Catch-up immunization for adolescents and young adults during pre-travel consultation in Japan.

Rubella and measles outbreaks in adults occur because of unimmunized or partially immunized status. Travel clinics play an important role in catch-up measles, rubella, mumps, and varicella immunization for adults. We evaluated the need for catch-up measles, rubella, mumps, and varicella immunization by young adults at our travel clinic. This retrospective observational study was conducted at the National Center for Global Health and Medicine from June 1, 2017 to May 31, 2018. Adults aged 16-49 years who received pre-travel consultation and had childhood immunization records were included. Individuals who fully or partially received planned measles, rubella, mumps, and varicella catch-up immunization were classified as "immunized." We calculated the proportion of "immunized" individuals and analyzed the factors associated with catch-up measles, rubella, mumps, and varicella immunization at pre-travel consultation using logistic regression analysis. Overall, 3,456 individuals received pre-travel consultations during the study period; 827 (336 men, median age 22 years) had childhood immunization records. The most common trip purposes were study (33%) and tourism (24%). The most common destination was Asia (39%). Catch-up immunization of any measles, rubella, mumps, and varicella vaccine was needed by 755 individuals. After consultation, 20-46% of these participants who needed catchup immunization received at least one dose of immunization. Factors that are negatively associated with measles, rubella, mumps, and varicella catch-up immunization were tourism (odds ratio 0.37 to 0.58), yellow fever vaccination (0.45 to 0.50) (excluding varicella), and each disease history (0.13 to 0.40) (excluding rubella and varicella). Further studies are needed to identify barriers to catch-up immunization.

Varicella in Adult Foreigners at a Referral Hospital, Central Tokyo, Japan, 2012-2016.

We report a case series of varicella among adult foreigners at a referral hospital in central Tokyo, Japan, during 2012-2016. This series highlights differences in varicella vaccination schedules by country and epidemiology by climate and identifies immigrants and international students as high-risk populations for varicella.

Rabies post-exposure prophylactic vaccination for returning travelers to Japan.

BACKGROUND: Rabies post-exposure prophylaxis (PEP) in Japan is administered using 6 subcutaneous doses (on days 0, 3, 7, 14, 30, and 90), which is not in line with international recommendations of 4 or 5 intramuscular doses. For reducing dose frequency, we evaluate the immunogenicity of PEP with a regimen of 6 subcutaneous doses. METHOD: This prospective single-center cross-sectional study was performed between September 2013 and December 2014. We included patients underwent rabies PEP by purified chick embryo-cultured rabies vaccine Kaketsuken (PCEC-K) at our clinic, and excluded patients with a history of pre-exposure prophylaxis or PEP using rabies immunoglobulin. The rabies virus-neutralizing antibody tests were performed at the first visit to our office (doses 1-4) and at the fifth and sixth doses. RESULTS: Data were available for 43 of 59 enrolled patients. Thirty-two patients did not start PEP within 48 h after exposure to animals. The seroprotection rates (≥0.5 IU/mL) were 90.7% and 75.7%, at days 30 and 90, respectively. Despite receiving a fifth dose, 85.3% of the patients exhibited decreasing antibody titers during days 30-90 (p < 0.001). CONCLUSIONS: The seroprotection rates of PCEC-K induced subcutaneously were insufficient to prevent rabies at day 30 and 90.

Age-related differences in clinical characteristics of invasive group G streptococcal infection: Comparison with group A and group B streptococcal infections.

PURPOSE: Invasive Group G streptococcal infection (iGGS) has increasingly been recognized as a cause of severe disease, mainly among elderly people with chronic illnesses. This study aimed to examine age-related differences in clinical characteristics of iGGS and describe its characteristics among very elderly individuals (≥80 years). METHODS: Fifty-four iGGS patients for whom detailed clinical information was available were identified from 2002 to 2014 in a tertiary care hospital in Japan. iGGS (n = 54) was compared with invasive Group A (iGAS; n = 17) and B streptococcal infection patients (iGBS; n = 52) based on patient age. RESULTS: The incidence of iGGS in our catchment area significantly increased during the study period. The prevalence of iGGS in the very elderly population was higher than that of iGAS or iGBS (p<0.001). Among iGGS patients, cardiovascular disease, chronic kidney disease, oxygen demand, and bacteremia with unknown focus of infection were more frequent in the very elderly population (p = 0.009, p = 0.02, p = 0.04, and p = 0.04, respectively). Altered mental status was present in half of iGGS patients aged ≥60 years (p = 0.03). In contrast, alcohol drinking and liver cirrhosis were significantly more frequent in patients with iGGS aged <60 years than in other age groups (p<0.001, p = 0.001, respectively). Levofloxacin resistance in GBS isolates was significantly more frequent among very elderly patients than among other age groups (p<0.001). CONCLUSIONS: The burden of iGGS has been increasing in our catchment area. Different iGGS-associated clinical characteristics were found in each age group. Unclear and atypical clinical manifestations and syndromes were likely to be observed in very elderly patients. Alcohol drinking and liver cirrhosis may contribute to iGGS even in patients aged <60 years. Understanding these age-related differences could be helpful for optimal diagnosis and treatment.

