Incidence of Viremia With DNA Viruses in Oncology Patients With Febrile Neutropenia.

BACKGROUND: Although febrile neutropenia (FN) is one of the most common adverse events produced by chemotherapy, its microbiological etiology is determined for only 15% to 30% of cases. OBJECTIVES: We investigated the rate of viremia with common DNA viruses in patients with FN. STUDY DESIGN: From June 2012 to April 2014, 72 blood samples from 24 patients receiving chemotherapy, who experienced FN episodes, were examined for the presence of herpes viruses and other DNA viruses. We used real-time polymerase chain reaction assays to detect herpes simplex virus type 1 and 2, varicella zoster virus, Epstein-Barr virus, cytomegalovirus, human herpes virus types 6 and 7, BK virus and human parvovirus B19 (B19). RESULTS: Viruses were identified in 14 of 72 samples (19.4%). The detected etiological agents were BK virus (5 episodes), human herpes virus type 6 (4 episodes), B19 (4 episodes), Epstein-Barr virus (2 episodes), and cytomegalovirus (1 episode). CONCLUSIONS: Our results indicate that viral infections are common causes in patients with FN. Therefore, viruses may be responsible for FN in a large proportion of patients in whom a causative microorganism could not be identified, and this viral etiology may explain their poor response to antibiotic therapy.

Macrolide-Resistant Mycoplasma pneumoniae Infection, Japan, 2008-2015.

We evaluated isolates obtained from children with Mycoplasma pneumoniae infection throughout Japan during 2008-2015. The highest prevalence of macrolide-resistant M. pneumoniae was 81.6% in 2012, followed by 59.3% in 2014 and 43.6% in 2015. The prevalence of macrolide-resistant M. pneumoniae among children in Japan has decreased.

Cellular and humoral immunity after vaccination or natural mumps infection.

BACKGROUND: This study measured cell-mediated immunity (CMI) and serum antibody to clarify the basis of breakthrough after vaccination and reinfection after mumps. METHODS: From a pool of 54 college students, 17 seronegative subjects and 14 subjects with intermediate level of antibodies against mumps were vaccinated with a monovalent mumps vaccine, and CMI was assessed using interferon-γ release assay. RESULTS: CMI positivity according to pre-existing antibody level, defined as titer <2.0 index units, negative; 2.0-3.9 index units, intermediate; and ≥4.0 index units, positive, was 8/17 (47.1%), 9/14 (64.3%) and 19/23 (82.6%) before vaccination, respectively. Of the 17 seronegative subjects, seven (41.2%) had a history of vaccination and/or natural infection, four (57.1%) of whom were CMI positive or intermediate. Ten (71%) of 14 subjects with intermediate antibody level had a history of vaccination or natural infection, eight (80%) of whom were CMI positive or intermediate. After vaccination the interferon (IFN)-γ and antibody titers increased significantly, but seven (41.2%) of the 17 seronegative subjects and 13 (92.9%) of the 14 intermediate-level subjects tested positive for both antibody and CMI. In a comparison of the natural infection group (confirmed as IgG seropositive and/or CMI positive without vaccination) versus the vaccination group, IgG antibody titer (mean ± SD) was 14.4 ± 8.0 versus 3.6 ± 2.4 index units (P < 0.01) and IFN-γ was 122.7 ± 90.0 pg/mL versus 59.5 ± 37.8 pg/mL (P > 0.05), respectively. CONCLUSION: Vaccination or even natural mumps infection did not always induce both cellular and humoral immunity.

Corynebacterium striatum Bacteremia Associated with a Catheter-Related Blood Stream Infection.

A 49-year-old woman visited our emergency department because of exertional dyspnea due to severe left ventricular functional failure. It progressed to disseminated intravascular coagulation and disturbance of consciousness on day 67 of admission. Gram-positive bacilli were detected from two different blood culture samples on day 67 of admission. An API-Coryne test and sequencing (1~615 bp) of the 16S rRNA gene were performed, and the strain was identified as Corynebacterium striatum. The bacterium was detected from the removed central venous catheter tip too, and the patient was diagnosed with catheter-related bloodstream infection by C. striatum. However, treatment was not effective, and the patient died on day 73 of admission.

Re-emergence of H3N2 strains carrying potential neutralizing mutations at the N-linked glycosylation site at the hemagglutinin head, post the 2009 H1N1 pandemic.

