Full mouth rehabilitation with fixed implant-supported prosthesis using temporary denture and double digital scanning technique: a case report / 대한치과보철학회지

When restoring with a dental digital system for implant-supported prosthesis, a double digital scanning technique is required: an intraoral scan of the three-dimensional implant location and intraoral scan after placement of temporary denture or provisional prosthesis. During the intraoral scan, the use of scan body as a stable landmark can improve the accuracy of digital impression and simplify laboratory process. In this case, a full-digital system was used to plan and fabricate a custom abutment, provisional prosthesis, and definitive prosthesis. After implant placement, the scan area of the intraoral scan body connected with implant and the intraoral scan body marked on the inside of temporary denture were superimposed. Out of the superimposed files, a custom abutment and provisional prosthesis were fabricated which match the vertical dimension of temporary denture, and definitive prosthesis was fabricated based on provisional prosthesis. We report this case because result has been functionally and esthetically satisfactory by using vertical dimension and central relation set during the fabrication of temporary denture to the definitive prosthesis.

Association between knee osteoarthritis and mortality: a serial propensity score-matched cohort study

Background/Aims@#The association between symptomatic knee osteoarthritis (OA) and higher cardiovascular disease (CVD) mortality is established; however, findings from studies that utilized regression analysis were limited, attributed to the strong association between OA and metabolic risk factors. This study aimed to evaluate the association between knee OA and mortality through propensity score matching. @*Methods@#This was a cohort study including Korean National Health and Nutrition Examination Survey (2010–2013) participants aged ≥ 50 years. By linking the survey data to cause of death data (through 2019) from Statistics Korea, mortality and cause-specific mortality data were obtained. Radiographic knee OA (ROA) was defined as bilateral Kellgren–Lawrence grade ≥ 2. Propensity score matching (1:1) was conducted between asymptomatic ROA, knee pain, and symptomatic ROA groups and normal groups, balancing the confounding factors. Time to death was analyzed using Cox proportional hazard modeling. @*Results@#A higher CVD mortality was observed in the symptomatic ROA group, but not in others; the risk estimates were asymptomatic ROA (hazard ratio [HR] 1.12; 95% confidence interval [CI] 0.77–1.65), knee pain (HR 0.61; 95% CI 0.27–1.38), and symptomatic ROA (HR 1.39; 95% CI 0.89–2.17). No association was found between the all-cause/cancer mortality and other groups. @*Conclusions@#When propensity score matching controls metabolic risk factor imbalances, the association between symptomatic knee OA and higher CVD mortality was weaker compared to results of prior studies that used regression adjustment. The results may be more precise estimates of the total risk of knee OA for mortality in Koreans.

Initial Preserved Renal Function as a Predictor of Favorable Renal Response to Rituximab in Refractory or Relapsing Lupus Nephritis: A Single-center Cohort Study in Korea

Objective@#Previous studies investigating the beneficial effect of rituximab on lupus nephritis (LN) reported controversial results. There have been few reports of renal response to rituximab according to renal function. We investigated the efficacy of rituximab in refractory/relapsing LN and the role of renal function as a predictor of renal response. @*Methods@#From 2016 to 2019, we retrospectively reviewed 22 patients with refractory/relapsing LN receiving rituximab. Renal responses (complete and partial) at 6 and 12 months were compared between normal (glomerular filtration rate [GFR]≥90 mL/min/1.73 m2 , n=11) and decreased (GFR＜90 mL/min/1.73 m2 , n=11) GFR groups. Multivariate Cox regression analysis was used to assess predictors of renal response. @*Results@#At baseline, the decreased GFR group had a higher urine proteinuria to creatinine ratio (p=0.008) and proportion of refractory LN (p=0.010) and previous cyclophosphamide therapy (p=0.035) than the normal GFR group. The overall renal response rate was 45.5% (10 patients) at 6 months and 54.5% (12 patients) at 12 months. Renal response rates were higher in the normal GFR group (81.8% and 90.9% at 6 and 12 months, respectively) than in the decreased GFR group (9.1% and 18.2% at 6 and 12 months, respectively; p＜0.001). Normal GFR and anti-La were associated with renal response to rituximab, with hazard ratios of 9.256 (p=0.008) and 5.478 (p=0.041), respectively. @*Conclusion@#Rituximab is an effective therapy for refractory/relapsing LN, particularly in patients with preserved renal function.