Imported Malaria at a Referral Hospital in Tokyo from 2005 to 2016: Clinical Experience and Challenges in a Non-Endemic Setting.

In this study, we reviewed imported malaria cases observed at the National Center for Global Health and Medicine, Tokyo, between 2005 and 2016, to comprehend their demographic and clinical characteristics. Data on 169 cases were used to analyze demographic information; data on 146 cases were used for the analysis of clinical information. The median patients' age was 34 years, and 79.3% of them were male. The proportion of non-Japanese patients increased and surpassed that of Japanese patients after 2015. In 82.2% of the cases, the region of acquisition was Africa, and Plasmodium falciparum was the dominant species (74.0%) followed by Plasmodium vivax (15.4%). We observed 19 (18.4%, 19/103) severe falciparum malaria cases. Mefloquine was the most commonly used drug for treatment until the early 2010s; atovaquone/proguanil was the most commonly used after its licensure in 2013. Although none of the patients died, four recrudescence episodes after artemether/lumefantrine (A/L) treatment and one relapse episode were observed. Overall, malaria was diagnosed on median day 4 of illness, and, thereon, treatment was initiated without delay. Diagnosis on day 5 or later was significantly associated with severe disease in Japanese cases (odds ratio = 4.1; 95% CI = 1.2-14.3). We observed a dominance of falciparum malaria, an increase in the number of non-Japanese cases, late treatment failure after A/L treatment, a low relapse rate, and an association between delayed malaria diagnosis and higher disease severity. Pretravel care and early diagnosis are necessary to reduce malaria-related mortality and morbidity in settings such as ours.

Wohlfahrtiimonas chitiniclastica Bacteremia Hospitalized Homeless Man with Squamous Cell Carcinoma.

We report a case of Wohlfahrtiimonas chitiniclastica bacteremia in an elderly man in Japan who had squamous cell carcinoma. Blood cultures were initially negative for W. chitiniclastica but were positive on day 20. Careful attention needs to be paid to this organism in patients who have chronic wounds with maggots.

Clinical characteristics and epidemiology of intestinal tapeworm infections over the last decade in Tokyo, Japan: A retrospective review.

BACKGROUND: Tapeworm (cestode) infections occur worldwide even in developed countries and globalization has further complicated the epidemiology of such infections. Nonetheless, recent epidemiological data on cestode infections are limited. Our objectives were to elucidate the clinical characteristics and epidemiology of diphyllobothriosis and taeniosis in Tokyo, Japan. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively reviewed 24 cases of human intestinal cestode infection from January 2006 to December 2015 at a tertiary referral hospital in Tokyo, Japan. The patients included were diagnosed with cestode infection based on morphological and/or molecular identification of expelled proglottids and/or eggs and treated in our hospital. Fifteen and 9 patients were diagnosed with diphyllobothriosis and taeniosis, respectively. The median patient age was 31 years (interquartile range [IQR]: 26-42 years), and 13 (54%) were male. Most of the patients (91.7%) were Japanese. All patients were successfully treated with praziquantel without recurrence. Diphyllobothriosis was caused by Diphyllobothrium nihonkaiense in all patients. Taeniosis was due to infection of Taenia saginata in 8 [88.9%] patients and T. asiatica in 1 [11.1%] patient. All patients with taeniosis were infected outside Japan, as opposed to those with diphyllobothriosis, which were domestic. The source locations of taeniosis were mostly in developing regions. The median duration of the stay of the patients with taeniosis at the respective source location was 1 month (IQR: 1-8). CONCLUSIONS/SIGNIFICANCE: The cestode infection, especially with D. nihonkaiense, has frequently occurred, even in Japanese cities, thereby implicating the probable increase in the prevalence of diphyllobothriosis among travelers, as the number of travelers is expected to increase owing to the Tokyo Olympics/Paralympics in 2020. In addition, medical practitioners should be aware of the importance of providing advice to travelers to endemic countries of taeniosis, including the potential risks of infection and preventive methods for these infections.

