Epidemiological aspects of tsutsugamushi disease (scrub typhus) inJapan in 1998 were analyzedusing questionnaires. Four hundred and sixteen scrub typhus cases were reported in 24 prefecturesin 1998. The annual number of the patients in 1998 was similar to those in the preceding three years.There was no sex difference. The patients at the age of 51 or greater accounted for 72% of the totalcases. Patients engaged in farming and forestry accounted for 32% and 14% cases, respectively. Fifty-six, 21 and 19% were reported in Kyusyu, Kanto and Tohoku-Hokuriku districts, respectively, 96% of the total cases being reported in these 3 districts. Most cases were reported from Aprilthrough June with some from October through December in Tohoku-Hokuriku districts, while mostcases were reported from October through December in other districts, including Kyusyu and Kantodistricts. Thus, there was a difference in epidemic seasons among the districts. Serotypes of scrub typhusrickettsia were analyzed by serum antibody titers in the Kyusyu district. The novel Kawasakiand Kuroki types were major strains; however, no geographical difference was seen within the Kyusyudistrict. Interestingly, 24 cases were diagnosed only by the new serotypes not by the classicalserotypes (Kato, Karp and Gilliam) in serological tests. This result suggests that further investigationsare required to determine the prevalent serotypes in each district and to improve the serologicaltests. This was the first comprehensive report of epidemiology of scrub typus in entire Japan. Informationobtained in the present study provides deep insight into prediction, diagnosis, treatment and prevention of scrub typhus in Japan.
Clinical features of tsutsugamushi disease (scrub typhus) were analyzed, based on 416 cases reportedin Japan in 1998. Three major clinical symptoms: eschar, fever and rash were found in 87%, 98% and 92% of the cases, respectively. Elevated levels of CRP, GOT, GPT and LDH were observedin 96%, 85%, 78% and 91%, respectively. These clinical and laboratory findings were observed in themajority of the cases and considered important for diagnosis. Disseminated intravascular coagulationdeveloped in 21 cases, indicating that scrub typhus can be life threatening. Lymphadenopathy wasobserved in 51% of the cases. Enlarged lymph nodes were limited to the local sites in 75% of theselymphadenopathy cases and most of these sites were adjacent to eschars . Most eschars werescabbed and located in the abdomen and the lower half of the body, especially the feet. This suggeststhat these parts are frequently exposed to tsutsugamushi mites. Furthermore, the skin is soft inthese parts and covered by cloth. These factors may make it possible for mites to keep biting withoutbeing noticed for several hours, long enough for rickettsial transmission. Interestingly, eschar andrash were absent in 14% and 8% of the cases, respectively. This result suggests that the cases withoutthe unique symptoms may have been misdiagnosed as common cold or other febrile illnesses.One hundred and fifty-four suspected cases were not scrub typhus cases by the serological tests. Thethree major clinical symptoms were present in approximately a half of these negative cases, escharbeing observed in approximately 70%. This may suggest the presence of new type of scrub typhuscan not be diagnosed by the present laboratory tests. Clinical features of scrub typhus in Japan werewell revealed, and information obtained in the present study is useful for improving clinical diagnosis.It should, however, be stressed that there were cases that could not be correctly diagnosed only bythe clinical symptoms, suggesting that it is important to improve the serological tests.
The clinical findings of tsutsugamushi disease and the fauna of trombiculid mites in HiroshimaPrefecture were studied in this report. We reviewed 63 cases of tsutsugamushi disease occurring between1990 and 1999, and most of cases were contracted in the area around the midportion of the Oota River (55 cases; 87.3%). Of these, 30 cases (47.1%) lived in Asakita-ku in Hiroshima City. Escharwas detected in 33/19 (84.6%) cases, and 97.6% (40/41), 88.9% (16/18) patients showed eruptionand lymphadenopathy respectively. Biochemical examination revealed liver dysfunction in 38.1% (8/21) patients. Of the 11 cases examined on peripheral blood smear, atypical lymphocytes weredetected in 10 cases (90.9%). Fifty-five cases (90.2%) occurred during the restricted season betweenSeptember and December each year. The predominance of Leptotrombidium scutellare was verified bycollection of trombiculid mites along the basin of the Oota River. Serum antibody titration on a patientin Asakita-ku showed reaction to Kawasaki type antigen definitive to L. scutellare. Therefore, wespeculate that L. scutellare is a candidate for the vector of Orientia tsutsugamushi in Hiroshima Prefecture.
