Temporal changes in SARS-CoV-2 clearance kinetics and the optimal design of antiviral pharmacodynamic studies: an individual patient data meta-analysis of a randomised, controlled, adaptive platform study (PLATCOV)

BACKGROUND

Effective antiviral drugs prevent hospitalisation and death from COVID-19. Antiviral efficacy can be efficiently assessed in vivo by measuring rates of SARS-CoV-2 clearance estimated from serial viral genome densities quantitated in nasopharyngeal or oropharyngeal swab eluates. We conducted an individual patient data meta-analysis of unblinded arms in the PLATCOV platform trial to characterise changes in viral clearance kinetics and infer optimal design and interpretation of antiviral pharmacometric evaluations.

METHODS

Serial viral density data were analysed from symptomatic, previously healthy, adult patients (within 4 days of symptom onset) enrolled in a large multicentre, randomised, adaptive, pharmacodynamic, platform trial (PLATCOV) comparing antiviral interventions for SARS-CoV-2. Viral clearance rates over 1 week were estimated under a hierarchical Bayesian linear model with B-splines used to characterise temporal changes in enrolment viral densities and clearance rates. Bootstrap re-sampling was used to assess the optimal duration of follow-up for pharmacometric assessment, where optimal was defined as maximising the expected Z score when comparing effective antivirals with no treatment. PLATCOV is registered at ClinicalTrials.gov, NCT05041907.

FINDINGS

Between Sept 29, 2021, and Oct 20, 2023, 1262 patients were randomly assigned in the PLATCOV trial. Unblinded data were available from 800 patients (who provided 16 818 oropharyngeal viral quantitative PCR [qPCR] measurements), of whom 504 (63%) were female. 783 (98%) patients had received at least one vaccine dose and 703 (88%) were fully vaccinated. SARS-CoV-2 viral clearance was biphasic (bi-exponential). The first phase (α) was accelerated by effective interventions. For all the effective interventions studied, maximum discriminative power (maximum expected Z score) was obtained when evaluating serial data from the first 5 days after enrolment. Over the 2-year period studied, median viral clearance half-lives estimated over 7 days shortened from 16·6 h (IQR 15·3 to 18·2) in September, 2021, to 9·2 h (8·0 to 10·6) in October, 2023, in patients receiving no antiviral drugs, equivalent to a relative reduction of 44% (95% credible interval [CrI] 19 to 64). A parallel reduction in viral clearance half-lives over time was observed in patients receiving antiviral drugs. For example, in the 158 patients assigned to ritonavir-boosted nirmatrelvir (3380 qPCR measurements), the median viral clearance half-life reduced from 6·4 h (IQR 5·7 to 7·3) in June, 2022, to 4·8 h (4·2 to 5·5) in October, 2023, a relative reduction of 26% (95% CrI -4 to 42).

INTERPRETATION

SARS-CoV-2 viral clearance kinetics in symptomatic, vaccinated individuals accelerated substantially over 2 years of the pandemic, necessitating a change to how new SARS-CoV-2 antivirals are compared (ie, shortening the period of pharmacodynamic assessment). As of writing (October, 2023), antiviral efficacy in COVID-19 can be efficiently assessed in vivo using serial qPCRs from duplicate oropharyngeal swab eluates taken daily for 5 days after drug administration.

FUNDING

Wellcome Trust.

Progress towards elimination of viral hepatitis: a Lancet Gastroenterology & Hepatology Commission update

