Severe Fever with Thrombocytopenia Syndrome (SFTS) is a newly emerging tick-borne disease caused by the SFTS virus (SFTSV), which belongs to the phlebovirus in the Bunyaviridae family. SFTSV is enveloped with a tripartite ambisense RNA genome. The L segment encodes the viral RNA-dependent RNA polymerase, the M segment encodes the two glycoproteins, Gc and Gn, and the S segment encodes the nucleoprotein (NP) and the nonstructural protein (NSs). NP participates in ribonucleoprotein (RNP) packaging and commonly detected early after infection, suggesting that the N protein is possible to be used as a target antigen for early diagnosis of SFTSV infection. In this study, we analyzed a highly immunogenic multi-epitope using GnGc and NP genes from a consensus sequence of SFTSV strain isolated from infected patients in Korea. The selected genes are constructed to the expression vector plasmid pJHL65 and the recombinant plasmid vector was transformed into the Δasd Δlon ΔcpxR Salmonella Typhimurium attenuated strain JOL912 and the expression of these antigens was verified by immunoblotting assay. We observed the significant levels of systemic IgG and mucosal IgM responses against the JOL912-derived antigen in the immunized BALB/c mice. The level of CD3+CD4+, CD3+CD8+ T lymphocyte subpopulation and TNF-α were also highly regulated in splenic T cells re-stimulated in vitro with NP and Gn/Gc multi-epitope selected antigens. Therefore, immunized mice with NP and Gn/GC multi-epitope recombinant proteins of attenuated Salmonella delivery system elicited T cell-related immune response, inducing an effective immune response. In conclusion, the attenuated Salmonella expressing NP-GnGc multi-epitopes could be a novel vaccine candidate against the SFTS virus.

A tick survey was conducted to monitor ticks using tick traps attached dry ice method at each four sites in Ulju and Gimhae counties, Gyeongsangnam-do from April to November, 2023. Two species belonging to one genera were collected with tick traps. A total of 1,064 ticks were collected as Haemaphysalis longicornis (Trap Index; TI 11.0), Haemaphysalis flava (TI <0.1) in Ulju and A total of 843 ticks were collected as Haemaphysalis longicornis (Trap Index; TI 8.7), Haemaphysalis flava (TI 0.1) in Gimhae 2023. Haemaphysalis longicornis was the most frequently collected, representing 99.2% in Ulju, 98.9% in Gimhae. In the collection environments, a total number of 685, 268, 64, and 47 ticks were collected from a glassland, a copse, a mountain path, and a grave of Ulju a total number of 469, 216, 83, and 75 ticks were collected from a glassland, a copse, a Grave, and a mountain path of Gimhae respectively. In the results of the isolation of Severe Fever with Thrombocytopenia Syndrome (SFTS) from the ticks, no pathogens were detected from RNA of 101 pools (Ulju), 98 pools (Gimhae) of the ticks using a Polymerase Chain Reaction method in 2023.

Q fever is a highly infectious tick-borne zoonotic disease caused by Coxiella burnetii, a major pathogen that can cause reproductive disorders in ruminants such as cattle. Being one of the livestock infectious diseases with uncelar causative factors and transmission routes, there is a high possibility of transmission between wildlife, disease vectors, and livestock. Despite extensive research due to its high infectivity and significant economic losses, much of the focus has been on aspects such as pathogen detection, immunodiagnosis, and veterinary medicine. However, understanding the ecological interaction between the vector (ticks) and reservoir hosts (rodents) is crucial for elucidation the transmission dynamics to livestock. In this presentation, we aim to discuss genetic variation analysis approaches and ecological co-occcurrence analysis to understand the transmission pathways between rodents, ticks, and cow.

African swine fever (ASF) is a hemorrhagic viral disease of pigs requiring laboratory diagnosis for confirmation. Though tissue and blood samples are considered optimal for ASF diagnosis, collection of these samples can be laborious, time-consuming, and pose a risk of contaminating the environment. Here, we suggest an alternative non-invasive sampling method, hair plucking, for ASF diagnosis. ASF virus was detected in plucked hair samples from experimentally infected pigs. Although the sensitivity was inferior to whole blood, the results suggest that hair plucking can be an alternative method that can also improve animal welfare.

