A novel peptide nucleic acid- and loop-mediated isothermal amplification assay for the detection of mutations in the 23S rRNA gene of Treponema pallidum.

Introduction. Macrolides could be a potential alternative treatment for Treponema pallidum infections in patients; however, macrolide-resistant T. pallidum is spreading rapidly worldwide.Hypothesis/Gap Statement. There are presently no alternatives to serological tests for syphilis that can be used to evaluate therapeutic effects due to the fact that T. pallidum cannot be cultured in vitro.Aim. In this study, we constructed a method for rapidly identifying T. pallidum and confirming macrolide resistance by using loop-mediated isothermal amplification (LAMP) with peptide nucleic acids (PNAs).Methodology. A set of LAMP primers was designed to span nucleotide positions 2058 and 2059 in 23S rRNA. A PNA clamping probe was also designed to be complementary to the wild-type sequence (A2058/A2059) and positioned to interfere with both the annealing of the 3' end of the backward inner primer and the concomitant extension. Prior to the LAMP assay, swab samples from suspected syphilitic lesions were boiled for DNA extraction.Results. The assay had an equivalent detection limit of 1.0×101 copies/reaction and showed specificity against 38 pathogens. In the presence of a 4 µM PNA probe, LAMP amplified up to 1.0×101 copies/reaction using plasmids harbouring the complementary mutant sequences (A2058G or A2059G), whereas amplification was completely blocked for the wild-type sequence up to a concentration of 1.0×103 copies/reaction. For the 66 PCR-positive clinical specimens, the overall detection rate via LAMP was 93.9 % (62/66). Amplification was successful for all 53 mutant samples and was incomplete for all nine WT samples by the PNA-mediated LAMP assays.Conclusion. We developed a PNA-mediated LAMP method that enabled us to rapidly identify T. pallidum and determine its macrolide susceptibility via a culture-independent protocol.

Prevalence of N. gonorrhoeae, C. trachomatis, M. genitalium, M. hominis and Ureaplasma spp. in the anus and urine among Japanese HIV-infected men who have sex with men.

The present study investigated the prevalence of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, M. hominis, and Ureaplasma spp. (biovars 1 and 2) in Japanese HIV-positive men who have sex with men (MSM). One-hundred-and-six Japanese HIV-infected MSM patients were enrolled. Anal and urine samples were collected and DNA testing for each microorganism was performed. Questionnaires regarding lifestyle habits and sexual behavior were administered. The prevalence of N. gonorrhoeae, C. trachomatis, M. genitalium, M. hominis, and Ureaplasma spp. in the anus was 5.6%, 8.9%, 4.4%, 5.6%, and 8.9%, respectively. A history of genital warts was an independent risk factor for detection of Mycoplasma spp. and Ureaplasma spp. The prevalence of these microorganisms in the anus of asymptomatic Japanese HIV-positive MSM was relatively high in agreement with previous reports from other countries.

Molecular Typing and Macrolide Resistance Analyses of Treponema pallidum in Heterosexuals and Men Who Have Sex with Men in Japan, 2017.

In recent years, syphilis notifications have increased dramatically in Japan. We carried out molecular typing and macrolide resistance analyses of Treponema pallidum subsp. pallidum samples collected from patients at four clinics and a hospital in Tokyo and Osaka prefectures in 2017. The macrolide resistant strain type 14d/f (SS14-like clade) was found in significantly more cases of syphilis among heterosexuals than in those among men who have sex with men (MSM); i.e., 79% (31/39) of the strains from heterosexuals were 14d/f compared to 37% (7/19) of those from MSM (odds ratio [OR], 6.6; 95% confidence interval [CI], 1.7 to 26.7; P = 0.002). In addition, 83% (50/60) of the strains were identified as macrolide resistant with an A2058G mutation in the 23S rRNA gene; 90% (35/39) of the strains from heterosexuals were macrolide resistant compared to 58% (11/19) of those from MSM. The odds of having the resistant mutation were considerably higher in the former (OR, 6.4; 95% CI, 1.3 to 33.5; P = 0.02). Heterosexual women and heterosexual men showed similar distributions, and the association remained the same when restricted to men. The strain type distribution and the prevalence of macrolide resistance differed substantially between syphilis strains from heterosexual cases and from MSM cases, suggesting distinct epidemiologic profiles for the two communities and providing important insight into the dynamics of syphilis in Japan.

