Rapid response to a COVID-19 outbreak at a nightclub in Kagoshima prefecture, Japan, in the early phase of the COVID-19 pandemic, June and July 2020: A descriptive epidemiological study.

INTRODUCTION: During COVID-19 pandemic in Japan, nightclubs were identified as high-risk locations for COVID-19 outbreaks, but an outbreak investigation in this setting is challenging because of the anonymous and opportunistic nature of interactions. METHODS: The joint rapid response team collected epidemiological data, conducted descriptive epidemiology to determine the characteristics of cases associated with the nightclub, and implemented countermeasures. Polymerase chain reaction (PCR) tests were performed by the Local Institute of Public Health, Kagoshima University, and several commercial laboratories. RESULTS: Between June 15 and July 20, 2020, 121 individuals tested positive for SARS-CoV-2 (59 confirmed and 62 asymptomatic) of whom 8 were nightclub staff who had no travel history of outside Kagoshima, 66 were guests, and 47 were subsequent contacts. The median age was 32 years (interquartile range: 24-43 years). One individual showed severe symptoms but there were no fatal. The epidemic curve showed one peak on June 30 and July 1 with a limited number of cases subsequently. Of the 121 cases, 116 and 5 were in individuals living in and outside Kagoshima Prefecture, respectively. Haplotype network analysis showed 5 genome-wide single-nucleotide variants between the isolates before and during this outbreak. CONCLUSIONS: There is a possibility that unidentified guests from outside Kagoshima Prefecture could infect staff who could subsequently spread the virus to guests and other staff, who were mainly a younger population. The rapid outbreak response enabled onward transmission in the community to be minimized. This outbreak investigation could provide insights for effective responses to challenging situations in future pandemic.

A highly attenuated vaccinia virus strain LC16m8-based vaccine for severe fever with thrombocytopenia syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) caused by a species Dabie bandavirus (formerly SFTS virus [SFTSV]) is an emerging hemorrhagic infectious disease with a high case-fatality rate. One of the best strategies for preventing SFTS is to develop a vaccine, which is expected to induce both humoral and cellular immunity. We applied a highly attenuated but still immunogenic vaccinia virus strain LC16m8 (m8) as a recombinant vaccine for SFTS. Recombinant m8s expressing SFTSV nucleoprotein (m8-N), envelope glycoprotein precursor (m8-GPC), and both N and GPC (m8-N+GPC) in the infected cells were generated. Both m8-GPC- and m8-N+GPC-infected cells were confirmed to produce SFTSV-like-particles (VLP) in vitro, and the N was incorporated in the VLP produced by the infection of cells with m8-N+GPC. Specific antibodies to SFTSV were induced in mice inoculated with each of the recombinant m8s, and the mice were fully protected from lethal challenge with SFTSV at both 103 TCID50 and 105 TCID50. In mice that had been immunized with vaccinia virus strain Lister in advance of m8-based SFTSV vaccine inoculation, protective immunity against the SFTSV challenge was also conferred. The pathological analysis revealed that mice immunized with m8-GPC or m8-N+GPC did not show any histopathological changes without any viral antigen-positive cells, whereas the control mice showed focal necrosis with inflammatory infiltration with SFTSV antigen-positive cells in tissues after SFTSV challenge. The passive serum transfer experiments revealed that sera collected from mice inoculated with m8-GPC or m8-N+GPC but not with m8-N conferred protective immunity against lethal SFTSV challenge in naïve mice. On the other hand, the depletion of CD8-positive cells in vivo did not abrogate the protective immunity conferred by m8-based SFTSV vaccines. Based on these results, the recombinant m8-GPC and m8-N+GPC were considered promising vaccine candidates for SFTS.

Development of an assay for detecting the residual viable virus in inactivated rabies vaccine by enzyme-linked immunosorbent assay.

Rabies is a zoonotic disease that can be prevented by vaccination. The confirmation of rabies virus inactivation is a critical step during the vaccine quality test; however, the current protocol conducted in Japan requires a large number of mice. The development and introduction of animal-free alternative assays are essential from the perspective of the 3Rs (reduction, refinement, and replacement) of animal testing. Here, we propose a novel inactivation assay for confirming the complete inactivation of the viable rabies virus using cultured Neuro-2a cells and an enzyme-linked immunosorbent assay (ELISA). The detection ability of ELISA was similar to that of a direct immunofluorescence assay, with the detection limit of ELISA being as low as 0.014 focus forming units/test. These results suggest that the assay could be used as a viral inactivation test. In comparison with a traditional in vivo assay, this assay has a higher detection ability, an objective interpretation, and would shorten the test duration from 25 days to 8 days.

