Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea

BACKGROUND

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes.

AIM

To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI).

METHODS

Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI.

RESULTS

This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI.

CONCLUSIONS

This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Vector Competence and the Susceptibility of Anopheles pullus and Anopheles belenrae to Plasmodium vivax-Infected Blood From Thai Patients

There are eight Anopheles spp. present in the Republic of Korea (ROK), including five members of the Anopheles Hyrcanus Group that cannot be identified using current morphological methods. The vector competence of only Anopheles sinensis s.s., An. lesteri, and An. kleini have been investigated. As the geographical distribution of Anopheles spp. varies in the ROK, determining the relative vector competence of the Anopheles spp. provides a basis for delineating malaria risks to Korean populations and U.S. military/civilian populations deployed to the ROK. Anopheles belenrae and An. pullus, collected from a malaria high-risk area in the ROK, were evaluated for vector competence of P. vivax. A total of 1,000 each of An. dirus (Thai strain), and Korean strains of An. pullus and An. belenrae were fed on P. vivax infected blood collected from Thai patients via artificial membrane feeding. The overall oocyst infection rates for An. dirus, An. pullus, and An. belenrae dissected on days 8-9 postfeed were 64.1, 12.0, and 11.6%, respectively. The overall sporozoite infection rates for those species dissected on days 14-15 postfeed were 84.5, 3.4, and 5.1% respectively. The salivary gland sporozoite indices for positive females with +4 (>1,000 sporozoites) were observed in An. dirus (72.8%), but not observed for either An. pullus or An. belenrae. Most sporozoite-positive An. pullus (83.3%) and An. belenrae (71.4%) females were observed with only +1 (1-10 sporozoites) salivary glands. These data indicate that both An. belenrae and An. pullus are very poor vectors of P. vivax.

Geographical Distribution and Epidemiologic Factors of Chigger Mites on Apodemus agrarius during Autumn in Korea

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

715 The Importance of Social Media to The Academic Surgical Literature: Relationship Between Twitter Activity and Readership Metrics

Aim

Social media (SoMe) has an increasing role within professional surgical practice, including the publishing and engagement of academic literature. This study aims to analyse the relationship between social media use and traditional and alternative metrics amongst academic surgical journals.

Method

Journals were identified through the InCites Journal Citation Reports 2019, and their impact factor (IF), h-index and CiteScore were noted. Social media platforms were examined, and Twitter activity interrogated between 1st January- 31st December 2019. Healthcare Social Graph (HSG) score and an aggregated Altmetric score were also calculated for each journal. Statistical analysis was carried out to look at the correlation between traditional metrics, Twitter activity and altmetrics.

Results

Journals with higher IF were more likely to use a greater number of SoMe platforms (R2=0.648; p < 0.0001). Journals with dedicated Twitter profiles had a higher IF than journals without (median, 2.96 vs 1.88; MWU=390; p < 0.001) however over a one-year period (2018-2019) having a twitter presence did not alter IF (MWU=744.5; p = 0.885). Increased Twitter activity was positively correlated with IF. Longitudinal analysis over six years suggested cumulative tweets correlated with an increased IF (R2=0.324, p = 0.004). Novel alternative measures including HSG score (R2=0.472, p = 0.005) and Altmetric score (R2=0.779, p = 0.001) positively correlated with IF.

Conclusions

Higher IF is associated with SoMe presence and activity, particularly on Twitter, with long term activity being of particular importance. Modern alternative metrics correlate with IF. This relationship is complex and future studies should look to understand this further.

