Since 1955, when sanitary conditions were poor, the incidence of intestinal parasitism has steadily decreased. Similarly, the number of requests for fecal examinations by physicians has also decreased. However, in our hospital, the incidence of parasites detected in fecal material has been increasing since 1994, regardless of the decreasing number of stool exams performed. Possible reasons for this situation can be summarized as follows: First, an ffective drug for treating Trichuris trichiura and Enterobius vermicularis infections has reduced the incidence of these two helminths. Second, an apparent increase in the incidence of infections with the tapeworms Diphyllobothrium latum and Diplogonoporus grandis may just be a reflection of patients athering at a few facilities for treatment. Third, the number of individuals infected with a single Ascaris is significantly increasing. Fourth, parasites related with travel abroad (Schistosoma haematobium and Opisthorchis viverrini) are appearing due to the increase in travel to and from fore gn countries. Of the above, we think particular attention should be paid to the increase in A. lumbricoides infections.
Pneumocystis carinii is a human respiratory pathogen which causes fatal pneumonia in patients under immunosuppressed or immune deficient conditions. Recent work have documented the usefulness of the polymerase chain reaction (PCR) method in the detection of P. carinii from clinical samples. Therefore, we described our experience in using PCR method in the detection of P. carinii from respiratory samples. In our study, bronchial washing or BALF were good for diagnosis of P. carinii pneumonia (PCP) by PCR. However, PCR method in the detection of P. carinii from swab or sputum was too sensitive because smal numbers of P. carinii organisms might be insignificant in causing the disease. It might reveal colonization or asymptomatic carrier state in the upper respiratory tract. Therefore, our result suggested that colonization or asymptmatic carrier state in the upper respiratory tract could eventually evolve into PCP. This would also facilitate basic progress in the pathology or epidemiology of P. carinii infection. In addition, an usefulness of prophylactic therapy for PCP was documented by PCR.
The purpose of this study was to investigate what viruses infiltrate into our nursing home, assess the related clinical symptoms in elderly subjects, and compare the incidences of infections with those in the general community. Between July 1994 and June 1995, 40 elderly persons dwelling in the nursing home were evaluated by clinical observation, serologic analysis, and viral culture of samples to determine the presence of viruses. Enteroviruses and herpes simplex I virus could be isolated from asymptomatic elderly subjects. Individuals with influenza B virus and RSV infections diagnosed by serology did have clinical symptoms. The prevalence of both influenza B virus and enteroviruses was related to that of such viruses in the general community. Our data suggest that respiratory viruses are readily transmitted from the community to nursing home residents.
From the winter of 1997 to the spring of 1988, a severe epidemic caused by influenza A (H3 N2) developed in Japan. During the epidemic (December 1997 to February 1998), 239 children were admitted to the pediatric ward of Nippon Kokan Hospital: as many as 76 (31.8%) were hospitalized with influenza A (H3N2) infection. Most were young healthy children (mean age, 3.7 years), suggesting the need of influenza immunization for this age group. 110 specimens of hospitalized children were examined by rapid antigen test of influenza A virus (Directigen Flu A, Becton Dickinson, USA). The rapid test showed about 90% sensitivity and specificity, as compared with isolation and serum hemagglutination inhibition test. Directigen Flu A proved to be a reliable, rapid screen for influenza A from symptomatic patients.
Since the number of outbreaks of pulmonary tuberculosis is increasing in Japan, epidemiological analysis is important to prevent the disease. Since Mycobacterium tuberculosis lacks the variety of biotypes among strains, genetical analysis is considered to be a promissing measure to differenciate various of this pathogen. We applied arbitrarily primed polymerase chain reaction (AP-PCR)-based DNA fingerprinting to clinically isolated strains of M. tuberculosis. Although genetic analyses of M. tuberculosis by AP-PCR were reported by several investigators, reproducibilities of their results were not sufficient to be widely accepted as a reliable epidemiological tool. To attain high reprodicibulity, we attempted to optimize AP-PCR conditions including primers and annealing temperature, and to purity of DNA preparations. In this study, high reproducibility was attained by using the mixed primers of 1309F and 92R, and DNA preparations with an absorbance ratio (A260/A280) of higher than 1.50. Twenty two clinical isolates, including strains isolated from one incidence of nosocomial infection and from that of intrafamilial infection were analyzed by the optimized method; consequently they were grouped into 16 types. This AP-PCR method requires only one week subculture of M. tuberculosis and less than 24 hours for analysis. This AP-PCR method allowed us to obtain the highly reproducible results within a considerably short term, which would be applicable to clinical epidemiological investigation.