The top 20 highest burdened countries (in disability-adjusted life years) account for more than 75% of the global burden of viral hepatitis. An effective response in these 20 countries is crucial if global elimination targets are to be achieved. In this update of the Lancet Gastroenterology & Hepatology Commission on accelerating the elimination of viral hepatitis, we convene national experts from each of the top 20 highest burdened countries to provide an update on progress. Although the global burden of diseases is falling, progress towards elimination varies greatly by country. By use of a hepatitis elimination policy index conceived as part of the 2019 Commission, we measure countries' progress towards elimination. Progress in elimination policy has been made in 14 of 20 countries with the highest burden since 2018, with the most substantial gains observed in Bangladesh, India, Indonesia, Japan, and Russia. Most improvements are attributable to the publication of formalised national action plans for the elimination of viral hepatitis, provision of publicly funded screening programmes, and government subsidisation of antiviral treatments. Key themes that emerged from discussion between national commissioners from the highest burdened countries build on the original recommendations to accelerate the global elimination of viral hepatitis. These themes include the need for simplified models of care, improved access to appropriate diagnostics, financing initiatives, and rapid implementation of lessons from the COVID-19 pandemic.

Primaquine in glucose-6-phosphate dehydrogenase deficiency: an adaptive pharmacometric assessment of ascending dose regimens in healthy volunteers

Background

Primaquine is an 8-aminoquinoline antimalarial. It is the only widely available treatment to prevent relapses of Plasmodium vivax malaria. The 8-aminoquinolines cause dose-dependent haemolysis in glucose-6-phosphate dehydrogenase deficiency (G6PDd). G6PDd is common in malaria endemic areas but testing is often not available. As a consequence primaquine is underused.

Methods

We conducted an adaptive pharmacometric study to characterise the relationship between primaquine dose and haemolysis in G6PDd. The aim was to explore shorter and safer primaquine radical cure regimens compared to the currently recommended 8-weekly regimen (0.75 mg/kg once weekly), potentially obviating the need for G6PD testing. Hemizygous G6PDd healthy adult Thai and Burmese male volunteers were admitted to the Hospital for Tropical Diseases in Bangkok. In Part 1, volunteers were given ascending dose primaquine regimens whereby daily doses were increased from 7.5 mg up to 45 mg over 15-20 days. In Part 2 conducted at least 6 months later, a single primaquine 45 mg dose was given.

Results

24 volunteers were enrolled in Part 1, and 16 in Part 2 (13 participated in both studies). In three volunteers, the ascending dose regimen was stopped because of haemolysis (n=1) and asymptomatic increases in transaminases (n=2; one was hepatitis E positive). Otherwise the ascending regimens were well tolerated with no drug-related serious adverse events. In Part 1, the median haemoglobin concentration decline was 3.7 g/dL (range: 2.1-5.9; relative decline of 26% [range: 15-40%]). Primaquine doses up to 0.87 mg/kg/day were tolerated subsequently without clinically significant further falls in haemoglobin. In Part 2, the median haemoglobin concentration decline was 1.7 g/dL (range 0.9-4.1; relative fall of 12% [range: 7-30% decrease]). The ascending dose primaquine regimens gave seven times more drug but resulted in only double the haemoglobin decline.

Conclusions

In patients with Southeast Asian G6PDd variants, full radical cure treatment can be given in under 3 weeks compared with the current 8-week regimen.

Funding

Medical Research Council of the United Kingdom (MR/R015252/1) and Wellcome (093956/Z/10/C, 223253/Z/21/Z).

Clinical trial number

Thai Clinical Trial Registry: TCTR20170830002 and TCTR20220317004.

Clinical antiviral efficacy of favipiravir in early COVID-19 (PLATCOV): an open-label, randomised, controlled, adaptive platform trial

In early symptomatic COVID-19 treatment, high dose oral favipiravir did not accelerate viral clearance.

BACKGROUND

Favipiravir, an anti-influenza drug, has in vitro antiviral activity against SARS-CoV-2. Clinical trial evidence to date is inconclusive. Favipiravir has been recommended for the treatment of COVID-19 in some countries.

METHODS

In a multicentre open-label, randomised, controlled, adaptive platform trial, low-risk adult patients with early symptomatic COVID-19 were randomised to one of ten treatment arms including high dose oral favipiravir (3.6g on day 0 followed by 1.6g daily to complete 7 days treatment) or no study drug. The primary outcome was the rate of viral clearance (derived under a linear mixed-effects model from the daily log10 viral densities in standardised duplicate oropharyngeal swab eluates taken daily over 8 days [18 swabs per patient]), assessed in a modified intention-to-treat population (mITT). The safety population included all patients who received at least one dose of the allocated intervention. This ongoing adaptive platform trial was registered at ClinicalTrials.gov (NCT05041907) on 13/09/2021.

