The effect of shortening the quarantine period and lifting the indoor mask mandate on the spread of COVID-19: a mathematical modeling approach.

In this paper, we present a mathematical model to assess the impact of reducing the quarantine period and lifting the indoor mask mandate on the spread of Coronavirus Disease 2019 (COVID-19) in Korea. The model incorporates important epidemiological parameters, such as transmission rates and mortality rates, to simulate the transmission of the virus under different scenarios. Our findings reveal that the impact of mask wearing fades in the long term, which highlights the crucial role of quarantine in controlling the spread of the disease. In addition, balancing the confirmed cases and costs, the lifting of mandatory indoor mask wearing is cost-effective; however, maintaining the quarantine period remains essential. A relationship between the disease transmission rate and vaccine efficiency was also apparent, with higher transmission rates leading to a greater impact of the vaccine efficiency. Moreover, our findings indicate that a higher disease transmission rate exacerbates the consequences of early quarantine release.

The economic impact of COVID-19 interventions: A mathematical modeling approach.

Prior to vaccination or drug treatment, non-pharmaceutical interventions were almost the only way to control the coronavirus disease 2019 (COVID-19) epidemic. After vaccines were developed, effective vaccination strategies became important. The prolonged COVID-19 pandemic has caused enormous economic losses worldwide. As such, it is necessary to estimate the economic effects of control policies, including non-pharmaceutical interventions and vaccination strategies. We estimated the costs associated with COVID-19 according to different vaccination rollout speeds and social distancing levels and investigated effective control strategies for cost minimization. Age-structured mathematical models were developed and used to study disease transmission epidemiology. Using these models, we estimated the actual costs due to COVID-19, considering costs associated with medical care, lost wages, death, vaccination, and gross domestic product (GDP) losses due to social distancing. The lower the social distancing (SD) level, the more important the vaccination rollout speed. SD level 1 was cost-effective under fast rollout speeds, but SD level 2 was more effective for slow rollout speeds. If the vaccine rollout rate is fast enough, even implementing SD level 1 will be cost effective and can control the number of critically ill patients and deaths. If social distancing is maintained at level 2 at the beginning and then relaxed when sufficient vaccinations have been administered, economic costs can be reduced while maintaining the number of patients with severe symptoms below the intensive care unit (ICU) capacity. Korea has wellequipped medical facilities and infrastructure for rapid vaccination, and the public's desire for vaccination is high. In this case, the speed of vaccine supply is an important factor in controlling the COVID-19 epidemic. If the speed of vaccination is fast, it is possible to maintain a low level of social distancing without a significant increase in the number of deaths and hospitalized patients with severe symptoms, and the corresponding costs can be reduced.

Diagnostic usefulness of the spot urine sodium/potassium ratio in cirrhotic patients with ascites.

BACKGROUND AND AIMS: The low-salt diet is considered important for control of ascites in cirrhotic patients. To validate whether the spot urine sodium (Na)/potassium (K) ratio could replace 24-h urine Na (uNa) excretion in assessing low-salt diet compliance. METHODS: We prospectively studied 175 patients. 24-h urine collection and spot urine collection were performed. Subsequently, 24-h uNa, urine creatinine (uCr), and spot urine Na and K were assessed. A complete urine collection was confirmed based on 24-h uCr excretion levels of 15mg/kg/day for men and 10mg/kg/day for women. The area under the receiver operating characteristic (AUROC) curve analysis was performed to evaluate the feasibility of spot urine Na/K ratio in predicting 24-h uNa greater than 78mmol/day. RESULTS: Out of 175 patients, 24-h urine samples were completely collected in 57 patients only. Moreover, urine samples were not completely collected in 118 patients because their 24-h uCr excretion level was less than the established criteria. In complete urine collection group, AUROC curve for spot urine Na/K ratio in predicting 24-h uNa greater than 78mmol/day was 0.874±0.051 (P<0.001). In the incomplete urine collection group, the AUROC was 0.832±0.039 (P<0.001). In complete urine collection group, the classical cutoff value greater than 1.0 of spot urine Na/K ratio showed 90.9% sensitivity and 56.0% specificity. CONCLUSIONS: The spot urine Na/K ratio reflects 24-h uNa, but the AUROC value obtained in this study is lower than that of a previous study. Considered the large number of patients with incomplete urine collection, validating 24-h complete urine collection criteria is necessary.