BACKGROUND: Seasonally prevalent H1N1 and H3N2 influenza A viruses have evolved by antigenic drift; this evolution has resulted in the acquisition of asparagine (N)-linked glycosylation sites (NGSs) in the globular head of hemagglutinin (HA), thereby affecting the antigenic and receptor-binding properties, as well as virulence. An epidemiological survey indicated that although the traditional seasonal H1N1 strain had disappeared, H3N2 became predominant again in the seasons (2010-11 and 2011-12) immediately following the H1N1 pandemic of 2009. Interestingly, although the 2009 pandemic H1N1 strain (H1N1pdm09) lacks additional NGSs, clinically isolated H3N2 strains obtained during these seasons gained N (Asn) residues at positions 45 and 144 of HA that forms additional NGSs. METHODS: To investigate whether these NGSs are associated with re-emergence of H3N2 within the subtype, we tested the effect of amino acid substitutions on neutralizing activity by using the antisera raised against H3N2 strains with or without additional NGSs. Furthermore, because the N residue at position 144 of HA was identified as the site of mismatch between the vaccine and epidemic strains of 2011-2012, we generated mutant viruses by reverse genetics and tested the functional importance of this particular NGS for antibody-mediated neutralization by intranasal inoculation of mice. RESULTS: The results indicated that amino acid substitution at residue 144 significantly affected neutralization activity, acting as an escape mutation. CONCLUSIONS: Our data suggest that the newly acquired NGSs in the HA globular head may play an important role in the re-emergence of endemic seasonal H3N2 strain by aiding the escape from humoral immunity.

Rubella specific cell-mediated and humoral immunity following vaccination in college students with low antibody titers.

OBJECTIVE: This study measured cell-mediated immunity (CMI) and antibodies to clarify the basis of rubella reinfection after vaccination. METHODS: In a pool of 65 college students, 39 who exhibited hemagglutination-inhibition (HI) antibody titers against rubella of ≤ 1:16 were vaccinated with a rubella vaccine. The CMI was assessed with interferon-gamma release assay. RESULTS: There was low correlation (r = 0.24) between the antibody titers and interferon-gamma levels at pre-vaccination status. Preexisting interferon-gamma levels were low in some subjects with low HI antibody titers of 1:8 and 1:16. Fifty-seven percent (4/7) of the subjects who were antibody-negative with past history of rubella vaccination at entry onto the study exhibited CMI. And 57% (4/7) of the subjects remained antibody-negative following a second vaccination, despite exhibiting CMI. HI antibody titers increased significantly after vaccination, whereas post-vaccination interferon-gamma levels did not exhibit significant increases. When subjects were divided (based on their past history of vaccination and antibody values) into natural infection and vaccination groups, HI antibody titers (mean ± SD) increased to 1:2(4.4 ± 1.4) from 1: 2(3.2 ± 0.4) (p = 0.065) in the natural infection group and to 1:2(4.4 ± 1.0) from 1:2(3.0 ± 0.8) (p < 0.00001) in the vaccination group following vaccination. The same classification revealed that interferon-gamma values did not increase significantly in either group following vaccination, but the interferon-gamma values at pre- and post-vaccination in the natural infection group were significantly higher than those at pre- and post-vaccination in the vaccination group (p < 0.05 and p < 0.05, respectively). CONCLUSION: Pre-vaccination interferon-gamma levels in each HI antibody titer group were similar. And there were some subjects with antibody-positive exhibited CMI-negative. These data may explain why rubella reinfection can occur in vaccinated seropositive individuals.

Varicella-zoster virus-specific, cell-mediated immunity with interferon-gamma release assay after vaccination of college students with no or intermediate IgG antibody response.

