Kanzo Suzuki

Analysis of Clostridium difficile Isolates from Nosocomial Outbreaks at Three Hospitals in Diverse Areas of Japan

ABSTRACT Clostridium difficile isolates recovered from patients with C. difficile-associated diarrhea (CDAD) at three hospitals located in diverse areas of Japan were analyzed by three typing systems, PCR ribotyping, pulsed-field gel electrophoresis (PFGE), and Western immunoblotting. At the three hospitals examined, a single PCR ribotype strain (type smz) was predominant and accounted for 22 (65%) of 34, 18 (64%) of 28, and 11 (44%) of 25 isolates, respectively. All of the 51 isolates that represented PCR ribotype smz were nontypeable by PFGE because of DNA degradation. Since the type smz strain did not react with any of the antisera against 10 different serogroups (A, B, C, D, F, G, H, I, K, and X), we prepared a new antiserum against a type smz isolate. All 51 type smz isolates presented identical banding patterns, reacting with the newly prepared antiserum (designated subserogroup JP-0 of serogroup JP). These results were compared with those of a strain from a hospital outbreak that occurred in New York, which has been identified as type J9 by restriction enzyme analysis and type 01/A by arbitrarily primed PCR but was nontypeable by PFGE because of DNA degradation. This strain was reported to be epidemic at multiple hospitals in the United States. The J9 strain represented a PCR ribotype pattern different from that of a type smz strain and was typed as subserogroup G-1 of serogroup G by immunoblot analysis. A single outbreak type causing nosocomial CDAD in Japan was found to be different from the strain causing multiple outbreaks in the United States, even though the outbreak strains from the two countries were nontypeable by PFGE because of DNA degradation.

Clinicopathological analysis on cancers of autopsy cases in a geriatric hospital

It is generally accepted that cancers in the eiderly are of low grade mallgnancy. In order to clarify this point, autopsy cases from a medical center for the elderly between 1982 and 1994 were pathologlcally analyzed. Three hundred and fifty (160 males, 190 females) out of a total of 871 (361 males, 510 females) autopsy cases were examined. The Incidence of cancer In varlous age groups were found to be as follows: <69 years, 24/67 (36%); 70–74 years, 401102 (39%); 75–79 years, 54/136 (39%); 80–84 years, 79/180 (44%); 85–89 years, 66/172 (38%); 90–94 years, 59/137 (43%); 95–99 years, 17/56 (30%); and >100 years, 12/21 (57%). The incidences did not significantly differ among the groups, that is, there was no age‐dependency in the Incidence of cancer. Furthermore, the incidences of multiple cancers (two or more different malignancies In one patient) also did not differ. However, deaths due to the cancers showed a tendency to decrease with age. The survival periods of clinical cancer cases without a surgical operation history (time period between the date of diagnosis and death), were age‐related for female cases. However, the rate of distant metastasis was not age‐related. The incidence of latent cancers in individuals over 85 years of age was 79/174 (45.4%) and significantly higher than the value of 69/234 (29.5%) for those under 85. The number of malignant tumors in various organs for the different age groups was also counted and the total numbers of clinical cancers and latent cancers in each organ were, 50 and 23 in the lung, 46 and 20 in the stomach, 41 and 31 in the colon, 0 and 39 in the prostate, and 14 and 0 in the mammary glands, respectively. All prostate cancers were latent cancers, and all mammary cancers were clinical cancers. These findings provide strong evidence that cancers In individuals of advanced age have less mailgnency potential.

Selection bias in evaluating of influenza vaccine effectiveness : A lesson from an observational study of elderly nursing home residents

Selection bias is of critical concern in the study of influenza vaccine effectiveness when using an observational study design. This bias is attributable to the inherently different characteristics between vaccinees and non-vaccinees. The differences, which are related both to vaccination and signs of clinical disease as an outcome, may lead to erroneous estimation of the effectiveness. In this report, we describe how selection bias among elderly nursing home residents may lead to a spurious interpretation of the protective effect of influenza vaccine. Our results should be a lesson in the importance of regarding selection bias when assessing influenza vaccine effectiveness.

Hypoalbuminemia, influenza vaccination and other factors related to the development of pneumonia acquired outside hospitals in southern Japan: A case–control study

Pneumonia is the third largest cause of death in Japan. Pneumonia continues to be one of the most common causes of morbidity, hospitalization and mortality, especially in the elderly. The aim of the present study was to evaluate the factors related to the development of pneumonia acquired outside hospitals among the Japanese elderly.

Immunogenicity of trivalent influenza vaccine in patients with lung cancer undergoing anticancer chemotherapy

ABSTRACT Lung cancer is a leading cause of cancer-related death, and patients with lung cancer are a priority group for influenza vaccination. However, few studies have assessed the immunogenicity of the influenza vaccine in these patients. Here, we performed a prospective study to evaluate the immunogenicity of the influenza vaccine in patients with lung cancer undergoing anticancer chemotherapy. Twenty-five patients with lung cancer undergoing anticancer chemotherapy and 26 patients with chronic obstructive pulmonary disease (COPD) as controls were enrolled. A trivalent influenza vaccine containing inactivated A/California/7/2009 (H1N1) pdm09, A/Texas/50/2012 (H3N2), and B/Massachusetts/2/2012 was administered as a single subcutaneous injection. Serum samples were collected before vaccination, and at 4–6 weeks after vaccination. Levels of serum antibody to hemagglutinin were measured. Among patients with lung cancer, the seroprotection rate (postvaccination titer > 1:40) was 84% for both A(H1N1) and A(H3N2), similar to the levels observed in patients with COPD. However, the seroprotection rate for the B strain was significantly lower in patients with lung cancer than in patients with COPD (64% versus 92%). Even after adjustment for potential confounders, patients with lung cancer had a significantly lower odds ratio for seroprotection against the B strain than patients with COPD. Moreover, in patients with lung cancer, those receiving the platinum doublet treatment tended to exhibit a lower seroprotection rate than those receiving a single agent. Thus, patients with lung cancer undergoing anticancer chemotherapy showed acceptable immune responses to a trivalent influenza vaccine, supporting the recommendation for annual influenza vaccination in these patients.

Association between monovalent influenza A (H1N1) pdm09 vaccine and pneumonia among the elderly in the 2009–2010 season in Japan: A case-control study

We investigated the association between monovalent influenza A (H1N1) pdm09 (H1N1pdm) vaccine and pneumonia in elderly people. Study design was a hospital-based, matched case-control study. Cases comprised patients ≥65 years old who had been newly diagnosed with pneumonia. For each case, 2 controls were defined as individuals with other diseases (not pneumonia) who were matched by sex, age, entry date, and the visited hospital. Study period was the interval from 1 September 2009 until 30 September 2010. Because a pandemic of influenza A (H1N1) occurred during study period, we analyzed selected subjects who had enrolled during the influenza A (H1N1) pandemic. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for pneumonia in H1N1pdm-vaccinated subjects compared with unvaccinated subjects using a conditional logistic regression model to assess the association between H1N1pdm vaccine and pneumonia. The subjects during the period of the influenza A (H1N1) pandemic were 20 cases and 40 controls. Subjects who had received H1N1pdm vaccine showed a significantly decreased OR for pneumonia (OR = 0.10, 95% CI = 0.01–0.98) compared with unvaccinated subjects. In conclusion, H1N1pdm vaccination may have prevented pneumonia among the elderly during the 2009–2010 influenza A (H1N1) pandemic in Japan.