Vaccination Prioritization Strategies for COVID-19 in Korea: A Mathematical Modeling Approach.

Coronavirus disease 2019 (COVID-19) vaccination has recently started worldwide. As the vaccine supply will be limited for a considerable period of time in many countries, it is important to devise the effective vaccination strategies that reduce the number of deaths and incidence of infection. One of the characteristics of COVID-19 is that the symptom, severity, and mortality of the disease differ by age. Thus, when the vaccination supply is limited, age-dependent vaccination priority strategy should be implemented to minimize the incidences and mortalities. In this study, we developed an age-structured model for describing the transmission dynamics of COVID-19, including vaccination. Using the model and actual epidemiological data in Korea, we estimated the infection probability for each age group under different levels of social distancing implemented in Korea and investigated the effective age-dependent vaccination strategies to reduce the confirmed cases and fatalities of COVID-19. We found that, in a lower level of social distancing, vaccination priority for the age groups with the highest transmission rates will reduce the incidence mostly, but, in higher levels of social distancing, prioritizing vaccination for the elderly age group reduces the infection incidences more effectively. To reduce mortalities, vaccination priority for the elderly age group is the best strategy in all scenarios of levels of social distancing. Furthermore, we investigated the effect of vaccine supply and efficacy on the reduction in incidence and mortality.

Multicenter Analysis of Clinical Features and Prognosis of COVID-19 Patients with Hepatic Impairment.

Background/Aims: Recent data indicate the presence of liver enzyme abnormalities in patients with coronavirus disease 2019 (COVID-19). We aimed to evaluate the clinical features and treatment outcomes of COVID-19 patients with abnormal liver enzymes. Methods: We performed a retrospective, multicenter study of 874 COVID-19 patients admitted to five tertiary hospitals from February 20 to April 14, 2020. Data on clinical features, laboratory parameters, medications, and treatment outcomes were collected until April 30, 2020, and compared between patients with normal and abnormal aminotransferases. Results: Abnormal aminotransferase levels were observed in 362 patients (41.1%), of which 94 out of 130 (72.3%) and 268 out of 744 (36.0%) belonged to the severe and non-severe COVID- 19 categories, respectively. The odds ratios (95% confidence interval) for male patients, patients with a higher body mass index, patients with severe COVID-19 status, and patients with lower platelet counts were 1.500 (1.029 to 2.184, p=0.035), 1.097 (1.012 to 1.189, p=0.024), 2.377 (1.458 to 3.875, p=0.001), and 0.995 (0.993 to 0.998, p>0.001), respectively, indicating an independent association of these variables with elevated aminotransferase levels. Lopinavir/ ritonavir and antibiotic use increased the odds ratio of abnormal aminotransferase levels after admission (1.832 and 2.646, respectively, both p<0.05). The median time to release from quarantine was longer (22 days vs 26 days, p=0.001) and the mortality rate was higher (13.0% vs 2.9%, p<0.001) in patients with abnormal aminotransferase levels. Conclusions: Abnormal aminotransferase levels are common in COVID-19 patients and are associated with poor clinical outcomes. Multivariate analysis of patients with normal aminotransferase levels on admission showed that the use of lopinavir/ritonavir and antibiotics was associated with abnormal aminotransferase levels; thus, careful monitoring is needed.

Addition of liver stiffness enhances the predictive accuracy of the PAGE-B model for hepatitis B-related hepatocellular carcinoma.

