The recently revised Japanese Law on Infectious Diseases designates pest, Lassa, Marburg, Ebola and Crimean-Congo hemorrhagic diseases should be treated in an MBSL-level ward and that it should be constructed in each prefecture.
However, pest can be treated with several antibiotics easily in an ordinary infectious disease ward. Lassa, Marburg and Ebola virus diseases are endemic in tropical Africa and only Lassa fever was imported into Japan in 1987. The probability of its importation to each prefecture is calculated on an assumption that a Lassa fever patient may be imported into Japan once in 10 years. Its incidence was calculated in comparison with the incidence of imported malaria from the African continent.
Its probability P is calculated as follows. Corrected number of imported malaria patients from the African continent per year for each prefecture CN is divided by 445. 445 is the number of imported malaria patients from the African continent in ten years. Finally 445/CN is the number of years needed for each prefecture to import one case of Lassa fever. The results indicate that it takes 37 years for Metropolitan Tokyo where the largest number of malaria patients are imported annually. Other prefectures need more than 100 to 10, 000 years, with an average of 1, 017 years, for importation of one patient of Lassa fever.
It is concluded that construction of an MBSL-level ward in each prefecture is unnecessary. The reports that the above mentioned viral hemorrhagic diseases can be treated safely in the ordinary infectious disease ward should be carefully reviewed.

View full abstract

An epidemiological study on 35 strains of Staphylococcus epidermidis was conducted in Juntendo University Hospital between 1994 and 1996. The strains were isolated from blood and blood vessel catheters. Three epidemiological markers; PFGE type (pulsed-field gel electrophoresis using Sma I), biotype by STAPHYOGRAM^® and antibiotype (antibiotic resistant pattern) were used. There were 12 types in PFGE type, 6 types in biotype and 7 types in antibiotype.
(1) The predominant types were PFGE type A (57.1%), biotype 1 (62.9%), and antibiotype I (resistant for oxacillin, ampicillin and gentamicin; 34.3%) in Juntendo University Hospital.
(2) The strains with antibiotic V-VII (resistant for over 6 antibiotics) showed only PFGE type A and B. All strains with PFGE type B showed biotype 4-6 (negative nitrate reduction strain).
(3) The strains having PFGE type A and B were isolated from various patient wards. The strains showing PFGE type A and antibiotype I were isolated from the pediatric ward.
(4) There was no strain with PFGE type C or D in 1996.
(5) Three patients in whom S. epidermidis was frequently isolated for a few months had the same types of PFGE type, biotype as well as antibiotype.

View full abstract

A total of 201 Shiga toxin-producing Escherichia coli (STEC) O157: H7 isolates from 22 epidemiologically unrelated familial infections in Osaka were analyzed by various epidemiological markers, such as Shiga toxin (STx) typing, antimicrobial resistant patterns, colicine typing, plasmid profiles and pulsed-field gel electrophoresis (PFGE) typing.
There were two cases where different type strains were detected in a family (family No.21 and 22). In the family No.21, three different strains were isolated from a 5-year-old male infant; one identical with that from his mother, and the others different in 4 markers except STx type. In the family No.22, two kinds of strain were detecteds in a 48-year-old father; one identical with those from other members of the family, and the other different in STx, plasmid profile and PFGE types. These facts showed the possibility of a simultaneous double infection from the common sources of infectious factors or a successive reinfection with different types of the agents.
Identical marker strains were detected from 8 out of 12 familial infection cases from July to September. Although infectious sources of these cases are not yet clearly identified, these results of epidemiological markers analysis indicate a probable circulation of the common contaminated foodstuffs.
A combined use of phenotypic and genotypic tests were shown to be useful for the epidemiological analysis. Further, it seemed necessary to examine epidemiological markers of more than one strain in familial infection or identical facilities generation cases. And also a collective analysis of the relating factors such as biological markers of the causative agents, the list of eaten foodstuffs, and successive outbreaks of the patients was thought most important.