Experiences of Response Measures against the 4 Suspected Cases of Ebola Virus Disease from West Africa in the National Center for Global Health and Medicine, Tokyo, Japan.

In Japan, infectious diseases are classified into 4 types based on how contagious and severe the pathogens are, and Ebola virus disease (EVD) is categorized as a category 1 infectious disease. The National Center for Global Health and Medicine in Tokyo, Japan, is designated as a specified hospital for category 1 infectious disease patients and has experienced 4 probable cases of EVD from West Africa. Even after the outbreak in West Africa is ended, we should continue to pay attention for new EVD outbreaks. Increasing the number of infectious disease specialists with the proper knowledge of viral hemorrhagic fever, including EVD, is a common problem for infectious disease physicians working in Japan, the academic society, and the government.

A Retrospective Single-center Analysis of 16 Cases of Imported Chikungunya Fever in Japan.

Objective Chikungunya fever (CHIK) is a re-emerging arboviral disease that is transmitted through the bite of infected Aedes mosquitoes. There is limited information regarding the epidemiology and clinical information of imported CHIK in Japan. The objective of this study was to review the epidemiology and clinical information of imported CHIK patients treated at the National Center for Global Health and Medicine (NCGM). Methods We evaluated all patients (n=16) who were diagnosed with imported CHIK and treated at the NCGM between October 1, 2005 and March 31, 2016. Results The primary complaint of 7 patients who presented to the NCGM after 31 days from disease onset was persistent arthritis, and the primary complaints of 9 patients who presented within 30 days after disease onset were a fever, headache, arthralgia, and rash. Eleven patients experienced a rash during the first week of illness. The median duration of the arthralgia was 75 days, and the joint pain lasted for >2 months in 8 patients and >6 months in 3 patients. Persistent arthralgia was not significantly associated with an age of >35 years (p=0.13) or patient sex (p=0.69). All 16 patients exhibited positive results for CHIK IgM, although only 4 exhibited positive real-time polymerase chain reaction results. Conclusion Physicians should consider CHIK in patients with a fever who have returned from areas where CHIK is endemic.

Comparison of the clinical and microbiological characteristics of Campylobacter and Helicobacter bacteremia: the importance of time to blood culture positivity using the BACTEC blood culture systems.

OBJECTIVE: Campylobacter spp. and Helicobacter spp. are rare but important causes of bacteremia in humans. Distinguishing these bacteria is complicated because of their similar phenotypic profiles. We conducted clinical and microbiological investigations of Campylobacter spp. or Helicobacter spp. bacteremia. Patients diagnosed with bacteremia from 2008 to 2014 were included. The clinical and microbiological characteristics of Campylobacter spp. and Helicobacter spp. bacteremia were compared. The BACTEC system was used in blood cultures. A receiver operating characteristic curve was plotted based on the time to blood culture positivity. RESULTS: Sixteen cases of Helicobacter spp. bacteremia (patient age: 61 ± 18 years) and 14 cases of Campylobacter spp. bacteremia (patient age: 49 ± 21 years) were identified. Median time to blood culture positivity was longer for the Helicobacter spp. cases than the Campylobacter spp. cases (91.4 h vs 55.3 h, p < 0.01). A time to blood culture positivity > 75 h predicted Helicobacter spp. bacteremia with a sensitivity of 0.88 and a specificity of 0.93 (area under the receiver operating characteristic curve of 0.90). In conclusion, a time to blood culture positivity was useful in distinguishing Helicobacter spp. bacteremia from Campylobacter spp. bacteremia.

A Case of Dengue Fever Imported from Burkina Faso to Japan in October 2016.

Dengue fever remains underreported in Africa due to a lack of awareness among healthcare providers, the presence of other febrile illnesses, and insufficient laboratory testing. We present a case of dengue fever imported from Burkina Faso to Japan, where an outbreak of dengue was reported on October 18, 2016. Phylogenetic analysis revealed that the isolate from our patient belonged to a distinct cluster of sylvatic dengue viruses, suggesting that dengue viruses have been maintained in mosquitoes and human cycles in Burkina Faso for more than 30 years.

Role of classic signs as diagnostic predictors for enteric fever among returned travellers: Relative bradycardia and eosinopenia.

