scholarly journals Nationwide Incidence of Chigger Mite Populations and Molecular Detection of Orientia tsutsugamushi in the Republic of Korea, 2020

2021 ◽  
Vol 9 (8) ◽  
pp. 1563
Author(s):  
Min-Goo Seo ◽  
Bong-Goo Song ◽  
Tae-Kyu Kim ◽  
Byung-Eon Noh ◽  
Hak Seon Lee ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
Republic Of Korea ◽  
Orientia Tsutsugamushi ◽  
Wild Rodents ◽  
Chigger Mite ◽  
Disease Epidemiology ◽  
Tsutsugamushi Disease ◽  
Control And Prevention ◽  
Disease Risks ◽  
The Republic

The Korea Disease Control and Prevention Agency has established regional centers at 16 locations to monitor vectors and pathogens. We investigated the geographical and temporal distribution of chigger mite populations to understand tsutsugamushi disease epidemiology in 2020. To monitor weekly chigger mite populations, 3637 chigger mites were collected from sticky chigger mite traps in autumn. Chigger mites appeared from the first week of October to the third week of December, peaking in the fourth week of October. The predominant species were Leptotrombidium scutellare, Leptotrombidium palpale, Neotrombicula kwangneungensis, Neotrombicula tamiyai, and Leptotrombidium pallidum. To monitor Orientia tsutsugamushi infection in chigger mites, 50,153 chigger mites were collected from 499 trapped wild rodents in spring and autumn, with a chigger index of 100.5. Approximately 50% of chigger mites were pooled into 998 pools, and the minimum infection rate (MIR) of O. tsutsugamushi was 0.1%. Jeongeup had the highest MIR for O. tsutsugamushi (0.7%). The Kato-related genotype was the most common (52.2%), followed by the Karp-related (17.4%), Boryong (13.0%), JG-related (8.7%), Shimokoshi (4.3%), and Kawasaki (4.3%) genotypes. Ecological and geographical studies focusing on the basic ecology and pathology of mites will improve our understanding of tsutsugamushi disease risks in the Republic of Korea.

scholarly journals Surveillance of Chigger Mite Vectors for Tsutsugamushi Disease in the Hwaseong Area, Gyeonggi-do, Republic of Korea, 2015

2020 ◽  
Vol 58 (3) ◽  
pp. 301-308
Author(s):  
Young Yil Bahk ◽  
Hojong Jun ◽  
Seo Hye Park ◽  
Haneul Jung ◽  
Seung Jegal ◽  
...  
Keyword(s):  
Communicable Disease ◽  
Global Climate ◽  
Republic Of Korea ◽  
Human Populations ◽  
Wild Rodents ◽  
Chigger Mite ◽  
Tsutsugamushi Disease ◽  
Vector Borne ◽  
The Republic ◽  
Abundance And Distribution

Owing to global climate change, the global resurgence of vector-borne infectious diseases and their potential to inflict widespread casualties among human populations has emerged as a pivotal burden on public health systems. Tsutsugamushi disease (scrub typhus) in the Republic of Korea is steadily increasing and was designated as a legal communicable disease in 1994. The disease is a mite-borne acute febrile disease most commonly contracted from October to December. In this study, we tried to determine the prevalence of tsutsugamushi disease transmitted by chigger mites living on rodents and investigated their target vector diversity, abundance, and distribution to enable the mapping of hotspots for this disease in 2015. A total of 5 species belonging to 4 genera (109 mites): Leptotrombidium scutellare 60.6%, L. pallidum 28.4% Neotrombicula tamiyai 9.2%, Euschoengastia koreaensis/0.9%), and Neoschoengastia asakawa 0.9% were collected using chigger mite collecting traps mimicking human skin odor and sticky chigger traps from April to November 2015. Chigger mites causing tsutsugamushi disease in wild rodents were also collected in Hwaseong for the zoonotic surveillance of the vector. A total of 77 rodents belonging to 3 genera: Apodemus agrarius (93.5%), Crocidura lasiura (5.2%), and Micromys minutus (1.3%) were collected in April, October, and November 2015. The most common mite was L. pallidum (46.9%), followed by L. scutellare (18.6%), and L. orientale (18.0%). However, any of the chigger mite pools collected from rodent hosts was tested positive for Orientia tsutsugamushi, the pathogen of tsutsugamushi disease, in this survey.

