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Nobuhiko Okabe

Publications and source records attributed to Nobuhiko Okabe.

At least 19 recordsLinked to original sources
PubMed2006

Outbreak of Chlamydia pneumoniae infection in a Japanese nursing home, 1999-2000.

OBJECTIVE: To identify risk factors for infection and severe illness due to Chlamydia pneumoniae. METHODS: To identify risk factors for infection, we conducted a case-control study among nursing home residents who had onset of symptoms during December 1, 1999, to February 20, 2000. To identify risk factors for severe illness among nursing home residents, we conducted a retrospective cohort study. SETTING: A nursing home providing long-term and day care services for elderly patients in Japan.Participants. Fifty-nine residents and 41 staff members of a nursing home. RESULTS: The attack rates for respiratory illness were 53% (31 of 59) among residents and 22% (9 of 41) among staff. Infection was confirmed in 15 resident and 2 staff case patients by isolation of C. pneumoniae from nasal swab specimens. Fifteen resident case patients developed severe illness (ie, bronchitis, pneumonia, and hypoxia); one case patient died. The median age of resident case patients was 87 years. We could identify neither the source of the outbreak nor significant risk factors for infection and severe illness in residents. However, residents with a higher level of physical activity were more likely to become infected, whereas older residents (aged more than 85 years) and those with a lower level of physical activity were more likely to develop severe illness (P>.05). Contact with residents was a risk factor for infection in staff (relative risk, undefined; P=.04). CONCLUSIONS: C. pneumoniae can cause large outbreaks of infection and severe illness among elderly persons, and its transmission is likely to be enhanced by close contacts among people in nursing homes. Therefore, early detection of an outbreak by means of better surveillance, and subsequent isolation of patients, may be effective control measures.

Aged↗
PubMed2006

[Cost-effectiveness analysis of routine immunization for varicella in Japan].

OBJECTIVE: Immunization for varicella is not currently included in routine immunizations in Japan. This study was conducted to assess test its cost-effectiveness when it becomes a routine. METHODS: We surveyed and collected information for the year beginning 15th June 2004 in one area. Almost all 11 pediatric clinics or hospitals in the area cooperated in this survey. There was a questionnaire form for families and for doctors. Absent days from routine tasks, i.e., job, housekeeping or study, for family nursing and others were asked on family form. Medical costs and other costs were asked on doctor form. Neither form included the patient's name or name of the medical institution. Doctors explained this survey to patients' family on their first visiting day and asked to cooperate. If they refused the doctor form was also discarded. Since family form was written after recovery and mailed, cooperation in this survey was voluntary. Opportunity cost for family nursing is estimated as opportunity cost based on the 2002 Basic Surveillance of Wage Structure. The burden of sequel cases was estimated assuming six million yen per Quality-adjusted Life Years (QALY). Total number of patients was estimated to be 0.84 million, which includes unvaccinated people in a birth cohort. We adopted incremental benefit cost ratios form societal viewpoint as a measure. RESULTS: We collected 402 data from the doctor form and 265 from the family form. Total disease burden in all of Japan is estimated to be 52.2 billion yen, but opportunity cost accounted for 80%. The incremental benefit cost rations averaged more than 4 when vaccination cost is assumed to be five to twelve thousand yen. The lower limit of the confidence intervals is about 1.5. DISCUSSION AND CONCLUSION: The disease burden of varicella was greater than measles in 2000, when there were measles 0.2 million patients. The incremental benefit cost ratio showed that there will almost surely be an additional benefit due to routine immunization is greater than the additional cost. Therefore, we found strong evidence for routine immunization for varicella.

Chickenpox↗
PubMed2006

[Synptons of outpatients as data for syndromic surveillance].