Can reactogenicity predict immunogenicity after COVID-19 vaccination?

Background/Aims@#This study aimed to assess the association between local and systemic reactogenicity and humoral immunogenicity after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. @*Methods@#Adverse events were prospectively evaluated using an electronic diary in 135 healthy adults who received a SARS-CoV-2 vaccine (AZD1222, AstraZeneca/Oxford, n = 42; or BNT162b2, Pfizer/BioNTech, n = 93). We semi-quantitatively measured anti-S1 immunoglobulin G (IgG) using an enzyme-linked immunosorbent assay at baseline, 3 weeks after the first dose of AZD1222 or BNT162b2, and 2 weeks after the second dose of BNT162b2. We evaluated the association between the maximum grade of local or systemic adverse events and the anti-S1 IgG optical density using multivariate linear regression with adjustment for age, sex, and use of antipyretics. @*Results@#The median age of the 135 vaccinees was 30 years (36 years in the AZD1222 group and 29 years in the BNT162b2 group) and 25.9% were male (9.5% in the AZD1222 group and 33.3% in the BNT162b2 group). Local and systemic adverse events were generally comparable after the first dose of AZD1222 and the second dose of BNT162b2. The grades of local and systemic adverse events were not significantly associated with anti-S1 IgG levels in the AZD1222 or BNT162b2 group. @*Conclusions@#Local and systemic reactogenicity may not be associated with humoral immunogenicity after SARS-CoV-2 vaccination.

Treatment Response to Idiopathic Retroperitoneal Fibrosis-associated Hydronephrosis With a Focus on IgG4/IgG3 Serum Concentration Ratio

Objective@#. Hydronephrosis, a common complication of idiopathic retroperitoneal fibrosis (iRPF), may lead to poor renal outcomes unless resolved in a timely manner. IgG4-related diseases characterized by elevated serum IgG4 levels are responsible for a few iRPF cases. However, the underlying immunologic features of most iRPF cases have not been clearly defined, and these cases exhibit varied responses to medical treatment. Thus, we investigated the predictive factors for hydronephrosis-associated outcomes among iRPF patients. @*Methods@#. We retrospectively included 18 iRPF patients with hydronephrosis in a tertiary referral hospital from 2012 to 2019. Hydronephrosis improvement was assessed on images taken 6 months after diagnosis. Categorical variables were compared using chi-square or Fisher’s exact test. Continuous variables were compared using Mann–Whitney U-test. @*Results@#. On follow-up images, 8 patients (44.4%) showed an improvement in hydronephrosis. Patients with improvement more frequently had reverse serum IgG4/IgG3 ratio (87.5% vs. 30%, p=0.025), abdominal aorta involvement (87.5% vs. 30%, p=0.025) and glucocorticoid treatment administration (87.5% vs. 30%, p=0.025) than those without improvement. The proportion of elevated serum IgG4 level did not differ between the two groups.Even in the 14 cases with normal serum IgG4 levels, reverse serum IgG4/IgG3 ratio was more frequently observed in patients with improvement than in those without improvement (83.3% vs. 12.5%, p=0.026). @*Conclusion@#. The reverse serum IgG4/IgG3ratio was associated with hydronephrosis improvement in iRPF patients, suggesting it to be a suitable serologic marker for predicting favourable responses to glucocorticoid treatment.

Virus Isolation from the First Patient with SARS-CoV-2 in Korea

Novel coronavirus (SARS-CoV-2) is found to cause a large outbreak started from Wuhan since December 2019 in China and SARS-CoV-2 infections have been reported with epidemiological linkage to China in 25 countries until now. We isolated SARS-CoV-2 from the oropharyngeal sample obtained from the patient with the first laboratory-confirmed SARS-CoV-2 infection in Korea. Cytopathic effects of SARS-CoV-2 in the Vero cell cultures were confluent 3 days after the first blind passage of the sample. Coronavirus was confirmed with spherical particle having a fringe reminiscent of crown on transmission electron microscopy. Phylogenetic analyses of whole genome sequences showed that it clustered with other SARS-CoV-2 reported from Wuhan.