scholarly journals Epidemiology of CoVID-19 and predictors of recovery in the Republic of Korea

2020 ◽  
Author(s):  
Ashis Kumar Das ◽  
Saji Saraswathy Gopalan
Keyword(s):  
Case Fatality ◽  
Evidence Base ◽  
Republic Of Korea ◽  
Current Evidence ◽  
Age Group ◽  
Multivariable Logistic Regression Model ◽  
Healthcare Settings ◽  
Control And Prevention ◽  
Vulnerable Patient ◽  
The Republic

AbstractBackgroundThe recent CoVID-19 pandemic has emerged as a threat to global health. Though current evidence on the epidemiology of the disease is emerging, very little is known about the predictors of recovery.ObjectivesTo describe the epidemiology of confirmed CoVID-19 patients in Republic of Korea and identify predictors of recovery.Materials and methodsUsing publicly available data for confirmed CoVID-19 cases from the Korea Centers for Disease Control and Prevention from January 20, 2020 to April 30, 2020, we undertook descriptive analyses of cases stratified by sex, age group, place of exposure, date of confirmation and province. Correlation was tested among all predictors (sex, age group, place of exposure and province) with the Pearson’s correlation coefficient. Associations between recovery from CoVID-19 and predictors were estimated using a multivariable logistic regression model.ResultsMajority of the confirmed cases were females (56%), from 20-29 age group (24.3%), and primarily from three provinces –– Gyeongsangbuk-do (36.9%), Gyeonggi-do (20.5%) and Seoul (17.1%). Case fatality ratio was 2.1% and 41.6% cases recovered. Older patients, patients from provinces such as Daegu, Gyeonggi-do, Gyeongsangbuk-do, Jeju-do, Jeollabuk-do and Jeollanam-do, and those contracting the disease from healthcare settings had lower recovery.ConclusionsOur study adds to the very limited evidence base on potential predictors of survival among confirmed CoVID-19 cases. We call additional research to explore the predictors of recovery and support development of policies to protect the vulnerable patient groups.

scholarly journals Geographical Distribution of Borrelia burgdorferi sensu lato in Ticks Collected from Wild Rodents in the Republic of Korea

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 866
Author(s):  
Seong Yoon Kim ◽  
Tae-Kyu Kim ◽  
Tae Yun Kim ◽  
Hee Il Lee
Keyword(s):  
Sequence Analysis ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Jeju Island ◽  
Republic Of Korea ◽  
Borrelia Burgdorferi Sensu Lato ◽  
Wild Rodents ◽  
The Republic ◽  
Tick Vectors ◽  
Pcr Targeting

Lyme disease is a tick-borne zoonotic disease caused by Borrelia burgdorferi sensu lato (s. l.) via transmission cycles involving competent tick vectors and vertebrate reservoirs. Here, we determined the prevalence and distribution of Borrelia genospecies in 738 ticks of at least three species from wild rodents in nine regions of the Republic of Korea (ROK). Ticks were analyzed using nested PCR targeting partial flagellin B gene sequences, followed by sequence analysis. The prevalence of Borrelia infection was 33.6%, and the most common genospecies were B. afzelii (62.5%), B. valaisiana (31.9%), B. yangtzensis (2.4%), B. garinii (1.6%), and B. tanukii (1.6%). Borrelia afzelii was found in all regions except Jeju Island; this predominant genospecies was found in the northern and central sampling regions. Borrelia valaisiana, B. yangtzensis, and B. tanukii were found only in the southern regions with B. valaisiana being the most common, whereas B. yangtzensis and B. tanukii were only found on Jeju Island. Our study is the first to describe the nationwide prevalence of B. burgdorferi s. l. in ticks from wild rodents in the ROK. Continuous surveillance in ticks, animals, humans, and different regions is required to avoid disease distribution and possible transmission to humans in the ROK.

scholarly journals Epidemiological Characteristics of Rodents and Chiggers with Orientia Tsutsugamushi in the Republic of Korea