OBJECTIVE: To review complaints (such as fever, respiratory symptoms, diarrhea, vomiting, and rashes) in the medical records of outpatients as potential sources of data for syndromic surveillance, and to examine the possibility of practical application from a statistical view point. MATERIALS AND METHODS: Using data obtained from a certain internal and pediatric clinic, we count the number of patients each day who suffered from one of the above five symptoms from January 1st, 2003 to June 30th, 2005. In order to detect outbreaks prospectively after January 1st, 2005, we at first estimate the baseline using the data from January 1st, 2003 to the day before any given day. We then predict the number of patients there ought to be in any given day and judge whether or not an outbreak has occurred. So as to evaluate the system, we check the sensitivity and specificity in its ability to detect outbreaks other than those seen in previous patterns. RESULTS: The total number of cases in which each of the above symptoms occurred were respectively: 11,896 cases of fever, 16,273 cases of respiratory symptoms, 3,672 cases of diarrhea, 3,485 cases of vomiting, and 542 cases of rash. We found prolonged outbreaks of fever and respiratory symptoms in February and March and shorter outbreaks of vomiting and diarrhea in January. The sensitivity and specificity of this system' s ability to detect outbreaks was very high and thus we can confirm that it showed satisfactory performance. DISCUSSION: We found large-scale outbreaks of influenza late in the 2004/2005 season, and small outbreaks of GI that seemed to be particularly related to the Noro virus. In both cases, these outbreaks seemed to be natural phenomena, not artificial, human induced phenomena such as outbreaks caused by bioterrorism attacks. However, since this system was able to detect these outbreaks, we would also be able to use it to detect an outbreak caused by a bioterrorism attack if the size of the outbreak was similar to these cases. CONCLUSION: In order to use this system to detect outbreaks in the community on a smaller level we would have to increase the number of medical institutions cooperating in this study. Moreover, we would need to find a way to handle the different electronic medical record systems and different writing styles used by different medical institutions in order to move toward the practical use of Syndromic Surveillance.

Child↗
PubMed2006

[Seasonal influenza activity in Japan and epidemiological investigation for avian influenza].

We analyzed the seasonal influenza activity in 2004/05 and 2005/06 seasons. In 2004/05 season, the prevalence of influenza started lately. The arrival of a peak of influenzal prevalence was the ninth week, and was late in comparison with an average year. The prevalence scale was very large, and the estimation number of patients was 17,700,000. Since the start of the 2004/05 season, influenza activity has mainly been associated with influenza B viruses. The start of prevalence of 2005/06 season was 50th week and was comparatively early. The peak of the prevalence was the 4th week, same as an average year. Since the start of the 2005/06 season, influenza activity has mainly been associated with influenza A/H3 viruses.H5N1 highly pathogenic avian influenza virus have spread through Africa and Europe from Asia. For purpose such as inhibition of the outbreak of new variant influenza, the prevention of human to human infection and expansion, early containment, the public health organization has to do unified epidemiological investigation immediately nationwide. By doing epidemiological investigation, the prevention of infection expansion, specification of the source of infection, assessment of the risk of infection, and early detection of new variant influenza virus and containment, are expected.

Animals↗
PubMed2006

Verocytotoxin-producing Escherichia coli, Japan, 1999-2004.

In 1999, an infectious disease prevention law was enacted in Japan that affected the nationwide infectious surveillance system. A total of 19,304 laboratory-confirmed verocytotoxin-producing Escherichia coli cases were reported through 2004. The annual incidence was 2.74/100,000 population; its fluctuation over time and space was associated with climate, socioeconomic, and population factors.

Age Distribution↗
PubMed2005

Peak rotavirus activity shifted from winter to early spring in Japan.

BACKGROUND: Since 1910, there have been many studies on acute gastroenteritis in children in Japan. These diseases, namely Kasei-shoni-kolera (pseudocholera infantum) or banshu-otosho (late autumn vomiting disease), are historically known to occur in the cooler season with a peak in November or December. Earlier we confirmed their causation by rotaviruses but found peaks in January or February from 1974 to 1981. The aim of the present study was to confirm the temporal shift in peak rotavirus activity. METHODS: Under the National Epidemiological Surveillance of Infectious Diseases program from 1983 through 2003, rotavirus positive patients 0-3 years old and clinically diagnosed with "infantile vomiting and diarrhea" at sentinel clinics were examined. Fecal samples were screened by electron microscopy and/or using commercial latex agglutination kits at prefectural/municipal Public Health Institutes, and we determined the trend for the "peak" month during 21 seasons. RESULTS: Peak rotavirus activity shifted gradually from January to March during the 21 consecutive seasons. The mean duration from December to the peak month (mean beginning peak duration) of the rotavirus season significantly varied among 3 periods of 7 consecutive seasons (1.7 +/- 0.5 months in 1982/1983-1988/1989, 2.3+/-0.8 months in 1989/1980-1995/1996, and 3.1 +/- 0.7 months in 1996/1997-2002/2003, respectively; P = 0.0026 by 1-way analysis of variance). This time series shift in the peak rotavirus infection was statistically significant (P = 0.0003 for trend). CONCLUSION: Our findings confirmed that the temporal trend in peak rotavirus activity in Japan has shifted gradually from winter to early spring for unknown reasons.

Age Distribution↗
PubMed2005

[Compile and evaluation of national surveillance on human echinococcosis in Japan, 1999 to 2002].