Since the first detection of African swine fever (ASF)-infected wild boar in October 2019, the ASF virus has been circulating among wild boars in the Republic of Korea. The priority for ASF control is to understand the epidemic situation correctly. The basic reproduction number (R0) can be used to describe the contagious disease epidemic situation since it can assess the contagiousness of infectious agents by presenting the average number of new cases generated by an infected case. The current study estimated R0 for the 2019/20 ASF epidemics in wild boars in the Republic of Korea using the reported number of ASF cases and a serial interval of the ASF virus. The estimated mean R0 was 2.10 (range: 0.06 – 10.24) for the 2019/20 ASF epidemics, 2.94 (range: 0.43 – 9.89) for the 2019 ASF epidemics, and 2.00 (range: 0.06 – 11.10) for the 2020 ASF epidemics. In addition, the estimated mean R0 was 3.82 (range: 1.16 – 8.78) in winter, 1.39 (range: 0.16 – 6.30) in spring, 4.82 (range: 0.26 – 17.08) in summer, and 2.21 (range: 0.51 – 5.86) in fall. Even though the Korean government has applied ASF control measures, including hunting or fencing, the ASF epidemic situation in wild boars has intensified. For ASF control in wild boars, tailor-made hunting, wild boar management, or active searching for carcasses are required to reduce the ASF virus. For ASF prevention in domestic pigs, no contact between wild boars and domestic pigs and a biosecurity plan by veterinarians are needed to decrease the risk of ASF virus transmission from wild boars to domestic pigs.

Since the first detection of the African swine fever (ASF) virus in the Republic of Korea in 2019, the Korean government has applied interventions, including fencing, increasing the biosecurity level at domestic pig farms, and the capture-and-removal of wild boars. In particular, wild boars are an important risk factor for ASF control because they can spread disease among susceptible animals, such as wild boars or domestic pigs. A capture-and-removal method aims to reduce the likelihood of ASF transmission from wild boars to domestic boars or among wild boars by decreasing the number of susceptible wild boars. This study estimated the required number of wild boars captured and removed for ASF control using population viability analysis. Population factors, such as a life span, sex ratio, or an inbreeding depression with different capture-and-removal proportions of wild boars, were included in the analysis. Ten scenarios with different capture-and-removal proportions of wild boars and different periods of culling were considered. According to the results, a method in which 75% of wild boars are captured-and-removed for at least three years showed long-term effectiveness for more than ten years. The current ASF control method, in which 33% of wild boars are captured-and-removed, decreased the number of wild boars for three years, after which the wild boar population increased to more than its initial number. Given the limited human and material resources for controlling ASF in the Republic of Korea, it is recommended that resources be prioritized to increase the capture-and-removal proportion of wild boars to take full advantage of the ASF-control effectiveness.

We report a massive outbreak of human Q fever cases, which occurred at totally 11 humans. The occurrence was related to a goat farm where Coxiella burnetii infection was diagnosed from goat tissues and environmental specimens. From January of 2018, continuous abortions from 6 goats occurred. Laboratory tests from 77 goat specimens for C. burnetii showed that 54 (70.1%) and 63 (81.8%) goats were positive by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The infection was also confirmed from the farmer, his wife and 9 persons from all 16 veterinary officials who had visited the farm for protective measures and preparing goat specimens for laboratory tests. The farm was found to be extensively contaminated with C. burnetii from the examination to the environmental specimens and epidemiological inspections, which might be the main source of C. burnetii infection to humans. The extensive contamination to the farm was derived from the uncareful handling of postpartum animal tissues or discharges by the farm owner. This report will contribute to the establishment of educational system on the biosecurity to novice farmers.

The milk fever and mastitis that occur during the colostrum period in dairy cattle cause great damage in the dairy industry by causing a rapid decline in the cattle’s health and decreasing milk production. In order to prevent this, gradual milking (GM), calcium injection with gradual milking (CG), and calcium injection with complete milking (CC) methods are used. However, differences in effectiveness between these methods have not been established. Therefore, this study was conducted to determine the effects of each preventive method on milk fever and mastitis. The results of this study showed that while there was a significant negative correlation of GM with milk fever and mastitis (r = –0.657, p < 0.05), there was no correlation of CG and CC with milk fever and mastitis. The incidence of milk fever was significantly lower in CG and CC than in GM (p < 0.05) but no differences in the incidence of mastitis were observed between the three groups. No significant differences in the rate of recovery from milk fever and mastitis were observed between the three groups. The recurrence rate of milk fever was significantly higher in CG and CC than in GM (p < 0.05), though no differences in the recurrence rate of mastitis were observed. This study showed an inverse relationship between the incidence rates of milk fever and mastitis when calcium injection was not used during the colostrum period. When calcium injections were used, the incidence of milk fever was reduced without affecting the incidence of mastitis regardless of the milking method, but the recurrence rate of milk fever was increased. The results of this study would be useful for controlling blood calcium concentrations and establishing efficient milking strategy in order to effectively prevent milk fever and mastitis in dairy cattle during the colostrum period.