BACKGROUND: The modified PAGE-B (mPAGE-B) and PAGE-B models reliably predict the risk of developing chronic hepatitis B (CHB)-related hepatocellular carcinoma (HCC). AIM(S): To investigate whether the addition of liver stiffness (LS) value, assessed using transient elastography, enhanced the predictive accuracies of these models METHODS: Patients with CHB who started anti-viral therapy (AVT) between 2007 and 2017 were enrolled. The training (Yonsei University Hospital) and validation (seven Korean referral institutes) cohorts contained 1211 and 973 patients, respectively. RESULTS: Based on multivariate analysis, older age (hazard ratio [HR] = 1.051, 95% confidence interval [CI] = 1.031-1.071), male sex (HR = 2.265, 95% CI = 1.463-3.506), lower platelet count (HR = 0.993, 95% CI = 0.989-0.997) and greater LS values (HR = 1.015, 95% CI = 1.002-1.028) were independently associated with an increased risk of HCC development (all P < 0.05). Thus, we developed a modified PAGELS -B model (maximum score 34) that included age, male sex, platelet count and LS value. The integrated area under the curve of the modified PAGELS model was greater than those of the PAGE-B and mPAGE-B models (0.760 vs 0.714 and 0.716, respectively) in the derivation dataset. The cumulative HCC incidence was significantly higher in the high-risk (modified PAGE-BLS score ≥ 24) group than in the intermediate-risk (modified PAGELS -B score 12-24) or low-risk (modified PAGELS -B score < 12) group (all P < 0.001). Similar results were observed in the validation cohort. CONCLUSIONS: The predictive accuracies of the PAGE-B and mPAGE-B models were validated in Korean patients with CHB receiving AVT. However, the modified PAGELS -B model featuring the addition of LS value showed higher predictability than the PAGE-B and mPAGE-B models.

Dynamics of liver stiffness-based risk prediction model during antiviral therapy in patients with chronic hepatitis B.

OBJECTIVE: The liver stiffness-based risk prediction models predict hepatocellular carcinoma (HCC) development. We investigated the influence of antiviral therapy (AVT) on liver stiffness-based risk prediction model in patients with chronic hepatitis B (CHB). METHODS: Patients with CHB who initiated AVT were retrospectively recruited from 13 referral Korean institutes. The modified risk estimation for hepatocellular carcinoma in chronic hepatitis B (mREACH-B) model was selected for the analysis. RESULTS: Between 2007 and 2015, 1034 patients with CHB were recruited. The mean age of the study population (639 men and 395 women) was 46.8 years. During AVT, the mREACH-B score significantly decreased from the baseline to 3 years of AVT (mean 9.21 → 7.46, P < 0.05) and was maintained until 5 years of AVT (mean 7.23, P > 0.05). The proportion of high-risk patients (mREACH-B score ≥11) was significantly reduced from the baseline to 2 years of AVT (36.4% → 16.4%, P < 0.001) and was maintained until 5 years of AVT (12.2%, P > 0.05). The mREACH-B scores at baseline and 1 year of AVT independently predicted HCC development (hazard ratio = 1.209-1.224) (all P < 0.05). The cumulative incidence rate of HCC was significantly different at 5 years of AVT among risk groups (high vs. high-intermediate vs. low-intermediate vs. low) from baseline (4.5% vs. 3.2% vs. 1.5% vs. 0.8%) and 1 year (11.8% vs. 4.6% vs. 1.8% vs. 0.6%) (all P < 0.05, log-rank tests). CONCLUSIONS: The mREACH-B score was dynamically changed during AVT. Thus, repeated assessment of the mREACH-B score is required to predict the changing risk of HCC development in patients with CHB undergoing AVT.

Assessment of Social Distancing for Controlling COVID-19 in Korea: An Age-Structured Modeling Approach.

The outbreak of the novel coronavirus disease 2019 (COVID-19) occurred all over the world between 2019 and 2020. The first case of COVID-19 was reported in December 2019 in Wuhan, China. Since then, there have been more than 21 million incidences and 761 thousand casualties worldwide as of 16 August 2020. One of the epidemiological characteristics of COVID-19 is that its symptoms and fatality rates vary with the ages of the infected individuals. This study aims at assessing the impact of social distancing on the reduction of COVID-19 infected cases by constructing a mathematical model and using epidemiological data of incidences in Korea. We developed an age-structured mathematical model for describing the age-dependent dynamics of the spread of COVID-19 in Korea. We estimated the model parameters and computed the reproduction number using the actual epidemiological data reported from 1 February to 15 June 2020. We then divided the data into seven distinct periods depending on the intensity of social distancing implemented by the Korean government. By using a contact matrix to describe the contact patterns between ages, we investigated the potential effect of social distancing under various scenarios. We discovered that when the intensity of social distancing is reduced, the number of COVID-19 cases increases; the number of incidences among the age groups of people 60 and above increases significantly more than that of the age groups below the age of 60. This significant increase among the elderly groups poses a severe threat to public health because the incidence of severe cases and fatality rates of the elderly group are much higher than those of the younger groups. Therefore, it is necessary to maintain strict social distancing rules to reduce infected cases.

