Ascertaining injury risk issues through big data analysis: text-mining based analysis of national emergency response data.

Objectives: Injury prevention can be achieved through various interventions, but it faces challenges due to its comprehensive nature and susceptibility to external environmental factors, making it difficult to detect risk signals. Moreover, the reliance on standardized systems leads to the construction and statistical analysis of numerous injury surveillance data, resulting in significant temporal delays before being utilized in policy formulation. This study was conducted to quickly identify substantive injury risk problems by employing text mining analysis on national emergency response data, which have been underutilized so far. Methods: With emerging issue and topic analyses, commonly used in science and technology, we detected problematic situations and signs by deriving injury keywords and analyzing time-series changes. Results: In total, 65 injury keywords were identified, categorized into hazardous, noteworthy, and diffusion accidents. Semantic network analysis on hazardous accident terms refined the injury risk issues. Conclusion: An increased risk of winter epidemic fractures due to extreme weather, self-harm due to depression (especially drug overdose and self-mutilation), and falls was observed in older adults. Thus, establishing effective injury prevention strategies through inter-ministerial and interagency cooperation is necessary.

Interference micro/nanolenses of salts for local modulation of Raman scattering.

Micro/nanolenses play a crucial role in optics and spectroscopy, but the effect of interference patterns within each lens has been largely unexplored. Herein, we investigate modulation of Raman scattering by the interference within a single micro/nanolens of a hygroscopic salt. Lenses having two different diameter (d) ranges, d > 2 µm and d ∼1 µm, are placed on a silicon substrate, followed by collection of a Raman intensity map of the silicon peak. Lenses with d > 2 µm show dark and bright circular fringes in the Raman map, resembling the Newton's rings formed by optical interference. In the smaller lenses (d ∼1 µm), the map yields only a single peak at the center, representing either an intensity maximum or minimum. In both diameter ranges, whether the Raman intensity is enhanced or suppressed is determined by interference conditions, such as wavelength of the excitation laser or thickness of the SiO2 layer. The interference in salt micro/nanolenses finds applications in local modulation of Raman scattering of a nanoscale object, as demonstrated in individual single-walled carbon nanotubes decorated with the salt lenses.

Prevalence, incidence, and outcomes of hepatitis E virus coinfection in patients with chronic hepatitis C.

This study aimed to elucidate the anti-hepatitis E virus (HEV) immunoglobulin G (IgG) prevalence and incidence of seroconversion and seroreversion as well as its risk factors and to analyze the clinical outcomes of HEV and hepatitis C virus (HCV) coinfected patients compared to those of HCV-monoinfected patients. We prospectively enrolled 502 viremic HCV patients with paired plasma samples (at intervals of ≥ 12 months) from 5 tertiary hospitals. Anti-HEV IgG positivity was tested using the Wantai ELISA kit in all paired samples. Mean age was 58.2 ± 11.5 years old, 48.2% were male, 29.9% of patients had liver cirrhosis, and 9.4% of patients were diagnosed with hepatocellular carcinoma (HCC). The overall prevalence of anti-HEV IgG positivity at enrollment was 33.3%, with a higher prevalence in males and increasing prevalence according to the subject's age. During the 916.4 person-year, the HEV incidence rate was 0.98/100 person-years (9/335, 2.7%). Hepatic decompensation or liver-related mortality was not observed. There were six seroreversion cases among 172 anti-HEV-positive patients (1.22/100 person-years). In conclusion, approximately one-third of the adult Korean chronic HCV patients were anti-HEV IgG positive. The HEV incidence rate was 1 in 100 persons per year, without adverse hepatic outcomes or mortality.

Etiology and clinical characteristics of acute viral hepatitis in South Korea during 2020-2021: a prospective multicenter study.