Multigene phylogenetics of euglenids based on single-cell transcriptomics of diverse phagotrophs

Euglenids are a well-known group of single-celled eukaryotes, with phototrophic, osmotrophic and phagotrophic members. Phagotrophs represent most of the phylogenetic diversity of euglenids, and gave rise to the phototrophs and osmotrophs, but their evolutionary relationships are poorly understood. Symbiontids, in contrast, are anaerobes that are alternatively inferred to be derived euglenids, or a separate euglenozoan group. Most phylogenetic studies of euglenids have examined the SSU rDNA only, which is often highly divergent. Also, many phagotrophic euglenids (and symbiontids) are uncultured, restricting collection of other molecular data. We generated transcriptome data for 28 taxa, mostly using a single-cell approach, and conducted the first multigene phylogenetic analyses of euglenids to include phagotrophs and symbiontids. Euglenids are recovered as monophyletic, with symbiontids forming an independent branch within Euglenozoa. Spirocuta, the clade of flexible euglenids that contains both the phototrophs (Euglenophyceae) and osmotrophs (Aphagea), is robustly resolved, with the ploeotid Olkasia as its sister group, forming the new taxon Olkaspira. Ploeotids are paraphyletic, although Ploeotiidae (represented by Ploeotia spp.), Lentomonas, and Keelungia form a robust clade (new taxon Alistosa). Petalomonadida branches robustly as sister to other euglenids in outgroup-rooted analyses. Within Spirocuta, Euglenophyceae is a robust clade that includes Rapaza, and Anisonemia is a well-supported monophyletic group containing Anisonemidae (Anisonema and Dinema spp.), 'Heteronema II' (represented by H. vittatum), and a clade of Neometanema plus Aphagea. Among 'peranemid' phagotrophs, Chasmostoma branches with included Urceolus, and Peranema with the undescribed 'Jenningsia II', while other relationships are weakly supported and consequently the closest sister group to Euglenophyceae remains unresolved. Our results are inconsistent with recent inferences that Entosiphon is the evolutionarily pivotal sister either to other euglenids, or to Spirocuta. At least three transitions between posterior and anterior flagellar gliding occurred in euglenids, with the phylogenetic positions and directions of those transitions remaining ambiguous.

Comparative Microbiome Analysis of Three Species of Laboratory-Reared Periplaneta Cockroaches

Cockroaches inhabit various habitats, which will influence their microbiome. Although the microbiome can be influenced by the diet and environmental factors, it can also differ between species. Therefore, we conducted 16S rDNA-targeted high-throughput sequencing to evaluate the overall bacterial composition of the microbiomes of 3 cockroach species, Periplaneta americana, P. japonica, and P. fuliginosa, raised in laboratory for several generations under the same conditions. The experiments were conducted using male adult cockroaches. The number of operational taxonomic units (OTUs) was not significantly different among the 3 species. With regard to the Shannon and Pielou indexes, higher microbiome values were noted in P. americana than in P. japonica and P. fuliginosa. Microbiome composition was also evaluated, with endosymbionts accounting for over half of all OTUs in P. japonica and P. fuliginosa. Beta diversity analysis further showed that P. japonica and P. fuliginosa had similar microbiome composition, which differed from that of P. americana. However, we also identified that P. japonica and P. fuliginosa host distinct OTUs. Thus, although microbiome compositions may vary based on multiple conditions, it is possible to identify distinct microbiome compositions among different Periplaneta cockroach species, even when the individuals are reared under the same conditions.

Providing essential clinical care for non-COVID-19 patients in a Seoul metropolitan acute care hospital amidst ongoing treatment of COVID-19 patients

We assessed infection control efforts by comparing data collected over 20 weeks during a pandemic under a dual-track healthcare system. A decline in non-COVID-19 patients visiting the emergency department by 37.6% (P<0.01) was observed since admitting COVID-19 cases. However, patients with acute myocardial infarction (AMI), stroke, severe trauma and acute appendicitis presenting for emergency care did not decrease. Door-to-balloon time (34.3 (± 11.3) min vs 22.7 (± 8.3) min) for AMI improved significantly (P<0.01) while door-to-needle time (55.7 (± 23.9) min vs 54.0 (± 18.0) min) in stroke management remained steady (P=0.80). Simultaneously, time-sensitive care involving other clinical services, including patients requiring chemotherapy, radiation therapy and haemodialysis did not change.

Clinical features of subungual melanoma according to the extent of Hutchinson's nail sign: a retrospective single-centre study

BACKGROUND

Hutchinson's nail sign (HS) is among the diagnostic criteria for subungual melanoma (SUM). However, there is minimal evidence supporting the overall clinical significance of HS in SUM.