Severe Fever with Thrombocytopenia Syndrome, Japan, 2013-2017.

We conducted an epidemiologic study of severe fever with thrombocytopenia syndrome (SFTS) in Japan during 2013-2017. Of 303 cases reported during that period, 133 (44%) were included in this study. The median time between onset of illness and diagnosis of SFTS shortened, from 11.5 to 3.0 days, but the case-fatality rate remained high, at 27%. In 64 patients (48%), a close contact with companion animals was reported within 2 weeks of disease onset. Of these 64 patients, 40 were surveyed further, and we confirmed that 3 had direct contact with body fluids of ill companion animals; 2 had direct contact with the saliva of an ill feral cat or pet dog. These patients reported no history of tick bite, suggesting that ill companion animals might be a source of SFTS virus transmission. Direct contact with the body fluids of ill companion animals should be avoided.

Seroprevalence of Jamestown Canyon virus in the Japanese general population.

BACKGROUND: Jamestown Canyon virus (JCV) is a mosquito-borne orthobunyavirus that causes acute febrile illness, meningitis, and meningoencephalitis, mainly among adults. JCV is widely distributed in North America and the number of JCV cases in the U.S. has increased in recent years. Therefore, the central nervous system disease caused by JCV can be considered a potentially re-emerging viral disease. However, the seroprevalence of JCV is unknown in Japan. The purpose of this study is to evaluate the seroprevalence of JCV in the Japanese population. METHODS: We used an IgG enzyme-linked immunosorbent assay (IgG-ELISA) with JCV-infected cell-lysates and/or a neutralizing (NT) antibody assay. The cut-off value of IgG-ELISA was determined using IgG-ELISA to analyze serum specimens from 37 healthy Japanese donors. IgG-ELISA was validated by assessing its sensitivity and specificity, using 38 human serum samples previously tested for the presence or absence of antibodies against JCV and snowshoe hare virus (SSHV), in an in-house NT antibody assay conducted by the Public Health Agency of Canada. The seroepidemiological study was performed using IgG-ELISA and NT antibody assay to analyze 246 human serum samples from the serum bank of the National Institute of Infectious Diseases (NIID) in Japan. RESULTS: The cut-off value of IgG-ELISA was determined at 0.20, based on the mean (- 0.075) and standard deviation (0.092) values using Japanese donors' sera. The sensitivity and the specificity of IgG-ELISA determined using 25 JCV-positive and 4 JCV-negative serum samples were 96 and 100%, respectively. Analysis of the 246 Japanese serum samples revealed that no specimen showed a higher value than the cut-off value of IgG-ELISA, and no sample tested positive by the NT antibody assay. CONCLUSIONS: Our results showed that JCV is not circulating significantly in Japan. To the best of our knowledge, this is the first report to demonstrate the seroprevalence of JCV in the general population in Japan.

A shigellosis outbreak associated with a sports festival at a kindergarten in Kitakyushu City, Japan.

INTRODUCTION: Shigellosis cases have decreased gradually in Japan in recent years, but indigenous shigellosis outbreaks sometimes occur in childcare facilities. From national surveillance data, we identified a shigellosis outbreak involving a kindergarten. METHODS: After detecting Shigella sonnei in Kitakyushu City, we conducted active case finding and epidemiological investigation in Kindergarten Z, including stool specimen collection and interviews. The stool specimens were cultured, and isolated strains were subjected to pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem-repeat analysis (MLVA). RESULTS: Between September 1 and December 31, 2014, we identified 19 cases: 14 confirmed, 2 suspected, and 3 asymptomatic. Of the 19 cases, 16 were epidemiologically associated with Kindergarten Z (10 pupils, 5 family members, and 1 teacher). On October 19, a pupil with gastrointestinal illness participated in the kindergarten's sports festival, in which the pupils were split into "red" and "white" teams; the pupil in question belonged to the red team. Attack rates of the red and white teams were 8% (7/82) and 0% (0/108), respectively (relative risk, 10.5; 95% confidence interval, 1.3-82.1). PFGE patterns were identical or similar for the isolates in all 17 cases; 7 isolates were identical, and the others had one locus difference on MLVA. CONCLUSIONS: We concluded that contact during the sports festival could have been responsible for spread of the shigellosis outbreak at the kindergarten, although the infection source was not determined. It is vital to inform guardians immediately after detection of shigellosis cases that symptomatic pupils should not participate in activities such as sports festivals.