Changes in Characteristics of Patients with Liver Cirrhosis Visiting a Tertiary Hospital over 15 Years: a Retrospective Multi-Center Study in Korea.

BACKGROUND: Liver cirrhosis has become a heavy burden not only for patients, but also for our society. However, little is known about the recent changes in clinical outcomes and characteristics of patients with cirrhosis-related complications in Korea. Therefore, we aimed to evaluate changes in characteristics of patients with liver cirrhosis in Daegu-Gyeongbuk province in Korea over the past 15 years. METHODS: We retrospectively reviewed the medical records of 15,716 liver cirrhotic patients from 5 university hospitals in Daegu-Gyeongbuk province from 2000 to 2014. The Korean Standard Classification of Diseases-6 code associated with cirrhosis was investigated through medical records and classified according to the year of first visit. RESULTS: A total of 15,716 patients was diagnosed with cirrhosis. A number of patients newly diagnosed with cirrhosis has decreased each year. In 2000, patients were most likely to be diagnosed with hepatitis B virus (HBV) cirrhosis, followed by alcoholic cirrhosis. There was a significant decrease in HBV (P < 0.001), but alcohol, hepatitis C virus (HCV), and non-alcoholic fatty liver disease (NAFLD) showed a significant increase during the study period (alcohol, P = 0.036; HCV, P = 0.001; NAFLD, P = 0.001). At the time of initial diagnosis, the ratio of Child-Turcotte-Pugh (CTP) class A gradually increased from 23.1% to 32.9% (P < 0.001). The most common cause of liver-related hospitalization in 2000 was hepatocellular carcinoma (HCC) (25.5%); in 2014, gastrointestinal bleeding with esophageal and gastric varices (21.4%) was the most common cause. Cases of hospitalization with liver-related complication represented 76.4% of all cases in 2000 but 70.9% in 2014. Incidence rate of HCC has recently increased. In addition, HCC-free survival was significantly lower in CTP class A than in classes B and C. Finally, there was significant difference in HCC occurrence according to causes (P < 0.001). HBV and HCV cirrhosis had lower HCC-free survival than alcoholic and NAFLD cirrhosis. CONCLUSION: In recent years, the overall number of cirrhosis patients has decreased. This study confirmed the recent trend in decrease of cirrhosis, especially of cirrhosis due to HBV, and the increase of HCV, alcoholic and NAFLD cirrhosis. Targeted screening for at-risk patients will facilitate early detection of liver diseases allowing effective intervention and may have decreased the development of cirrhosis and its complications.

Efficacy of long-term tenofovir disoproxil fumarate therapy in chronic hepatitis B patients with partial virologic response in real practice.

BACKGROUND/AIMS: The optimal management of chronic hepatitis B (CHB) patients with partial virologic response (PVR) to tenofovir disoproxil fumarate (TDF) remains unclear. We aimed to evaluate the long-term efficacy of prolonged TDF therapy in treatment-naïve CHB patients with PVR to TDF therapy in real practice. METHODS: We retrospectively investigated the efficacy of prolonged TDF therapy in treatment-naïve CHB patients with PVR to TDF. PVR was defined as a decrease in serum hepatitis B virus (HBV) DNA over 2 log10 IU/mL from baseline, with detectable HBV DNA by real-time polymerase chain reaction at week 48. RESULTS: We included 232 patients who underwent TDF therapy for over 48 weeks. Forty-two patients (18.1%) showed PVR. In multivariate analysis, hepatitis B e antigen (HBeAg) positivity, and high levels of serum HBV DNA at baseline and week 12 were independent predictive factors for PVR during TDF therapy. Out of 42 patients with PVR, 39 (92.9%) achieved virologic response (VR) during continuous TDF treatment; the cumulative VR rates at 24, 36, and 48 months were 79.8%, 88.2%, and 95.6%, respectively. With an additional 12 months of therapy, VR was achieved in 28/31 (90.3%) patients with HBV DNA < 100 IU/mL, compared to 5/11 (45.5%) patients with HBV DNA ≥ 100 IU/mL, at week 48. CONCLUSION: The vast majority of patients achieved VR through prolonged TDF therapy, thus TDF treatment can be maintained in nucleos(t)ide-naïve patients with PVR at week 48, especially in those with low viremia.