2020 ◽  
Vol 58 (5) ◽  
pp. 559-564
Author(s):  
Jung Wook Park ◽  
Dae Sung Yu ◽  
Gi Seong Lee ◽  
Jin Jong Seo ◽  
Jae Keun Chung ◽  
...  
Keyword(s):  
Risk Factors ◽  
Logistic Regression ◽  
Regression Analysis ◽  
Preventive Measures ◽  
Republic Of Korea ◽  
Orientia Tsutsugamushi ◽  
Rural Region ◽  
The Republic ◽  
Human Infections ◽  
Epidemiological Characteristics

A survey of rodents and chiggers associated with Orientia tsutsugamushi was conducted in a rural region of the Republic of Korea (Korea) between 2014 and 2018. Overall Apodemus agrarius 15.2% had the highest seropisitive for O. tsutsugamushi, followed by Myodes regulus 11.4%. Monthly risk factors using logistic regression analysis were not associated with O. tsutsugamushi infections in rodents. The overall prevalence rate of O. tsutsugamushi among chiggers was 0.3%. The chigger (Leptotrombidium scutellare) and monthly (October) risk factors were associated with O. tsutsugamushi human infections (P<0.05). Orientia tsutsugamushi infections are endemic in rodents in Korea and people, for example, soldiers who are active outdoors, must employ preventive measures, especially during October (P<0.05). When there are many reports of O. tsutsugamushi infections in Korea. The Boryong strain 85.7% (2/14) was the most common strain detected in chiggers, followed by the Shimokoshi 7.1% (1/14) and Karp 7.1% strains.

scholarly journals National Monitoring of Mosquito Populations and Molecular Analysis of Flavivirus in the Republic of Korea in 2020

2021 ◽  
Vol 9 (10) ◽  
pp. 2085
Author(s):  
Min-Goo Seo ◽  
Hak Seon Lee ◽  
Sung-Chan Yang ◽  
Byung-Eon Noh ◽  
Tae-Kyu Kim ◽  
...  
Keyword(s):  
Mosquito Species ◽  
Migratory Bird ◽  
Republic Of Korea ◽  
Armigeres Subalbatus ◽  
National Monitoring ◽  
Control And Prevention ◽  
The Republic ◽  
Flavivirus Infection ◽  
Genotype V

The Korea Disease Control and Prevention Agency has established centers at 16 locations to screen vector populations and pathogens. The aims of this study were to determine the relative spatiotemporal distributions of mosquitoes that are flavivirus vectors, and to correlate them with instances of flaviviral disease in the Republic of Korea (ROK). We collected 67,203 mosquitoes in traps at 36 collection sites in 30 urban regions and migratory bird habitats in 2020. The trap index was 36.6, and the predominant mosquito species were the Culex pipiens complex, Armigeres subalbatus, Aedes albopictus, Aedes vexans, and Culex tritaeniorhynchus. The mosquitoes were pooled into 4953 pools to monitor flavivirus infection. We determined that the minimum infection rate of flavivirus was 0.01%. Japanese encephalitis virus (JEV) was detected in only seven pools of Culex orientalis from Sangju, and we isolated JVE from two pools. All detected JEV was found to be genotype V by phylogenetic analysis. To the best of our knowledge, this is the first study to isolate genotype V JVE from Culex orientalis in the ROK. Subsequent geographical and ecological studies on mosquitoes will help improve our understanding of the relative risk of flavivirus infection. Future studies should analyze mosquito species distribution and improve flavivirus monitoring and long-term surveillance.

scholarly journals 1648. Prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in Striped Field Mice in Gwangju, Republic of Korea

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S602-S603
Author(s):  
Dong-Min Kim ◽  
Mi Seon Bang ◽  
Choon-Mee Kim ◽  
Na Ra Yun ◽  
Jun-won Seo
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Immunofluorescence Assay ◽  
Republic Of Korea ◽  
Leptospira Interrogans ◽  
Orientia Tsutsugamushi ◽  
Wild Rodents ◽  
Passive Hemagglutination ◽  
Blood Samples ◽  
Suburban Areas ◽  
Close Proximity