Differences in the Likelihood of Acyclovir Resistance-Associated Mutations in the Thymidine Kinase Genes of Herpes Simplex Virus 1 and Varicella-Zoster Virus.

Acyclovir (ACV) resistance-associated mutations in two recombinant herpes simplex virus 1 (HSV-1) clones were compared. Recombinant HSV-1 lacking its thymidine kinase (TK) and expressing varicella-zoster virus (VZV) TK ectopically had no mutations in the VZV TK gene. In contrast, recombinant HSV-1 expressing HSV-1 TK ectopically harbored mutations in the HSV-1 TK gene. These results suggest that the relatively low frequency of ACV-resistant VZV is a consequence of the characteristics of the TK gene.

In vitro evaluation of minimum inhibitory concentration of several antibacterial agents against Rickettsia japonica using a plaque reduction assay system.

The study was conducted to determine the minimum inhibitory concentrations (MICs) of several antibacterial agents against Rickettsia japonica, which causes Japanese spotted fever. A plaque reduction assay as an in vitro culture method was conducted to determine the MICs of antibacterial agents (4 types of tetracyclines: tetracycline, doxycycline, minocycline, and tigecycline; 3 types of quinolones: ciprofloxacin, ofloxacin, and levofloxacin; and 2 types of macrolides: azithromycin and clarythromycin) against R. japonica. R. japonica was sensitive to the antibacterial agents tested with MICs similar to those against other spotted fever rickettsia determined in previously described plaque reduction assays.

[Murine typhus in a Japanese traveler returning from Indonesia: a case report].

We report herein on a 20-year-old Japanese man who was referred to our hospital for fever and diarrhea after returning from Indonesia. On admission, his blood test was essentially normal, besides a slight elevation in inflammatory markers. After excluding malaria and dengue fever, empiric use of ceftriaxone was initiated for suspected enteric fever, which was unsuccessful. However, drastic clinical improvement was observed after initiation of minocycline. The polymerase chain reaction test for Rickettsia typhi was positive from serum samples on admission, confirming the diagnosis of murine typhus. Although rarely seen in Japan, clinicians should be aware of this disease when examining patients with fever coming back from murine typhus endemic areas.

An outbreak of SARS-CoV-2 omicron variant and deaths of three lions in a zoo.

There have been reports of the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from humans to various mammalian species. Some infected animals show clinical signs and may even die in rare cases. Outbreaks of SARS-CoV-2 have been reported in zoos where susceptible animals are bred in high population densities. However, there have been few reports of omicron variant outbreaks in zoo animals. From late 2022 to 2023, an outbreak of the SARS-CoV-2 omicron variant occurred in one Japanese zoo. A total of 24 lions were housed in the zoo; 13 of them showed respiratory symptoms, and the three oldest lions died. Molecular and histopathological analyses revealed that the deceased lions were infected with SARS-CoV-2 omicron BF.7.15. Virus-neutralization tests showed that all 21 lions were positive for antibodies against the omicron variant, but not against the delta variant. In addition, three tigers and one bear in the same or neighboring building as the lions possessed antibodies against the omicron variant. This is a very rare report on the outbreak of a SARS-CoV-2 omicron variant infection that resulted in the death of animals. This finding demonstrates the importance of continuous countermeasures to protect non-vaccinated animals from SARS-CoV-2 infection.

Undermining incision and healing of deep pressure ulcers: a prospective cohort study of pressure ulcers by the Japanese national hospital organization.