This prospective, 12-center study investigated the etiology and clinical characteristics of acute viral hepatitis (AVH) during 2020-2021 in South Korea, and the performance of different diagnostic methods for hepatitis E virus (HEV). We enrolled 428 patients with acute hepatitis, of whom 160 (37.4%) were diagnosed with AVH according to predefined serologic criteria. The clinical data and risk factors for AVH were analyzed. For hepatitis E patients, anti-HEV IgM and IgG were tested with two commercial ELISA kits (Abia and Wantai) with HEV-RNA real-time RT-PCR. HAV, HEV, HBV, HCV, Epstein-Barr virus (EBV), cytomegalovirus, and herpes simplex virus accounted for AVH in 78.8% (n = 126), 7.5% (n = 12), 3.1% (n = 5), 1.9% (n = 3), 6.9% (n = 11), 1.2% (n = 2), and 0.6% (n = 1) of 160 patients (median age, 43 years; men, 52.5%; median ALT, 2144 IU/L), respectively. Hospitalization, hemodialysis, and intensive care unit admission were required in 137 (86.7%), 5 (3.2%), and 1 (0.6%) patient, respectively. Two patients developed acute liver failure (1.3%), albeit without mortality or liver transplantation. Ingestion of uncooked clams/oysters and wild boars' blood/bile was reported in 40.5% and 16.7% of patients with HAV and HEV, respectively. The concordance rate between the anti-HEV-IgM results of both ELISA kits was 50%. HEV RNA was detected in only 17% of patients with HEV. The diagnosis of HEV needs clinical consideration due to incomplete HEV diagnostics.

Profile of Nivolumab in the Treatment of Resected Esophageal Squamous Cell Carcinoma: A Review of the Clinical Data.

Esophageal cancer (EC) is the seventh most common malignancy globally. There are two main histological subtypes: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma. ESCC is the predominant histological type of esophageal cancer worldwide and has worse prognosis than esophageal adenocarcinoma. However, effective treatment for patients with ESCC remains limited. Moreover, the risk of recurrence remains high in patients with resectable ESCC even with perioperative multidisciplinary treatment, such as chemoradiotherapy or chemotherapy. Nivolumab, a human monoclonal immunoglobulin G4 antibody that inhibits programmed cell death protein 1, has recently been identified as a potential treatment for patients with metastatic esophageal cancer based on the results of the ATTRACTION-3 and CheckMate 648 trials. The CheckMate 577 trial showed survival benefits of postoperative nivolumab monotherapy compared with placebo in patients with resectable locally advanced esophageal cancer who did not achieve a pathological complete response after preoperative chemoradiotherapy. In this review, we discuss the data on the efficacy and safety of postoperative nivolumab and share future perspectives on immune checkpoint inhibitors as perioperative therapy for patients with locally advanced ESCC.

First case report of splenomegaly with splenic infarction due to aortic graft infection.

BACKGROUND: Diagnosis of aortic graft infections (AGI) is challenging. Here, we report a case of AGI with splenomegaly and splenic infarction. CASE PRESENTATION: A 46-year-old man who underwent total arch replacement for Stanford type A acute aortic dissection one year prior presented to our department with fever, night sweat, and a 20-kg weight loss over several months. Contrast-enhanced computed tomography (CT) revealed splenic infarction with splenomegaly, fluid collection, and thrombus around the stent graft. Positron emission tomography-CT (PET-CT) revealed abnormal 18F-fluorodeoxyglucose uptake in the stent graft and spleen. Transesophageal echocardiography revealed no vegetations. The patient was diagnosed with an AGI and underwent graft replacement. Blood and tissue cultures in the stent graft yielded Enterococcus faecalis. After the surgery, the patient was successfully treated with antibiotics. CONCLUSIONS: Splenic infarction and splenomegaly are the clinical findings of endocarditis but are rare in graft infection. These findings could be helpful to diagnose graft infections, which is often challenging.

Radiologic changes of long term foot insole use in symptomatic pediatric flatfoot.

Clinically, flatfoot, known as pes planus, is quite prevalent. It is classified into 2 types: flexible and rigid, both of which may or may not have symptoms. If a flexible flatfoot is symptomatic, it must be treated to prevent subsequent complications. In principle, most physicians initially use conservative methods, such as foot insoles. This study aimed to demonstrate the effect of long term use of a foot insole using plain radiography as an objective measurement in children with symptomatic flexible flatfoot (SFFF) in large samples. This study analyzed the medical records of 292 children aged < 18 years who were diagnosed with SFFF. Of these, 200 children (62 boys and 138 girls, mean age: 6.49 ± 2.96 years) were selected and conservatively treated with foot insoles. They were periodically followed up within 3 to 4 months to modify the foot insole and perform radiologic evaluations, such as foot radiography. The calcaneal pitch angle (CPA) and talo first metatarsal angle were measured and compared individually using foot lateral radiographs, which were pictured in a bilateral barefoot state. The treatment was terminated by repeating the same procedure until the symptoms disappeared. A significant improvement (P < .001) was observed in the radiological indicators, both CPA and talo first metatarsal angle, regardless of age, after the application of soft foot insoles. However, the right foot CPA in the group with valgus deformity was an exception (P = .078). This study showed that in children diagnosed with SFFF under 18 years of age, wearing a periodically revised foot insole as conservative treatment could not only decrease the symptoms, but also improve the radiologic indices.

