To investigate the impact of imipenem resistance on the mortality rate among patients with Acinetobacter bacteraemia. A retrospective, pairwise-matched (1:1), risk-adjusted (age, Pitt bacteraemia score) cohort study was performed at three tertiary care hospitals in Korea from January 2000 to June 2005. Forty patients with imipenem non-susceptible Acinetobacter bacteraemia (INAB group) and 40 matched subjects (1:1 ratio) with imipenem-susceptible Acinetobacter bacteraemia (ISAB group) were included. Both groups had similar clinical features related to the severity of illness. The 30 day mortality rate was higher in the INAB group (57.5%) than the ISAB group (27.5%) (P = 0.007). The rate of discordant antimicrobial therapy was higher in the INAB group (65.0%) than the ISAB group (20.0%) (P < 0.001). The 30 day mortality rate was higher in the patients with discordant antimicrobial therapy (67.6%) than concordant antimicrobial therapy (23.9%) (P < 0.001). Multivariate analysis showed that age, the Pitt bacteraemia score, immunosuppressive status, and discordant antimicrobial therapy were independent risk factors for 30 day mortality among patients with Acinetobacter bacteraemia (P < 0.05). When discordant antimicrobial therapy was excluded in the multivariate analysis, the imipenem resistance was associated with 30 day mortality (P = 0.005). Imipenem resistance has a significant impact on the mortality rate among patients with Acinetobacter bacteraemia, and this is mainly attributable to the higher rate of discordant antimicrobial therapy.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne viral disease. The SFTS virus (SFTSV) has been detected in the Haemaphysalis longicornis, which acts as a transmission host between animals and humans. SFTSV was first confirmed in China in 2009 and has also been circulating in Japan and South Korea. However, it is not known if a genetic connection exists between the viruses in these regions and, if so, how SFTSV is transmitted across China, South Korea, and Japan. We therefore hypothesize that the SFTSV in South Korea share common phylogenetic origins with samples from China and Japan. Further, we postulate that migratory birds, well-known carriers of the tick H. longicornis, are a potential source of SFTSV transmission across countries. Our phylogenetic analysis results show that the SFTSV isolates in South Korea were similar to isolates from Japan and China. We connect this with previous work showing that SFTSV-infected H. longicornis were found in China, South Korea, and Japan. In addition, H. longicornis were found on migratory birds. The migratory bird routes and the distribution of H. longicornis are concurrent with the occurrence of SFTSV. Therefore, we suggest that migratory birds play an important role in dispersing H. longicornis-borne SFTSV.

Context: Dipeptidyl peptidase 4 (CD26/DPP4) is expressed on blood T cells and also circulates in a soluble form (sCD26/DPP4).Objective: We aimed to evaluate blood T cell and circulating CD26/DPP4 and its association with metabolic parameters in patients with type 2 diabetes mellitus (T2DM).Designs: We measured CD26/DPP4 expression (percentage of CD26+ cells using flow cytometry) on CD4+ and CD8+ T cells, serum CD26/DPP4 level and activity, and various metabolic parameters in T2DM patients not on DPP4 inhibitor therapy (n = 148). Nondiabetic subjects (n = 50) were included as a control group.Results: Compared with the healthy controls, CD26/DPP4 expression on CD4+ T cells and CD8+ T cells was higher in T2DM patients. Serum CD26/DPP4 levels and enzymatic activities were also higher in patients with T2DM than in the control group only when metformin and/or thiazolidinedione-treated T2DM patients were excluded; metformin and/or thiazolidinedione-treated T2DM patients had lower values compared with other T2DM patients. Various parameters in T2DM patients were related to CD26/DPP4 expression on the T cells (hemoglobin A1c), serum sCD26/DPP4 (hemoglobin A1c and insulin resistance assessed by updated homeostasis model assessment), and serum CD26/DPP4 activity (insulin resistance assessed by updated homeostasis model assessment, γ-glutamyl transferase, and alanine aminotransferase) by multivariate analyses. After active glucose control for 12 weeks in drug-naive T2DM patients (n = 50), CD26/DPP4 expression on blood T cells was significantly decreased.Conclusions: Our results suggest that the CD26/DPP4 level on blood T cells was associated with glucose control status in patients with T2DM.

Climate change affects the survival and transmission of arthropod vectors as well as the development rates of vector-borne pathogens. Increased international travel is also an important factor in the spread of vector-borne diseases (VBDs) such as dengue, West Nile, yellow fever, chikungunya, and malaria. Dengue is the most important vector-borne viral disease. An estimated 2.5 billion people are at risk of infection in the world and there are approximately 50 million dengue infections and an estimated 500,000 individuals are hospitalized with dengue haemorrhagic fever annually. The Asian tiger mosquito (Aedes albopictus) is one of the vectors of dengue virus, and populations already exist on Jeju Island, South Korea. Currently, colder winter temperatures kill off Asian tiger mosquito populations and there is no evidence of the mosquitos being vectors for the dengue virus in this location. However, dengue virus-bearing mosquito vectors can inflow to Jeju Island from endemic area such as Vietnam by increased international travel, and this mosquito vector's survival during colder winter months will likely occur due to the effects of climate change. In this section, we show the geographical distribution of medically important mosquito vectors such as Ae. albopictus, a vector of both dengue and chikungunya viruses; Culex pipiens, a vector of West Nile virus; and Anopheles sinensis, a vector of Plasmodium vivax, within Jeju Island, South Korea. We found a significant association between the mean temperature, amount of precipitation, and density of mosquitoes. The phylogenetic analyses show that an Ae. albopictus, collected in southern area of Jeju Island, was identical to specimens found in Ho Chi Minh, Vietnam, and not Nagasaki, Japan. Our results suggest that mosquito vectors or virus-bearing vectors can transmit from epidemic regions of Southeast Asia to Jeju Island and can survive during colder winter months. Therefore, Jeju Island is no longer safe from vector borne diseases (VBDs) due to the effects of globalization and climate change, and we should immediately monitor regional climate change to identify newly emerging VBDs.

To investigate the antimicrobial resistance, extended-spectrum β-lactamases (ESBLs) and clones of Klebsiella pneumoniae isolates causing bacteraemia or urinary tract infection (UTI) in Korea, a total of 406 K. pneumoniae isolates from patients with bacteraemia (221 isolates) and UTI (185 isolates) were collected from 10 tertiary-care Korean hospitals from July 2006 to October 2007. In vitro antimicrobial susceptibility testing was performed for all isolates and ESBL production was tested. Multilocus sequence typing (MLST) analyses were performed to characterize genotypes of ESBL-producing K. pneumoniae isolates. PFGE was performed for sequence type 11 (ST11) isolates. Forty-seven UTI isolates (25.4 %) produced ESBLs, while 30 bacteraemia isolates (13.6 %) produced ESBLs (P=0.002). Among 77 ESBL-producing isolates, thirty-two (41.6 %) produced SHV-type ESBLs. bla _CTX-M genes such as bla _CTX-M-14 and bla _CTX-M-15 were detected in 36.4 %. MLST and PFGE analyses showed that ST11 was dominant in ESBL-producing K. pneumoniae isolates causing UTI (57.4 %) and in those causing bacteraemia (70.0 %) and has been prevalent in Korean hospitals. ST11 isolates harbour a combination of different ESBL genes. The ST11 clone of ESBL-producing K. pneumoniae isolates prevails in Korea, but most isolates might acquire ESBL genes independently or several different clones might be distributed in Korea.