Abstract Background Scrub typhus, anaplasmosis, and leptospirosis are well-known diseases that are considered common, widespread rodent-borne infectious diseases Methods This study investigated the prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in wild rodents through molecular detection using organ samples and through serological assay using blood samples of mice collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea (ROK). Results A total of 47 wild rodents, identified as Apodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in A. agrarius sera was analyzed; 17.4% (8/46) were identified as O. tsutsugamushi through indirect immunofluorescence assay and 2.2% (1/46) were identified as Leptospira species through passive hemagglutination assay. Using polymerase chain reaction, the spleen, kidney and blood samples were investigated for the presence of O. tsutsugamushi, A. phagocytophilum, and L. interrogans. Out of the 47 A. agrarius, 19.1% (9/47) were positive for A. phagocytophilum and 6.4% (3/47) were positive for L. interrogans, while none were positive for O. tsutsugamushi. Four out of 46 (8.7%) blood samples, six out of 45 (13.3%) spleen samples, and one out of 47 (2.1%) kidney samples were positive for A. phagocytophilum. Three out of 47 (6.4%) kidney samples were positive for L. interrogans. The sequencing results of PCR positive samples demonstrated >99% similarity with A. phagocytophilum and L. interrogans sequences Conclusion A. phagocytophilum was mostly detected in the spleen, whereas L. interrogans was mostly detected in the kidneys. Notably, A. phagocytophilum and L. interrogans were detected in A. agrarius living in close proximity to humans in the metropolitan suburbans. The results of this study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban areas of ROK Disclosures All authors: No reported disclosures.

scholarly journals Rodent-borne bacterial infections in Gwangju, Korea

2018 ◽  
Author(s):  
Mi Seon Bang ◽  
Choon-Mee Kim ◽  
Dong-Min Kim ◽  
Na Ra Yun
Keyword(s):  
Bacterial Infections ◽  
Bacterial Pathogens ◽  
Immunofluorescence Assay ◽  
Republic Of Korea ◽  
Wild Rodents ◽  
Passive Hemagglutination ◽  
Suburban Areas ◽  
Metropolitan City ◽  
Close Proximity ◽  
The Republic

AbstractBackgroundThis study investigated the prevalence ofOrientia tsutsugamushi, Anaplasma phagocytophilum,andLeptospira interroganin wild rodents through molecular detection in organ samples collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea.Methodology/Principal FindingsA total of 47 wild rodents, identified asApodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in rodent sera was analyzed; 17.4% (8/46) were identified asO. tsutsugamushithrough indirect immunofluorescence assay and 2.2% (1/46) were identified asLeptospiraspp. through passive hemagglutination assay. Using molecular methods, the spleen, kidney, and blood samples were evaluated for the presence ofO. tsutsugamushi, A. phagocytophilum, andL. interrogans. Out of 47 wild rodents, 25.5% (12/47) were positive for bacterial pathogens by PCR, where 19.1% (9/47) were positive forA. phagocytophilumand 6.4% (3/47) were positive forL. interrogans, while none were positive forO. tsutsugamushi. In addition, testing for bacterial infection in different tissues indicated that 8.7% (4/46) were positive forA. phagocytophilumin the blood, 13.3% (6/45) were positive forA. phagocytophilumin the spleen, and 6.4% (3/47) and 2.1% (1/47) were positive forL.interrogansandA. phagocytophilum, respectively, in the kidney.Conclusions/SignificanceIn this study, tropisms forA. phagocytophilumin the spleen andL. interrogansin the kidney were identified. Notably,A. phagocytophilumandL. interroganswere detected in wild rodents living in close proximity to humans in the metropolitan suburban areas. Results of the present study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban area of Republic of Korea.Author SummaryMany zoonotic diseases are spreading not only in the Republic of Korea (ROK), but also worldwide. Scrub typhus, anaplasmosis, and leptospirosis are well known diseases that are considered common, widespread rodent-borne infectious diseases. Rodents serve as important reservoirs for zoonotic pathogens such asO. tsutsugamushi, A. phagocytophilum, andL. interrogans,which may be fatal to humans. Our study demonstrated the prevalence of these pathogens in wild rodents, through molecular assays and seroprevalence in organ samples. We captured 47 wild rodents in the Gwangju metropolitan city area of ROK. All were identified asA. agrarius. The prevalence of rodent-borne bacteria was 17.4% in the sera, where 25.5% was positively detected as bacterial pathogens via polymerase chain reaction. Our results indicate the importance of detecting rodent-borne bacteria in wild rodents living close to humans in suburban areas of ROK. Our data was limited to only a few samples of rodents in two regions. More samples may have to be collected over longer periods of time, to investigate the infectious nature of these pathogens in detail.