A nurse-led mHealth intervention to alleviate depressive symptoms in older adults living alone in the community: A quasi-experimental study.

BACKGROUND: The prevalence of geriatric depression has increased worldwide, becoming a major contributor to the burden of health care costs. Geriatric depression is difficult to detect in daily life because of its atypical presentation for each person. Therefore, there is an emerging need to develop personalised mHealth interventions for older adults with depression based on data from an ecological momentary assessment. OBJECTIVE: To develop and evaluate the effect of a nurse-led mHealth intervention of geriatric depression in older adults living alone. DESIGN: A quasi-experimental research design was used, and the study followed the transparent reporting of evaluations with a nonrandomised design statement. SETTING: The nurse-led mHealth intervention was developed and evaluated in a community senior centre in Seoul, Korea. PARTICIPANTS: Sixty-four older adults living alone with depressive symptoms were recruited between 1 October 2018 and 1 October 2019. METHODS: Study participants were randomly assigned to the intervention or control groups by drawing lots. In the intervention group, nurses repeatedly assessed older adults' depressive symptoms using an ecological momentary assessment via a mobile tablet. The intervention consisted of weekly sessions, which included (1) standardised mHealth device training, (2) a nurse-led mHealth programme, and (3) art activities. The control group received care as usual. Intra- and inter-group differences were evaluated using paired t-tests and analysis of covariance was used to assess subjective depression symptoms. A linear mixed-model was used to analyse the relationship between groups and momentary scores over time. RESULTS: The average age of the final sample was 76.2 years (SD = 6.06), 63.6 % (28/44) of whom were female. Compared with the control group (n = 23), the intervention group (n = 21) showed a decreased depression score (t = 4.041, p = .027). There was no statistical difference between the intervention and control groups based on traditional scales and the ecological momentary assessment. However, our data from the ecological momentary assessment captures clear fluctuating patterns across the days during the study, which traditional scales could not measure. CONCLUSIONS: Most of the older adults successfully participated in a nurse-led mHealth intervention that included multiple components of a non-pharmacological approach to address depression. Mental health nurses should perform critical roles to personalise mHealth activities considering the older adult's autonomy and supportive decision-making, specifically when using high-technological intervention. Future research should maximise the methodological and clinical advantage of an ecological momentary assessment of geriatric depression. REGISTRATION: Clinical Research Information Service number KCT0005073.

Developing a Multimodal Monitoring System for Geriatric Depression: A Feasibility Study.

The Internet of Medical Things is promising for monitoring depression symptoms. Therefore, it is necessary to develop multimodal monitoring systems tailored for elderly individuals with high feasibility and usability for further research and practice. This study comprised two phases: (1) methodological development of the system; and (2) system validation to evaluate its feasibility. We developed a system that includes a smartphone for facial and verbal expressions, a smartwatch for activity and heart rate monitoring, and an ecological momentary assessment application. A sample of 21 older Koreans aged 65 years and more was recruited from a community center. The 4-week data were collected for each participant (n = 19) using self-report questionnaires, wearable devices, and interviews and were analyzed using mixed methods. The depressive group (n = 6) indicated lower user acceptance relative to the nondepressive group (n = 13). Both groups experienced positive emotions, had regular life patterns, increased their self-interest, and stated that a system could disturb their daily activities. However, they were interested in learning new technologies and actively monitored their mental health status. Our multimodal monitoring system shows potential as a feasible and useful measure for acquiring mental health information about geriatric depression.

Effectiveness of Novel Sympathetic Nerve Entrapment Point Injections for Chronic Migraine: A Pilot Study.