Virus Isolation from the First Patient with SARS-CoV-2 in Korea

Novel coronavirus (SARS-CoV-2) is found to cause a large outbreak started from Wuhan since December 2019 in China and SARS-CoV-2 infections have been reported with epidemiological linkage to China in 25 countries until now. We isolated SARS-CoV-2 from the oropharyngeal sample obtained from the patient with the first laboratory-confirmed SARS-CoV-2 infection in Korea. Cytopathic effects of SARS-CoV-2 in the Vero cell cultures were confluent 3 days after the first blind passage of the sample. Coronavirus was confirmed with spherical particle having a fringe reminiscent of crown on transmission electron microscopy. Phylogenetic analyses of whole genome sequences showed that it clustered with other SARS-CoV-2 reported from Wuhan.

Virus Isolation from the First Patient with SARS-CoV-2 in Korea

Novel coronavirus (SARS-CoV-2) is found to cause a large outbreak started from Wuhan since December 2019 in China and SARS-CoV-2 infections have been reported with epidemiological linkage to China in 25 countries until now. We isolated SARS-CoV-2 from the oropharyngeal sample obtained from the patient with the first laboratory-confirmed SARS-CoV-2 infection in Korea. Cytopathic effects of SARS-CoV-2 in the Vero cell cultures were confluent 3 days after the first blind passage of the sample. Coronavirus was confirmed with spherical particle having a fringe reminiscent of crown on transmission electron microscopy. Phylogenetic analyses of whole genome sequences showed that it clustered with other SARS-CoV-2 reported from Wuhan.

Comparison of Clinical, Angiographic Features and Outcome in Takayasu's Arteritis and Behçet's Disease With Arterial Involvement

OBJECTIVE@#Takayasu's arteritis (TAK) is a vasculitis that primarily involves the aorta and its branches. In Behçet's disease (BD), systemic vasculitis is one of major manifestations. We aimed to compare clinical and angiographic features and outcome between TAK and BD with arterial involvement.@*METHODS@#We retrospectively reviewed medical records of 206 TAK patients and 50 BD patients between 1995 and 2015. Angiographic lesions were evaluated via computed tomography, magnetic resonance imaging, and/or conventional angiography.@*RESULTS@#Fever (30% vs. 9.2%, p<0.001) and arthralgia (36% vs. 7.3%, p<0.001) were more common in BD. C-reactive protein was higher in BD compared with TAK (5.85 mg/dL vs. 2.08 mg/dL, p<0.001). Stenosis (89.8% vs. 60%, p<0.001) and occlusion (65.5% vs. 32%, p<0.001) were more observed in TAK. In contrast, aneurysm was common in BD (62% vs. 20.9%, p<0.001). The carotid artery (73.3% vs. 30%, p<0.001), subclavian artery (71.4% vs. 16%, p<0.001), descending aorta (35% vs. 12%, p=0.002), renal artery (23.8% vs. 10%, p=0.032), superior mesenteric artery (18.4% vs. 4%, p=0.012), and brachiocephalic trunk (13.6% vs. 2%, p=0.020) were more commonly involved in TAK, whereas the femoral artery (10% vs. 2.4%, p=0.027) was more frequently involved in BD. During follow-up, arterial dissection (10% vs. 1.9%, p=0.016), rupture (12% vs. 0.5%, p<0.001), and arterial replacement/resection (66% vs. 9.7%, p<0.001) were more observed in BD.@*CONCLUSION@#TAK differs from BD regarding clinical features and vascular involvement patterns. BD exhibits a higher rate of vascular complications.

In vitro activity of lopinavir/ritonavir and hydroxychloroquine against severe acute respiratory syndrome coronavirus 2 at concentrations achievable by usual doses