BACKGROUND: The lack of characteristic clinical findings and accurate diagnostic tools has made the diagnosis of enteric fever difficult. We evaluated the classic signs of relative bradycardia and eosinopenia as diagnostic predictors for enteric fever among travellers who had returned from the tropics or subtropics. METHODS: This matched case-control study used data from 2006 to 2015 for culture-proven enteric fever patients as cases. Febrile patients (>38.3°C) with non-enteric fever, who had returned from the tropics or subtropics, were matched to the cases in a 1:3 ratio by age (±3 years), sex, and year of diagnosis as controls. Cunha's criteria were used for relative bradycardia. Absolute eosinopenia was defined as an eosinophilic count of 0/µL. RESULTS: Data from 160 patients (40 cases and 120 controls) were analysed. Cases predominantly returned from South Asia (70% versus 18%, p <0.001). Relative bradycardia (88% versus 51%, p <0.001) and absolute eosinopenia (63% versus 38%, p = 0.008) were more frequent in cases than controls. In multivariate logistic regression analysis, return from South Asia (aOR: 21.6; 95% CI: 7.17-64.9) and relative bradycardia (aOR: 11.7; 95% CI: 3.21-42.5) were independent predictors for a diagnosis of enteric fever. The positive likelihood ratio was 4.00 (95% CI: 2.58-6.20) for return from South Asia, 1.72 (95% CI: 1.39-2.13) for relative bradycardia, and 1.63 (95%CI: 1.17-2.27) for absolute eosinopenia. The negative predictive values of the three variables were notably high (83-92%);. however, positive predictive values were 35-57%. CONCLUSIONS: The classic signs of relative bradycardia and eosinopenia were not specific for enteric fever; however both met the criteria for being diagnostic predictors for enteric fever. Among febrile returned travellers, relative bradycardia and eosinopenia should be re-evaluated for predicting a diagnosis of enteric fever in non-endemic areas prior to obtaining blood cultures.

Detection of Zika virus in a traveller from Vietnam to Japan.

We report an imported case of Zika fever in a traveller from Vietnam. Zika virus (ZIKV) is currently widespread in Vietnam. Ongoing transmission of ZIKV has been reported in Southeast Asia, and with frequent travel between neighbouring regions, careful surveillance for imported cases is needed.

Amoxicillin and Ceftriaxone as Treatment Alternatives to Penicillin for Maternal Syphilis.

There is no proven alternative to penicillin for treatment of maternal syphilis. We report 2 case-patients with maternal syphilis who were successfully treated without penicillin. We used amoxicillin and probenecid for the first case-patient and amoxicillin, probenecid, and ceftriaxone for the second case-patient.

Imported Leptospira licerasiae Infection in Traveler Returning to Japan from Brazil.

We describe a case of intermediate leptospirosis resulting from Leptospira licerasiae infection in a traveler returning to Japan from Brazil. Intermediate leptospirosis should be included in the differential diagnosis for travelers with fever returning from South America. This case highlights the need for strategies that detect pathogenic and intermediate Leptospira species.

Chikungunya Fever in Traveler from Angola to Japan, 2016.

Simultaneous circulation of multiple arboviruses presents diagnostic challenges. In May 2016, chikungunya fever was diagnosed in a traveler from Angola to Japan. Travel history, incubation period, and phylogenetic analysis indicated probable infection acquisition in Angola, where a yellow fever outbreak is ongoing. Thus, local transmission of chikungunya virus probably also occurs in Angola.

A case of consecutive infection with Zika virus and Chikungunya virus in Bora Bora, French Polynesia.

Chikungunya fever (CHIK) and Zika virus (ZIKV) infection have similar endemic areas and clinical manifestations. We report a case of CHIK at 1 year after a ZIKV infection in Bora Bora (French Polynesia), which we diagnosed based on IgM to the CHIK virus and neutralizing antibodies to ZIKV.

A fatal case of melioidosis with pancytopenia in a traveler from Indonesia.

Melioidosis, an infectious disease with high mortality, caused by Burkholderia pseudomallei, is endemic in southeast Asia and northern Australia. In Indonesia, autochthonous cases have been rarely reported, with most cases being sporadic and occurring in travelers. Herein, we report a fatal case of neurological melioidosis in a traveler from Indonesia presenting with septic shock.

Six Cases of Paratyphoid Fever Due to Salmonella Paratyphi A in Travelers Returning from Myanmar Between July 2014 and August 2015.

We report six cases of Salmonella enterica serotype Paratyphi A infections in travelers returning from Myanmar. In 2015, 31 cases of paratyphoid fever were reported in Japan, and 54.8% of those traveled to Myanmar. Among them, six patients presented to our hospital. They had traveled to Myanmar from July 2014 to August 2015 for business purposes. All six isolates were phage type 1, and they were resistant to nalidixic acid.