[History of pandemic influenza in Japan].

In Japan, influenza like epidemics were described many times since Heian era. However, Spanish flu as the modern medicine invaded Japan in 1918, thus almost infected 390,000 patients died with associated pneumonia. After the discovery of influenza virus in 1933, Japan experienced pandemic influenza--Asian flu(H2N2) in 1957. After about 10 years, Hong Kong flu (H3N2) came to Japan at 1968. However, we had many reliable antibiotics but had not any antiviral drug at the early time. After year 2000, we fortunately obtained reliable three antiviral drugs such as amantadine, oseltamivir and zanamivir. Moreover, very useful rapid test kits for influenza A and B viruses were developed and used in Japan. 2009 H1N1 influenza epidemic occured in Japan after the great epidemic in Mexico and North America but elderly patient was few. With together, host conditions regarding with high risk are changing. Lessons from past several pandemic influenza are those that many issues for changing high risk conditions, viral genetic changes, developing antiviral agents, developing new useful vaccins and determinating bacterial secondary pathogens are important.

Bactericidal activity in filtrated supernatant of Streptococcus sanguinis against multidrug-resistant Pseudomonas aeruginosa.

In the past decade, multidrug-resistant Pseudomonas aeruginosa (MDRP) infection has become a serious clinical problem, due to the limitation of drug choices to fight against the bacteria. Here we explored the bactericidal activity in the filtrated supernatant of Streptococcus (S.) sanguinis against Pseudomonas (P.) aeruginosa. S. sanguinis is one of the alpha-hemolytic streptococci that commonly reside in the human oral cavity. A strain of S. sanguinis, isolated from the sputum of a pulmonary-disease patient, was cultured for overnight. The filtered supernatant was tested for bactericidal effect using the minimum bactericidal concentration method on 20 strains of P. aeruginosa, including two MDRP and five mucoid-type strains. The viable number of P. aeruginosa was decreased with time after exposing to the filtrated supernatant of S. sanguinis, and collapsed bacteria were detected with electron microscopy. Of the 20 strains, 19 (95%) strains of P. aeruginosa were affected by bactericidal effect. Among other species of bacteria examined, the filtrated supernatant of S. sanguinis showed remarkable bactericidal effect on 49% of indole-positive Proteus species (4/9 strains) and 60% of Acinetobacter (A.) baumannii (6/10 strains). We next investigated the property of bactericidal activity in filtrated supernatant by treating with proteinase K or autoclave. There was no change in the bactericidal activity of the filtrated supernatant after each treatment, excluding the involvement of protein and plasmid. Here, we identify the bactericidal activity in the filtrated supernatant of S. sanguinis against MDRP. This unexpected observation may contribute to the development of a novel therapeutic drug against P. aeruginosa.

Spatial distribution and vertical profile of polybrominated diphenyl ethers and hexabromocyclododecanes in sediment core from Tokyo Bay, Japan.

Brominated flame retardants (BFRs), hexabromocyclododecanes (HBCDs) and polybrominated diethyl ethers (PBDEs) were detected in three sediment cores and six surface sediments of Tokyo Bay, Japan. HBCDs were detected for the first time in this region with concentrations ranging from 0.056 to 2.3 ng/g dry wt, implying their widespread contamination, even though their concentrations were lower than summation operatorPBDEs (di- to nona-BDEs) and BDE-209. Levels of these compounds were higher near to the highly populated industrial area of the bay implicating industrial and human activities as sources of these compounds. Summation operatorPBDEs increased in the sediment layer up to the mid-1990s and decreased afterwards, whereas BDE-209 showed an increasing trend until now, following the usage of different commercial BDE mixtures. HBCDs first appeared in the mid-1970s and increased until today. The annual surficial flux of HBCDs (0.62-2.4 ng/cm2/yr) is equal to summation operatorPBDEs (0.95-2.6 ng/cm2/yr) but lower than that of BDE-209 (17-58 ng/cm2/yr).