Case-control study of risk factors for incident syphilis infection among men who have sex with men in Tokyo, Japan.

INTRODUCTION: In Japan, syphilis notifications have increased. Men who have sex with men (MSM) in Tokyo have contributed substantially to the increase in syphilis notifications. We thus aimed to determine the correlates of incident syphilis among them. METHODS: MSM who attended a Tokyo clinic that serves sexual minorities were recruited in a case-control study in 2015. A case was seropositive for primary/secondary/asymptomatic syphilis at enrolment visit and seronegative at prior visit or had oral ulcers positive for Treponema pallidum DNA at enrolment. For each case, two controls seronegative at enrolment and prior visit were selected. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) were estimated to assess for correlates of case status. RESULTS: Among 35 cases, the median age was 37 (range = 21-63) years and was similar to the 71 controls. Among HIV-positive participants (26 cases and 67 controls), cases were independently associated with higher frequency of anal or oral sex (OR = 3.4; 95% CI = 1.4-8.6; increase per category from < 1/month, ≥ 1/month but < 1/week, to ≥ 1/week) and no or inconsistent condom use during anal or oral sex (OR = 3.0; 95% CI = 1.1-8.3; increase per category from using every time, occasionally, to never), adjusted for residency and time between visits. DISCUSSION: Modifiable behaviours were associated with incident syphilis, and dissemination of prevention messages are needed.

Comparative evaluation of the Geenius HIV 1/2 Confirmatory Assay and the HIV-1 and HIV-2 Western blots in the Japanese population.

Accurate diagnosis of earlier HIV infection is essential for treatment and prevention. Currently, confirmation tests of HIV infection in Japan are performed using Western blot (WB), but WB has several limitations including low sensitivity and cross-reactivity between HIV-1 and HIV-2 antibodies. To address these problems, a new HIV testing algorithm and a more reliable confirmation and HIV-1/2 differentiation assay are required. The Bio-Rad Geenius HIV-1/2 Confirmatory Assay (Geenius) has recently been approved and recommended for use in the revised guidelines for diagnosis of HIV infection by the Center for Disease Control and Prevention (USA). We made comprehensive comparison of the performance of Geenius and the Bio-Rad NEW LAV BLOT 1 and 2 (NLB 1 and 2) which are WB kits for HIV-1 and HIV-2, respectively, to examine if Geenius is a suitable alternative to these WB assays which are now being used in HIV testing in Japan. A total of 166 HIV-1 positive samples (146 from patients with established HIV-1 infection and 20 from patients with acute infection), five HIV-1 seroconversion panels containing 21 samples and 30 HIV-2 positive samples were used. In addition, a total of 140 HIV negative samples containing 10 false-positives on screening tests were examined. The sensitivity of Geenius and NLB 1 for HIV-1 positive samples was 99.3% and 98.6%, respectively. Geenius provided more positive results in the samples from acute infections and detected positivity 0 to 32 days earlier in seroconversion panels than NLB 1. NLB 2 gave positive results in 12.3% of HIV-1 positive samples. The sensitivity of both Geenius and NLB 2 for HIV-2 positive samples was 100%. The specificity of Geenius, NLB 1 and NLB 2 was 98.5%, 81.5% and 90.0%, respectively. Geenius is an attractive alternative to WB for confirmation and differentiation of HIV-1 and HIV-2 infections. The adaptation of Geenius to the HIV testing algorithm may be advantageous for rapid diagnosis and the reduction of testing costs.