No studies to date have investigated the ability of sympathetic nerve entrapment point saline (SNEP) injections to achieve long-term pain relief in patients with migraine. Therefore, this study aimed to investigate the safety and long-term efficacy of repeat splenius capitis (SC) SNEP injections in patients with migraine (with/without tension-type headache). This retrospective, single-arm study included 12 patients with migraine. Isotonic saline was injected into their SC approximately six times for 3 months. Headache frequency, duration (hour/week), intensity (using the visual analog scale), and quality of life (using the Headache Impact Test-6) were assessed during the follow-up visits for up to 24 months after the first injection. Changes before and after treatment were assessed using repeated-measures analysis of variance. Significant reductions in headache frequency, duration, and intensity were observed at all assessment points after SNEP injections when compared with the baseline values (p < 0.05), while the patients' headache-related quality of life also improved. Treatment was continued for up to 3 months to maintain these improvements, and no worsening of status or adverse effects were observed in any of the patients over the following 24 months. Our results show that SNEP injections may offer persistent, substantial, and clinically relevant benefits in patients with migraine.

Hepatic Encephalopathy Caused by Long-Term Amiodarone Use.

This case describes a 72-year-old Japanese woman with hypertrophic cardiomyopathy and non-sustained ventricular tachycardia who had received a total of 215 g of amiodarone over six years and presented with hepatic encephalopathy. The abdominal non-contrast computed tomography showed diffusely increased attenuation of the liver parenchyma. The liver biopsy revealed drug-induced steatohepatitis. No genetic variations in the urea cycle were found. She was ultimately diagnosed with drug-induced steatohepatitis and urea cycle abnormalities caused by long-term amiodarone use. Amiodarone may cause drug-induced steatohepatitis and urea cycle abnormalities, which could induce hyperammonemia. Although case reports of amiodarone-induced hyperammonemia and hepatic encephalopathy have already been reported, we present a typical picture of an amiodarone-induced bright liver, including the mechanism of amiodarone-induced hyperammonemia, to provide an educational learning point for many readers.

Utility of ultrasound as a promising diagnostic tool for stroke-related sarcopenia: A retrospective pilot study.

Stroke patients undergo extensive changes in muscle mass which lead to stroke-related sarcopenia. Stroke-related sarcopenia has a significant impact on the functional outcome of stroke survivors. So, it is important to measure muscle mass in stroke patients. This study aimed to examine the correlation between ultrasonographic quadriceps muscle thickness (QMT) and dual-energy X-ray absorptiometry (DXA) derived appendicular lean mass (ALM) in patients with acute hemiplegic stroke. Twenty five participants were included (13 men and 12 women) in this study, who were diagnosed with stroke within 1 month. For both paretic and non-paretic legs, QMT was measured by an ultrasound and ALM was obtained by performing DXA scan. We analyzed the difference and the correlation between ultrasonographic QMT and DXA-derived lean body mass of both paretic and non-paretic legs. Stroke patients were divided into 2 groups according to the paretic knee extensor power. Ultrasonographic QMT, DXA scan findings, and functional parameters were compared. There was a significant correlation between QMT and ALM index, and between QMT and site-specific lean mass (SSLM) of both the legs for both the sexes (P < .05). In multivariate linear regression model, we made adjustments for the confounding factors of age, sex, body mass index (BMI) and paretic knee extensor power. We observed a positive relationship between QMT and ALM index (P < .05), and between QMT and SSLM of both the legs (P < .05). The % QMT showed higher difference than % SSLM between paretic and non-paretic legs (10.25% vs 4.58%). The QMT measurements of ultrasound show a great relationship with DXA scan findings. Ultrasound better reflects the change of muscle mass between paretic and non-paretic legs than DXA scan at an acute phase of stroke. Ultrasound could be a useful tool to evaluate stroke-related sarcopenia.

A Pilot Analysis on the Efficacy of Multiple Trigger-Point Saline Injections in Chronic Tension-Type Headache: A Retrospective Observational Study.

This study aimed to investigate the efficacy of new targeted trigger-point injections (TPIs) using isotonic saline in patients with chronic tension-type headache (CTTH). Of 121 patients with headache who were retrospectively reviewed, 19 were included in this study and were categorized into two groups: those who received TPIs more than four times (group 1); and those who received TPIs less than, or equal to, four times (group 2). The patients received ultrasound-guided isotonic saline injections into the active trigger points once weekly. The primary outcome was an effect on headache intensity, determined using the visual analog scale (VAS), whereas the secondary outcome was an effect on quality of life, evaluated using the Henry Ford Hospital Headache Disability Inventory (HDI). The mean symptom duration of the 19 patients (11 men and 8 women; mean age, 52.5 years; and range, 23−81 years) was 16 months. The most frequently injected muscle was the splenius capitis. Patient demographics were similar between the two groups (p > 0.05). Simple linear regression revealed that symptom duration (p = 0.001) and baseline VAS score (p = 0.009) were significantly associated with the number of injections. At one month after the first injection, the mean VAS and HDI scores in group 2 were significantly lower than those in group 1 (p < 0.05), whereas the scores significantly decreased immediately after the last injection in both groups (p < 0.05). No adverse effects were reported in any patient. Our results indicate that the administration of new targeted TPIs using isotonic saline into the head and neck muscles of patients with CTTH can effectively relieve headache intensity and safely improve their quality of life.