[Patient assessment for zanamivir therapy (second report) -- a survey of patients with influenza who were prescribed zanamivir during the 2001/2002 season in Japan].

Patients diagnosed as influenza who were prescribed zanamivir were surveyed from December 2001 to April 2002 in Japan as the same 2000/2001 influenza season. A total of 751 survey questionnaires were returned. We analyzed the efficacy of zanamivir against 367 patients who were diagnosed as influenza by rapid diagnosed kit and took zanamivir within 48 hours after onset of symptoms. Following the first zanamivir treatment, symptom relief was reported by 24.0% of the patients within 12 hours, 52.6% within 24 hours and 79.6% within 48 hours. The patients reported that the severest influenza symptom was fever, 28.4% of the patients started to feel reduction of fever within 12 hours, 62.2% within 24 hours. All of the 751 patients, 98.8% reported that the Diskhaler could be used as instructed by the doctor or pharmacist and 91.3% found the device easy or very easy to use. These results showed that the effect of zanamivir started very fast and the diskhaer was well accepted. This was the same as the previous results.

[Host and exacerbation factors related to influenza susceptibility].

The host factor of susceptibility to influenza are divided with two ones. First is HI titer (more than 40 or not) in each host according to the age groups to the prevalent influenza virus type. Second is the host conditions which mean high risk factors in influenza patients, especially CPE, lung fibrosis, the decreased lung-function patients and heart failure. I divided those patients with 5 groups from normal persons to high risk patients, and described the vaccine policy and the treatment procedures.

Significant reduction of nosocomial pneumonia after introduction of disinfection of upper airways using povidone-iodine in geriatric wards.

We investigated the efficacy of disinfection of the upper airway using povidone-iodine against nosocomial pneumonia in geriatric wards. Cases of nosocomial pneumonia were retrospectively analyzed between January 1991 and March 1995 in geriatric wards (190 beds). Moreover, the relationship concerning methicillin-resistant Staphylococcus aureus (MRSA) isolates between patient and environment was investigated using pulsed-field gel electrophoresis (PFGE) with the SmaI restriction enzyme. The incidence of nosocomial pneumonia decreased significantly (p < 0.05). Major causative organisms of nosocomial pneumonia were MRSA and Pseudomonas aeruginosa, which significantly decreased. PFGE studies showed that the patterns of MRSA isolates show a strong association between patient and environment. Our study indicates that disinfection of the upper airways by povidone-iodine is very important in the prevention of nosocomial pneumonia in geriatric wards.

Drug-resistant genes and serotypes of pneumococcal strains of community-acquired pneumonia among adults in Japan.

BACKGROUND: A high frequency of drug-resistant pneumococci has been reported in Asian countries. Few data on the drug-resistance or serotype of pneumococcal strains responsible for community-acquired pneumonia (CAP), however, are available for the past two decades in Japan. METHODOLOGY: Susceptibility to antibiotics and the genotype of antibiotic-resistant genes and serotypes of Streptococcus pneumoniae isolates from 114 adult patients with CAP were examined in a nationwide study in Japan between 2001 and 2003. RESULTS: Most of the cases were non-bacteraemic pneumonia and the case fatality rate was 4.4%. The most frequent genotype of the pbp gene was pbp1a + 2x + 2b (gPRSP; 36.8%) followed by pbp 2x (28.1%) and of the macrolide-resistant gene, it was ermB (50.0%). The most common serotype was 19F (29.1%), followed by serotype 23F (13.2%), 6B (12.3%) and 3 (11.4%). The coverage of serotypes of isolates by a 23-valent pneumococcal polysaccharide vaccine (PPV) would be 82.5% in these patients with CAP. Most of strains with serotypes 19F and 23F were gPRSP. A cluster of serotype 3 strains associated with the pbp 2x and ermB gene was also noted. CONCLUSION: A high frequency of altered pbp gene mutations or of macrolide-related genes and a high serotype coverage by the 23-valent PPV found in our study of pneumococcal pneumonia facilitates attempts to increase the coverage rate of the 23-valent PPV in adults older than 65 years in Japan.