Undermining is one of the most challenging complications of deep pressure ulcers. Recommendations in most guidelines are based only on expert opinions. Here, we examined the relationship between surgical incision of the undermined space and pressure ulcer healing through a Japanese multicenter prospective cohort study. A total of 162 patients with undermining in 40 national hospitals in Japan were enrolled from July 2007 to June 2009. The incision group included 39 patients (24.1%) whose undermining was surgically incised during the observational period. Their 4-week follow-up data on pressure ulcer severity and areas of healthy granulation tissue were recorded as outcome variables using the DESIGN-R pressure ulcer assessment tool. The 4-week follow-up was restarted after the incision in the incision group. The outcome variables over time were compared between the two groups using a linear mixed model with or without adjustment for demographic and other variables. The incision group showed more rapid improvement in the total and granulation DESIGN-R scores compared with the nonincision group (p < 0.001 and p = 0.007, respectively, in the crude models). This study may provide the first considerable evidence to support that surgical incision of undermining may promote healing of deep pressure ulcers.

Risk factors and risk scoring tool for infection during tissue expansion in tissue expander and implant breast reconstruction.

Tissue expander and implant (TE/I) breast reconstruction has been increasing recently. In TE/I breast reconstruction, infection leads to reconstruction failure and is the most serious complication. The infection rate was reported to be higher during the tissue expander period than the implant period. However, few studies have investigated the risk factors for infection during tissue expansion following TE/I breast reconstruction. The goal of this study was to identify risk factors for infection during tissue expansion in TE/I breast reconstruction and to develop a simple risk scoring tool for infection that can be used for clinical application. In this retrospective cohort study, 981 patients who received TE/I breast reconstruction were surveyed and analyzed at one of the main clinics performing TE/I breast reconstruction in Japan. Numerous potential risk factors were collected from the clinical charts. Multiple logistic regression analyses were used to identify risk factors for infection. To develop a risk scoring tool, we converted the coefficients of the identified predictors estimated in the multiple logistic regression analyses into simplified risk scores. We assessed the tool discrimination by drawing a receiver operating characteristic curve and calculating the area under the curve. Infection was noted in 47 patients (4.79%) during tissue expansion. In multiple logistic regression analyses, diabetes, repeated expander insertions, larger expander size (≥400 cc), postoperative hormone therapy before silicone implant surgery, preoperative chemotherapy, and nipple-sparing mastectomy were identified as risk factors for infection during expansion. The area under the curve of the risk scoring tool for infection was 0.734 (95% CI: 0.662-0.807). We have revealed risk factors and proposed a risk scoring tool for infection during tissue expansion in TE/I breast reconstruction. This study may contribute to the prevention and prediction of infection.

[Medical study of cases diagnosed as rubella in adults].

BACKGROUND: In 2012, the number of rubella cases sharply increased in Japan. It continued to rise in 2013. Between October 2012 and May 2013, 10 cases of congenital rubella syndrome (CRS) were reported nationwide. This current rubella outbreak comprised mainly males who were between 20 to 39 years of age, and had not received the rubella vaccine. Data have been lacking on the clinical characteristics of adults infected with the rubella virus. METHODS: Using medical charts, we collected data from 27 patients who were diagnosed with clinically or laboratory-confirmed rubella infection at Tokyo Metropolitan Komagome Hospital from January 2012 to April 2013. RESULTS: Of the 27 patients studied, their median age was 34.5 years and 70.4% were male between 21-56 years of age. For the 11 cases with known vaccination status, 9 (81.8%) occurred in persons who had not received a rubella vaccine. A total of 33.3% of the patients were hospitalized, due to persistent fever, poor oral intake, or dehydration. Major clinical symptoms were fever (96.3% of cases), lymphadenopathy (92.6%), rash (85.2%), conjunctivitis (77.8%), and headache (63.0%). The mean duration of fever was 5 days (range, 3-9). The exanthema consisted of punctate, pink maculopapules; however, the rash became confluent in 37.0%, and pigmented in 18.5% of the patients. Initial laboratory data were as follows:white cells, 3,800/microL (range: 2,000-8,300); platelets, 129,000/microL (range, 63,000 - 230,000); aspartate aminotransferase, 27IU/L (range, 16 - 49); lactase dehydrogenase, 279IU/L (range, 168-440) [all described in medians]. Rubella-specific immunoglobulin M antibodies from the serum sample obtained at the initial visit were detected in 17 cases (65.4%). Likewise, measles-specific immunoglobulin M antibodies were detected in 7 cases (26.9%), all of which were false-positive. CONCLUSIONS: The clinical characteristics of rubella in adults resembled measles in some part, which may cause difficulty for physicians to differentiate between the two diseases. Vaccinating rubella-susceptible individuals now is critical to interrupt rubella virus transmission, and to prevent further CRS cases.