Long-term Prognosis of Acute-on-Chronic Liver Failure Survivors.

GOALS: We aimed to investigate significant factors influencing the long-term prognosis of patients who survived acute-on-chronic liver failure (ACLF). BACKGROUND: The mortality of ACLF is predominantly affected by the organ failure severity. However, long-term outcomes of patients who survive ACLF are not known. STUDY: A cohort of 1084 cirrhotic patients who survived for more than 3 months following acute deterioration of liver function was prospectively followed. ACLF was defined by the European Association for the Study of the Liver Chronic Liver Failure Consortium definition. RESULTS: The mean follow-up duration was 19.4±9.9 months. In the subgroup of patients without previous acute decompensation (AD), ACLF occurrence did not affect long-term outcomes. However, in patients with previous AD, ACLF negatively affected long-term transplant-free survival even after overcoming ACLF (hazard ratio, 2.00, P=0.012). Previous AD was the significant predictive factor of long-term mortality and was independent of the Model for End-stage Liver Disease score in these ACLF-surviving patients. Organ failure severity did not affect transplant-free survival in patients who survived an ACLF episode. CONCLUSIONS: A prior history of AD is the most important factor affecting long-term outcomes following an ACLF episode regardless of Model for End-stage Liver Disease score. Prevention of a first AD episode may improve the long-term transplant-free survival of liver cirrhosis patients.

Daclatasvir and asunaprevir combination therapy for patients with chronic hepatitis C virus genotype 1b infection in real world.

BACKGROUND/AIMS: Previous studies have reported a high rate of sustained virologic response (SVR) and a low rate of serious adverse events with the use of daclatasvir (DCV) and asunaprevir (ASV) combination therapy. We evaluated the efficacy and safety of DCV and ASV combination therapy for patients with chronic hepatitis C virus (HCV) genotype 1b infection in real world. METHODS: We enrolled 278 patients (184 treatment-naïve patients) from five hospitals in Daegu and Gyeongsangbuk-do. We evaluated the rates of rapid virologic response (RVR), end-of-treatment response (ETR), and SVR at 12 weeks after completion of treatment (SVR12). Furthermore, we investigated the rate of adverse events and predictive factors of SVR12 failure. RESULTS: The mean age of patients was 59.5 ± 10.6 years, and 140 patients (50.2%) were men. Seventy-seven patients had cirrhosis. Baseline information regarding nonstructural protein 5A (NS5A) sequences was available in 268 patients. Six patients presented with pretreatment NS5A resistance-associated variants. The RVR and the ETR rates were 96.6% (258/267) and 95.2% (223/232), respectively. The overall SVR12 rate was 91.6% (197/215). Adverse events occurred in 17 patients (7.9%). Six patients discontinued treatment because of liver enzyme elevation (n = 4) and severe nausea (n = 2). Among these, four achieved SVR12. Other adverse events observed were fatigue, headache, diarrhea, dizziness, loss of appetite, skin rash, and dyspnea. Univariate analysis did not show significant predictive factors of SVR12 failure. CONCLUSION: DCV and ASV combination therapy showed high rates of RVR, ETR, and SVR12 in chronic HCV genotype 1b-infected patients in real world and was well tolerated without serious adverse events.

Potential effects of climate change on dengue transmission dynamics in Korea.

Dengue fever is a major international public health concern, with more than 55% of the world population at risk of infection. Recent climate changes related to global warming have increased the potential risk of domestic outbreaks of dengue in Korea. In this study, we develop a two-strain dengue model associated with climate-dependent parameters based on Representative Concentration Pathway (RCP) scenarios provided by the Korea Meteorological Administration. We assess the potential risks of dengue outbreaks by means of the vector capacity and intensity under various RCP scenarios. A sensitivity analysis of the temperature-dependent parameters is performed to explore the effects of climate change on dengue transmission dynamics. Our results demonstrate that a higher temperature significantly enhances the potential threat of domestic dengue outbreaks in Korea. Furthermore, we investigate the effects of countermeasures on the cumulative incidence of humans and vectors. The current main control measures (comprising only travel restrictions) for infected humans in Korea are not as effective as combined control measures (travel restrictions and vector control), dramatically reducing the possibilities of dengue outbreaks.