To clarify the clinical features of nosocomial pneumonia during mechanical ventilation (ventilator-associated pneumonia) and to select the appropriate antibiotic therapy for patients, we performed a clinical analysis of 19 patients (26 episodes) with this condition. The following results were obtained. 1, The average age of the patients was 68 years old (male 16, female 3). 2, VAP occurred three times in 2 cases, twice in 3 cases, and once in 14 cases. 3, The duration of mechanical ventilation was from 7 days to 11 years and 5 months (the average was 2.1 years).4, The microorganism isolated from the aspiration sputum of the VAP patients was Psedomonas aeruginosafrequently, but it was difficult to determine whether this microorganism was the causative microorganism. Ten strains of Staphylococcus aureus (MRSA seven strains and MSSA three strains) were newly isolated at the same time as VAP and especially in the cases in which these were thought to be causative micrrorganisms, all the patients died within a short time. 5, Antibiotics were clinically effective for 53.8% of all the VAP patients and carbapenem antibiotics (for example, IPM/CS) were also used for the effective group. 6, Regarding the risk factors for VAP, factors such as the duration of mechanical ventilation, the existence of chronic obstructive pulmonary disease, a hyponutritional state, prior antibiotics, aspiration of gastric contents, histamine-type-2 receptor antagonist, and multiple organ failure showed significant differences and were suspected to be associated with the appearance of VAP.
To determing the efficacy of a single influenza vaccine administration in the elderly receiving annual influenza vaccination, antibody response to influenza vaccine was compared between once and twice injections in a geriatric cohort. Influenza vaccination had been done for 69 inpatients in the year prior to the study, and was administered twice for 34 of them and once for the other 35 during the study period. Influenza vaccine was injected twice to 77 inpatients who had not received influenza vaccine in the year prior to the study. Hemoagglutination inhibition (HI) antibody titer for influenza A/H1N1, A/H3N2, and B was measured before vaccination, after the first vaccination, after the second vaccination, and after the epidemic period, September 1995 to April 1996. HI antibody titer prior to vaccination was significantly higher in the patients who had received influenza vaccination the previous year. The influenza vaccine induced an increase in HI titer in almost all subjects, and the geometric mean of the HI titer after vaccination in the patients who received vaccine once was comparable to that of the patients injected vaccine twice. The number of patients with HI titers of over 128×increased, and the frequency ranged from 60.0% to 97.1% for the influenza viruses of the three subtypes. The frequency of HI titers over 128×was not significantly different among the three groups. The second vaccination did not increase the number of patients with HI titers over 128×when compared with the number after the first injection in the patients who had received influenza vaccine the previous year. These results suggest that prior vaccination does not diminish the antibody response to influenza vaccine in the elderly. The efficacy of a single influenza vaccination is comparable to that achieved by twice injections in the elderly receiving annual influenza vaccination.
Sixty-two episodes of fungemia which occurred in patients with hematological disorders between 1976 and 1996 in our hospital were analyzed with respect to background and prognostic factors. Forty-four of the patients were male and 18 were female. The underlying diseases were acute leukemia in 36 cases, chronic myelogenous leukemia in 9, malignant lymphoma in 9 and others in 8 cases. Trichosporon beigelii and Candida tropicalis were the most frequently isolated fungal pathogens. The prevalence of C. crusei increased while that of C. albicans decreased after 1988. Fuungemia frequently occurred in patients with following factors: 1) advanced disease, such as relapse of acute leukemia or malignant lymphoma or blast crisis of chronic myelogenous leukemia; 2) neutrophil count less than 100μl; 3) administration of antibiotics; 4) focal infection, gastrointestinal hemorrhage or urinary catheterization; and 5) isolation of causative organisms from surveillance cultures obtained just before the onset of fungemia. The mortality rate of patients with fungemia was 74%. Absence of hypotension, increased neutrophil count for a week after the onset of fungemia, and the intravenous administration of Amphotericin B (AMPH) were good prognostic factors. Fungemia frequently occurred in patients with advanced disease and had a very poor prognosis. These results emphasized the importance of isolation of fungus from surveillance cultures, early initiation of AMPH administration, and attempts to increase neutrophil counts with G-CSF and other measures for improving the prognosis of fungemia in patients with hematological disorders.