View full abstract

A 62-year-old woman admitted for rectal carcinoma suffered from a post-operative bacterial infection. Oxy-imino-beta-lactams including cefotiam (CTM) and cefozopran (CZOP) were prescribed for this case, but the patient developed a wound abscess followed by peritonitis.
She recovered from the bacterial infection after drainage and recurrent washing of the abscess. An ephemeral aggravation of infectious signs was observed just after creation of an artificial anus, and CZOP was again administered, and no evident bacterial infection occurred. The patient recovered, then was followed as an outpatient to date.
A CAZ-resistant (MIC, >16μg/ml) E. coli was recovered from pus of her wound abscess. Since the CAZ-resistance decreased (MIC, 64μg/ml-0.13μg/ml) by the presence of clavulanate (CVA) in this isolate, this strain was speculated to be an extended spectrum beta-lactamase (ESBL) producer at an early stage of infection. A similar strain was also isolated from the feces. Therefore, we immediately took measures to block the nosocomial spread of this microorganism, and we succeeded in preventing a nosocomial outbreak of this strain.
It was later confirmed by PCR analysis and DNA sequencing analysis that this CAZ-resistant E. coli strain produces an ESBL (SHV-5-2a=SHV-12).
This is the first report of a case of infection with SHV-derived ESBL producing E. coli strain in Japan. We are concerned that further dissemination of this kind of microorganism might occur in the near future also in Japan, as it has been widely observed in European countries and the US. We believe that it will be very important to distinguish the type of beta-lactamases for rigorous bacterial infection control with the prudent use of antibiotics. In other words, we in Japan must recall that various gram-negative bacterial species that produce TEM-, SHV-derived ESBLs, Toho-1, AmpC, or IMP-1 are already widespread. Thus, we should take this fact into consideration when we do antibiotic susceptibility tentings and interpretation of the results for promotion of accurate chemotherapy.

View full abstract

The bacteriocidal effect of electrolysed functioning water against Helicobacter pylori was exam ined by both the culture method (viable count on agar plate) and the bacterial ATP content analysis (biolumminescence assay). The culture method revealed the water's reduced bacteriocidal effect on organic substances such as horse serum and bovine serum albumin. The bacterial ATP content determined by the treatment with lysis solution correlated with the bacterial cell count. The ATP of bacteria treated with electrolysed functioning water, benzalkonium chloride, and chlorhexidine gluconate was still present after contact with these solutions for 30 minutes, while the bacterial growth was completely inhibited by the culture method. Therefore, it was suggested that the bacterial ATP was derived from the coccoid form which was observed morphologically due to the action of these solutions. These results demontrate that these solutions are not effective bacteriocidally against the coccoid form. Consequently, when we utilize functioning water in the field, we should keep in mind its nonbacteriocidal effect against the coccoid form, as well as its reduced effect under the condition of the contamination by organic substances.

View full abstract

Efficacy of a 3-drug combination (Zidovudine (AZT) +Lamivudine (3TC) +Indinavir (IDV)) has been evaluated in 17 anti-viral naive patients with HIV infection for 24 months. Our genotypic resistance assay was able to analyze more than 80% of the patients whose viral load (VL) was over 3, 000 copies/ml. This therapy was continued in 11 patients (65%) for 24 months. Among them, VL was undetectable (VI<400copies/ml) in patients at 24 month (47% by intent-to-treat, 72% by on treatment). Of the 11 patients, a 3TC resistance-related mutantion was detected in only one case. The therapy was discontinued in 6 cases. Main reasons of the discontinuation were side effects. However, if the therapy was switched to other combinations when VL was undetectable, VL remained undetectable in 5 cases at 24 month.

View full abstract

The prevalence of virulence-related genes of localized-and aggregated-adherent Escherichia coli (EPEC and EAggEC), such as eaeA, aggR and astA was compared between E. coli isolated from 0 to 5 year old children with and without diarrhea in Saga Prefecture. In the case of eaeA, 233 cases in Aichi Prefecture were included. The subjects were 74 diarrheal patients from which no diarrheagenic bacteria were detected besides E. coli. The control subjects were 304 nursery school children without diarrhea, and E. coli was isolated from 278 children in which 105 strains were of 0-serotype. EaeApositive E. coli was isolated from nine (12.2%) Saga cases, 19 (8.2%) Aichi cases and 6 (5.7%) control subjects aggR-positive E. coli was isolated from 10 (13.5%) cases and 6 (5.7%) control subjects and astA-positive E. coli from 10 (13.5%) cases and 14 (13.3%) control subjects.
No significant difference (p>0.05) was observed in the prevalence of eaeA, aggR and astA between healthy and diarrheal children, even in age-matched and 0-serotypable E. coli limited comparisons. The pathogenicity of EPEC and EAggEC should be investigated, considering other known or unidentified factors.