Background/Aims@#As the coronavirus disease-2019 global pandemic progresses, screening of antiviral agents effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is urgently needed. In addition, considering the viral load kinetics of SARS-CoV-2, which peaks early in the illness, and the massive burden of the disease, which may increase in the near future, identifying well-tolerated oral antivirals becomes increasingly important. We examined the in vitro activity of lopinavir/ritonavir and hydroxychloroquine on SARS-CoV-2, at concentrations which can be used to treat coronavirus-19 patients with little concern of toxicity. @*Methods@#Lopinavir/ritonavir (7/1.75 μg/mL), hydroxychloroquine base (1 or 2 μg/mL), or a combination thereof were administered 1 hour after the inoculation of SARS-CoV-2 to Vero cells at a multiplicity of infection of 0.05. We examined cytopathic effects of virus 48 hours after administration of the respective treatments and measured viral loads at three time points (0, 24, and 48 hours post-treatment) by quantitative real-time reverse-transcription polymerase chain reaction, and compared the results obtained from the different antiviral regimens tested. @*Results@#The severity of cytopathic effects was lower in lopinavir/ritonavir-treated cells, and viral load was significantly reduced in this group compared with the control group (p < 0.001). However, hydroxychloroquine did not show significant inhibitory effects on anti-SARS-CoV-2-mediated cytotoxicity or on viral load at either concentration. @*Conclusions@#Lopinavir/ritonavir showed significant inhibitory effects on SARS-CoV-2 in vitro at its usual plasma concentration. However, the in vitro antiviral activity of hydroxychloroquine at concentrations commonly used in humans was minimal, whether used alone or in combination with lopinavir/ritonavir.

Liver enzyme elevation in patients with ankylosing spondylitis treated with tumor necrosis factor inhibitors: a single-center historical cohort study

Background/Aims@#Tumor necrosis factor inhibitors (TNFi) have been known to induce liver enzyme elevation, sometimes associated with viral reactivation or toxic hepatitis. We evaluated the incidence and risk factors of TNFi-associated liver enzyme elevation in Korean ankylosing spondylitis (AS) patients who previously had normal liver enzymes. @*Methods@#Retrospectively, we collected data from the records of 363 AS patients treated with TNFi at a tertiary hospital from 2003 to 2017. Liver enzyme elevation was defined as abnormal elevation of aspartate aminotransferase and/or alanine aminotransferase levels on two or more consecutive visits. Patients with previously diagnosed liver disease were excluded. @*Results@#The incidence of liver enzyme elevation was 23.7% (occurring in 86 of 363 patients). The median duration of TNFi exposure before liver enzyme elevation was 3.72 months (interquartile range, 1.77 to 12.51). There was no difference in the occurrence of liver enzyme elevation with concomitant disease-modifying anti-rheumatic drugs and TNFi compared to TNFi alone (23.9% vs. 23.6%). In multivariate analysis, the hazard ratios for liver enzyme elevation were 4.62 (95% confidence interval [CI], 1.43 to 15.01) for male sex, 4.06 (95% CI, 2.11 to 7.84) for underlying non-alcoholic fatty liver disease, and 2.53 (95% CI, 1.38 to 4.64) for hyperlipidemia. After switching to another TNFi, the liver enzyme elevation was not normalized in nine of 13 patients. @*Conclusions@#Liver enzyme elevation was observed in a quarter of patients with AS receiving a TNFi. Male sex, non-alcoholic fatty liver disease, and hyperlipidemia were independent risk factors for liver enzyme elevation. Switching to another TNFi had a limited effect on restoring normal liver enzyme levels.

Adolescent Type 2 Autoimmune Pancreatitis / 대한내과학회지

There are two forms of autoimmune pancreatitis (AIP). Type 1 is associated with immunoglobulin G4 (IgG4)-related systemic fibro- inflammatory disease, whereas type 2 AIP is localized to the pancreas and not associated with IgG4. The number of children presenting with type 2 AIP has recently increased. Here, we report a case of type 2 AIP in a 16-year-old adolescent who presented with clinical acute pancreatitis and associated pancreatic masses. He was diagnosed with type 2 AIP based on pancreatic biopsy results showing granulocytic epithelial lesions and supportive radiological imaging and steroid responsiveness.

Endoscopic Transpapillary Gallbladder Stenting for Acute Cholecystitis in a Patient with Metastatic Pancreatic Cancer / 대한내과학회지

Percutaneous transhepatic gallbladder drainage is an effective treatment for acute cholecystitis in poor surgical candidates. Endoscopic gallbladder drainage procedures, such as endoscopic ultrasound-guided gallbladder drainage, endoscopic gallbladder stenting, and endoscopic naso-gallbladder drainage, have been used as alternative treatments for acute cholecystitis. These procedures are associated with increased patient comfort and physiologic drainage. We report a case of endoscopic gallbladder stenting for acute cholecystitis in a 62-year-old male undergoing chemotherapy for metastatic pancreatic cancer. After endoscopic gallbladder stenting, the patient’s acute cholecystitis resolved and he was able to undergo scheduled chemotherapy. The inserted double-pigtail plastic stent will be left in situ permanently. The choice of drainage modality for acute cholecystitis will generally be based on resources, patient preferences, local expertise, and clinical context.

