCS) is a pathological condition in which the left renal vein (LRV) is compressed between the superior mesenteric artery (SMA) and aorta. NCS can predispose patients to the onset of chronic kidney disease because of persistent increase in LRV pressure. Although NCS in children is often idiopathic, it can also be caused by underlying pathologies such as retroperitoneal tumours. To the best of our knowledge, there have been no reports regarding paediatric cases of NCS complicated with intestinal malrotation. Here, we report the case of a 12-year-old girl with intestinal malrotation complicated with NCS whose haematuria resolved after surgical intervention for intestinal malrotation. The present case findings indicate that intestinal malrotation with concomitant weight loss is a potential underlying aetiology in NCS. Thus, when NCS is especially diagnosed with gastrointestinal symptoms, intestinal malrotation should be considered as an underlying aetiology.

Thermolabile polymorphism of carnitine palmitoyltransferase 2: A genetic risk factor of overall acute encephalopathy.

OBJECTIVES: Acute encephalopathy is an acute brain dysfunction after preceding infection, consisting of multiple syndromes. Some syndromes, such as acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), are severe with poor outcome, whereas others, such as clinically mild encephalitis/encephalopathy with reversible splenial lesion (MERS), are mild with favorable outcome. Previous study reported the association of the thermolabile polymorphism in Carnitine Palmitoyltransferase 2 (CPT2) gene and severe syndromes of acute encephalopathy. To further explore the pathogenetic role of CPT2 in acute encephalopathy, we conducted a case-control association study of a typical thermolabile CPT2 polymorphism, rs2229291, in 416 patients of acute encephalopathy, including both severe and mild syndromes. METHODS: The case cohort consisted of 416 patients, including AESD, MERS, and other syndromes. The control subjects were 100 healthy Japanese. rs2229291 was genotyped by Sanger sequencing. Genetic distribution was compared between the patients and controls using Cochran-Armitage trend test. RESULTS: Minor allele frequency of rs2229291 was significantly higher in AESD (p = 0.044), MERS (p = 0.015) and entire acute encephalopathy (p = 0.044) compared to the controls. The polymorphism showed no significant association with influenza virus, or with outcome. CONCLUSIONS: This study provided evidence that CPT2 is a susceptibility gene for overall acute encephalopathy, including both severe and mild syndromes, and suggested that impairment of mitochondrial metabolism is common to various syndromes of acute encephalopathy.

A case of refractory cytomegalovirus-related thrombocytopenia that achieved complete remission without antiviral therapy.

Cytomegalovirus (CMV) is one of the major infectious etiologies that induce thrombocytopenia. Although immune thrombocytopenic purpura (ITP) in children is often preceded by viral infections, thrombocytopenia associated with active CMV infection is considered CMV-related thrombocytopenia (CMV-thrombocytopenia), which can be distinguished from ITP. CMV-thrombocytopenia is reported to be less responsive to standard therapies for ITP and may require antiviral therapies. We herein report a case of refractory CMV-thrombocytopenia that achieved complete remission without antiviral therapy. A 20-month-old boy presented with a 2-day history of fever and systemic petechiae. There were no abnormal findings except for an extremely low platelet count (8000/µl) on blood examinations. He was clinically diagnosed with ITP, and intravenous immunoglobulin was administered twice, but his platelet count did not increase. CMV infection was suspected serologically, and a high CMV DNA load was detected in serum by real-time quantitative polymerase chain reaction (PCR). Without antiviral treatment, the CMV DNA load decreased below the detection limit on the 11th day of admission, followed by complete remission of the thrombocytopenia. The present case suggests that spontaneous recovery of thrombocytopenia can be expected in immunocompetent patients with CMV-thrombocytopenia in whom decreased CMV DNA load is observed.

Zinc monotherapy for young children with presymptomatic Wilson disease: A multicenter study in Japan.

BACKGROUND AND AIM: Few studies of zinc monotherapy for presymptomatic Wilson disease have focused on young children. We therefore evaluated long-term efficacy and safety of zinc monotherapy for such children and established benchmarks for maintenance therapy. METHODS: We retrospectively and prospectively examined children under 10 years old with presymptomatic Wilson disease who received zinc monotherapy from time of diagnosis at 12 participating pediatric centers in Japan. RESULTS: Twenty-four patients met entry criteria. Aspartate aminotransferase and alanine aminotransferase decreased significantly beginning 1 month after initiation of treatment and usually remained under 50 U/L from 1 to 8 years of treatment. Twenty four-hour urinary copper decreased significantly at 6 months and usually remained under 75 µg/day and between 1 and 3 µg/kg/day for the remainder of the study. All patients continued to take zinc, and none became symptomatic. In patients under 6 years old who received 50 mg/day of zinc as an initial dose, aspartate aminotransferase and alanine aminotransferase significantly decreased at 1 month after initiation of treatment, as did γ-glutamyltransferase and 24-h urinary copper at 6 months. CONCLUSIONS: To our knowledge, this is the first multicenter study of zinc monotherapy for young children with presymptomatic Wilson disease. Such monotherapy proved highly effective and safe. Maintaining normal transaminase values (or values under 50 U/L when normalization is difficult) and 24-h urinary copper excretion between 1 and 3 µg/kg/day and under 75 µg/day is a reasonable goal. An initial dose of 50 mg/day is appropriate for patients under 6 years old.