Significance of the Cytological Signs of Human Papillomavirus Infection in Anal Pap Smears of Human Immunodeficiency Virus-Infected Japanese Men Who Have Sex with Men

Purpose: The incidence of invasive anal cancer (IAC) has been increasing among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). Although cytological diagnosis is the modality of choice for screening cases of IAC, it is associated with lower sensitivity and specificity. Therefore, the present study aimed to evaluate new cytological signs of human papillomavirus (HPV) infection that may contribute to improving anal cytology. Methods: Anal cytology and HPV testing were performed using SurePath liquid-based cytology on samples obtained from 37 HIV-positive Japanese MSM. Subsequently, a histological biopsy based on high-resolution anoscopy was performed in MSM with abnormal cytological findings indicative of atypical squamous cells of undetermined significance (ASC-US) +. Also, anal Papanicolaou (Pap) smears were performed to determine cellularity, presence of dysplastic squamous cells, and other cytological signs of HPV infection. Results: Of the 37 MSM who underwent anal cytology, six tested negative for intraepithelial lesion or malignancy, three cases exhibited ASC-US, 17 exhibited low-grade squamous intraepithelial lesion (LSIL), nine exhibited high-grade squamous intraepithelial lesion (HSIL), and two remained undiagnosed. The anal Pap smears of 28 (96.6%) of the 29 MSM with abnormal cytological findings of ASC-US+ exhibited anal intraepithelial neoplasia (AIN), as revealed by histological biopsy. The median value (minimum­maximum) of the cellularity of anal Pap smears was 12 (0­70.5) nsc/hpf. In 26 MSM with LSIL and HSIL, the median dysplastic squamous cells count was 14 (2­152) dsc/smear and the cytological sign of HPV infection was 11 (2­71) hpv/smear. Of all anal Pap smears that revealed ASC-US+, 96.6% exhibited cytological signs of HPV infection. Compression-positive binucleated cells were the most prevalent among all cytological signs of HPV infection. Conclusion: For anal cytology, instead of considering a small number of dysplastic squamous cells, screening based on cytological signs of HPV infection may be beneficial for improving the diagnosis of AIN.

Human papillomavirus prevalence in the anus and urine among HIV-infected Japanese men who have sex with men.

BACKGROUND: The present study investigated human papillomavirus (HPV) prevalence in anal and urine samples, and evaluated cytological findings among human immunodeficiency virus (HIV)-infected Japanese men who have sex with men (MSM). METHODS: A total of 148 patients were enrolled. Anal and urine samples were collected from each participant, and a HPV-DNA test and genotyping were performed using flow-through hybridization. In addition, anal cytology was evaluated based on Papanicolaou staining. Questionnaires regarding lifestyle habits and sexual behavior were obtained. RESULTS: The ß-globin gene was positive in 131 (88.5%) anal samples and 139 (94.0%) urine samples. Among the ß-globin-positive samples, the HPV prevalence in anal and urine samples was 80.9% and 30.9%, respectively. High-risk HPV (HR-HPV) was detected in 57.3% of anal samples and 20.9% of urine samples. Among 122 adequate cytological samples, anal cytological abnormalities were observed in 99 cases (81.1%). Anal cytological tests revealed that atypical squamous cells of an undetermined significance (ASCUS) were detected in 57 (46.7%) patients, followed by low-grade squamous intraepithelial lesions (SIL) in 35 (28.7%), high-grade SIL in five (4.1%), and atypical squamous cells cannot exclude high-grade SIL (ASC-H) in two (1.6%), respectively. The nadir counts of CD4-positive T-lymphocyte less than 200 µL and anal HR-HPV infection were independent risk factors for anal cytological atypia over ASC-H. CONCLUSIONS: The present study demonstrated high HPV prevalence in the anus and urine, and showed a high incidence of anal cytological atypia associated with HR-HPV infections among HIV-infected MSM patients.

Identification of Novel Recombinant Forms of Hepatitis B Virus Generated from Genotypes Ae and G in HIV-1-Positive Japanese Men Who Have Sex with Men.

