While most systemic pediatric Haemophilus influenzae infections are caused by the type b strain（Hib）, nontypeable H. influenzae：（NTHi） has been considered a respiratory tract pathogen common in local infection such as acute otitis media, acute pneumonia, secondary chronic respiratory disease and other otorhinolaryngologic infections. Recent findings show, however, that NTHi also causes invasive infections such as meningitis, bacteremia, and lower respiratory tract infections such as pneumonia. A review of NTHi epidemiology from the 1990s onward shows that NTHi causes significant morbidity in pediatric acute otitis media, sinusitis, conjunctivitis and lower respiratory diseases such as pneumonia in Japan. This summary also reviews the worldwide influence of Streptococcus pneumoniae and Hib vaccines on causative pathogens, and several studies about increasing incidence of invasive infections due to NTHi. This review also touches on the emergence of treatment- and drug-resistant H. influenzae, which are now major public health challenges. As a cause of bacterial pediatric infection, NTHi is an important target for prevention.

View full abstract

Molecular epidemiological analysis of 96 rabies viruses isolated from animals in Tokyo in the 1950s involves Japanese fixed virus, Komatsugawa, Takamen, and Nishigahara strains. Strains isolated in Tokyo were divided into Tokyo 1 and Tokyo 2, and grouped into a worldwide distribution cluster differing from Takamen and Nishigahara. Tokyo 1 was grouped into the same cluster as viruses isolated from United States west coast dogs in the 1930s and 1940s. Tokyo 2 was grouped into the same cluster as the Komatsugawa strain, also known as a cluster of viruses from the Khabarovsk raccoon dog, and the Lake Baikal stepped fox in Russia. These findings suggest that 1950s Tokyo rabies viruses were related to those in Russia and the USA.

View full abstract

Titanium dioxide (TiO₂) photocatalysis causes oxidative destruction dependent on electrons excited by ≦ 400nm ultraviolet (UV）rays. Many studies have covered the destruction of organics and bacteria and bacteriophage inactivation by photocatalysis. We studied the inactivation by new nonwoven siliconized titanium dioxide fabric of the feline calicivirus F9 (FCV-F9), human adenovirus GB (HAdv3-GB), and influenza A and B virus (A/New Caledonia, B/Shandong, and 5 clinical strains). We spotted 10μL of viral suspensions containing infectious 5 log₁₀ 50％ tissue culture doses (TCID₅₀)onto 1cm² pieces of TiO₂-coated nonwoven control fabric treated or not treated with UV light (λ_max, 365nm, 1,100- 1,300μW/cm²). We then measured the virus titers of 50μL of viral suspension recovered from these fabrics. FCV-F9 and HAdv3-GB infectivity titers were reduced by over 3.5 log₁₀TCID₅₀t after 30 min of irradiation, but influenza viral titer was reduced to where it was undetectable even without UV irradiation. Comparing individual viral titer reduction due to nonwoven fabric contact without UV irradiation exposure,showed that FCV-F9 and HAdv3-GB titer infectivity was not reduced. In contrast, influenza A and B titer infectivity was reduced to 2 log₁₀TCID₅₀ after 5 min of contact with the nonwoven fabric and to 3 log₁₀TCID₅₀ after 30 min of contact. Titers of 6 of 7 influenza A and B strains were reduced by over 4 log₁₀TCID₅₀ within 30 min. Siliconized TiO₂-coated nonwoven fabric thus efficiently inactivated FCV-F9 and HAdV-GB and absorbed influenza viruses.