Infliximab-Induced Lupus in Crohn's Disease / 대한내과학회지

Infliximab (IFX) is an anti-tumor necrosis factor (TNF) monoclonal antibody used to treat rheumatoid arthritis, ankylosing spondylitis, and Crohn's disease. Rarely, anti-TNF-induced lupus (ATIL) may occur. ATIL differs from classical drug-induced lupus. We report a 49-year-old woman who developed polyarthralgia after 2 years of IFX treatment for Crohn's disease. Based on the autoantibody profiles, ATIL was diagnosed and low-dose glucocorticoid, hydroxychloroquine, and celecoxib were prescribed. However, arthralgia and hemolytic anemia developed. Because the anti-dsDNA titers waxed and waned, she was switched to vedolizumab, a monoclonal antibody to the human lymphocyte α4β7 integrin. Six months after switching treatment, the arthralgia had improved and the anti-dsDNA antibody normalized. Here, we report a case of ATIL that resolved after switching from infliximab to vedolizumab.

Association between the Nutritional Status at Birth and Need for Respiratory Support on the First Day of Life

PURPOSE: Nutritional markers, such as total protein, albumin, and vitamin D have been reportedly associated with neonatal outcomes. This study aimed to assess the correlation between nutritional markers at birth and the need for respiratory support on the first day of life. METHODS: This retrospective study included 94 newborns admitted to the neonatal intensive care unit of Kyungpook National University Children's Hospital between March and December 2017. We measured levels of nutritional markers, including serum total protein, albumin, ferritin, 25-hydroxyvitamin D (25-OHD), and prealbumin, from cord blood or blood sample within 24 hours after birth. Respiratory support was defined as the use of nasal continuous positive airway pressure, humidified high-flow nasal cannula, or mechanical ventilation on the first day of life. RESULTS: The mean gestational age and birth weight were 36.6±2.3 weeks and 2,714±575 g, respectively. Serum total protein, albumin, prealbumin, and ferritin levels at birth were significantly correlated with gestational age and birth weight. Total protein, albumin, ferritin, and 25-OHD levels were not correlated with the time to recover birth weight after adjusting for gestational age. Moreover, prealbumin levels at birth were significantly lower in small-for-gestational-age infants than in appropriate-for-gestational-age infants. The need for respiratory support on the first day of life decreased 0.058- and 0.001-fold for every 1 g/dL increase in serum total protein (95% confidence interval [CI], 0.004 to 0.833; P=0.036) and albumin (95% CI, 0.000 to 0.136; P=0.009) levels, respectively. CONCLUSION: Nutritional status at birth could be associated with the need for respiratory support on the first day of life, regardless of the Apgar score.

Clustering and Switching Patterns in Semantic Fluency and Their Relationship to Working Memory in Mild Cognitive Impairment

BACKGROUND AND PURPOSE: Semantic verbal fluency test is a neuropsychological assessment that can sensitively detect neuropathological changes. Considering its multifactorial features tapping various cognitive domains such as semantic memory, executive function, and working memory, it is necessary to examine verbal fluency performance in association with underlying cognitive functions. The objective of the current study was to investigate semantic fluency patterns of people with mild cognitive impairment (MCI) based on clustering and switching and their relationship with working memory. METHODS: Twenty-six individuals with MCI and 23 normal elderly adults participated in this study. A semantic verbal fluency test (animal version) was administered and the performance was analyzed using the following measures: number of correct words, cluster size, and number of switches. Scores of digit forward (DF) and backward span tasks were employed as working memory measures. RESULTS: Analyses of variance revealed significant group differences in the numbers of correct words and switches. Multivariate logistic regression and receiver-operating characteristic analyses showed that the number of switches more sensitively distinguished MCI existence than the number of correct words. Stepwise linear regression analysis showed that DF task and age significantly predicted the number of correct words while only the DF task significantly predicted the number of switches. CONCLUSIONS: Decrement in semantic verbal fluency in MCI seems to be associated with impaired switching abilities. Working memory capacity might serve as the underlying cognitive factor related to decreased verbal fluency in MCI.