[A case of severe Legionella pneumonia in which survival was achieved without sequelae with the use of extracorporeal membrane oxygenation (ECMO)].

A 54-year-old man presented with fever and dyspnea about a week before his admission. We diagnosed Legionella pneumonia from his chest X-ray imaging which showed bilateral lobe consolidation excluding the left upper lobe, and his sputum culture yielded Legionella pneumophilla serogroup 1. Combination therapy with levofloxacin and rifampin was started on admission. However, the patient developed severe acute respiratory distress syndrome (ARDS) and then extracorporeal membrane oxygenation (ECMO) was initiated on the 2nd day. His respiratory status gradually improved after that and he was weaned from ECMO on the 7th day. He was discharged without sequelae on the 36th day. The outcome suggests that use of ECMO should be considered for patients with severe Legionella pneumonia.

Evaluation of a novel severe combined immunodeficiency mouse model for antiviral drug evaluation against Chandipura virus infection.

Chandipura virus (CHPV) is a negative-sense single-stranded RNA virus known to cause fatal encephalitis outbreaks in the Indian subcontinent. The virus displays tropism towards the pediatric population and holds significant public health concerns. Currently, there is no specific, effective therapy for CHPV encephalitis. In this study, we evaluated a novel C.B-17 severe combined immunodeficiency (SCID) mouse model which can be used for pre-clinical antiviral evaluation. Inoculation of CHPV developed a lethal infection in our model. Plaque assay and immunohistochemistry detected increased viral loads and antigens in various organs, including the brain, spinal cord, adrenal glands, and whole blood. We further conducted a proof-of-concept evaluation of favipiravir in the SCID mouse model. Favipiravir treatment improved survival with pre-symptomatic (days 5-14) and post-symptomatic (days 9-18) treatment. Reduced viral loads were observed in whole blood, kidney/adrenal gland, and brain tissue with favipiravir treatment. The findings in this study demonstrate the utility of SCID mouse for in vivo drug efficacy evaluation and the potential efficacy of favipiravir against CHPV infection.

Specific COVID-19 risk behaviors and the preventive effect of personal protective equipment among healthcare workers in Japan.

As coronavirus disease 2019 (COVID-19) outbreaks in healthcare facilities are a serious public health concern, we performed a case-control study to investigate the risk of COVID-19 infection in healthcare workers. We collected data on participants' sociodemographic characteristics, contact behaviors, installation status of personal protective equipment, and polymerase chain reaction testing results. We also collected whole blood and assessed seropositivity using the electrochemiluminescence immunoassay and microneutralization assay. In total, 161 (8.5%) of 1,899 participants were seropositive between August 3 and November 13, 2020. Physical contact (adjusted odds ratio 2.4, 95% confidence interval 1.1-5.6) and aerosol-generating procedures (1.9, 1.1-3.2) were associated with seropositivity. Using goggles (0.2, 0.1-0.5) and N95 masks (0.3, 0.1-0.8) had a preventive effect. Seroprevalence was higher in the outbreak ward (18.6%) than in the COVID-19 dedicated ward (1.4%). Results showed certain specific risk behaviors of COVID-19; proper infection prevention practices reduced these risks.

Determining the optimal inner air cell pressure for the effective reduction of interface pressure.

Alternating-pressure air mattresses can reduce interface pressure and prevent pressure ulcer development. However, bottoming out sometimes occurs, resulting in an increase in interface pressure. Therefore, optimal settings should be determined based on interface pressures and inner air cell pressures. The purpose of this study was to investigate the most effective inner air cell pressure to reduce interface pressure without causing bottoming out. A new alternating air mattress was used, which comprised three layers: a base layer, fitting (F) layer, and alternating layer. The alternating layer comprises inflated (I) cells and deflating (D) cells. The study participants were 13 healthy volunteers over 18 years of age, each of whom adopted supine position on the mattress. The pressures in the D cells were gradually deflated under different I cell and F layer pressure settings. We measured peak sacral pressure and inner air cell pressure to obtain the bottoming out cut-off values by using receiver-operating-characteristic (ROC) curves. We then investigated the effectiveness of different settings to reduce the peak sacral pressures. A number of test conditions were evaluated. Results indicated that the D cell pressure cut-off points were 1.26 kPa and 1.21 kPa, for phases 1 (F = 4 kPa, I = 4 kPa) and 4 (F = 1 kPa, I = 4 kPa), respectively. These settings significantly reduced the interface pressure (P < 0.001, P = 0.026, respectively). Our results suggest that appropriate configuration of inner air cell pressure could reduce interface pressure without causing bottoming out.