The rare hepatitis B virus (HBV) genotype G (HBV/G) coinfects HIV-1-positive individuals along with HBV/A and generates recombinants. However, the circulation of HBV A/G recombinants remains poorly understood. This molecular epidemiologic study examined HBV A/G recombinants in Japanese HIV-1-positive men who have sex with men (MSM). Initially, blood specimens submitted for confirmatory tests of HIV infection in Osaka and Tokyo, Japan, from 2006 to 2013 were examined for HIV-1, and HIV-1-positive specimens were screened for HBV. Among 817 specimens from HIV-1-positive individuals, HBsAg was detected in 59 specimens; of these, HBV/Ae (alternatively A2), a subgenotype of HBV/A prevalent in Europe and North America, was identified in 70.2%, HBV/C in 17.5%, and HBV/G in 10.5%, and HBV/E in 1.8% according to the core gene sequence. The full-length genome analysis of HBV was performed on HBV/G-positive specimens because some HBV A/G recombinants were historically overlooked by genotyping based on a partial genome analysis. It revealed that five of the specimens contained novel Ae/G recombinants, the core gene of which had a high sequence similarity to HBV/G. Detailed analyses showed that novel recombinants were coinfected with HBV/Ae in a recombinant-dominant fashion. No major drug-resistant mutations were found in the newly identified HBV Ae/G recombinants. Some of the individuals asymptomatically coinfected with HIV/HBV suffered mild liver injury. This study demonstrated that novel Ae/G HBV recombinants were identified in Japanese HIV-1-positive MSM. The pathogenicity of novel HBV Ae/G recombinants should be examined in a future longitudinal study. Surveillance of such viruses in HIV-1-positive individuals should be emphasized.

[Evaluation of the serological response to syphilis treatment using an automated RPR test].

We evaluated the clinical usefulness of serological monitoring with an automated rapid plasma reagin (RPR) test in syphilis patients. Serum samples were obtained from 68 syphilis patients, including 57 cases infected with human immunodeficiency virus (HIV) from our clinic between February 2010 and May 2012. RPR titers were measured with both the conventional serial dilution manual method and the automated method before (baseline) and at several intervals after treatment. The criteria of a cure were defined based on RPR titers as equal to and/or more than a 4-fold decrease (with the manual method) or by RPR values lowered to the level of equal and/or less than 25% (with the automated method) within 6 months in comparison with baseline values. A serological cure was observed in 19 (95%) and 17 (85%) of the 20 cases with the manual method and the automated method after 6 months, respectively. For the other 3 cases, the RPR value ratios with the automated method were 25.4%, 25.9% and 37.9%. Among all 68 patients, 9 cases (13.2%) did not meet the criteria for a cure by both methods within 6 months, but all cases did within 12 months. The ratio of RPR values after several months against that of baseline was evaluated with a t-test; the RPR values with the automated method were significantly lower than those obtained with the manual method (p < 0.05), especially at 1 and 2 months (p < 0.01). The RPR value ratios of HIV-positive cases were significantly higher 1 and 2 months after (with the manual method) and 1 month after (with the automated method) than those of HIV-negative cases; however, no statistical significance was observed after 6 months between the RPR ratio of HIV-positive and HIV-negative cases. Based on these results, we infer that the RPR test with the automated method can be used in the same manner as the manual method for treatment monitoring of HIV-positive and HIV-negative syphilis patients, especially in the early phase of treatment.

[Prevalence of HIV and sexually transmitted infections and characteristics of men who have sex with men at a community-based center in Yokohama, Japan].