This study measured Varicella-zoster virus (VZV) specific cell-mediated immunity (CMI) and antibodies to clarify immune response after vaccination in 68 college students with negative or intermediate IgG antibody status. The enrolled numbers of negative, intermediate, and positive VZV-IgG antibody were 27, 41, and 28 students, respectively. The positive rates of CMI were 3.7% (1/27), 41.5% (17/41), and 96.4% (27/28) before vaccination, respectively. After vaccination, the IgG antibody titers became significantly higher in the intermediate IgG group compared to those in the negative IgG group (P < 0.01), but CMI did not differ significantly between the two groups. Ninety-three percent (38/41) of the intermediate IgG antibody group and 41% (11/27) of the negative IgG antibody group became positive for the IgG antibody after vaccination (P < 0.0001). When subjects were divided into negative, intermediate, and positive CMI by interferon-gamma values before vaccination, the IgG antibody and interferon-gamma values increased significantly in the positive CMI group compared to the negative CMI group after vaccination (P < 0.01 and P < 0.01, respectively). All (17/17) of positive CMI group and 61% (27/44) of negative CMI group became positive for the IgG antibody after vaccination (P < 0.01). Ninety-four percent (16/17) of positive CMI group and 59% (28/44) of negative CMI group became positive for CMI after vaccination (P < 0.05). Ninety-six percent (22/23) of the subjects with a history of vaccination became IgG seropositive after a second dose of vaccination, but 22% (5/23) of them remained negative for CMI. CMI is valuable information to identify potential non-responders to vaccination and to predict risk of clinical VZV infection.

Detection of bacteria and fungi in blood of patients with febrile neutropenia by real-time PCR with universal primers and probes.

Febrile neutropenia is the main treatment-related cause of mortality in cancer patients. During June 2012 to April 2014, 97 blood culture samples were collected from patients receiving chemotherapy for hematological malignancy and cancer with febrile neutropenia episodes (FNEs). The samples were examined for the presence of bacteria and fungi using real-time PCR amplification and sequencing of 16S and 18S rRNA genes. Bacteria were identified in 20 of 97 samples (20.6%) by the real-time PCR assay and in 10 of 97 (10.3%) samples by blood culture. In 6 blood culture-positive samples, the real-time PCR assay detected the same type of bacteria. No fungi were detected by the real-time PCR assay or blood culture. During antibiotic therapy, all samples were negative by blood culture, but the real-time PCR assay yielded a positive result in 2 cases of 2 (100%). The bacterial DNA copy number was not well correlated with the serum C-reactive protein titer of patients with FNEs. We conclude that a real-time PCR assay could provide better detection of causative microbes' in a shorter time, and with a smaller blood sample than blood culture. Using a real-time PCR assay in combination with blood culture could improve microbiological documentation of FNEs.

[Long effect of a booster on rubella antibodies from each original HI titer following vaccination].

This study was performed to clarify which titers of a pre-existing antibody could be efficiently boosted by vaccination and to assess the persistence of the antibodies. Two hundred healthy volunteer students with HI antibody titers of < or = 1:32 were enrolled. There were 6-16% of subjects with the negative HI antibody who had B-cell memory against rubella, because the EIA-IgM antibody remained negative and/or the avidity of the EIA-IgG antibody was high after vaccination. Furthermore most of them had already been vaccinated just once before. The ratio of those in whom the antibody levels increased significantly at one month after vaccination were 98%, 87%, 67% and 32% in subjects with an HI antibody titer of <1:8, < or =1: 8, < or =1:16 and < or =1:32 at pre-vaccination, respectively. The titers decreased significantly at two years after vaccination, however the ratio of decrease under each original level being 4%, 21.9%, 42.6% and 73.5% in each group of <1:8, < or =1: 8, < or =1:16 and < or = 1: 32, respectively. In comparison with the numbers of the subjects with <1: 8, the ones with < or = 1: 8, < or = 1:16 and < or = 1:32 increased 1.5-, 2.5- and 4.7-fold, respectively. Therefore, the recommendation of an HI antibody titer < or = 1:16 for vaccination in Japan is thought to be loose, although this is to decrease the risk of congenital rubella syndrome. We think that a new assay for cellular immunity for rubella should be developed in the future in order to ascertain whether congenital rubella syndrome will be prevented or not.

Management of refractory Mycoplasma pneumoniae pneumonia: utility of measuring serum lactate dehydrogenase level.

It has been suggested that cytokines are associated with refractory Mycoplasma pneumoniae pneumonia, and steroid administration is reported to be effective in this situation. In order to elucidate the characteristics of refractory M. pneumoniae pneumonia, we analyzed five pediatric patients with refractory M. pneumoniae pneumonia, which was defined as showing prolonged fever and deterioration of clinical and radiological findings despite administration of appropriate antibiotics, compared with 15 pediatric patients with M. pneumoniae pneumonia who responded to treatment promptly (control group). Serum lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and interleukin (IL)-18 levels were significantly higher in the refractory group than in the control group at the initiation of corticosteroid use (LDH: 571 vs 292 IU/L, p = 0.0129; ALT: 25 vs 11 IU/L, p = 0.0143; AST: 41 vs 26 IU/L, p = 0.0404; IL-18: 579 vs 365 pg/mL, p = 0.0402). Significant correlation was found between serum values of IL-18 and LDH (r(2) = 0.504, p = 0.0433). The administration of corticosteroids to patients in the refractory group resulted in the rapid improvement of symptoms and decrease in serum LDH levels in all patients. A serum LDH level of ≥410 IU/L, which was calculated from receiver operating characteristic curve analysis, seemed to be an appropriate criterion for the initiation of steroid therapy. In conclusion, serum IL-18 and LDH levels can be used as parameters to determine which patients are candidates for corticosteroid therapy. In addition, serum LDH levels seem to be a useful marker for the evaluation of therapeutic efficacy in refractory M. pneumoniae pneumonia.

