Satoshi Kutsuna

Autochthonous dengue fever, Tokyo, Japan, 2014.

After 70 years with no confirmed autochthonous cases of dengue fever in Japan, 19 cases were reported during August–September 2014. Dengue virus serotype 1 was detected in 18 patients. Phylogenetic analysis of the envelope protein genome sequence from 3 patients revealed 100% identity with the strain from the first patient (2014) in Japan.

Zika fever imported from Thailand to Japan, and diagnosed by PCR in the urines.

In July 2014, a Japanese traveller returning from Thailand was investigated for fever, headache, rash and conjunctivitis. Zika virus RNA was detected in his urine sample by real-time reverse transcription polymerase chain reaction. Serological tests showed cross reactivity of IgM against the dengue virus. Zika fever could be misdiagnosed or missed and should be considered in febrile patients with a rash, especially those returning from Thailand.

First case of Plasmodium knowlesi infection in a Japanese traveller returning from Malaysia.

This is the first case of Plasmodium knowlesi infection in a Japanese traveller returning from Malaysia. In September 2012, a previously healthy 35-year-old Japanese man presented to National Center for Global Health and Medicine in Tokyo with a two-day history of daily fever, mild headaches and mild arthralgia. Malaria parasites were found in the Giemsa-stained thin blood smear, which showed band forms similar to Plasmodium malariae. Although a nested PCR showed the amplification of the primer of Plasmodium vivax and Plasmodium knowlesi, he was finally diagnosed with P. knowlesi mono-infection by DNA sequencing. He was treated with mefloquine, and recovered without any complications. DNA sequencing of the PCR products is indispensable to confirm P. knowlesi infection, however there is limited access to DNA sequencing procedures in endemic areas. The extent of P. knowlesi transmission in Asia has not been clearly defined. There is limited availability of diagnostic tests and routine surveillance system for reporting an accurate diagnosis in the Asian endemic regions. Thus, reporting accurately diagnosed cases of P. knowlesi infection in travellers would be important for assessing the true nature of this emerging human infection.

Parvimonas micra as a causative organism of spondylodiscitis: a report of two cases and a literature review.

Spondylodiscitis caused by Parvimonas micra, a rarely reported infection, might be under-detected using conventional methods. This report of the detection and treatment of two cases of spondylodiscitis due to P. micra and review of the literature indicates that the use of gene sequencing methods might improve the accuracy of diagnosing this infection.

The first case of adult-onset PFAPA syndrome in Japan

A 26-year-old woman presented with fever and pharyngitis. She previously experienced four periodic febrile episodes at 30- to 40-day intervals. We suspected periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome, and prescribed predisolone, thereby her fever rapidly subsided. Her febrile episodes improved after daily cimetidine treatment. Genetic testing results of genomic DNA for periodic fever syndromes were negative, although she was heterozygous for p.Glu148Gln variation in MEFV, supporting the diagnosis of PFAPA syndrome.

Comparison of clinical characteristics and laboratory findings of malaria, dengue, and enteric fever in returning travelers: 8-year experience at a referral center in Tokyo, Japan

BACKGROUND Without specific symptoms, diagnosis of febrile illness in returning travelers is challenging. Dengue, malaria, and enteric fever are common causes of fever in returning travelers and timely and appropriate treatment is important. However, differentiation is difficult without specific diagnostic tests. METHODS A retrospective study was conducted at the National Centre for Global Health and Medicine (NCGM) from April 2005 to March 2013. Febrile travelers returning from overseas who were diagnosed with dengue, malaria, or enteric fever were included in this study. Clinical characteristics and laboratory findings were compared for each diagnosis. RESULTS During the study period, 86 malaria, 85 dengue, and 31 enteric fever cases were identified. The mean age of the study cohort was 33.1 ± 12 years and 134 (66.3%) study participants were male. Asia was the most common area visited by returning travelers with fevers (89% of dengue, 18.6% of malaria, and 100% of enteric fever cases), followed by Africa (1.2% of dengue and 70.9% of malaria cases). Clinical characteristics and laboratory findings were significantly different among each group with each diagnosis. Decision tree models revealed that returning from Africa and CRP levels <10 mg/L were factors specific for diagnosis of malaria and dengue fever, respectively. CONCLUSION Clinical manifestations, simple laboratory test results, and regions of travel are helpful to distinguish between dengue, malaria, and enteric fever in febrile returning travelers with non-specific symptoms.