Airborne transmission from a neonate with Netherton syndrome during an outbreak of MRSA.

We encountered a 4 month outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection that was difficult to control despite implementation of standard prevention methods. A neonate with Netherton syndrome had accelerated scaling of the skin and continued positive results for MRSA from clinical samples. The results of air sampling suggested the possibility of airborne transmission. The MRSA outbreak stopped after the patient was transferred to an isolation room, suggesting that airborne MRSA can play a role in MRSA colonization. Isolation rooms should be considered in specific circumstances, as described in the present study.

Recurrent neonatal herpes simplex virus infection with central nervous system disease after completion of a 6-month course of suppressive therapy: Case report.

A boy at 12 days of age developed neonatal herpes simplex virus (HSV) type 2 infection with central nervous system (CNS) disease. After a 21-day course of high-dose intravenous acyclovir, the patient recovered with negative results for HSV DNA in serum and cerebrospinal fluid. Two weeks after a 6-month course of oral valacyclovir suppressive therapy with negative virological assessment, the disease recurred. Another 21-day course of intravenous acyclovir and subsequent 1-year course of oral suppressive therapy were completed. He showed mild developmental delay in language-social skills at 18 months of age. Although recurrences of neonatal HSV infection with CNS disease after suppressive therapy are uncommon, both clinical and virological assessments at the end of the suppressive therapy may be required. Administration of extended long-term suppressive ACV therapy should be considered to reduce the rate of recurrence.

Mutations in HADHB, which encodes the ß-subunit of mitochondrial trifunctional protein, cause infantile onset hypoparathyroidism and peripheral polyneuropathy.

Mitochondrial trifunctional protein (MTP) is a hetero-octamer composed of four α- and four ß-subunits that catalyzes the final three steps of mitochondrial ß-oxidation of long chain fatty acids. HADHA and HADHB encode the α-subunit and the ß-subunit of MTP, respectively. To date, only two cases with MTP deficiency have been reported to be associated with hypoparathyroidism and peripheral polyneuropathy. Here, we report on two siblings with autosomal recessive infantile onset hypoparathyroidism, peripheral polyneuropathy, and rhabdomyolysis. Sequence analysis of HADHA and HADHB in both siblings shows that they were homozygous for a mutation in exon 14 of HADHB (c.1175C>T, [p.A392V]) and the parents were heterozygous for the mutation. Biochemical analysis revealed that the patients had MTP deficiency. Structural analysis indicated that the A392V mutation identified in this study and the N389D mutation previously reported to be associated with hypoparathyroidism are both located near the active site of MTP and affect the conformation of the ß-subunit. Thus, the present patients are the second and third cases of MTP deficiency associated with missense HADHB mutation and infantile onset hypoparathyroidism. Since MTP deficiency is a treatable disease, MTP deficiency should be considered when patients have hypoparathyroidism as the initial presenting feature in infancy.

Hyperferritinemia in neonatal and infantile human parechovirus-3 infection in comparison with other infectious diseases.

Human parechovirus-3 (HPeV-3) has been associated with severe clinical manifestations in neonates and infants in the form of sepsis or hemophagocytic lymphohistiocytosis (HLH)-like illness. To clarify the clinical features of HPeV-3 infection, we compared clinical signs and laboratory findings among enteroviruses (EVs), HPeV-3, and other infections. Participants were 26 febrile infants in whom EVs (n = 20) or HPeV-3 (n = 6) were isolated from throat swab or fecal specimens. Clinical and laboratory data were compared among EVs, HPeV-3, respiratory syncytial virus (RSV) infection (n = 15), and bacterial meningitis (n = 8) groups. Apnea was frequently seen in the HPeV-3 group although there were no significant differences in other clinical symptoms. Leukocyte count was significantly lower in the HPeV-3 group than in the EV and RSV group. Platelet count was significantly lower in the HPeV-3 group than in the RSV group. Serum ferritin levels in the HPeV-3 group (mean, 2437 ng/ml) and EV group (mean, 552 ng/ml) were significantly higher than in the RSV group (mean 237 ng/ml; P = 0.008 and P = 0.002, respectively). The frequency of patients with clearly high ferritin levels ≥1000 ng/ml was comparatively higher in the HPeV-3 group (4/6) than the EV group (3/20) (P = 0.03). In the HPeV-3 group, ferritin levels were high on Days 4-5. Elevated ferritin levels, decreased leukocyte and platelet counts could offer diagnostic clues to HPeV-3 infection in infant. These laboratory findings might be associated with aberrant immune response to HPeV-3, which could contribute to the development of sepsis or HLH-like illness in neonates.