Nationwide surveillance of macrolide-resistant Mycoplasma pneumoniae infection in pediatric patients.

We conducted nationwide surveillance to investigate regional differences in macrolide-resistant (MR) Mycoplasma pneumoniae strains in Japan. The prevalence of MR M. pneumoniae in pediatric patients gradually increased between 2008 and 2012. Although regional differences were observed, high levels of MR genes were detected in all seven surveillance areas throughout Japan and ranged in prevalence from 50% to 93%. These regional differences were closely related to the previous administration of macrolides.

Therapeutic efficacy of macrolides, minocycline, and tosufloxacin against macrolide-resistant Mycoplasma pneumoniae pneumonia in pediatric patients.

The importance of macrolide-resistant (MR) Mycoplasma pneumoniae has become much more apparent in the past decade. We investigated differences in the therapeutic efficacies of macrolides, minocycline, and tosufloxacin against MR M. pneumoniae. A total of 188 children with M. pneumoniae pneumonia confirmed by culture and PCR were analyzed. Of these, 150 patients had a strain with an MR gene and 134 had one with an A-to-G mutation at position 2063 of M. pneumoniae 23S rRNA domain V. Azithromycin (n = 27), clarithromycin (n = 23), tosufloxacin (n = 62), or minocycline (n = 38) was used for definitive treatment of patients with MR M. pneumoniae. Defervescence within 48 h after the initiation of antibiotic therapy was observed in 41% of the patients in the azithromycin group, 48% of those in the clarithromycin group, 69% of those in the tosufloxacin group, and 87% of those in the minocycline group. The average number of days of fever after the administration of antibiotic treatment was lower in the minocycline and tosufloxacin groups than in the macrolide groups. The decrease in the M. pneumoniae burden, as estimated by the number of DNA copies, after 48 to 96 h of treatment was more rapid in patients receiving minocycline (P = 0.016) than in those receiving tosufloxacin (P = 0.049), azithromycin (P = 0.273), or clarithromycin (P = 0.107). We found that the clinical and bacteriological efficacies of macrolides against MR M. pneumoniae pneumonia was low. Our results indicated that minocycline rather than tosufloxacin can be considered the first-choice drug for the treatment of M. pneumoniae pneumonia in children aged ≥ 8 years.

In vitro activities of 11 antimicrobial agents against macrolide-resistant Mycoplasma pneumoniae isolates from pediatric patients: results from a multicenter surveillance study.

Macrolide-resistant Mycoplasma pneumoniae is emerging in several countries, and it is mainly observed in children. To our knowledge, we conducted the first multicenter prospective epidemiological study of macrolide-resistant M. pneumoniae in order to investigate regional differences in the susceptibility of macrolide-resistant M. pneumoniae to antibacterial agents. The in vitro activities of 11 antimicrobial agents against macrolide-resistant M. pneumoniae isolates from 5 different areas of Japan were investigated. Among 190 M. pneumoniae isolates from pediatric patients, 124 (65.2%) isolates showed macrolide resistance and possessed an A2063G transition in domain V of the 23S rRNA. These isolates showed high resistance to erythromycin, clarithromycin, and azithromycin with minimum inhibitory concentrations (MICs) ≥ 16 µg/ml. Conversely, quinolones such as garenoxacin, moxifloxacin, tosufloxacin, and levofloxacin exhibited potent antimycoplasmal activity. No regional differences were observed with respect to the MICs among the 5 areas in Japan.

Clinical efficacy of macrolide antibiotics against genetically determined macrolide-resistant Mycoplasma pneumoniae pneumonia in paediatric patients.