Effects of Virologic Response to Treatment on Short- and Long-term Outcomes of Patients With Chronic Hepatitis B Virus Infection and Decompensated Cirrhosis.

BACKGROUND & AIMS: Little is known about the effects of antiviral therapy on short- and long-term survival of patients with hepatitis B virus (HBV)-related decompensated cirrhosis. We aimed to determine whether a maintained virologic response (MVR, defined as persistent undetectable HBV DNA during therapy) associates with short-term (6 mo) and long-term (6-120 mo) survival of patients with decompensated cirrhosis. METHODS: We performed a 10-year observation analysis using data from the Epidemiology and Natural History of Liver Cirrhosis study of patients with decompensated liver cirrhosis in Korea. Of the entire cohort (1595 patients enrolled at onset of decompensation since 2005), our analysis comprised 295 patients who immediately began treatment with entecavir (n = 179) or lamivudine (n = 116) after decompensation. We collected laboratory test results, data on hepatocellular carcinoma (HCC) development, and Child-Turcotte-Pugh and model for end-stage liver disease (MELD) scores. The mean follow-up time was 62.3 ± 36.5 months. The primary end point was time of liver transplant-free survival. RESULTS: The median survival time was 7.7 years; 60.1% of patients survived for 5 years and 45.7% survived for 10 years without liver transplantation. An MVR was observed in 116 patients (39.3%); these patients had significantly longer times of transplant-free survival than patients without MVR. Survival times associated with the occurrence of HCC; survival of patients without HCC was excellent if they survived the first 6 months after initiation of antiviral therapy, whereas the survival rates of patients with HCC decreased persistently over time. A baseline MELD score above 20 and multiple complications were associated with short-term mortality. MVR was the factor most strongly associated with long-term transplant-free survival. Significantly higher proportions of patients who received entecavir survived 10 years compared with patients who received lamivudine, but no difference was observed among patients with MVRs. Patients with MVRs had significant improvement in hepatic function over time, but nonsignificant reductions in risk of HCC or HCC-related mortality. CONCLUSIONS: In a 10-year observation study of patients in Korea with HBV-related decompensated cirrhosis, we found baseline MELD score and MVR to entecavir or lamivudine to associate with short- and long-term transplant-free survival. The benefits of an MVR are maintained for up to 10 years even after decompensation, but patients are still at risk for HCC.

Evaluating the efficacy of switching from lamivudine plus adefovir to tenofovir disoproxil fumarate monotherapy in lamivudine-resistant stable hepatitis B patients.

BACKGROUND: The efficacy of switching to tenofovir disoproxil fumarate (TDF) monotherapy from lamivudine (LAM) plus adefovir dipivoxil (ADV) combination therapy (stable switching) in patients with LAM-resistant chronic hepatitis B (CHB) and undetectable hepatitis B virus (HBV) DNA is not clear. METHODS: In this non-inferiority trial, patients with LAM-resistant CHB and undetectable serum HBV DNA (<20 IU/mL) for >6 months after initiating LAM+ADV combination therapy were randomized (1:2) either to continue the combination therapy (LAM+ADV group, n = 58) or switched to TDF monotherapy (TDF group, n = 111). They were followed-up with serum biochemistry tests and HBV DNA measurement at 12-week intervals for 96 weeks. The primary endpoint of this study was the proportion of patients with viral reactivation at week 96. RESULTS: Patients with CHB enrolled in this study (n = 169) included 74 patients with compensated liver cirrhosis. In total, 9 patients (4 in the LAM+ADV group and 5 in the TDF group) dropped-out from the study. After a mean follow-up period of 96 weeks, the proportion of HBV reactivation observed was 6.8% (4/58) in the LAM+ADV group and 4.5% (5/111) in the TDF group by using intention-to-treat analysis (difference, -2.3%; 95% CI, -9.84-5.24%). None of the subjects in either group experienced viral reactivation based on per protocol analysis. No serious adverse reactions were observed. In the subgroup analysis for estimated glomerular filtration rate (eGFR) before and after treatment, decreased eGFR was observed only in the TDF group with cirrhosis (85.22 vs. 79.83 mL/min/1.73 m2, p = 0.000). CONCLUSIONS: Stable switching to TDF monotherapy yielded non-inferior results at 96 weeks compared to the results obtained with LAM+ADV combination therapy in patients with LAM-resistant CHB and undetectable HBV DNA. However, TDF monotherapy in patients with cirrhosis requires close attention with respect to renal function. TRIAL REGISTRATION: ClinicalTrials.gov NCT01732367.