OBJECTIVES: To investigate the characteristics of men who have sex with men (MSM) in a sample of men who sought voluntary testing and counseling (VCT) for human immunodeficiency virus (HIV) and sexually transmitted infections (STIs) in a community-based center in Yokohama, Japan. The prevalence of HIV/STIs and the incidence rate of HIV were also assessed. METHODS: We investigated VCT records of 449 clients who received free anonymous night VCT services between 2008 and 2011. The tests included rapid HIV antibody, Treponema pallidum antibody (TP Ab), and hepatitis B surface antigen (HBs Ag) tests. We also analyzed VCT records of 82 clients who had at least two tests at our center to estimate the HIV incidence rate. RESULTS: The number of MSM who visited the community center for the first time was 423. Those who resided in Kanagawa Prefecture accounted for 78.5% of the sample, and 30.5% had never been tested for HIV previously. The rate of consistent condom use in the past six months was 44.9%. The results revealed that 3.1%, 10.2%, and 1.7% of MSM tested positive for HIV, TP Ab, and HBs Ag respectively. There was no significant difference in age, residence, previous HIV-testing rates, and the rate of consistent condom use in the past six months between subjects who underwent multiple HIV tests at the community center and those who did not undergo any test after the first visit. HIV-positive individuals were all referred to hospitals nearby. Of 82 repeat HIV testers, one was a seroconverter, indicating an incidence rate of 1.00 per 100 person-years (95% confidence interval, 0.00-5.58). CONCLUSION: Our VCT services were accepted by MSM with a high risk of HIV/STIs infection. HIV prevalence was higher than that at local health centers. The HIV incidence rate was equivalent to the previous study that estimated HIV incidence rate from national and sentinel surveillance data. Creating and sustaining alternative VCT venues targeting MSM with high risk of HIV/STIs infection should be considered in other prefectures in Japan to facilitate the early detection and treatment of HIV/STIs.

[Evaluation of a new vesion of the human immunodeficiency virus antigen and antibody combination assay with improved sensitivity in HIV-1 p24 antigen detection].

The performance of a new version of the HIV p24 antigen and antibody combination assays (Genscreen Ultra HIV Ag-Ab) was evaluated by comparing it with three other fourth-generation enzyme immunoassays (Architect HIV Ag/Ab Combo assay, VIDAS HIV DUO Quick and Genscreen Plus HIV Ag-Ab). The assays were examined with 200 HIV positive samples, 1,000 HIV negative samples, 30 samples (28 positives including 24 samples of subtype A, B, B', C, D, F, G, B/D, CRF01_AE in HIV-1 group M, one sample of HIV-1 group O, three samples of HIV-2 and two negatives) of one worldwide HIV performance panel, 59 samples of ten HIV-1 seroconversion panels and the WHO international standard HIV-1 p24 antigen. Both the sensitivity and specificity of Genscreen Ultra HIV Ag-Ab were 100%. All of the 28 positive samples in the worldwide HIV performance panel were positive. The days of the earliest detection in the ten seroconversion panels were the same in three assays (Genscreen Ultra HIV Ag-Ab, Architect HIV Ag/Ab combo assay and VIDAS HIV DUO Quick). Genscreen Plus HIV Ag-Ab which is a former version of the Genscreen Ultra HIV Ag-Ab detected the earliest positive sample one bleed slower than the other three assays in 5 of 10 seroconversion panels. The p24 antigen limit of detection was determined in two ways, using the WHO international standard and three samples from HIV-1 antigen panels; the values obtained were 1IU/mL and 3.5-9.9 pg/mL for Genscreen Ultra HIV Ag-Ab, 1U/mL and 7.1-9.9 pg/mL for Architect HIV Ag/Ab combo assay, 0.5IU/mL and 4.0-7.1 pg/mL for VIDAS HIV DUO Quick, and 32.0-56.5 pg/mL for Genscreen Plus HIV Ag-Ab. In this study, we have shown that Genscreen Ultra HIV Ag-Ab has the sensitivity, specificity and p24 antigen limit of detection that is equal to those of two typical fourth-generation assays. This assay can be considered useful and reliable for HIV screening.

Switching tenofovir/emtricitabine plus lopinavir/r to raltegravir plus Darunavir/r in patients with suppressed viral load did not result in improvement of renal function but could sustain viral suppression: a randomized multicenter trial.

