Human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) were recently discovered, and are known as etiologic agents of exanthem subitum (roseola). HHV-6 and HHV-7 are T-lymphotropic, and have been classified as betaherpesviruses. In monitoring of herpesviruses after hematopoietic stem cell transplantation, each herpesvirus had a unique temporal profile of detection. HHV-6 DNA was detected most frequently at 3 weeks, whereas cytomegalovirus and Epstein-Barr virus DNA were detected later. HHV-7 DNA was not detected throughout the observation period. In in vitro hematopoietic colony assays, HHV-6 suppressed all three lineages of hematopoiesis, i.e., erythroid, granulocyte/macrophage, and megakaryocyte, whereas HHV-7 did not have any suppressive effect. Molecular epidemiological analysis revealed that HHV-7 was transmitted horizontally from grandparents to parents to children through close contact within a household. Either parent could transmit HHV-7 to the children. Follow-up studies of the amount of viral DNA in saliva samples revealed that the amount of HHV-7 DNA was rather constant for each individual, and that "high producers" and "low producers" could be distinguished. Transferred antibodies against HHV-7 tended to be higher and remain longer after birth than those of HHV-6, and these findings are consistent with the clinical observation that HHV-6 infection occurs earlier than HHV-7 infection.

GB virus-C (GBV-C)/hepatitis G virus (HGV) is a positive, single-strand RNA virus that has been classified in the family Flaviviridae. Interestingly, GBV-C/HGV appears to have a truncated or absent core protein at the amino terminus of the polyprotein. GBV-C/HGV is transmitted parenterally and probably sexually. Most GBV-C/HGV infections appear to be asymptomatic, persistent, and no correlation between virus infection and liver dysfunction although the disease-inducing activity of GBV-C/HGV remains to be investigated. Furthermore, there was no evidence of pathogenesis in the liver by experiment with chimpanzees. From these results, GBV-C/ HGV might be considered as a kind of "orphan" virus in search of a disease. Epidemiological investigation demonstrated that GBV-C/HGV infection is present in about 1-1.4% of the healthy population in developed countries and in 8-14.6% in developing countries. The genome of GBV-C/HGV exhibits a sequence variation among different isolates. On the basis of this variation, it has been proposed that GBV-C/HGV can be classified into at least four major genotypes, consisting of type 1 (West Africa), type 2 (US/Europe), type 3 (Asia), and type 4 (Southeast Asia).

Antimicrobial susceptibility patterns of strains of Escherichia coli isolated between 1994 and 1998 were studied. Of the 1,283 strains examined, 75% were recovered from urine, 8.7% from wounds, 3.2% from blood, 2.6% from pus, and 10.5% from other sources. Isolates from inpatients and outpatients accounted for 46.1% and 53.9%, respectively. Gentamicin and nalidixic acid showed the greatest efficacy against isolates from both inpatients and outpatients, revealing a >90% sensitivity. Drugs with the lowest efficacies were ampicillin and amoxicillin-clavulanic acid, which showed a >45% resistance. Tetracycline showed a significant decline in resistance from 1994 to 1998 among strains from both inpatients and outpatients (P < 0.001). This decline may be related to a policy of restrictive antibiotic reporting by the Microbiology Laboratory and seminars for general practitioners, subsequent to an island-wide survey an antibiotic resistance. A similar pattern of declining resistance was also observed for cefuroxime. E. coli sensitivity to co-trimoxazole was relatively stable during the study period. Although the overall prevalence of resistance among E. coli strains is relatively low, on-going surveillance of bacterial resistance must continue. The microbial antibiogram can provide general practitioners and clinicians with data essential for optimum empiric choices. Further, the introduction of a policy of restrictive reporting may act "synergistically" with the education of doctors on resistance patterns, to effect island-wide reduction of antimicrobial resistance.

The elderly lose teeth as a result of dental caries and periodontitis caused by pathogenic oral bacteria. Periodontitis produces inflammatory cytokines due to the presence of lipopolysaccharides from oral gram-negative bacteria. Although the number of circulating inflammatory cytokines is related to the severity of the periodontitis, it is unclear whether the concentrations also correlate with periodontitis in the elderly. We investigated the relationship between periodontitis status and the concentrations of serum interleukin-6 (IL-6) in the serum from 276 subjects of 70- and 80-year-olds. Of the 276 subjects, 227 (82%) were dentate, 149 (54%) were found to be positive for serum IL-6, and 29 (13%) of the dentate subjects had severe periodontitis. However, there were no significant differences between the severity of periodontitis or the number of teeth and the mean serum IL-6 concentrations. These results provided no evidence to support an association between circulating IL-6 and periodontitis in the elderly.

Giardia lamblia cysts in fecal specimens are detected by conventional morphological methods. The direct immunofluorescence monoclonal antibody assay (DFA) is also applied to detect G. lamblia cysts in feces, but little is known about the usefulness of DFA in fecal specimens stored under various conditions. The aim of the present study was to evaluate the DFA for detection of G. lamblia cysts and to compare these results with the direct smear method in long-term storage of non-fixed fecal specimens. Fecal specimens with G. lamblia cysts were stored in a refrigerator at 5°C (14 samples), a freezer at −20°C (9 samples), or in 3.9% formalin-saline solution at room temperature (28 samples). G. lamblia cysts were detected by DFA in all stored specimens, while they were detected in only 56% of refrigerated and 93% of frozen specimens by the direct smear method. The storage period of all samples testing negative by direct smear was more than 24 months. Many degenerated cysts were recognized by DFA when cysts were negative by the direct smear method. Our results indicate that DFA is a useful method for detecting G. lamblia cysts in fecal samples that have undergone long-term storage.