View full abstract

A two-phase combined measles-rubella vaccine （MR） immunization schedule was introduced for age 1 and prior to primary school entry in Japan in April 2006. Further immunization was also introduced for 13 （Phase 3） and 18-year-old （Phase 4） cohorts for the 5-year period from April 2008 to March 2013. We surveyed Phases 3 and 4 MR immunization immunogenicity and safety. From August 2007 to December 2009, we conducted 3 Phase 3 and 15 Phase 4 immunizations. We then took paired serum samples （pre- and 4-6 weeks post-immunization）, and measured measles antibody titers using hemagglutination inhibition （HI） and neutralizing test （NT）, and rubella antibody titers using HI. Prepositive measles HI antibody titer （≧8） was 72％ （13/18） and pre-positive measles NT antibody titer （≧2） was 100％（ 18/18）. Post-positive measles HI and NT antibody titers were 94％ （17/18） and 100％ （18/18）. Mean post-immunization measles HI and NT antibody titers were significantly higher than pre-titers, with four-fold or greater increases seen in 9 （50％） and 6 （33％） subjects. Pre-positive rubella HI antibody titer （≧8）was 94％ （17/18）, and post-positive rubella HI antibody titer 100％ （18/18）. Mean post-immunization rubella HI antibody titer was significantly higher than pre-titer, with four-fold or greater increases seen in 8 subjects （44％）. Paired HI antibody titers were measured in pre- and post-Phase 1 immunization for measles in 3 subjects and for rubella in 2 subjects. Those with post-Phase 1 measles HI antibody titers of 32, 64, and 128 yielded titers of 16, 8, and ＜8 pre-Phase 3 or Phase 4 immunization, showing antibody reduction or seronegative conversion. Those with post-Phase 1 rubella HI antibody titers of 128 and 256 yielded titers of 64 and 32 in pre-Phase 4 immunization, showing antibody reduction. Seroconversion or four-fold or greater increases in titer were seen post-immunization in 60％ （3/5） of these subjects. A clinical reaction survey of all subjects 4 weeks post-immunization, showed only 1 case of mild fever and no local or systemic adverse reactions such as generalized urticaria or anaphylaxis. In conclusion,Phases 3 and 4 MR immunogenicity was satisfactory.

View full abstract

National Institute of Infectious Diseases We studied measles outbreak in Ibaraki Prefecture in spring 2002 as members of Field Epidemiology Training Program Japan (FETPJ). Of 84 cases diagnosed by not laboratory test but clinically, 67 (79.8％) were junior high school students, 9 (10.7％) were other students, and 8 (9.5％) were ordinary adult and infant citizens. Of the 84, 46 (54.8％) had been vaccinated. Most did not show typical Koplik spots. The city in which the school was located promoted vaccinations for infants and children aged 7.5 years old to grade 1 in High school. Questionnaire given to junior high students were detected 86 cases, of whom 57 (66.3％) were male. Overall, 4 peaks of clusters were observed in an epidemic curve, among which graduatesʼfarewell parties and graduation ceremonies were the most common opportunities for measles virus exposure. The overall vaccination rate at school was 82.2％, vaccine efficacy extremely low at 72.5％, and vaccine failure high at 15.2％. Symptoms among those vaccinated were significantly milder than those not vaccinated. Immunity of those vaccinated as infants may have been decreased due to scarcity of measles cases in the last 10 years. In such situations - much less in typical measles among susceptible non affected and non vaccinated subjects - atypical or mild measles may be difficult to diagnose. These findings may keep clarify the need to introduce two-dose measles immunization in Japan.

View full abstract

To determine an efficient measles vaccination program for school teachers, we studied knowledge about measles history, immunization, and immunity status among 269 school teachers in Ichihara City in 2009. We found that (1) many are uncertain about disease and immunization history, with neither history related to the immunity status of neutralizing antibody titer (NT), (2) particle agglutination (PA) and enzyme immunoassay (EIA) testing have replaced NT in commercial laboratories, but persons having antibodies fewer than 8-fold of the NT titer as a sensitivity desigration for measles, and 11 false-positive immunity results are indicated in PA testing (cutoff : 256-fold) and 140 false-positive sensitivity results in EIA testing (cutoff : 16.0 EIA), and (3) sensitivity cases are 7.1％ in the naturally infected generation born before 1977 and 23.7％ in the vaccinated generation born after 1978. Given “herd” immunity, we concluded that all vaccinated-generation persons should be administered additional vaccination regardless of sensitivity due to history, immunization, and PA or EIA antibody testing.

View full abstract

Subjects with primary human immunodeficiency virus (HIV) infection often have acute retroviral syndrome. Some develop rhabdomyolysis, which can lead to acute renal failure. A 21-year-old man admitted for consciousness disturbance was initially considered to have aseptic meningitis associated with primary HIV infection. On hospitalization day 3, he developed severe rhabdomyolysis with elevated serum creatine kinase (CK) of 218,100 IU/L with serum creatinine normal at 0.9mg/dL. Following massive extracellular fluid infusion and urinary alkalinization, serum CK decreased smoothly, without renal failure. Severe rhabdomyolysis was concomitant with systemic inflammatory response syndrome (SIRS) only on admission day. Acute renal failure in those with rhabdomyolysis may be influenced by renal possibly due to SIRS and tubular damage from reactive oxygen species, rather than by tubular obstruction by myoglobin casts, although this depends on the extent of myolysis. Acute renal failure is prevented in those with primary HIV infection developing rhabdomyolysis, based on renal blood flow control, if condition causing SIRS do not become a complication.