Clinical and molecular analysis of six Japanese patients with a renal form of pseudohypoaldosteronism type 1.

Pseudohypoaldosteronism type 1 (PHA1) is a rare condition characterized by neonatal salt loss with elevated plasma aldosterone and renin levels. Two types of PHA1 have been described: an autosomal recessive systemic form and an autosomal dominant renal form, in which the target organ defect is confined to the renal tubules. The dominant renal form of PHA1 is caused by heterozygous mutations in the NR3C2 gene, which encodes the mineralocorticoid receptor (MR). We determined clinical and biochemical parameters in two familial and four sporadic Japanese patient and analyzed the status of the NR3C2 gene. Failure to thrive was noted in five of the six patients. In one of the familial cases, the mother had an episode of failure to thrive when she was a toddler, but received no medical treatment. NaCl supplementation was discontinued in four of the six patients after they reached one year of age and they have grown normally thereafter. However, in one patient, 9 g/day of salt has been required to maintain serum Na concentration after 1 year of age. Analysis of NR3C2 identified three novel mutations [c. C1951T (p.R651X), c.304_305delGC (p.A102fsX103), c.del 603A (p.T201fsX34)] and one previously reported mutation [c.A2839G (p.947X)]. p.R651X was identified in one familial case and one unrelated sporadic patient. The patient who has been supplemented with large amount of salt was heterozygous for c.del 603A in exon 2. In conclusion, our study expands the spectrum of phenotypes, and characterized mutations of NR3C2 in the renal form of PHA1.

Efficacy of immunoglobulin plus prednisolone for prevention of coronary artery abnormalities in severe Kawasaki disease (RAISE study): a randomised, open-label, blinded-endpoints trial.

BACKGROUND: Evidence indicates that corticosteroid therapy might be beneficial for the primary treatment of severe Kawasaki disease. We assessed whether addition of prednisolone to intravenous immunoglobulin with aspirin would reduce the incidence of coronary artery abnormalities in patients with severe Kawasaki disease. METHODS: We did a multicentre, prospective, randomised, open-label, blinded-endpoints trial at 74 hospitals in Japan between Sept 29, 2008, and Dec 2, 2010. Patients with severe Kawasaki disease were randomly assigned by a minimisation method to receive either intravenous immunoglobulin (2 g/kg for 24 h and aspirin 30 mg/kg per day) or intravenous immunoglobulin plus prednisolone (the same intravenous immunoglobulin regimen as the intravenous immunoglobulin group plus prednisolone 2 mg/kg per day given over 15 days after concentrations of C-reactive protein normalised). Patients and treating physicians were unmasked to group allocation. The primary endpoint was incidence of coronary artery abnormalities during the study period. Analysis was by intention to treat. This trial is registered with the University Hospital Medical Information Network clinical trials registry, number UMIN000000940. FINDINGS: We randomly assigned 125 patients to the intravenous immunoglobulin plus prednisolone group and 123 to the intravenous immunoglobulin group. Incidence of coronary artery abnormalities was significantly lower in the intravenous immunoglobulin plus prednisolone group than in the intravenous immunoglobulin group during the study period (four patients [3%] vs 28 patients [23%]; risk difference 0·20, 95% CI 0·12-0·28, p<0·0001). Serious adverse events were similar between both groups: two patients had high total cholesterol and one neutropenia in the intravenous immunoglobulin plus prednisolone group, and one had high total cholesterol and another non-occlusive thrombus in the intravenous immunoglobulin group. INTERPRETATION: Addition of prednisolone to the standard regimen of intravenous immunoglobulin improves coronary artery outcomes in patients with severe Kawasaki disease in Japan. Further study of intensified primary treatment for this disease in a mixed ethnic population is warranted. FUNDING: Japanese Ministry of Health, Labour and Welfare.