Ixodidae에 속하는 일부 참진드기들은 중증열성혈소판감소증후군(severe fever with thrombocytopenia syndrome; SFTS)을 비롯한 질병을 매개하는 공중보건학적으로 중요한 해충이다. 우리나라에서는 2013년 이후로 SFTS 환자 발생수가 지속적으로 증가하는 경향을 보이며, 경상북도는 전국적으로 2번째로 많은 SFTS 환자가 발생하는 지역이다. 본 연구에서는 2019년 경북 상주 지역의 진드기 분포를 조사하기 위해 시민의 생활 반경 주변을 도심 녹지지역, 관리 취약지역 및 농촌지역으로 구별하여 flagging 방법을 통해 진드기를 채집하였고, 채집 진드기내 SFTS 바이러스 보균 여부를 조사하였다. 채집된 진드기 수를 Collection Index (CI = tick number / 1h / 2 people)로 산출한 결과, 상주시 내 총 26개 지점에서 작은소피참진드기와 개피참진드기, 일본참진드기를 포함하는 총 CI 143의 진드기가 채집되었고, 그 중 작은소피참진드기가 96.5%(CI 138)로 우점종으로 확인되었다. 채집된 진드기의 약 92%(131 CI)는 인적이 드물고 시청이나 관계 당국의 관리가 이루어지지 않는 관리 취약지역에서 채집되었으나, 도심의 녹지지역와 농촌 지역에서는 8.4%(CI 12)의 진드기만 관찰되었다. 총 CI 143의 진드기를 26개 pooling 한 후 SFTS 바이러스 존재 여부를 조사하였으나, 모두 음성으로 확인되었다. 본 연구의 결과는 지역주민들로 하여금 진드기 매개 질병으로부터 안전한 생활을 하기 위한 권고 자료로 활용할 수 있을 것으로 기대된다.

Purpose: This study aimed to examine the effects of simulation-based learning on the critical thinking disposition, communication confidence, and performance confidence in nursing care for children with fever. Method: A one-group pre- and post-test design was used. A total of 59 nursing students participated. Results: The results of this study showed that the effectiveness of simulation-based learning showed statistically significant improvement in critical thinking disposition, communication confidence and performance confidence. Conclusion: The findings indicate that simulation-based learning in the nursing care of children with fever may be an effective teaching-learning method for nursing students.

A tick survey was conducted to monitor ticks using tick traps attached dry ice and a flagging method at each four sites in Busan, Ulju, and Geoje areas of Gyeongnam Province from April to November, 2018. Haemaphysalis longicornis was the most frequently collected, representing 99.8% in Ulju. A total of 27,247 ticks were collected as H. longicornis (Trap Index; TI 283.2), H. flava (TI 0.3), and Ix. nipponensis (TI 0.3). In the collection environment, a total number of 15,672, 5,798, 4,876, and 901 ticks were collected from glassland, tump, tomb, and mountain path, respectively. On the other hand, H. longicornis and Ix. nipponensis were collected with flaggings at the four sites in Ulju, Busan, and Geoje in May and June, 2018. A total of 1,517 ticks collected H. longicornis (Flagging Index; FI 9.3) and Ix. nipponensis (FI 0.1) in Ulju. Haemaphysalis longicornis were collected 2,183 (FI 13.6) and 1,596 (FI 10.0) in Geoje and Busan, respectively. In the results of the isolation of Severe Fever with Thrombocytopenia Syndrome (SFTS) from the ticks, no pathogens detected from RNA of 557 pools of the ticks using a Polymerase Chain Reaction method in 2018.

Milk fever is a metabolic disease with manifestation of clinical signs due to hypocalcemia, which usually occurs within 48-72 h after delivery. However, even after a successful treatment of milk fever, recurrence of milk fever may occur, and studies on recurrent milk fever are still lacking. Accordingly, the present study was conducted for the purpose of identifying the characteristics of recurrent milk fever according to farm, season, parity, and dystocia that can cause physiological changes in the mother during peri- and postpartum periods. The analysis results showed that the incidence rate of initial and recurrent milk fever according to breeding farm was 5.7%-14.1% and 3.1%-7.2%, respectively, demonstrating a positive correlation between the initial and recurrent milk fever (r = 0.613, p < 0.01). With respect to season, the incidence rate of initial and recurrent milk fever during summer was 12.3% and 7.5%, respectively, which were significantly higher than that of other seasons (p < 0.05). In addition, the recurrence rate, the ratio of recurrence relative to initial milk fever, was highest during summer with 62.7%. Regarding parity, the incidence rate of initial and recurrent milk fever in 3rd parity was 11.1% and 5.8%, respectively, which was significantly higher than in 1st and 2nd parity (p < 0.05). Furthermore, the recurrence rate in 4th parity was 64.1%, showing a pattern of increase in incidence rate with increase in parity. Finally, there were no differences in the incidence rate of initial and recurrent milk fever according to eutocia and dystocia. The findings indicated that the incidence rate of initial milk fever should be reduced to effectively prevent the recurrent milk fever, while animals with 3rd parity or higher should be expected to occur high rate of recurrent milk fever, especially during summer, and the necessary preparations should be made for intensive treatment of such individuals.