BACKGROUND: Whether tenofovir nephrotoxicity is reversible after its withdrawal is unknown. Furthermore, there are no data on the viral efficacy of raltegravir (RAL) plus ritonavir-boosted Darunavir (DRV/r) in patients with suppressed viral load. METHODS: This multicenter, randomized trial compared renal function and viral efficacy in patients with suppressed viral load treated with RAL+DRV/r and ritonavir-boosted lopinavir (LPV/r) plus tenofovir/emtricitabine (TVD), who had been previously on LPV/r+TVD. The primary endpoint was the proportion of patients with >10% improvement in estimated glomerular filtration rate (eGFR) at 48 weeks calculated with Cockcroft-Gault equation. RESULTS: 58 randomized and treatment-exposed patients were analyzed (28 on RAL+DRV/r and 30 on LPV/r+TVD). Greater than 10% improvement in eGFR was noted in 6 (25%) out of 24 with RAL+DRV/r and 3 (11%) of 28 with LPV/r+TVD, and the difference was not statistically significant (p=0.272, 95% CI -0.067 to 0.354). Sensitivity analyses using three other equations for eGFR showed the same results. Urinary ß2 microglobulin, a sensitive marker of tenofovir tubulopathy, significantly improved with RAL+DRV/r than with LPV/r+TVD (-271 versus -64 µg/gCr, p=0.026). Per protocol analysis showed that the HIV-RNA was <50 copies/mL at week 48 in all patients of both arms (24 in RAL+DRV and 29 in LPV/r+TVD). CONCLUSIONS: Switching LPV/r+TVD to RAL+DRV/r did not significantly increase the proportion of patients who showed >10% improvement in renal function among those with relatively preserved eGFR. However, the switch improved urinary ß2 microglobulin, suggesting that discontinuation of TDF might be beneficial in the long-term. RAL+DRV/r showed favorable viral efficacy in patients with suppressed viral load. TRIAL REGISTRATION: ClinicalTrials.gov NCT01294761 http://clinicaltrials.gov/ct2/show/NCT01294761?term=SPARE&rank=2, Umin Clinical Trials Registry UMIN000005116 http://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000006083&language=J).

Emergence in Japan of an HIV-1 variant associated with transmission among men who have sex with men (MSM) in China: first indication of the International Dissemination of the Chinese MSM lineage.

A survey of HIV-1 strains circulating in the Tokyo-Kanagawa metropolitan area of Japan during 2004 to 2011 (n = 477) identified six Japanese males (patients 1 to 6), who harbored viruses with genome segments derived from a distinct CRF01_AE variant uniquely found among men who have sex with men (MSM) in China (designated CN.MSM.01-1). These six HIV infections were diagnosed in 2010 and 2011 among MSM (3 of 75) and men with unknown risk factors (3 of 63) and differed from the vast majority of HIV infections among MSM in Japan, which are overwhelmingly characterized by subtype B (239 of 246 [97.2%]). Approximately one-third (91 of 239 [38.1%]) of subtype B strains from MSM in Japan belong to a large monophyletic cluster (designated JP.MSM.B-1). In addition, we identified a smaller subtype B cluster (n = 8) (designated JP.MSM.B-2) that also contains strains from two Chinese MSM living in Japan. Interestingly, patients 5 and 6 were found to be coinfected with CRF01_AE (CN.MSM.01-1) and subtype B (JP.MSM.B-2 or JP.MSM.B-1) variants that are unique to the HIV-1 epidemics among MSM in China and Japan, respectively. Our study demonstrates for the first time the effect of the expanding HIV epidemic among MSM in China on transmission in neighboring countries and shows the ongoing mixing of CRF01_AE and subtype B lineages unique to HIV-1 that cocirculate in MSM populations in East Asia. This finding highlights the importance of strengthening epidemiological surveillance in the region and the need for effective measures to limit transmission among MSM in East Asia.

[Japanese HIV-infected men who have sex with men screened for anal intraepithelial neoplasia].