Increased levels of cytokines and high-mobility group box 1 are associated with the development of severe pneumonia, but not acute encephalopathy, in 2009 H1N1 influenza-infected children.

BACKGROUND: The 2009 A(H1N1) influenza virus has caused a large outbreak, and resulted in major complications of severe pneumonia and acute encephalopathy in the pediatric population in Japan. METHODS: This study examined six patients with acute encephalopathy, 34 patients with severe pneumonia, five patients with both pneumonia and encephalopathy, and 46 patients without severe complications. The concentrations of 27 cytokines were examined in the cerebrospinal fluid of patients with encephalopathy, and the levels of these cytokines, Cytochrome c, high-mobility group box 1 (HMGB1) were measured in the serum of all patients. RESULTS: Patients with severe pneumonia had higher serum concentrations of 16 cytokines, including Th1 cytokines, Th2 cytokines, chemokines, and growth factors, than patients with uncomplicated influenza. The distribution of 27 cytokines in the CSF did not parallel the serum levels in 11 patients with acute encephalopathy. HMGB1 concentrations in the serum were significantly higher in pneumonia patients with or without encephalopathy than in uncomplicated influenza patients, and were significantly associated with the upregulation of 10 cytokines. CONCLUSIONS: Elevated levels of Th2 cytokines appear to be unique to influenza caused by 2009 H1N1 influenza virus and HMGB1 could play an important role in the pathogenesis of severe pneumonia. There appear to be different pathologic processes for encephalopathy and pneumonia.

[Effect of repeated intravitreal bevacizumab injections for secondary macular edema of branch retinal vein occlusion].

PURPOSE: To evaluate the effects of intravitreal bevacizumab (IVB) injections for secondary macular edema of branch retinal vein occlusion (BRVO). SUBJECTS AND METHODS: We treated 91 patients (91 eyes) with IVB injections (1.25 mg/0.05 ml), including 27 eyes which received two injections. Visual acuity and central retinal thickness (CRT) were measured at 1, 4, 8 and 12 weeks after injection. RESULTS: The mean visual acuity and CRT improved from 0.25 (610.8 microm) at baseline to 0.47 (238.4 microm) 4 weeks after injection and 0.45 (368.7 microm) after 12 weeks. Twenty seven eyes among the total of 91 eyes had a second injection due to recurrence or worsened metamorphopsia. In these cases, mean visual acuity and CRT improved from 0.33 (483.7 microm) at baseline to 0.44 (234.3 microm) 4 weeks after injection and 0.42 (296.8 microm) after 12 weeks. Comparing the efficacy by the number of treatments, visual acuity and CRT improved more significantly in a first time treatment group. CONCLUSIONS: IVB injection is generally effective, but recurrence occurred in 26/47 eyes based on CRT. The second injection is effective, however, its effect is weak when compared with the first injection.

[A rare case of intracranial meningioma with intratumoral metastatic breast cancers].

We report an uncommon case of breast cancer metastasis to an intracranial meningioma. A 47-year-old female was admitted to our hospital due to general convulsion. She had undergone a radical operation for left breast cancer 4 years refore, and received postoperative adjuvant therapies. MRI revealed a solid well-circumscribed tumor in the right frontal convexity. The patient underwent tumor resection successfully. The pathological examination revealed ductal carcinoma in the tissue of a transitional meningioma. Tumor-to tumor metastasis is a rare event. Literature review and discussion of such an uncommon occurrence was presented.

Rapid detection of Epstein-Barr virus DNA by loop-mediated isothermal amplification method.

BACKGROUND: The loop-mediated isothermal amplification (LAMP) method is a novel technique for the amplification of specific DNA sequences. OBJECTIVES: To establish the LAMP method for amplifying Epstein-Barr virus (EBV) DNA and to examine its reliability for the detection of EBV DNA in clinical specimens. STUDY DESIGN: Sera from 108 patients, who were initially suspected of primary EBV infection, were tested by the EBV LAMP method, and the results were compared with those of the real-time PCR assay. Serological examination was regarded as the standard diagnostic method. RESULTS: To diagnose primary EBV infection, the sensitivity of LAMP was 86.4% and the specificity was 100%. The sensitivity of the real-time PCR assay was 84.1% and the specificity was 98.4%. Longitudinal analysis showed that the detection rate of EBV DNA in serum by the LAMP method decreased with time in accordance with the decrease of the EBV load. EBV DNA could not be detected in serum 40 days after onset of symptoms. CONCLUSIONS: These results indicate that the sensitivity and specificity of the LAMP method are comparable to those of real-time PCR and that detecting EBV DNA in serum by this method is potentially useful for diagnosing primary EBV infection.