Actuating compact wearable augmented reality devices by multifunctional artificial muscle.

An artificial muscle actuator resolves practical engineering problems in compact wearable devices, which are limited to conventional actuators such as electromagnetic actuators. Abstracting the fundamental advantages of an artificial muscle actuator provides a small-scale, high-power actuating system with a sensing capability for developing varifocal augmented reality glasses and naturally fit haptic gloves. Here, we design a shape memory alloy-based lightweight and high-power artificial muscle actuator, the so-called compliant amplified shape memory alloy actuator. Despite its light weight (0.22 g), the actuator has a high power density of 1.7 kW/kg, an actuation strain of 300% under 80 g of external payload. We show how the actuator enables image depth control and an immersive tactile response in the form of augmented reality glasses and two-way communication haptic gloves whose thin form factor and high power density can hardly be achieved by conventional actuators.

Trend Analysis of the Profiles of 12 Sexually Transmitted Disease Pathogens in the Republic of Korea in 2019.

BACKGROUND: Sexually transmitted diseases (STDs) are common infectious diseases in humans transmitted through unprotected sexual activities. In South Korea, despite the high annual incidence of STDs, detailed examinations of pathogen-specific factors and causes for delays in diagnosis and treatment are still lacking. Furthermore, STD prevalence patterns and important pathogen-specific factors remain unclear. Herein, we retrospectively analyzed the epidemiology of STDs in South Korea in 2019 by analyzing the association of pathogen-specific infection patterns with factors such as sex, age, region, and month. METHODS: We obtained the STD test results of 172,973 individuals from the Seoul Clinic Laboratory in 2019, most of whom had multiple infections; hence, 275,296 STD-positive cases were included in this analysis. Through deoxyribonucleic acid (DNA) amplification, they were categorized by pathogen type. Subsequently, they were further classified by month, region, and age while concurrently being stratified according to sex. RESULTS: Among the 12 pathogens detected in this study, Gardnerella vaginalis had the highest prevalence, with 92,490 cases in both sex groups; moreover, many of them were concurrently infected by two or more pathogens. The prevalence of STDs did not differ according to month or region. Conversely, the pathogen-specific prevalence rates significantly differed according to age. Older adults had higher prevalence rates of Chlamydia trachomatis, Trichomonas vaginalis, Candida albicans, and herpes simplex virus type 1 infections than younger adults. CONCLUSION: These pathogen-specific prevalence patterns provide information that helps to understand population vulnerability according to region and age and helps develop STD prevention and treatment strategies in South Korea.

Clinical Impact of Hormone Replacement Therapy on Atrial Fibrillation in Postmenopausal Women: A Nationwide Cohort Study.

Individuals with atrial fibrillation (AF), especially women, have an increased risk of stroke and death. Although hormone replacement therapy (HRT) is widely used in postmenopausal women, the association between HRT use and AF risk is unclear. We aimed to investigate the association between various types of HRT and AF. This was a population-based retrospective cohort study from The Korean National Health Insurance Service-National Sample Cohort (2004-2015). Participants were aged 45-60 years and were free from cardiovascular disease and AF at baseline. Overall, 13,452 (64.03%) women had never received HRT, 5671 (26.99%) had received HRT, and 1885 (8.98%) were currently receiving HRT. In multivariable analysis, the relative hazards for AF were significantly higher among current users (p < 0.001) and lower among past users (p = 0.069). Current users-except those using estradiol-only HRT-had significantly elevated AF risk. Among past users, only estradiol plus progestin HRT users had a reduced AF risk after adjusting for covariates (p = 0.027). Ongoing HRT posed an increased risk of AF. The degree of risk varied based on the specific type of estrogen and progestins co-administration. These findings indicate that, with respect to AF risk, oral estradiol-containing HRT is superior to HRT containing oral conjugated equine estrogen or tibolone.

Association Between Vitamin E and Handgrip Strength in the Korean General Population in KNHANES VII (2018).