BACKGROUND AND OBJECTIVE: Since 2000, the prevalence of macrolide-resistant (MR) Mycoplasma pneumoniae has increased among paediatric patients in Japan. To determine the efficacy of macrolides against MR M. pneumoniae pneumonia, microbiological and clinical efficacies were compared during the antibiotic treatment. METHODS: Samples from a total of 30 children with M. pneumoniae pneumonia, as confirmed by PCR and serology, were analyzed. Primers for domain V of 23S rRNA were used, and DNA sequences of the PCR products were compared with the sequence of an M. pneumoniae reference strain. RESULTS: Isolates from 21 patients demonstrated point mutations, and these patients were defined as MR. The remaining nine patients, whose isolates showed no point mutations, were categorized as control (macrolide-sensitive) patients. The number of M. pneumoniae in nasopharyngeal samples from the control group decreased rapidly 48 h after initiation of macrolide treatment and showed a close relationship with clinical outcome. In contrast, the number of M. pneumoniae 48 h after initiation of macrolide treatment were significantly higher in samples from MR patients than in samples from macrolide-sensitive patients. In 15 of 21 MR patients, fever persisted for more than 48 h after the initiation of macrolide treatment. When treatment was changed to minocycline, fever disappeared within 48 h in all these MR patients. There were no differences between MR patients who demonstrated a reduction in fever and those in whom fever persisted after 48 h of macrolide treatment. CONCLUSIONS: The microbiological and clinical efficacies of macrolides for treating patients with MR M. pneumoniae pneumonia were low. These results show that macrolides are clearly less effective in patients with MR M. pneumoniae pneumonia.

[What EIA assay levels correspond to rubella antibody HI assay titer?].

In 2004, a Japanese-government-supported research group recommended that women without rubella antibody or with low titers < or = 1:16 of HI antibody should be vaccinated to decrease the risk of congenital rubella syndrome. We compared HI antibody titer with EIA-IgG levels in 520 college students with < or = 1:64, HI antibody measuring rubella antibodies in the same specimen using HI and EIA assay kits from Denka Seiken Co. (Japan) and Dade Behring Co. (Germany). The positive predictive value of the EIA assay using the kit from Denka Seiken Co. was 99.8% and the negative predictive value 91.3%, respectively, compared to 97.9% (positive > or = 15 IU/mL), 98.1% (positive > or = 10 IU/mL), and 93.4%, using the kit from Dade Behring Co. Between HI titers and EIA-IgG measured with the Denka kit, the coefficient index was 0.715 (p < 0.0001). Between those measured with the Dade kit, the coefficient index was 0.610 (p < 0.0001). Between EIA-IgG levels measured using the two kits, the coefficient index was 0.753 (p < 0.0001). The HI value of 1:16 corresponds approximately to 9.0 with the kit (positive > or = 4.0) from Denka, and to 30 IU/mL with the kit from Dade. EIA-IgG levels > or = 10 IU/mL are considered globally as protective antibody titers, meaning that the Japanese recommendation of < or = 1:16 for vaccination is too loose. Japanese EIA kit values for the rubella antibody should also be expressed in IU/mL using the global standard.

[Safety and efficacy in two-dose vaccination using measles and rubella combined (MR) vaccine].

Measles and rubella combined (MR) vaccine and two-dose-vaccination have been used in Japan since 2006. only children undergoing monovalent measles and rubella vaccination undergo a second vaccination. We intend to administer MR vaccine twice to Japanese children from 2011, so studied the safety and efficacy of two-dose MR vaccination. Subjects were 75 pre school children undergoing MR vaccine manufactured by Biken at one year old in a clinical trial. Children were observed for adverse events for 28 days after the second MR vaccination. Efficacy was determined by measuring antibodies for measles and rubella before and after (six to eight weeks later) the second vaccination. Results showed that fever frequency decreased significantly from 27.3% to 14.9% (p < 0.05), and eruption decreased from 12.2% to 6.8% from the first to the second vaccination, whereas, the frequency of redness and swelling at the inoculation site increased from 7.3% to 10.8% and 2.9% to 8.1%. Differences are not statistically significant. Measles antibody titer determined by NT assay and rubella antibody titer measured by HI assay increased significantly from prevaccination to postvaccination (p < 0.0001). Measles antibodies measured by NT and EIA assays and rubella antibody measured by HI assay turned positive in all subjects after the second MR vaccination. In conclusion, two-dose MR vaccination should be safe and effective in eliminating measles and rubella in Japan.