National surveillance on human ecinococcosis has been performed since April 1999 when it was stipulated as a Category IV Disease under the Infectious Diseases Prevention Law. During the last 4 years of surveillance, 3 cases with unilocular hydatidosis (age range 27-81 years; median age 55 years) and 51 cases with alveolar hydatidosis (age range 15-86 years; median age 64 years) have been reported. The numbers of reported cases with alveolar hydatidosis have been increased with age, and the largest number reported in the age group > or = 71 years. Three cases with unilocular hydatidosis have been reported from health centers in Honshu, and were likely to be imported cases. Seventeen reported cases had clinical symptoms. None of the reported cases had information on infection route. Fifty out of 51 cases with alveolar hydatid disease have been reported from health centers in Hokkaido. When analyzing the cases by subdividing Hokkaido into six regional districts, large number of cases were reported from health centers in Ishikari-Shiribeshi-Iburi region (20 cases) and in Nemuro-Abashiri-Kushiro region (15 cases). As detailed addresses of the cases were masked, we compared the number of cases per 100,000 residents in regions. Health center in Nemuro-Abashiri-Kushiro region (2.13/100,000) had largest rate and second was Souya-Rumoi region (2.05/100,000). The results from current surveillance data only suggest the generation situation of human echinococcosis in several years ago or more, so the generation situation between 1999 April and 2002 December in surveillance is unknown.

Adult↗
PubMed2005

Multiplex PCR assay for rapid identification of oculopathogenic adenoviruses by amplification of the fiber and hexon genes.

Eye infections caused by adenovirus (Ad) often result in nosocomial infections and community epidemics with significant rates of morbidity. No antiviral agent effective against Ad is yet available for clinical use. Therefore, early diagnosis is still the mainstay for patient management and the prevention of epidemics. A multiplex PCR assay based on amplification of a combination of the fiber and hexon genes which can identify the six important oculopathogenic serotypes of Ads (Ad serotype 3[Ad3], Ad4, Ad7, Ad8, Ad19, and Ad37) in a single-tube amplification reaction was developed. Ad serotypes could be distinguished by the different amplicon sizes. The assay correctly identified prototype strains as well as isolates in clinical specimens. In comparison with a previously described PCR-restriction fragment polymorphism method, our assay gave unequivocal results for clinical specimens. Our multiplex PCR has the potential to serve as a rapid and cost-effective tool for the typing of important ocular Ads.

Adenoviruses, Human↗
PubMed2005

Bias of vaccination coverage in a household questionnaire survey in Japan.

BACKGROUND: Although a household questionnaire survey is important for estimating vaccination coverage, it raises several problematic issues. METHODS: A household survey was conducted on 900 subjects aged 2, 4, and 6 years living in Obu City, Japan, and a second survey for non-respondents to the first survey was then conducted. Questionnaires bearing a subject's name were used for half of the subjects, while the others were anonymous (the named and nameless groups, respectively). The vaccination dates of six kinds of vaccines, including poliovirus and measles vaccine, for those in the named group were reviewed using the administrative records at the Obu City Health Center. RESULTS: The response rate was 70.1% in the first survey and 84.1% in the first and second surveys combined. The response rate for both groups was nearly equal. Based on administrative records in the named group, the vaccination coverage in the respondents was 0.9-2.9% higher than that in total subjects, and that in the respondents to the first survey was 0.8-4.9% higher. There were very few inconsistencies in the vaccination status between responses to the questionnaire and data of administrative records among respondents in the named group. CONCLUSIONS: These results suggested that vaccination coverage from a household questionnaire survey in Japan might not be extremely biased by either non-responses or incorrect answers.

Bias↗
PubMed2005

[Background of recent JE vaccine issues].

In Japan, more than 5,000 patients were reported in 1950, and there have been less than 10 cases annually since 1992. However, Japanese encephalitis virus caused of Japanese encephalitis (JE) are still existed highly and widely in the country, reported by National Institute of Infectious Diseases with serological examination among domestic pig population. JE immunization had been provided to children as category 1 routine immunization in Japan. However, the Ministry of Health, Labor and Welfare (HOHLW) decided not to recommend JE immunization to children as a routine immunization at May 2005. Major reason on this decision was that the Minter of MOHLW certified to pay loss of medical costs for the case of ADEM (acute disseminated encephalomyelopathy) after JE immunization, recognized as adverse events with JE vaccine, although MOHLW stated that the strict scientific evidence was unknown. MOHLW stated also that it is expected Vero cell derived JE vaccine should be replaced with the present mouse brain derived JE vaccine as the next generation, to be able to avoid theoretical possibility of neurological adverse events associated with JE vaccine. Small but increasing number of requests recently to be certified as health injuries on ADEM cases associated with JE immunization is also another reason for MOHLLW's decision. Further, fifth doses of JE vaccine given to children at 14-15 years old as a routine immunization was decided to be discontinued by MOHLW at July 2005, considering present epidemiological situation on JE and JE immunization status in Japan, although four doses has been recommended continuously as routine. The background details on JE vaccine issues decided by MOHLW in 2005 were reviewed on this paper.