OBJECTIVES

To identify clinicopathological features of SUM according to the extent of HS.

METHODS

Retrospective cohort study was performed with consecutive SUM patients at a single centre from January 2006 to December 2017. The extent of HS was defined by the number of affected nail folds (range 0-4). Comparison groups were organized as follows: patients with HS (affecting ≥1 nail folds) vs. without HS; patients with HS affecting ≥2 nail folds vs. HS affecting <2 nail folds; patients with HS affecting ≥3 nail folds vs. HS affecting <3 nail folds. Clinicopathological characteristics of SUM were compared between the groups.

RESULTS

Sixty-one SUM patients were included. Forty-six (75.4%) exhibited HS; 22 (47.8%) on a toe and 24 (52.2%) on a finger. In multivariate analysis, nail destruction [hazard ratio (HR), 10.00; 95% confidence interval (CI), 2.61-38.30; P = 0.001] was significantly associated with the presence of HS and amputation was significantly associated with HS affecting ≥2 nail folds (HR, 4.75; 95% CI, 1.36-16.61; P = 0.015). High T stage (HR, 1.85; 95% CI, 1.20-2.85; P = 0.005, Fig. 2) was significantly associated with HS appearing in ≥3 nail folds.

CONCLUSION

Besides its value of detecting SUM, HS provides useful clinical information. The number of nail folds exhibiting HS could be a useful clinical clue for planning therapeutic strategies for SUM.

Genetic and pathogenic diversity of severe fever with thrombocytopenia syndrome virus (SFTSV) in South Korea

To investigate nationwide severe fever with thrombocytopenia syndrome virus (SFTSV) infection status, we isolated SFTSVs from patients with suspected severe fever with thrombocytopenia syndrome (SFTS) in 207 hospitals throughout South Korea between 2013 and April 2017. A total of 116 SFTSVs were isolated from 3137 SFTS-suspected patients, with an overall 21.6% case fatality rate. Genetic characterization revealed that at least 6 genotypes of SFTSVs were co-circulating in South Korea, with multiple reassortments among them. Of these, the genotype B-2 strains were the most prevalent, followed by the A and F genotypes. Clinical and epidemiologic investigations revealed that genotype B strains were associated with the highest case fatality rate, while genotype A caused only one fatality among 10 patients. Further, ferret infection studies demonstrated varying clinical manifestations and case mortality rates with different strains of SFTSV, which suggests this virus could exhibit genotype-dependent pathogenicity.

Topically applied treatments for external genital warts in nonimmunocompromised patients: a systematic review and network meta-analysis

Selecting a topical treatment from among the numerous topical agents for external genital warts remains challenging without clear evidence. Our aim was to evaluate comparatively the efficacy and safety of topical agents for external genital warts using a network meta-analysis. We included all randomized controlled trials that evaluated any topically applied treatment for external genital warts. Using the R package netmeta, network meta-analyses were performed with a frequentist approach. We identified 41 relevant studies comprising 6371 patients. Among conventional agents, podophyllotoxin 0·5% solution (odds ratio 1·94, 95% confidence interval 1·02-3·71) was significantly more efficacious than imiquimod 5% cream for lesion clearance; however, it was associated with a higher overall adverse event rate. Sinecatechins 15% ointment (odds ratio 0·21, 95% confidence interval 0·12-0·34) was significantly less efficacious than imiquimod 5% cream. Idoxuridine, polyhexamethylene biguanide, cidofovir and SB206 showed comparable therapeutic efficacies with conventional therapies. None of the treatments were significantly different from each other with respect to recurrence, patients with severe adverse events, or patients who withdrew because of treatment-related adverse events. Conventional modalities were efficacious and well tolerated, although each of them had their advantages and disadvantages. Additional efficacy and safety studies are warranted for unconventional agents.

Factors associated with HIV/AIDS-related stigma and discrimination by medical professionals in Korea: A survey of infectious disease specialists in Korea

Objectives

This study sought to identify factors associated with this discrimination by medical professionals in Korea.