Infliximab-Induced Lupus in Crohn's Disease / 대한내과학회지

Infliximab (IFX) is an anti-tumor necrosis factor (TNF) monoclonal antibody used to treat rheumatoid arthritis, ankylosing spondylitis, and Crohn's disease. Rarely, anti-TNF-induced lupus (ATIL) may occur. ATIL differs from classical drug-induced lupus. We report a 49-year-old woman who developed polyarthralgia after 2 years of IFX treatment for Crohn's disease. Based on the autoantibody profiles, ATIL was diagnosed and low-dose glucocorticoid, hydroxychloroquine, and celecoxib were prescribed. However, arthralgia and hemolytic anemia developed. Because the anti-dsDNA titers waxed and waned, she was switched to vedolizumab, a monoclonal antibody to the human lymphocyte α4β7 integrin. Six months after switching treatment, the arthralgia had improved and the anti-dsDNA antibody normalized. Here, we report a case of ATIL that resolved after switching from infliximab to vedolizumab.

Sudden Deaths of Neonates Receiving Intravenous Infusion of Lipid Emulsion Contaminated with Citrobacter freundii

At an intensive care unit, four neonates died consecutively within 80 minutes. Citrobacter freundii was isolated from blood samples of the 4 patients. It was also cultured from the leftover SMOFlipid that had been infused intravenously into the patients. In this in vitro study, we evaluated the bacterial growth kinetics and change in size of fat globules in SMOFlipid contaminated with C. freundii. Following the growth of bacteria, pH of SMOFlipid decreased to < 6, and the number of fat globules larger than 5 µm increased. Pulmonary fat embolism is proposed as a possible cause of the sudden deaths as well as fulminant sepsis.

Effects of Mirror Therapy Using a Tablet PC on Central Facial Paresis in Stroke Patients

OBJECTIVE: To investigate the effects of mirror therapy using a tablet PC for post-stroke central facial paresis. METHODS: A prospective, randomized controlled study was performed. Twenty-one post-stroke patients were enrolled. All patients performed 15 minutes of orofacial exercise twice daily for 14 days. The mirror group (n=10) underwent mirror therapy using a tablet PC while exercising, whereas the control group (n=11) did not. All patients were evaluated using the Regional House–Brackmann Grading Scale (R-HBGS), and the length between the corner of the mouth and the ipsilateral earlobe during rest and smiling before and after therapy were measured bilaterally. We calculated facial movement by subtracting the smile length from resting length. Differences and ratios between bilateral sides of facial movement were evaluated as the final outcome measure. RESULTS: Baseline characteristics were similar for the two groups. There were no differences in the scores for the basal Modified Barthel Index, the Korean version of Mini-Mental State Examination, National Institutes of Health Stroke Scale, R-HBGS, and bilateral differences and ratios of facial movements. The R-HBGS as well as the bilateral differences and ratios of facial movement showed significant improvement after therapy in both groups. The degree of improvement of facial movement was significantly larger in the mirror group than in the control group. CONCLUSION: Mirror therapy using a tablet PC might be an effective tool for treating central facial paresis after stroke.

In vitro antiviral activity of ribavirin against severe fever with thrombocytopenia syndrome virus

BACKGROUND/AIMS: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by severe fever with thrombocytopenia syndrome virus (SFTSV), a novel bunyavirus. As yet, there is no effective antiviral therapy for SFTS. Ribavirin is a broad-spectrum antiviral agent, which has been tried for treatment of SFTS. In this study, antiviral activity of ribavirin against SFTSV has been investigated. METHODS: Vero cell-grown SFTSV strain Gangwon/Korea/2012 was treated with ribavirin at various concentrations. Antiviral activity of ribavirin was evaluated by inhibition of the SFTSV cytopathic effect in Vero cells and quantification of viral RNA load in culture supernatant using one-step real-time reverse transcription polymerase chain reaction. Cytotoxicity of ribavirin was determined by a tetrazolium-based colorimetric method. RESULTS: Ribavirin reduced SFTSV titers in a dose-dependent manner, with a half-maximal inhibitory concentration ranged from 3.69 to 8.72 μg/mL. Cytopathic effects were reduced as ribavirin concentration increased. No significant cytotoxicity was detected at ribavirin concentrations of ≤ 31.3 μg/mL. CONCLUSIONS: Ribavirin exhibited inhibitory activity against SFTSV replication in vitro, which suggests that ribavirin can be used as a potential antiviral agent for SFTS.