Animals↗
PubMed2005

[Capsular polysaccharide antibodies after pneumococcal polysaccharide vaccination in patients with chronic respiratory disease].

We investigated the antibody response to a 23-valent pneumococcal polysaccharide vaccine (23PSV), in 151 patients (average age: 70 years old) with chronic respiratory disease. Serotype-specific IgG antibodies to 4 pneumococcal capsular polysaccharides (6B, 14, 19F, and 23F) were analyzed by ELISA before, and one month after, 23PSV vaccination in all patients. Patients showed a significant increase in specific IgG levels to Streptococcus pneumoniae after 23PSV vaccination (5.5 times-20.9 times). Even patients aged over 80, patients with respiratory failure, and patients receiving corticosteroid therapy developed a significant immunologic response to 23PSV. Local pain or induration occurred in 9.1-14.3% and fatigue or chills occurred in 0.7-6.5% of patients. All adverse reactions disappeared in 2 or 3 days and there was no severe adverse events. Further studies are needed to confirm the exact protective antibody level and to examine the decline of antibody level after vaccination.

Aged↗
PubMed2005

[Present situation and control on emerging respiratory infectious diseases such as SARS and avian influenza].

Infectious diseases have been recognized again due to appearing of emerging and re-emerging infectious diseases in the world. Most of them occur not only in developing countries but also in developed countries, and in Asian region. The pathogen is mainly virus and most of them are suspected zoonotic origin. SARS emerged in the world abruptly and disappeared in 2003. We have had many lessons and learn on control measures, public health, economic impacts, human rights, international cooperation and infectious diseases. The outbreaks of avian influenza among fowls have been occurred since 2004, and some fatal human cases infected with avian influenza virus are detected in Viet Nam, Thailand, Cambodia and Indonesia. Although the total number of human cases are still limited and human to human transmission mode is not yet detected, it has been concerned the possibility to shift new types of influenza for human as pandemic. It is necessary to recognize correctly on existing of infectious diseases, to enhance surveillance, to call partnerships among several sectors such as medical institutes, medical education institutes, research institutes and public health departments. Further, infectious disease control should tackle in global level.

Animals↗
PubMed2004

Nosocomial Serratia marcescens outbreak in Osaka, Japan, from 1999 to 2000.

OBJECTIVES: To investigate and control an outbreak of bloodstream infections (BSIs) caused by Serratia marcescens and to identify risk factors for respiratory colonization or infection with S. marcescens. DESIGN: Epidemiologic investigation, including review of medical and laboratory records, procedural investigations, pulsed-field gel electrophoresis (PFGE) typing of environmental and patient isolates, statistical study, and recommendation of control measures. PATIENTS AND SETTING: All patients admitted to a 380-bed, secondary-care hospital in Osaka Prefecture, Japan, from July 1999 through June 2000 (study period). RESULTS: Seventy-one patients were colonized or infected with S. marcescens; 3 patients who developed primary BSIs on the same ward within 5 days in June 2000 had isolates with indistinguishable PFGE patterns and indwelling intravenous catheters for more than 5 days. On multivariate analysis, among 36 case-patients with positive sputum specimens and 95 control-patients, being bedridden (odds ratio [OR], 15.91; 95% confidence interval [CI95], 4.17-60.77), receiving mechanical ventilation (OR, 7.86; CI95, 2.27-27.16), being older than 80 years (OR, 3.12; CI95, 1.05-9.27), and receiving oral cleaning care (OR, 3.10; CI95, 1-9.58) were significant risk factors. S. marcescens was isolated from the fluid tanks of three nebulizers and a liquid soap dispenser. The hospital did not have written infection control standards, and many infection control practices were found to be inadequate (eg, respiratory equipment was used without disinfection between patients). CONCLUSIONS: Poor hospital hygiene and the lack of standard infection control measures contributed to infections hospital-wide. Recommendations to the hospital included adoption of written infection control policies.

Adult↗