OBJECTIVE: To investigate the association between vitamin E and handgrip strength (HGS) with multiple factors. METHODS: A total of 1,814 participants were included (822 men and 981 women) from the Korean subjects of the 7th Korea National Health and Nutrition Examination Survey in 2018. Data were analyzed using multiple logistic regression to determine the correlation between vitamin E and HGS with potential confounding factors. RESULTS: In the multiple logistic regression model, only the young age group (19-40 years) of men showed a positive relationship between vitamin E and HGS. However, in older age groups (41-80 years) of men and all age groups of women, there was no statistically significant result. After adjusting for confounding factors, young men showed higher vitamin E levels and higher HGS. Conversely, women and older age groups did not show significant results after adjusting for confounding factors. CONCLUSION: In this study, the serum vitamin E level had a positive effect on HGS in young men (<40 years). Further research is needed on this topic regarding vitamin E intake and other objective measures.

Sporadic amyotrophic lateral sclerosis with seropositive neuromyelitis optica spectrum disorder: A case report.

RATIONALE: Neuromyelitis optica spectrum disorder (NMOSD) is a severe inflammatory disorder of the central nervous system with an autoantibody against aquaporin-4 protein (AQP4), and amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. We report a female patient with ALS who had asymptomatic AQP4 antibody at the diagnosis of ALS, and NMOSD occurred 4 years later after the diagnosis of ALS. PATIENT CONCERNS: She was already bedridden and had tracheostomy because of ALS which was diagnosed at her age of 55. At the time of her ALS diagnosis, she had no brain or spinal cord lesions, but was seropositive for AQP4 antibody. At her age of 59, new-onset complete paralysis of all extremities and severe pain on the posterior neck and both shoulders occurred and visited the hospital. DIAGNOSIS: Longitudinally extensive transverse myelitis was diagnosed, which was the onset attack of seropositive NMOSD. The diagnosis was confirmed based on the international consensus diagnostic criteria for NMOSD with MR imaging, cerebrospinal fluid exam and laboratory work-ups with AQP4 antibody test. INTERVENTIONS: High dose methylprednisolone was administered for 5 days. Plasma exchange as a further treatment was recommended, but she and her family refused. OUTCOMES: Her pain was relieved after steroid treatment, but there was no improvement of her leg weakness. LESSONS: This case is a rare combination of neuroinflammatory and neurodegenerative diseases. Considering the alterations of blood-brain barrier along with the progression of ALS, it highlights that the consequence of ALS pathogenesis might affect the development of NMOSD. And the careful follow-up is recommended even in patients with profound weakness, especially if those who were at risk of developing certain neurological disorders.

Comparative analysis of mutational hotspots in the spike protein of SARS-CoV-2 isolates from different geographic origins.

The spike (S) protein mutations of SARS-CoV-2 are of major concern in terms of viral transmission and pathogenesis. Hence, we developed a PCR-based method to rapidly detect the 6 mutational hotspots (H49Y, G476S, V483A, H519Q, A520S, and D614G) in the S protein and applied this method to analyze the hotspots in the viral isolates from different geographical origins. Here, we identified that there was only the D614G mutation in the viral isolates. As of September 30, 2020, the analysis of 113,381 sequences available from the public repositories revealed that the SARS-CoV-2 variant carrying G614 has become the most prevalent form globally. Our results support recent epidemiological and genomic data demonstrating that the viral infectivity and transmission are enhanced by the S protein D614G mutation.

Novel indel mutation in the N gene of SARS-CoV-2 clinical samples that were diagnosed positive in a commercial RT-PCR assay.

Commercially available reverse transcription-polymerase chain reaction (RT-PCR) kits are being used as an important tool to diagnose SARS-CoV-2 infection in clinical laboratories worldwide. However, some kits lack sufficient clinical evaluation due to the need for emergency use caused by the current COVID-19 pandemic. Here we found that a novel insertion/deletion mutation in the nucleocapsid (N) gene of SARS-CoV-2 samples is a cause of negative results for the N gene in a widely used assay that received emergency use authorization (EUA) from US FDA and Conformite Europeenne-in vitro diagnostics (CE-IVD) from EU. Although SARS-CoV-2 is diagnosed positive by other target probes in the assay, our findings provide an evidence of the genetic variability and rapid evolution of SARS-CoV-2 as well as a reference in designing commercial RT-PCR assays.