The serodiagnosis of human immunodificiency virus (HIV) infection has widely been establishedby the screening test and the confirmatory test. At present, Western blot (WB) assay is mostly usedas the confirmatory test. However, this method has the problem in that the sensitivity and the specificityare not enough. A new confirmatory test “CHIRON RIBA HIV-1/HIV-2 STA” developed by Chiron Corporationuses an immunoblot enzyme immunoassay technique for detection of and HIV-1 and/or HIV-2 antibodies.This assay employs four recombinant viral antigens (gp120, gp41, p24/p26 and p31) and asynthetic viral antigen (HIV-2 envelope peptide). The characteristic of this method is that the HIV-1infection and the HIV-2 infection can be differentiated from each other. We therefore compared thisSIA method with the WB1 assay for detection of and HIV-1 antibodies and with the WB2 assay fordetection of and HIV-2 antibodies. Eighty samples from normal adults without HIV infection and known to be negative by threeHIV screening tests, respectively, were tested by SIA, WB1 and WB2 assays. The negative rates (specificities) were 97.5%, 80.0% and 87.5% by the SIA, WB1 assay and WB2 assay, respectively.With forty samples from patients without HIV infection but known to be positive by at least one HIVscreening test, the negative rates (specificities) were 97.5%, 72.5% and 85.5% by the SIA, WB1 assayand WB2 assay, respectively. The results indicated that the SIA method was more specific than twoWB assays. Forty samples from patients with HIV-1 infection and known to be positive by three HIVscreening tests, were tested by the SIA and WB1 assay. The positive rates (sensitivities) were 97.5% and 75.0% by the SIA and WB1 assay, respectively. With thirteen samples from patients withHIV-2 infection and known to be positive by three HIV ncreening test, the positive rates (sensitivities) were 100% and 92.3% by the SIA and WB1 assay, respectively. The results indicated that theSIA method was more sensitive than the WB1 assay. Three sets of sera, which were collected during seroconversion for HIV-1 antibody, were used tocompare the positive readings by the SIA and WB1 assay. The SIA method indicated the positivereadings earlier than the WB1 assay. The present findings indicated that the SIA method was more specific and sensitive than the WB assay, and would be useful as a confirmatory test.
During surveillance done as part of the investigation of nosocominal infections due to methicillinresistantStaphylococcus aureus (MRSA), we have been aware of the close relationship between thepresence of certain plasmids and the characteristic patterns of antibiotic resistance. The hypothesisthat a mechanism for the rapid and widespread dissemination of resistance to multiple aminoglycosidesin clinical isolates of MRSA at our university hospital was the result of transfer of a singleplasmid among these strains was examined. About 45% of the total isolates of MRSA (91/200 isolates) carried a 35.5 kb plasmid (designatedpCL4) and these isolates always showed resistance to gentamicin, tobramycin, kanamycin, amikacin, astromicin, and arbekacin. Mating experiments between a susceptible strain and resistant MRSA isolatescarrying pCL4 showed high frequency transfer of the plasmid. The aminoglycoside resistancepatterns of all the transconjugants obtained corresponded well with those of parental strains. However, the plasmid could not necessarily be detected in the transconjugants, whereas the transformantsobtained by means of electroporation usually possessed the plasmid. The plasmid-encodedaminoglycoside-resistance determinant, which has been identified as the gene aacA/aphD that encodesthe bifunctional enzyme AAC (6') /APH (2''), either in the transconjugants and transformantscould be transposed to their chromosomes in the absence of whole-plasmid integration resulting froma recombination event. Southern hybridization analysis using an aacA /aphD specific probe demonstratedthat there are multiple sites of the insertions indistinguishable among the chromosomes ofplasmid-free transconjugants and transformants. These results indicate that rapid dissemination ofmultiple-aminoglycoside-resistance in nosocominal strains of MRSA resulted from transfer of a conjugativeplasmid and has been facilitated by translocations of the resistance gene to the chromosome.