The first case of imported relapsing fever in Japan.

Tick-borne relapsing fever (TBRF) is endemic in discrete areas throughout the world; however, a domestic or imported case of relapsing fever has not been reported in Japan. Here, we report the first imported case. A previously healthy 20-year-old woman presented to our hospital on October 8, 2010, because of recurrent fever and lower leg pain. Before consultation, she had experienced four febrile episodes at 10-12-day intervals after returning from her stay in Uzbekistan from 1 to 8 September. Giemsa stain of peripheral blood showed Borrelia spirochetes. The spirochete was identified as Borrelia persica by sequencing of the amplicons of flaB using polymerase chain reaction and phylogenetic analysis. The patient was diagnosed with TBRF, and she completed a 10-day course of minocycline 100 mg twice daily. After treatment, her periodic fever subsided. Physicians should be aware of TBRF in patients with recurrent fever who have returned from TBRF-endemic countries, including areas of the former USSR.

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.

Multidrug-resistant Acinetobactor baumannii isolated from a traveler returned from Brunei

We report a case of multidrug-resistant (MDR) Acinetobactor baumannii isolates obtained from a traveler returned from Brunei. Whole-genome sequencing analysis revealed that the isolates harbored blaOxA-23 and armA. The minimum inhibitory concentrations of antibiotics against the strain were as follows: imipenem, 32 μg/ml; meropenem, 32 μg/ml; ciprofloxacin, 16 μg/ml; amikacin, ≧ 1024 μg/ml; arbekacin, ≧ 1024 μg/ml; aztreonam, 64 μg/ml; colistin, 4 μg/ml. A. baumannii harboring both blaOxA-23 and armA is rarely reported in Japan, and, to the best of our knowledge, this is the second report of A. baumannii harboring both resistant genes in Japan.

Impact of rapid identification of positive blood cultures using the Verigene system on antibiotic prescriptions: A prospective study of community-onset bacteremia in a tertiary hospital in Japan

Background Rapid identification of positive blood cultures is important for initiation of optimal treatment in septic patients. Effects of automated, microarray-based rapid identification systems on antibiotic prescription against community-onset bacteremia (COB) remain unclear. Methods We prospectively enrolled 177 patients with 185 COB episodes (occurring within 72 h of admission) over 17 months. Bacteremia episodes due to gram-positive bacteria (GP) and gram-negative bacteria (GN) in the same patient were counted separately. For GP bacteremia, patients with ≥2 sets of positive blood cultures were included. The primary study objective was evaluating the rates of antibiotic prescription changes within 2 days of rapid identification using the Verigene system. Results Bacteremia due to GN and GP included 144/185 (77.8%) and 41/185 (22.2%) episodes, respectively. Antibiotic prescription changes occurred in 51/185 cases (27.6% [95%CI:21.3–34.6%]) after Verigene analysis and 70/185 cases (37.8% [30.8–45.2%]) after conventional identification and susceptibility testing. Prescription changes after Verigene identification were more frequent in GP (17/41[41.5%]) than in GN (34/144[23.5%]). Among bacteremia due to single pathogen targeted by Verigene test, bacterial identification agreement between the two tests was high (GP: 38/39[97.4%], GN: 116/116[100%]). The Verigene test correctly predicted targeted antimicrobial resistance. The durations between the initiation of incubation and reporting of the results for the Verigene system and conventional test was 28.3 h (IQR: 25.8–43.4 h) and 90.6 h (68.3–118.4 h), respectively. In only four of the seven episodes of COB in which two isolates were identified by conventional tests, the Verigene test correctly identified both organisms. Conclusion We observed a high rate of antibiotic prescription changes after the Verigene test in a population with COB especially in GP. The Verigene test would be a useful tool in antimicrobial stewardship programs among patients with COB.