Validation of prognostic scores to predict short-term mortality in patients with acute-on-chronic liver failure.

BACKGROUND AND AIM: The aim of this study was to validate the chronic liver failure-sequential organ failure assessment score (CLIF-SOFAs), CLIF consortium organ failure score (CLIF-C OFs), CLIF-C acute-on-chronic liver failure score (CLIF-C ACLFs), and CLIF-C acute decompensation score in Korean chronic liver disease patients with acute deterioration. METHODS: Acute-on-chronic liver failure was defined by either the Asian Pacific Association for the study of the Liver ACLF Research Consortium (AARC) or CLIF-C criteria. The diagnostic performances for short-term mortality were compared by the area under the receiver operating characteristic curve. RESULTS: Among a total of 1470 patients, 252 patients were diagnosed with ACLF according to the CLIF-C (197 patients) or AARC definition (95 patients). As the ACLF grades increased, the survival rates became significantly lower. The areas under the receiver operating characteristic of the CLIF-SOFAs, CLIF-C OFs, and CLIF-C ACLFs were significantly higher than those of the Child-Pugh, model for end-stage liver disease, and model for end-stage liver disease-Na scores in ACLF patients according to the CLIF-C definition (all P < 0.05), but there were no significant differences in patients without ACLF or in patients with ACLF according to the AARC definition. The CLIF-SOFAs, CLIF-C OFs, and CLIF-C ACLFs had higher specificities with a fixed sensitivity than liver specific scores in ACLF patients according to the CLIF-C definition, but not in ACLF patients according to the AARC definition. CONCLUSIONS: The CLIF-SOFAs, CLIF-C OFs, and CLIF-C ACLFs are useful scoring systems that provide accurate information on prognosis in patients with ACLF according to the CLIF-C definition, but not the AARC definition.

Reduced risk of hepatocellular carcinoma by achieving a subcirrhotic liver stiffness through antiviral agents in hepatitis B virus-related advanced fibrosis or cirrhosis.

BACKGROUND AND AIM: A subcirrhotic range of liver stiffness (sc-LS), assessed by transient elastography, is associated with better outcomes in patients with chronic hepatitis B (CHB). We investigated whether the achievement of sc-LS by antiviral therapy (AVT) reduced the risk of developing hepatocellular carcinoma (HCC) in patients with CHB-related advanced fibrosis or cirrhosis. METHODS: In total, 209 patients with CHB-related advanced fibrosis or cirrhosis, who received paired transient elastography examinations during AVT between 2007 and 2012, were enrolled. The cut-off LS value for ultrasonographic cirrhosis was defined as 11.6 kPa. RESULTS: The median age of the study population was 51 years, with males predominating (n = 138, 66.0%). The median LS value at enrollment was 14.1 kPa (interquartile range: 9.5-24.1 kPa). After 2 years of AVT, 140 (67.0%) patients achieved sc-LS. During the study period, 28 (13.4%) patients developed HCC after 2 years of AVT. On multivariate analysis, the achievement of sc-LS after AVT was independently associated with a decreased risk of HCC development (hazard ratio [HR] = 0.485, P = 0.047), whereas older age (HR = 1.071) and male gender (HR = 3.704) were independently associated with an increased HCC risk (both P < 0.05). Patients with a cirrhotic range of LS value after 2 years of AVT were at a higher risk of HCC development than those with sc-LS (log-rank test, P = 0.020). CONCLUSIONS: The achievement of sc-LS after AVT can reduce the risk of HCC development in patients with CHB, even when advanced fibrosis or cirrhosis is apparent on starting AVT.