The prevalence of and the risk factors for abnormal anal cytology among Japanese men who have sex with men (MSM) who have human immunodeficiency virus (HIV) infection have not been fully investigated up to now. We conducted a nested case-control study of 81 HIV-infected Japanese MSM treated with antiretroviral therapy at a sexuality minority affirmative clinic between April 2010 and March 2011. Results showed that 41 (50.6%) of the 81 had normal anal cytology, 13 (16.0%) atypical squamous cells, 24 (29.6%) low-grade squamous intraepithelial lesions, and 3 (3.7%) high-grade squamous intraepithelial lesions. No carcinoma cases were seen. Multivariate analysis showed abnormal anal cytology to be associated with a history of genital condyloma (OR 4.19, p = .021). We concluded that abnormal anal cytology was common among HIV-infected Japanese MSM. Effective screening and management should be planned for precancerous anal lesions.

Plasmodium vivax PCR genotyping of the first malaria case imported from South Korea into Japan.

Although indigenous malaria was successfully eradicated in Japan in 1959, malaria remains one of the most important health concerns in the control of imported infectious diseases. However, in South Korea, the re-emergence of indigenous vivax malaria was reported in 1993 in the Demilitarized Zone (the border region with North Korea), from where a vivax malaria case was imported into Japan in 2002. In this study, we conducted genotyping of the circumsporozoite protein gene, the apical membrane antigen-1 gene, and the merozoite surface protein-1 gene of Plasmodium vivax in one patient, and estimated the geographical origin of the parasites. This estimate was based on the findings of previous studies, which showed the coexistence of at least two distinct genotypes of antigenic molecules of endemic P. vivax in South Korea. One genotype is similar to that of a Chinese strain CH-5, and the other is similar to that of a North Korean isolate. The results of this study showed that the DNA sequences of the patient's P. vivax parasites were similar to those of the North Korean isolate. It may even be possible in the near future for seasonally synchronized North Korean P. vivax parasites to be imported into parts of Japan and to establish breeding populations.

Clinical features of 62 imported cases of dengue fever in Japan.

To describe the clinical features of dengue cases in Japan, a retrospective study was conducted on 62 laboratory-confirmed Japanese dengue cases presented to Tokyo Metropolitan Komagome Hospital between 1985 and 2000. Age distribution was from 18 to 62 years old (mean, 31.5 years). All cases were imported from abroad and diagnosed as dengue fever. Clinical manifestations included fever (100%), headache (90%), and skin rash (82%). Laboratory examinations revealed leukocytopenia (71%), thrombocytopenia (57%), elevated levels of serum aspartate aminotransferase (78%), and lactate dehydrogenase (71%). Antibody responses were consistent with that of secondary flavivirus infection in 60% of cases. Severity of symptoms in patients with primary dengue antibody response and those with secondary flavivirus antibody responses didn't show statistical significance. Dengue virus infection should be taken into consideration in the differential diagnosis of febrile patients who recently entered Japan from tropical or subtropical countries.

A case of symptomatic primary HIV infection.

A 30-year-old homosexual Japanese man had fourteen days of fever, malaise, appetite loss, sore throat, and four days of diarrhea and slightly congested eyes before he developed a skin eruption. He presented with measles-like exanthems on his face, trunk, and extremities. Deep red enanthems were seen on his left buccal mucosa opposite the premolar teeth, and whitish enanthems were seen on the buccal and gingival mucosa. HIV RNA was detected at the high concentration of 5.8 x 10(6) copies /ml in his serum. Cerebrospinal fluid examination revealed aseptic meningitis with 5,488 copies /ml of HIV RNA. Anti-HIV 1 antibodies against Gp160 and p24 tested by Western blot assay showed seroconversion on day 5 of his admission, seven days after he developed the skin eruptions. The fever lasted for three weeks from the initial onset, and the skin eruptions lasted for twelve days. Histopathologically, a mononuclear cell infiltration was seen mainly in the upper dermis surrounding small vessels and sweat ducts, with CD8+ cytotoxic T lymphocytes predominant. Additionally, CD1a+ putative interdigitating dendritic cells had also infiltrated perivascularly, and were surrounded by CD8+ and CD4+ T cells. In situ hybridization study failed to detect HIV products in skin biopsy specimens. Our findings suggested that CD8+ T cells and their interaction with CD1a+ dendritic cells in the skin may be important in inducing skin manifestations in acute HIV infections.