View full abstract

Encephalopathy with reversible lesion of the corpus callosum splenium has a favorable prognosis, but that in 2009 influenza A/H1N1 is unknown. We report a case of clinically mild encephalopathy with a reversible lesion of the corpus callosum splenium in which 2009 influenza A/H1N1 virus was confirmed by laboratory tests. A 15-year-old Japanese girl seen at the emergency unit for loss of consciousness 18 hours after fever onset had been diagnosed with influenza A, and administered zanamivir. Diffusion-weighted magnetic resonance imaging (MRI) indicated lesions of the corpus callosum splenium, and electroencephalography showed slow basic activity, suggesting influenza A related to encephalopathy. She required intensive care with ventilation for two days. Her consciousness had become normal by day 6 after onset, and MRI findings improved on day 7. She recovered without adverse sequelae.

View full abstract

A 36-year-old woman undergoing a myomectomy developed postoperative surgical-site peritonitis and hematoma. Eight days postoperatively, she developed a 38℃-plus fever and accumulated ascites, with fever unchanged despite antimicrobial β-lactams therapy. Following transvaginal ascitic drainage, her fever disappeared. Recurrent 38℃ fever and inflammation were cured by clindamycin of 1.2g/day. M. hominis detected from ascites drainage was considered the primary causative organism. Nongenito-urinary M. hominis infection is often difficult to detect, as in our case. Gram staining, for example, is not useful in ascertaining small organisms such as Mycoplasma spp. having no cell walls to stain. M. hominis grows slowly, requiring over three days to form colonies on blood agar plates, requiring time to identify pathogens. We report case showing the importance of suspecting M. hominis of causing gynecological surgical-site infection. When common bacterial pathogen cultures remain negative and when empiric β-lactam antibiotic treatment is ineffective, M. hominis should be suspected. In conclusion, M. hominis should be considered a causative following myomectomy resection.

View full abstract

We report a case of thoracoabdominal aortic aneurysm (TAAA) due to Salmonella Enteritidis making final diagnosis difficult. A 63-year-old man with a history of diabetes mellitus, hypertension, and cerebral infarction was seen elsewhere for a 40℃ fever, vomiting, and shaking on day 1 after onset. He was diagnosed with Salmonella bacteremia and hospitalized by us for intensive care. Computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound imaging did not, however, show critical findings of aneurysm, endocarditis, or osteomyelitis, and laboratory testing suggest significant inflammatory symptoms. He did not respond to antibiotics, but had an intermittent low fever during the first hospitalization. On day 48 after onset during the second hospitalization, abdominal CT showed an aneurysm -3cm in diameter in the thoracoabdominal aorta above the renal artery- small enough to have been missed in earlier diagnosis. Surgery and TAAA graft replacement were done on day 64. Bacterial culture of the graft showed no Salmonella growth due to long-term in vivo antibiotic exposure. He recovered without significant complications, with oral ciprofloxacin antibiotic therapy continued to the present. This case indicates the importance of an early diagnosis through continuous blood culture and imaging for Salmonella sp blood stream infection.

View full abstract

A 70-year-old woman admitted for nausea and diarrhea was diagnosed with Legionella pneumonia based on chest X-ray and urinary antigen testing. Despite severe complications, she recovered thanks to ciprofloxacin administration. On hospital day 8, she went into hypovolemic shock necessitating emergency gastrointestinal (GI) fiberscopy, which showed active lower gastric bleeding. The exposed artery was clipped endoscopically and proton pump inhibitor was started. At hospital day 16, the womanʼs active GI bleeding recurred, requiring further endoscopic clipping. On hospital day 20, oozing occurred in the middle gastric body. To prevent recurrent bleeding, extensive gastrectomy was done on hospital day 28. Legionella pneumonia is common pneumonia, as are GI symptoms in Legionella pneumonia, but GI bleeding is rare. Only cases of GI bleeding secondary to Legionella pneumonia have been reported in Japan, in addition to our case, and four of the 5 died after GI bleeding, indicating the dismal prognosis. The relationship between Legionella pneumonia and GI bleeding, although uncertain and rare, requires especially close observation.

View full abstract