A questionnaire survey on the theory of postoperative infection prophylaxis was conducted to obtain the consensus on perioperative antimicrobial use among gynecologists in Japan in the period from April to July 2000. Fifty-six of the 83 gynecologists replied, and the following consensus was obtained. An antimicrobial prophyaxis (AMP) agent should be chosen based on their efficacy against the pathogens expected to be contaminants, such as Staphylococcus spp., Escherichia coli and Bacteroides fragilis group. Use an AMP agent that achives a bactericidal concentrations in both the serum and operating site. Use an AMP agent that has little unfavourable side effects. The newer agents should be considered as a therapeutics for postoperative infections. The therapeutic antimicrobial agents having no cross-resistance to the AMP agents should be used, if postoperative infection is suspected or developed. The most commonly used agent for clean operations are cefazolin (CEZ), followed by cefotiam (CTM) and cefmetazole (CMZ). The most commonly used agent for clean-contaminated operations where low grade level of bacterial invasion expected is CTM, followed by CEZ and CMZ, where as operations where mild grade level of bacterial invasion expected is flomxef (FMOX), followed by CTM and other cephalosporins.
A questionnaire survey on the theory of postoperative infection prophylaxis was conducted to obtain the consensus on perioperative antimicrobial use among orthopedists in Japan in the period from April to September 2000. Fifty of the 91 orthopedists replied, and the following consensus was obtained. An antimicrobial prophyaxis (AMP) agent should be chosen based on their efficacy against the pathogens expected to be contaminants, such as Staphylococcus spp., and Streptococcus spp., Use an AMP agent that achieves a bactericidal concentration in both the serum and operating site. Use an AMP agent that has little unfavourable side effects. Use an AMP agent that affects minimally the normal bacterial flora. The most commonly used agents are the penicillins and first and second generation cephalosporins. The optimal strategy for most commonly used agents entails infusion of the forst dose between approximately 30 minutes pre and post-skin incision and the therapeutic levels should be maintained througout the operation. The AMP agents having no cross-resistance to the prophylactic agents should be used, if postoperative infection is suspected or developed. The most commonly used agent for both clean operations with or wothout foreign implants and dirty operations is cefazolin (CEZ), followed by cefotiam (CTM) and flomoxef (FMOX).
We studied the serological cross-reactions among Bartonella henselae, Chiamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody (IFA) method, using sera from 8 patients with cat scratch disease (CSD), 13 patients with C. pneumoniae infection and 12 patients with acute Q fever. B. henselae IgG antibody was negative in 13 patients with C. pneumoniae infection, and was positive in 3 (titers being 1: 64) of 12 patients with Q fever, whereas B. henselae IgM antibody was negative in all the patients with C. pneumoniae infection or Q fever. C. burnetii IgG antibody was removed by absorption of these 3 sera with C. burnetii antigens, whereas B. henselae IgG antibody did not change. C. pneumoniae IgG antibody was positive in 3 (titers being 1: 125 in two, 1: 32 in one) of 8 patients with CSD. Both C. pneumoniae and B. henselae IgG antibody titers were significantly reduced by absorption of these 3 sera with B. henselae antigens. C. burnetii IgG or IgM antibodies were negative in all patients with CSD. In conclusion, no serological cross-reaction between B. henselae and C. burnetii was observed. On the other hand, B. henselae IgG antibody cross-reacted to C. pneumoniae antigens, whereas C. pneumoniaeIgG antibody did not cross-react to B. henselae antigens. Our findings suggest that determination of B. henselae IgG or IgM antibodies were not influenced by C. pneumoniae and C. burnetii antigens.
Influenza vaccination is strongly recommended for the elderly persons. Especially elderly patients with neurological diseases are at the high risk because they have more tendencies to develop pneumonia than healthy elderly persons. We vaccianted 105 elderly patients with neurological diseases (cerebrovascular disease, Parkinson disease etc.) and 134 people of a control group. Both groups were inoculated with influenza HA vaccine once. The HI titer increase in elderly patients with neurological diseases was equally good enough in the control group and no significant differences was shown in both groups. No severe side effects and adverse reactions were observed in the elderly patient group. This study shows that influenza vaccination is effective and safe for elderly patients with neurological diseases as the well as healthy elderly person and the HI titer increase after a single influenza vaccine injection is expected to be effective to protect influenza infection.