View full abstract

We analyzed 18 Salmonella Paratyphi A and 12 Salmonella Typhi isolates from domestic and imported cases in Aichi, Japan, using pulsed-field gel electrophoresis. Paratyphoid fever cases have increased and outbreaks of Salmonella Paratyphi A occasionally occur in Japan, but S. Paratyphi A has not been extensively analyzed.
Our study suggests significant genetic homogeneity among Salmonella Paratyphi A belonging to different phage types, which is in contrast to the genetic heterogeneity of Salmonella Typhi. These results suggest that a limited number of clones are responsible for paratyphoid fever.

View full abstract

Antibody levels for diphtheria, tetanus and pertussis in 84 young adult females were measured. They had been immunized with whole cell pertussis-diphtheria-tetanus toxoid (DTwP) vaccine as a routine immunization in their infancy. Their history of DTwP vaccination were confirmed in their Maternal and Child Health Handbook, which includes their immunization record. Among the 84 cases, 4 cases (4.7%) had been immunized with the first dose of DTwP, 5 cases (6.0%) with the second dose, 23 cases (27.4%) with the third dose and 52 cases (61.9%) with the fourth dose. Of the 84 cases, 89.3% had received DTwP vaccine more than the third dose. In the 15-19 years after the last DTwP vaccination, the antibody positive rate for diphtheria and tetanus (≥0.01 IU/ml) were 86.9% and 94.0%, respectively. On the other hand, antibody positive rate for anti-pertussis toxin (anti-PT) and anti-filamentous hemaggulutinin (anti-FHA) (≥10 EU/ml) were 35.7% and 55.9%, respectively. The positive rate for pertussis compared with those for diphtheria and tetanus were lower. These findings suggested that DTwP vaccination in infancy does not provide sufficient immunity for young adults against pertussis, but DTwP vaccination provides adequate immunity against diphtheria and tetanus.

View full abstract

A total of 16 strains of Aeromonas species were isolated from feces of 348 patients with sporadic diarrhea in western Kanagawa, Japan from 1996 to 1998. Of the 16 isolates, 7 were Aeromonas hydrophila, 1 was A. sobria and 8 were A. caviae. The strains of A. hydrophila were examined for hemolytic activities, hemolysin gene types and 0-serogroups. Although all 7 strains of A. hydrophila showed hemolytic activities on sheep blood agar, in the test for hemolytic activities in culture supernatant, only 1 of the these strains showed no hemolytic activity against sheep erythrocytes. From the results of PCR assay, the tested strains of A. hydrophila were grouped into 2 hemolysin gene types of [ahh1+ahh3+aerA] (n=6) and [ahhl+aerA] (n=1) both of which are recognized to be enteropathogenic. Five of the 7 strains of A. hydrophila belonged to serogroup O11. These results suggest that 7 strains of A. hydrophila isolates are recognized to be enteropathogenic strains and serogroup O11 is the major O-serogroup of enteropathogenic A. hydrophila in humans.

View full abstract

A 66-year-old male was admitted to our hospital, presenting a high fever and generalized. erythema on June 9, 1999. Physical examination revealed many eschars on his legs. Laboratory examinations were as follows: platelet counts, 5.5×10⁴/μl: FDP, 25μg/ml: TAT, 70.9ng/ml: GOT, 177 IU/l, GPT, 174 IU/l: CRP, 32.3mg/dl. Based on thesefindings, he was diagnosed as having rickettsiosis with DIC, and minocycline (200mg/day) and heparin were started immediately, but had no clinical effect for 3days. Blood gas analysis showed severe hypoxia and the chest CT scan revealed increased CT value in all lung fields with reticular shadows in the lower fields and pleural effusion, suggested interstitial pneumonia. Methyl-prednisolone pulse therapy was started on June 12, after which he completely recovered. Anti-Rikettia japonica IgM antibody was found to be×8, 192 by immunaluorescent test, establishing the diagnosis of Japanese spotted fever. Acute respiratory failure with interstitial pneumonia shadows should be emphasized as a complication of severe rickettsiosis.

View full abstract