Subjects and Methods

This study was a cross-sectional survey. We conducted web-based surveys against infectious disease specialists and infectious disease nurse. We evaluated the frequency of human immunodeficiency virus (HIV)/AIDS-related discrimination by medical professionals by health service type on the 5-point scale. We identified the association between several factors and HIV/AIDS-related stigma and discrimination by medical professionals on the 5-point scale.

Results

A total of 81 experts, 57 infectious disease specialists (approximately 27% of all infectious disease specialists in Korea) and 24 infectious disease nurse practitioners, participated in this study. The frequency of stigma and discrimination increased significantly when invasive treatment included both outpatient and inpatient services (both P < 0.05). Medical professional's preconceptions, fear of infection, and lack of knowledge have an association with HIV/AIDS-related stigma and discrimination by medical professionals.

Conclusion

HIV/AIDS-related stigma and discrimination by medical professionals in Korea might be associated with factors related to the fear of medical professionals.

Imaging of toxocariasis

Parasitäre Erkrankungen werden in Europa relativ selten diagnostiziert und behandelt. Somit sind auch klinische Besonderheiten und bildgebende Merkmale weniger bekannt. In den heutigen Zeiten von Migration und weltweiter Flüchtlingsströme ist die Kenntnis parasitärer Infektionen zunehmend von Bedeutung. Anhand von klinischen Beschreibungen der Echinokokkose, Schistosomiasis, Fasciolosis und Ascariasis wurden entsprechende Berichte in der Zeitschrift für Gastroenterologie publiziert. In der hier präsentierten Veröffentlichung werden klinische Besonderheiten und Bildgebungsmerkmale der Toxocariasis diskutiert.

Seroprevalence of Severe Fever with Thrombocytopenia Syndrome Virus Antibodies in Rural Areas, South Korea

We investigated 1,228 residents of 3 rural areas in South Korea and determined that 50 (4.1%) were positive for severe fever with thrombocytopenia syndrome virus antibodies. Fever and gastrointestinal symptoms in the previous 3 years and career duration were associated with virus seropositivity.

The accuracies of abdominal computed tomography and the neutrophil-to-lymphocyte ratio used to predict the development of clinically severe acute cholecystitis in elderly patients visiting an emergency department

Background

Mortality in patients with severe acute cholecystitis (AC) remains high, and the prognosis for elderly patients tends to be poor. A comparative analysis of clinical, laboratory, and abdominal computed tomography (CT) parameters was conducted in this study to investigate the effectiveness of each index for predicting clinically severe AC in elderly patients in the emergency department (ED).

Methods

This was a single-center, retrospective study that included 156 patients (≥65 years of age) with AC who were admitted in the ED between January 2012 and December 2014. Parameters including age, gender, initial clinical findings, laboratory findings, and CT findings in the ED were examined for their ability to predict severity.

Results

Forty-five patients were diagnosed with clinically severe AC. The white blood cell count, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein, erythrocyte sedimentation rate, protein, albumin, and prothrombin time/International Normalized Ratio values were significantly higher in the severe group than in the nonsevere group (P < 0.05). In addition, the CT parameters of increased pericholecystic fat stranding and pericholecystic fluid collection were significantly higher in the severe group than in the nonsevere group (P < 0.001, P < 0.001). Increased pericholecystic fat stranding (odds ratio [OR], 8.17; 95% confidence interval [CI], 2.29-29.22; P = 0.001), pericholecystic fluid collection (OR, 6.55; 95% CI, 1.39-30.92; P = 0.018), and an NLR cutoff value of 9.9 (OR, 4.20; 95% CI, 1.01-17.53; P = 0.049) were independent predictors of severe AC in elderly patients.

Conclusions

The CT parameters of increased pericholecystic fat stranding and pericholecystic fluid collection with an NLR cutoff of 9.9 were useful for predicting the severity of AC in elderly patients in the ED.

