To investigate what viruses are related to acute bacterial respiratory tract infections, we prospectively evaluated 113 cases with respiratory tract infections (always accompanying by purulent sputum) experienced between July 1998 and March 2000. Acute viral infections were detected in 25 cases (22%); 10 cases of influenza A virus and 6 cases of respiratory syncytial (RS) virus. The epidemiology of the influenza A virus and RS virus was mainly identified as from December to February in both winter seasons. A bacteriological examination of sputum cultures isolated 12 cases of Streptococcus pneumoniae and 10 cases of Haemophilus influenzae during the same periods and mixed infections of both viruses and bacteria were recognised in 16 cases (14%). These results suggest a significantly high percentage of mixed infections of both viruses and bacteria. However, it was unkown whether the patients with acute bacterial respiratory infections had been infected with viruses prior to the bacterial infections. The frequency of appearence of respiratory tract infections tended to increase with the seasonable epidemiology of viral infections.
No report has been found comparing Chlamydia pneumoniae (C. pneumoniae) pneumonia radiographically with other atypical pneumonias, Chlamydia psittaci (C. psittaci) pneumonia and Mycoplasma pneumoniae (M. pneumoniae) pneumonia. We described the chest radiographs of three kinds of pneumonia cases: 46 cases of C. pneumoniae pneumonia, 39 cases of C. psittaci pneumonia, and 131 cases of M. pneumoniae pneumonia. Radiographic shadows were categorized into main shadows and sub-shadows. The main shadows are classified from the viewpoint of the characteristics; air space consolidation (AS), ground-glass opacity (GG), reticular shadow (RS), bronchopneumonia (BP), and small nodular shadows (SN). The size, the site, and the number of the main shadows were also analyzed. In comparison among the three pneumonias, BP was the most frequent in M. pneumoniae pneumonia (0.40/case). AS predominated in C. pneumoniae pneumonia (0.67/case), and GG in C. psittaci pneumonia (0.62/case). The number of main shadows was equal, about 1.4 /case in three pneumonias. Large shadows were less frequent in M. pneumoniae pneumonia than C. pneumoniae pneumonia (p=0.02) and C. psittaci pneumonia (p=0.01). Main shadows were more frequent in the outer zone in M. pneumoniae pneumonia than C. psittaci pneumonia (p=0.01), and in the middle zone in C. psittaci pneumonia than in M. pneumoniae pneumonia (p=0.02). Cases with bilateral main shadows were less commom in M. pneumoniae pneumonia (9%) than C. pneumoniae pneumonia (33%, p=0.001) and C. psittaci pneumonia (30%, p=0.005). Thickening of bronchovascular bundles as a sub-shadow was most frequently noted in M. pneumoniae pneumonia. Some differences among the three atypical pneumonias were seen in the chest radiograph. However, no specific findings of C. pneumoniae pneumonia were shown radiographically in this study.
Dentists and dental health care workers are at risk of contracting hepatitis C virus (HCV) through dental treatment, since HCV RNA was reported to be easily detectable in the saliva of patients with chronic HCV liver disease. We tested for the presence of HCV RNA in saliva before and after removal of dental calculus, and in splashes on the chin-length face shields of dentists following treatment of six patients with HCV chronic liver diseases. We used a sensitive reverse transcription polymerase chain reaction (RT-PCR) method, to estimate exposure to HCV. All patients were anti-HCV and HCV RNA seropositive. HCV RNAs in saliva before or after scaling treatment were detected in three of the six, but none of the face shields showed positive samples. In conclusion, dentists and dental health care workers should be aware of the possibility of HCV infection via contact with serum and saliva during dental practice.
Intravenous vancomycin was approved in 1991 in Japan and has been widely used for treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Consequently, ever since the initial discovery of vancomycin intermediate-resistant S. aureus in Japan, the vancomycin resistance of this organism has been a great concern in clinical settings. We investigated whether vancomycin resistance had emerged in MRSA isolated in our hospital since the approval of the use of intravenous vancomycin. Vancomycin susceptibility was evaluated on the basis of minimum inhibitory concentrations determined by the agar dilution method and a heterogeneous resistance examination. The median minimum inhibitory concentration of the 69 MRSA strains isolated in 1988 and the 74 isolated in 1998 was 0.75μg/ml and 1.0μg/ml, respectively (p<0.001), however, all of the strains were classified in the susceptible group. None of them was an MRSA heterogeneously resistant to vancomycin (hetero-VRSA), which has been defined as a strain having a 1/106 or greater heterogeneously resistant subpopulation to vancomycin. In another set of investigations, no hetero-VRSA were found among 12 other MRSA strains isolated after intravenous administration of vancomycin for 14 or more days (range: 14 to 77 days). We conclude that while the use of intravenous vancomycin may have slightly lowered the vancomycin susceptibility of MRSA in our hospital, the decrease is so small that it may not be significant clinically. In addition, no hetero-VRSA were found in our hospial.