[Refractory AIDS-associated Kaposi's sarcoma treated successfully with paclitaxel: a case report].

We report a case of a 45-year-old Japanese man with AIDS-associated Kaposi's sarcoma (KS) involving skin, liver, and lungs. Antiretroviral therapy was started in conjunction with pegylated liposomal doxorubicin (PLD). A clinical response was observed initially, but symptoms recurred following cessation of medication. The chemotherapeutic agent was changed to paclitaxel (PTX), since the therapeutic response to PLD was reduced and the total dose reached the maximum dose of 500 mg/m2. The patient had a good response to PTX and tolerated the medication well. Symptoms did not recur after completing 8 courses of chemotherapy. PTX should be considered as an alternative agent in treating KS when there are problems with the use of PLD.

A sting in the tail: An embedded stingray spine in a mid-1st millennium AD adult male skeleton from Rebun Island, Hokkaido, Japan.

OBJECTIVES: We report here a stingray spine (Dasyatidae) found embedded in the femur of a male skeleton from the archaeological site of Uedomari-5, Rebun Island, Hokkaido, Japan. MATERIALS: A single well-preserved but incomplete human skeleton. METHODS: Macroscopic observation and low power magnification, CT imaging, radiocarbon dating and stable isotope (carbon, nitrogen) analysis. RESULTS: The stingray spine is tentatively identified as Bathytoshia brevicaudata. CT imaging shows no healing, indicating that death occurred shortly afterwards. The skeleton has been directly radiocarbon dated to the Okhotsk period (cal AD 429-827), with δ13C (-13.7‰) and δ15N (19.3‰) values indicating a diet focused on marine foods. CONCLUSIONS: The absence of healing in what would have been a non-lethal injury strongly suggests that the spine tipped an arrowhead, rather than being the result of an accidental encounter with a living stingray. It is possible that the injury reflects a period of increased conflict coinciding with, or following on from, the expansion of the Okhotsk culture from Sakhalin into northern Hokkaido. SIGNIFICANCE: Uedomari-5 provides the first example, to our knowledge, of a stingray spine directly embedded in human bone at an archaeological site. More widely, the finding contributes to our knowledge of conflict in northern hunter-gatherer communities. LIMITATIONS: Given the early excavation date (1949-50), there is little contextual information available for the burials. SUGGESTIONS FOR FURTHER RESEARCH: ZooMS (Zooarchaeology by Mass Spectrometry) may be able to identify the stingray species. Archival research may provide more information concerning the excavations at Uedomari-5.

Genetic Characterization of Human Rabies Vaccine Strain in Japan and Rabies Viruses Related to Vaccine Development from 1940s to 1980s.

The rabies virus is widely distributed and vaccines are an important strategy to prevent its spread. The whole-genome sequences of rabies strains in relation to vaccine development provide essential information to maintain vaccine quality and develop new vaccines. However, the genetic characteristics of the purified chick embryo cell culture rabies vaccine, KM Biologics (PCECV-KMB), developed in Japan in the 1970s, have not been explored. In this study, we conducted a genome-wide analysis of the open reading frame regions of rabies strains discovered from the 1940s-1980s and used to develop chick embryo cell-adapted HEP-Flury small plaque-forming (CEF-S) strain, which is a vaccine strain of PCECV-KMB. The genetic characteristic of CEF-S, developed by acclimation of the HEP-Flury-NIID strain to one-day eggs and subsequently to chick embryo cells, were confirmed by comparing the genome identity and revealing the nine amino acid mutations between CEF-S and HEP-Flury-NIID. The efficacy of PCECV-KMB was evaluated using attack strains isolated in Thailand in the 1960s-1970s during vaccine development. Phylogenetic analyses of the attack strains classified them in the same Asian clade as the 2000s imported cases from the Philippines to Japan, suggesting that PCECV-KMB is adequate for preventing the spread of the current rabies virus.