Clinical Implication of Tests for Prostate-specific Antigen in Brain-dead Organ Donors

BACKGROUND

Although cancer screening tests are not mentioned under brain-dead organ donor care guidelines in Korea, we assessed the level of prostate-specific antigen (PSA), an important prostate cancer marker, and performed prostate biopsies when needed in brain-dead organ donors. We believe that insisting on a screening test for cancer diagnosis in donors' organs is important.

MATERIALS AND METHODS

Data were collected between January 2010 and July 2015 from Ajou University Hospital. We retrospectively analyzed the PSA levels and prostate biopsy results in 111 male brain-dead organ donors (mean age, 48.4 years).

RESULTS

The mean PSA level was 7.395 ng/mL (range, 0.062 to 61.780; reference, 0 to 4 ng/mL). Ultrasonography or computed tomographic examination did not reveal prostate cancer, and a rectal examination was not performed. After checking the PSA levels, prostate biopsies were performed in 16 patients based on the recommendations of a urologist, and 4 patients (3.6% of 111) were diagnosed with prostate cancer. All cancers involved adenocarcinomas (acinar type) histopathologically. In 2 patients, the Gleason score was 6 (3 + 3), whereas the other 2 showed a score of 7 (3 + 4). Among the patients diagnosed with prostate cancer, 1 donated his liver and corneas, and the remaining 3 could not donate.

CONCLUSION

Well-defined cancer screening tests are needed in Korea. Additionally, when the probability of organ transplantation-induced cancer metastasis is low or a recipient is at a high risk owing to not receiving organs, the law should allow organ donation even if prostate cancer is diagnosed in the donor.

Efficacy and safety of combination therapy with SGLT2 and DPP4 inhibitors in the treatment of type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

This review evaluated the efficacy and safety of a combination therapy comprising a sodium-glucose cotransporter type 2 inhibitor (SGLT2i) and dipeptidyl peptidase-4 inhibitor (DPP4i) in type 2 diabetes.

METHODS

A literature search through to May 2017 was carried out of PubMed, Embase and the Cochrane Central Register of Controlled Trials. Studies were eligible if they were randomized controlled trials (RCTs) comparing SGLT2i plus DPP4i (SGLT2i/DPP4i) against DPP4i±placebo or SGLT2i±placebo and published in English. The primary outcome was change in HbA_1c from baseline.

RESULTS

Eight RCTs comparing SGLT2i/DPP4i and DPP4i, and five RCTs comparing SGLT2i/DPP4i and SGLT2i, with three RCTs involving both comparisons, were included in the present review. SGLT2i/DPP4i resulted in a greater mean HbA_1c reduction [weighted mean difference (WMD]): -0.62%] than did DPP4i alone, which was a much less marked reduction (WMD: -0.35%) than with SGLT2i alone. Also, significant differences in body weight loss from baseline were observed only with SGLT2i/DPP4i vs. DPP4i, but not vs. SGLT2i. The risk of hypoglycaemic events was low and similar between treatment groups. When subjects were stratified based on baseline HbA_1c, any reduction by SGLT2i/DPP4i in relation to DPP4i was proportional to baseline HbA_1c levels. However, compared with SGLT2i, HbA_1c reductions with SGLT2i/DPP4i were modest regardless of baseline HbA_1c.

CONCLUSION

Combination therapy with SGLT2i and DPP4i is both efficacious and safe. In particular, a marked additional glucose-lowering effect is evident when SGLT2i is combined with or added to DPP4i, and not vice versa. However, baseline HbA_1c determined the additional glucose-lowering effects of SGLT2i in combined treatment with DPP4i.