The aim of this study was to elucidate the mechanism of clarithromycin (CAM) resistance in laboratory strains and clinical isolates of Helicobacter pylori. The CAM resistance in laboratory strains was induced in vitro by CAM exposure. The majority of CAM-resistant strains were highly resistant to CAM (MICs>100μg/ml). These CAM-resistant strains also showed cross resistance to azithromycin, rokitamycin and clindamycin. The sites of point mutations in these resistant strains were identified as follows; the conserved domain V of genes encoding 23S rRNA were amplified first by PCR and this PCR products (1.4 kb) were subsequently digested with Bsal and MboII and RFLP patterns were analyzed. 1.4 kb amplicons of CAM-susceptible strains yielded two DNA bands of 1000 by and 400 by when digested with BsaI but no digestion product was seen by MboII digestion. In contrast to this, two types of RFLP patterns were observed for the resistant strains induced in vitro by CAM; one was the formation of three bands (700 bp, 400 by and 300 bp) after BsaI digestion, and the other was the formation of two bands (approximately 700 bp) by MboII digestion. RFLP patterns of CAM-susceptible and CAM-resistant clinical isolates obtained from patients before and after CAM medication were similar to those observed for the CAM-susceptible strains and CAMresistant strains developed in the laboratory. These results strongly suggest that the CAM resistance of H. Pylori was caused by point mutation of 23S rRNA.
TAK-751S is a synthetic trisaccharide coupled to Chromosorb P using a spacer sequence of 8-methoxycarboyloctyl (MCO). Its chemical structure is similar to a human receptor (Gb3) of Stx produced by enterohemorrhagic Escherichia coli (EHEC). In vitro efficacy of TAK-715S was studied by using ACHN cultured cell assay, which is sensitive and specific for measuring low level of Stx. Under various conditions, TAK-751S was mixed with purified Stx1 and Stx2, and residual free toxins in the solution were measured by using ACHN cells. TAK-715S was demonstrated to bind specifically to Stx1 and Stx2 under the condition similar to a human intestine while Chromsorb P did not bind to any Stx. The binding activity was stable in the presence of various processed foods, fresh vegetables and fruits. Antibiotics such as fosfomycin, kanamycin and norfloxacin did not disturb its binding capability. Minimum inhibitory concentrations of these antibiotics against Staphylococcus aureus FDA209P or E. coli NIH J JC-2 neither changed after incubating with TAK-751S for 60 min at 37°C. These results suggest that TAK-751S can be given orally with various foods and antibiotics for the elimination of Stx1 and Stx2 in the gut of patients with EHEC infections.
A 73-year-old male was admitted to our hospital because of detection of Shigella flexneri 2a from his stool. Antimicrobial treatment with levofloxacin (LVFX) was started, but could not eliminate the organism in the stool. In the examination of drug susceptibility, this strain was highly resistant to all new quinolones. The minimal inhibitory concentration of norfloxacin, ofloxacin and ciprofloxacin to this strain was 12.5μg/ml, 6.25μg/ml and 6.25μg/ml, respectively. The dual mutations were detected in the codon 83 and 87 of the gyrA gene by sequencing the quinolone-resistance determining region (QRDR). There was, however, no significant difference between the intracellular uptake of ciprofloxacin in this strain and in the ciprofloxacin-sensitive strain. The amount of ciprofloxacin in this strain unchanged when carbonyl cyanide m-chlorophenyl hydrazone (CCCP) was added. These results suggest that the advanced resistance in Shigella flexneri against new quinolones could be acquired by only this dual mutations without the change of the active efflux mechanism.
While it is well known that most Cytomegalovirus (CMV) infections can occur in childhood without any clinical manifestation, this virus is an important cause of serious illness in infants and in immunocompromised individuals, including patients receiving immunosuppressive drugs, organ and bone marrow transplant recipients and patients with acquired immune deficiency syndrome. However, CMV rarely occurs as a spontaneous primary infection in immunocompetent adults, although it can cause several clinical symptoms and mononucleosis in such patients. We described our experience with a patient who was a 23-year-old Japanese man, given a diagnosis of CMV mononucleosis, and in whom lymphocyte subpopulations and neutrophil function were investigated. Some noteworthy points of the case are reported.