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Tomoyoshi Komiya

Publications and source records attributed to Tomoyoshi Komiya.

7 recordsLinked to original sources
PubMed2006

Rapid detection and quantification of Japanese encephalitis virus by real-time reverse transcription loop-mediated isothermal amplification.

We established a rapid, quantitative real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay targeting the envelope gene of Japanese encephalitis virus. The RT-LAMP enabled us to detect the target product within 1 hr by only reacting reverse transcriptase and Bst DNA polymerase in a single tube at an isothermal temperature. The detection sensitivity of the RT-LAMP for Japanese encephalitis virus was 1 PFU, similar to that of conventional reverse transcription-polymerase chain reaction (RT-PCR). Flaviviruses of the Japanese encephalitis virus group, such as Dengue virus and West Nile virus, could not be detected. This confirmed the specificity of the RT-LAMP assay for Japanese encephalitis virus. A standard curve was constructed by plotting viral titer against the time for virus detection by the RT-LAMP, validating the quantitative accuracy of the assay. In addition, the amount of virus estimated by RT-LAMP was strongly correlated (r = 0.902) with that determined by plaque assay, a conventional method for virus quantification. These results indicate that the RT-LAMP assay established in this study is specific for Japanese encephalitis virus, and allows more rapid detection and quantification of the virus.

Animals↗
PubMed2005

Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection.

OBJECTIVE: To examine whether Coxiella burnetii (C. burnetii) is involved in chronic fatigue syndrome (CFS), we administered tetracycline antibiotics to subjects with CFS, and followed changes in clinical symptoms, PCR findings, and C. burnetii antibody titers. PATIENTS AND METHODS: The subjects were 8 patients with CFS and 213 with nonspecific complaints such as chronic fatigue and low-grade fever for several months or longer but not meeting the diagnostic criteria for CFS. All were examined for C. burnetii infection by nested PCR and the indirect immunofluorescence test (IF). RESULTS: Four CFS patients (the CFS group) and 54 controls [the post-Q fever fatigue syndrome (QFS) group] positive for C. burnetii were treated mainly with minocycline or doxycycline (100 mg/day) for 3 months. After treatment, all 58 patients tested negative for C. burnetii infection. In the CFS group, no significant difference was noted between the mean pre- and post-treatment temperatures or headache scores. Similarly, there was no significant improvement in performance status (PS) scores. In the QFS group, however, mean temperatures and headache scores were significantly decreased after treatment (p<0.001). PS scores were also improved. CONCLUSION: These results suggest the possibility of direct involvement of C. burnetii in the pathological state of CFS to be low, despite the C. burnetii infection rate being high in CFS patients. This is a pilot study and further larger investigations are necessary to confirm our preliminary results.

Adolescent↗
PubMed2004

Improvement of chronic nonspecific symptoms by long-term minocycline treatment in Japanese patients with Coxiella burnetii infection considered to have post-Q fever fatigue syndrome.

OBJECTIVE: To address the presence of post-Q fever fatigue syndrome (post-QFS) in Japan, and to evaluate the efficacy of minocycline for this condition. PATIENTS AND METHODS: In 20 Coxiella burnetii (C. burnetii) seropositive patients with persistent nonspecific symptoms including general fatigue, low-grade fever, myalgia and arthralgia, changes in subjective symptoms, C. burnetii antibody titers and C. burnetii DNA were evaluated after antibiotic treatment. RESULTS: After treatment mainly with minocycline (100 mg/day for 3 months), the clinical picture improved in all 20 patients as evidenced by decreases in body temperature (13/17), general fatigue (20/20) and headache (9/12). The mean performance status (PS) score improved from 5.0 to 1.8 (p<0.01). All 7 who had been positive for C. burnetii DNA, became negative together with an improvement in subjective symptoms. Indirect immunofluorescence tests demonstrated 6 of the 20 patients to be positive for C. burnetii IgM antibody to phase II antigen (1:32), and 18 to be positive for IgG antibody (1:128, 1:256). Antibody titers of both IgM (6/6, 1:16) and IgG (18/18, 1:16) decreased markedly after treatment. CONCLUSION: These results of an open label study in Japan suggest that minocycline administration is useful for improving chronic nonspecific symptoms considered to be post-Q fever fatigue syndrome caused by C. burnetii infection.

Adult↗
PubMed2004

[A case of Q fever infection causing acute exacerbation of chronic respiratory failure].

The authors report a case of Q fever infection that caused acute exacerbation of chronic respiratory failure, which had developed as a sequela of pulmonary tuberculosis. This case was found on wide-ranging serological screening for respiratory infection performed in order to investigate the prevalence of Q fever in Japan. A 73-year-old man who had been treated for hypertension and sequelae of pulmonary tuberculosis was admitted to our hospital because of fever, productive cough, and dyspnea on effort. Hypoxia and right heart failure were detected on arterial blood analysis and ultrasonography. The acute exacerbation was triggered by respiratory infection and although the infection improved on azithromycin treatment after admission, respiratory failure continued for the period of admission. Home oxygen therapy was required for the management of chronic respiratory failure on discharge. Paired serum samples were tested for antibodies against Coxiella burnetii by indirect immunofluorescence, showing an elevated antibody titer in the convalescent phase. We believe that Q fever infection caused acute exacerbation of chronic respiratory failure, and that C. burnetii is an agent that might influence the clinical course of chronic respiratory failure.

Acute Disease↗
PubMed2003

Epidemiological survey on the route of Coxiella burnetii infection in an animal hospital.

The source of Q fever infection, was investigated by serological and polymerase chain reaction (PCR) analysis of specimens from humans and pets in an animal hospital. Two animal health technicians showed a positive serological reaction against Coxiella burnetiiat the start. One of the two positive subjects remained PCR-positive for about 1 year and the other converted to PCR-negative, but the IgG antibody titer remained at 1 : 128 after minocycline treatment. Among animals housed in the hospital, two dogs were PCR-positive at the start, and the infection was transmitted to three cats about 5 months later. All these animals became negative for C. burnetii DNA after minocycline treatment. Furthermore, C. burnetii was isolated from the sera of the two humans and two dogs. C. burnetiiisolates from the humans and dogs were analyzed, and it was found that the sequence homology of the com1 region was high, 99.9%, and the QpH1 plasmid was detected. These results suggest that these isolates were the same type, and it was considered that the infection was derived from the dogs, though the time of infection could not be confirmed.

Animals↗
PubMed2003

Seroprevalence of Coxiella burnetii infections among cats in different living environments.

The seroprevalence of Coxiella burnetii infection among pet cats in Japan and Korea and stray cats in Japan was investigated by an indirect fluorescent antibody technique and PCR test. Forty-four (14.2%) of 310 pet cats in Japan were seropositive, as were 15 (41.7%) of 36 stray cats in Japan and 10 (8.6%) of 116 pet cats in Korea. The antibody positive rate in stray cats was significantly higher than that in pet cats, but there was no correlation between the rates in Japanese and Korean pet cats. In this study, the prevalence of C. burnetii infection among cats in different living environments was found and it is difficult to deny that stray cats would be one of the important sources of infection for human Q fever.

Animals↗