scholarly journals Epidemiology of COVID-19 and Predictors of Recovery in the Republic of Korea

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Ashis Kumar Das ◽  
Saji Saraswathy Gopalan
Keyword(s):  
Case Fatality ◽  
Evidence Base ◽  
Republic Of Korea ◽  
Current Evidence ◽  
Age Group ◽  
Multivariable Logistic Regression Model ◽  
Healthcare Settings ◽  
Control And Prevention ◽  
Vulnerable Patient ◽  
The Republic

Background. The recent COVID-19 pandemic has emerged as a threat to global health. Though current evidence on the epidemiology of the disease is emerging, very little is known about the predictors of recovery. Objectives. To describe the epidemiology of confirmed COVID-19 patients in the Republic of Korea and identify predictors of recovery. Materials and Methods. Using publicly available data for confirmed COVID-19 cases from the Korea Centers for Disease Control and Prevention from January 20, 2020, to April 30, 2020, we undertook descriptive analyses of cases stratified by sex, age group, place of exposure, date of confirmation, and province. Correlation was tested among all predictors (sex, age group, place of exposure, and province) with Pearson’s correlation coefficient. Associations between recovery from COVID-19 and predictors were estimated using a multivariable logistic regression model. Results. Majority of the confirmed cases were females (56%), 20-29 age group (24.3%), and primarily from three provinces—Gyeongsangbuk-do (36.9%), Gyeonggi-do (20.5%), and Seoul (17.1%). The case fatality ratio was 2.1%, and 41.6% cases recovered. Older patients, patients from provinces such as Daegu, Gyeonggi-do, Gyeongsangbuk-do, Jeju-do, Jeollabuk-do, and Jeollanam-do, and those contracting the disease from healthcare settings had lower recovery. Conclusions. Our study adds to the very limited evidence base on potential predictors of recovery among confirmed COVID-19 cases. We call additional research to explore the predictors of recovery and support development of policies to protect the vulnerable patient groups.

scholarly journals Monitoring Chigger Mites for Orientia tsutsugamushi in Field Small Mammals in Hwaseong-si, Gyeonggi-do, Korea, 2019-2020

2021 ◽  
Vol 59 (3) ◽  
pp. 319-324
Author(s):  
Young Yil Bahk ◽  
Seong Kyu Ahn ◽  
Jinyoung Lee ◽  
Hyung Wook Kwon ◽  
Sung Jong Hong ◽  
...  
Keyword(s):  
Small Mammals ◽  
Scrub Typhus ◽  
Rapid Diagnosis ◽  
The Other ◽  
Orientia Tsutsugamushi ◽  
Chigger Mite ◽  
Apodemus Agrarius ◽  
Tsutsugamushi Disease ◽  
Pcr Test

Incidence of tsutsugamushi disease (scrub typhus) caused by Orientia tsutsugamushi, is steadily increasing. It is a mite-borne disease transmitted by chigger mites. In this study, the chigger mites were collected from field small mammals in Hwaseong-si (city), Gyeonggi-do (province), Korea, 2019 and 2020. The field small mammals captured were 56 Apodemus agrarius (94.9%) and 3 Crocidura lasiura (5.1%). A total of 7,531 chigger mites were collected from the captured small mammals. Using PCR test, 153 chigger mite pools were examined and 17 pools were reported positive for O. tsutsugamushi. The O. tsutsugamushi were identified to 5 strains; Jecheon strain was most prevalent, followed by Boryong strain. The other strains were OI011, Taguchi, and Shimokoshi. Collectively, these results provide essential regional information on mite-borne tsutsugamushi disease in the Hwaseong-si, and further contribute to bring awareness and rapid diagnosis for the tsutsugamushi disease.

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