Mycoplasma pneumoniae-associated Hepatitis without Lung Involvement.

Mycoplasma pneumoniae (M. pneumoniae) is a major cause of community acquired respiratory infections. And it also causes a number of extrapulmonary manifestations including cardiovascular, dermatological, musculoskeletal, and hematological systems. But, acute hepatitis without lung involvement is rare in adults. Here, we report a case of 32-year-old man who presented with fever, chilling, myalgia, and headache. Biochemical analysis showed severely impaired liver function and leukopenia. Laboratory tests and liver biopsy demonstrated a hepatocellular pattern of M. pneumoniae-associated acute hepatitis. Clinical symptoms and laboratory parameters are improved rapidly under treatment with macrolide. Therefore, We recommend that phsycians should consider a possibility of M. pneumoniae infection in acute hepatitis without lung and extrapulmonary involvement, when other more frequent causes have been excluded.

Assessment of optimal strategies in a two-patch dengue transmission model with seasonality.

Emerging and re-emerging dengue fever has posed serious problems to public health officials in many tropical and subtropical countries. Continuous traveling in seasonally varying areas makes it more difficult to control the spread of dengue fever. In this work, we consider a two-patch dengue model that can capture the movement of host individuals between and within patches using a residence-time matrix. A previous two-patch dengue model without seasonality is extended by adding host demographics and seasonal forcing in the transmission rates. We investigate the effects of human movement and seasonality on the two-patch dengue transmission dynamics. Motivated by the recent Peruvian dengue data in jungle/rural areas and coast/urban areas, our model mimics the seasonal patterns of dengue outbreaks in two patches. The roles of seasonality and residence-time configurations are highlighted in terms of the seasonal reproduction number and cumulative incidence. Moreover, optimal control theory is employed to identify and evaluate patch-specific control measures aimed at reducing dengue prevalence in the presence of seasonality. Our findings demonstrate that optimal patch-specific control strategies are sensitive to seasonality and residence-time scenarios. Targeting only the jungle (or endemic) is as effective as controlling both patches under weak coupling or symmetric mobility. However, focusing on intervention for the city (or high density areas) turns out to be optimal when two patches are strongly coupled with asymmetric mobility.

Assessment of scoring systems for acute-on-chronic liver failure at predicting short-term mortality in patients with alcoholic hepatitis.

AIM: To assess the performance of proposed scores specific for acute-on-chronic liver failure in predicting short-term mortality among patients with alcoholic hepatitis. METHODS: We retrospectively collected data from 264 patients with clinically diagnosed alcoholic hepatitis from January to December 2013 at 21 academic hospitals in Korea. The performance for predicting short-term mortality was calculated for Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA), CLIF Consortium Organ Failure score (CLIF-C OFs), Maddrey's discriminant function (DF), age, bilirubin, international normalized ratio and creatinine score (ABIC), Glasgow Alcoholic Hepatitis Score (GAHS), model for end-stage liver disease (MELD), and MELD-Na. RESULTS: Of 264 patients, 32 (12%) patients died within 28 d. The area under receiver operating characteristic curve of CLIF-SOFA, CLIF-C OFs, DF, ABIC, GAHS, MELD, and MELD-Na was 0.86 (0.81-0.90), 0.89 (0.84-0.92), 0.79 (0.74-0.84), 0.78 (0.72-0.83), 0.81 (0.76-0.86), 0.83 (0.78-0.88), and 0.83 (0.78-0.88), respectively, for 28-d mortality. The performance of CLIF-SOFA had no statistically significant differences for 28-d mortality. The performance of CLIF-C OFs was superior to that of DF, ABIC, and GAHS, while comparable to that of MELD and MELD-Na in predicting 28-d mortality. A CLIF-SOFA score of 8 had 78.1% sensitivity and 79.7% specificity, and CLIF-C OFs of 10 had 68.8% sensitivity and 91.4% specificity for predicting 28-d mortality. CONCLUSION: CLIF-SOFA and CLIF-C OF scores performed well, with comparable predictive ability for short-term mortality compared to the commonly used scoring systems in patients with alcoholic hepatitis.