Prevalence and Density of Digenetic Trematode Metacercariae in Clams and Oysters from Western Coastal Regions of the Republic of Korea

A survey was performed to know the recent infection status of digenetic trematode metacercariae in clams and oysters from 4 sites in western coastal regions of the Republic of Korea (=Korea). Four species of clams (Mactra veneriformis, Ruditapes philippinarum, Cyclina sinensis, and Saxidomus purpuratus) were collected from Taean-gun, Chungcheongnam-do (Province), Buan-gun (County) and Gochang-gun, Jeollabuk-do, and oysters, Crassostrea gigas, from Shinan-gun, Jeollanam-do were transferred to our laboratory on ice and examined by the artificial digestion method. The metacercariae of Himasthla alincia were detected in 3 species of clams, M. veneriformis, R. philippinarum, and C. sinensis from the 3 surveyed areas. The positive rate and the mean density per clam infected were 98.9% (30.8 metacercariae) in M. veneriformis, 60.0% (5.0) in R. philippinarum, and 96.0% (28.4) in C. sinensis. The positive rate (mean density) of Acanthoparyphium tyosenense metacercariae in M. veneriformis was 50.0% (2.1) from Taean-gun and 70.0% (2.8) from Gochang-gun. The metacercariae of Parvatrema spp. were detected in M. veneriformis and R. philippinarum from Taean-gun and Gochang-gun; the positive rate (mean density) was 63.3% (4,123) and 50.0% (19) in M. veneriformis, and 6.7% (126) and 100% (238) in R. philippinarum from the 2 regions, respectively. The metacercariae of Gymnophalloides seoi were detected in all 30 oysters from Shinan-gun, and their average density per oyster was 646. From the above results, it has been confirmed that more than 3 species of metacercariae are prevalent in clams from the western coastal regions, and G. seoi metacercariae are still prevalent in oysters from Shinan-gun, Jeollanam-do, Korea

Serological and Molecular Detection of Toxoplasma gondii and Babesia microti in the Blood of Rescued Wild Animals in Gangwon-do (Province), Korea

Infections of Toxoplasma gondii and Babesia microti are reported in many wild animals worldwide, but information on their incidence and molecular detection in Korean wild fields is limited. In this study, the prevalence of T. gondii and B. microti infection in blood samples of 5 animal species (37 Chinese water deer, 23 raccoon dogs, 6 roe deer, 1 wild boar, and 3 Eurasian badgers) was examined during 2008–2009 in Gangwon-do (Province), the Republic of Korea (=Korea) by using serological and molecular tests. The overall seropositivity of T. gondii was 8.6% (6/70); 10.8% in Chinese water deer, 4.3% in raccoon dogs, and 16.7% in roe deer. PCR revealed only 1 case of T. gondii infection in Chinese water deer, and phylogenic analysis showed that the positive isolate was practically identical to the highly pathogenetic strain type I. In B. microti PCR, the positive rate was 5.7% (4/70), including 2 Chinese water deer and 2 Eurasian badgers. Phylogenetic analysis results of 18S rRNA and the β-tubulin gene showed that all positive isolates were US-type B. microti. To our knowledge, this is the first report of B. microti detected in Chinese water deer and Eurasian badger from Korea. These results indicate a potentially high prevalence of T. gondii and B. microti in wild animals of Gangwon-do, Korea. Furthermore, Chinese water deer might act as a reservoir for parasite infections of domestic animals.

Viral and serological kinetics in Zika virus-infected patients in South Korea

Zika virus is a mosquito-borne flavivirus that causes clinical symptoms similar to those observed in dengue and chikungunya virus infections. The Korea Centers for Disease Control and Prevention initiated laboratory testing using a real-time reverse transcription-polymerase chain reaction in January 2016. More than 1,000 suspected cases of infection were tested and nine were confirmed as imported cases of Zika virus infection from January to July 2016. The travel destinations of the infected individuals were Brazil, Philippines, Viet Nam, Guatemala, Puerto Rico, and the Dominican Republic. Phylogenetic analysis based on the partial envelope gene indicated that the viruses belonged to the Asian genotype circulating in South America. We further investigated the duration for which the viral RNA and virus-specific antibodies were detectable after the symptom onset. After the day of symptom onset, Zika virus was detectable until 6 days in serum, 14 days in urine and saliva, and 58 days in semen. Immunoglobulin M against Zika virus was detected as early as 2 days after the symptom onset and was maintained at these levels until 41 days, whereas Immunoglobulin G was detectable from 8 days after the symptom onset and was maintained until 52 days. These findings would help diagnostic laboratories improve their testing programs for Zika virus infection.