During the 1996/97, 1997/98, 1998/99, and 1999/2000 seasons, isolations of influenza virus and/or confirmations of hemagglutin gene of virus from the throat swab of patients in 9 medical institutions in Tama, Tokyo were carried out by RT-PCR and tissue culture with MDCK cells. In 1996/97 and 1997/98 seasons, type A (H3N2) was the predominant type of influenza virus, which was 85% in the 1996/97 and 97% in the 1997/98, but small-scale outbreaks with type B virus was also confirmed in the 1996/97 season (during the 8th and 10th week). On the other hand, in the other two seasons, 2 different kinds of types of virus were discovered, which was type A (H3N2) and type B in 1998/99 season, and H3N2 and H1N1 of type A virus in 1999/2000 season. In the 1998/99 season, type A (H3N2) prevailed in the first half, and type B gradually replaced type A (H3N2) after the 5th week in 1999, whereas 2 different kinds of type A in the 1999/2000 mixed during the outbreak. From the presented data, the difference of mode by age groups and year could be explained. Namely, most specimens and positive cases in 1996/97 and 1997/98 seasons were those from low age groups (fifteen years of age and below). In 1998/99 and 1999/2000 seasons, the number of specimens from high age groups (sixteen years of age or over) accounted for above 50%, and about 70% of type A (H3N2)-positive cases. Contrary, the frequency of type B virus in 1998/99 season and type A (H1N1) in 1999/2000 season was higher in the low age groups than the high ones.
Pacemaker infection is one of the severe complication of pacemaker inplantation. We report a case of pacemaker infection caused by Staphylococcuschleiferi which is a coagulase-negative staphylococcus, and its relation with human infection is not well characterized. In 1994, a 80-year-old male presented with a pacemaker pocket infection, cutaneous inflammation but no fever 2 months after insertion of a pacemaker. S. schleiferi was isolated from the pus. The patient was given cefazolin for 5 days. One month later he was readmitted because of cutaneous inflammation and the extruted generator was removed. S. schleiferi was isolated from the generator. After the patient was treated with cefazolin for 3 weeks, four consecutive wound cultures were all negative. A new generator was inserted on the same side. One month after re-insertion, the patient again presented a cutaneous inflammation, and S. schleiferi was isolated from the pus as well as the generator and the leads on their removal. Twenty six days later, a new pacing system was inserted on the other side. There was no further recurrence of the infection. Removal of the entire pacing system was necessary to cure the infecion. We expect further information of human infections caused by S. schleiferi.
We experienced a double infection of tuberculosis and amebiasis of the liver. A 28 year old male with AIDS was admitted to our hospital because of severe diarrhea and liver abscess by Entamoeba histolytica. In spite of improvement of the diarrhea and liver abscess by the therapy against E. historicica, serum levels of γ-GTP and ALP remained high and hepatosplenomegaly gradually increased. A liver biopsy was performed. Pathology showed a granulomatous lesion with Langhans' giant cells. From this specimen, IS6110 gene, a specific DNA for Mycobacterium tuberculosis was detected by PCR method. After anti-tuberculosis treatment was given for 6 months the increased serum γ-GTP, ALP decreased and hepatosplenomegaly diminished.
A 67-year-old male was admitted to our hospital due to a high fever with abnormal shadows on chest X-ray films. On admission, his laboratory data showed hyponatremia, rhabdomyolysis and liver dysfunction. Encephalopathy, acute renal failure and respiratory failure developed, despite fluid management and antimicrobial therapy. His condition worsened rapidly in a few days enough to require mechanical ventilation. Legionnaires' disease was suspected, because pneumonia was found to be associated with multiple organ dysfunction. Intravenous erythromycin and methylprednisolone were administered. The patient's condition was rapidly improved, although he needed hemodialysis for 30 days. Later, indirect fluorescent antibody testing of the patient's serum against Legionella pneumophila was definitely positive (1: 1024). We reported the first case of severe Legionnaires' disease in Miyazaki Prefecture, Japan.