RESULTS

In the final analysis, the mITT population contained data from 114 patients randomised to favipiravir and 126 patients randomised concurrently to no study drug. Under the linear mixed-effects model fitted to all oropharyngeal viral density estimates in the first 8 days from randomisation (4,318 swabs), there was no difference in the rate of viral clearance between patients given favipiravir and patients receiving no study drug; a -1% (95% credible interval: -14 to 14%) difference. High dose favipiravir was well-tolerated.

INTERPRETATION

Favipiravir does not accelerate viral clearance in early symptomatic COVID-19. The viral clearance rate estimated from quantitative measurements of oropharyngeal eluate viral densities assesses the antiviral efficacy of drugs in vivo with comparatively few studied patients.

Antiviral efficacy of molnupiravir versus ritonavir-boosted nirmatrelvir in patients with early symptomatic COVID-19 (PLATCOV): an open-label, phase 2, randomised, controlled, adaptive trial

BACKGROUND

Molnupiravir and ritonavir-boosted nirmatrelvir are the two leading oral COVID-19 antiviral treatments, but their antiviral activities in patients have not been compared directly. The aim of this ongoing platform trial is to compare different antiviral treatments using the rate of viral clearance as the measure of antiviral effect.

METHODS

PLATCOV is an open-label, multicentre, phase 2, randomised, controlled, adaptive pharmacometric platform trial running in Thailand, Brazil, Pakistan, and Laos. The component of the trial reported here was conducted in the Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. We recruited low-risk adult patients aged 18-50 years with early symptomatic COVID-19 (<4 days of symptoms). Eligible patients were randomly assigned using block randomisation via a centralised web app to one of seven treatment groups: molnupiravir, ritonavir-boosted nirmatrelvir, casirivimab-imdevimab, tixagevimab-cilgavimab, favipiravir, fluoxetine, or no study drug. The no study drug group comprised a minimum proportion of 20% of patients at all times, with uniform randomisation ratios applied across the active treatment groups. Results for the concurrently randomised molnupiravir, ritonavir-boosted nirmatrelvir, and no study drug groups are reported here. The primary endpoint was the rate of oropharyngeal viral clearance assessed in a modified intention-to-treat population, defined as patients with more than 2 days of follow-up. Safety was assessed in all participants who took at least one dose of the medication. The viral clearance rate was derived under a Bayesian hierarchical linear model fitted to the log10 viral densities in standardised duplicate oropharyngeal swab eluates taken daily over 1 week (18 measurements). Treatment groups with a probability of more than 0·9 that viral clearance was accelerated by more than 20% compared with no drug entered a non-inferiority comparison (with a 10% non-inferiority margin) compared with the platform's current most effective drug. This ongoing trial is registered at ClinicalTrials.gov, NCT05041907.

FINDINGS

Between June 6, 2022, and Feb 23, 2023, 209 patients in Thailand were enrolled and concurrently randomly assigned to molnupiravir (n=65), ritonavir-boosted nirmatrelvir (n=59), or no study drug (n=85). 129 (62%) of the patients were female and 80 (38%) were male. Relative to the no study drug group, the rates of viral clearance were 37% (95% credible interval 16-65) faster with molnupiravir and 84% (54-119) faster with ritonavir-boosted nirmatrelvir. In the non-inferiority comparison, viral clearance was 25% (10-38) slower with molnupiravir than ritonavir-boosted nirmatrelvir. Molnupiravir was removed from the study platform when it reached the prespecified inferiority margin of 10% compared with ritonavir-boosted nirmatrelvir. Median estimated viral clearance half-lives were 8·5 h (IQR 6·7-10·1) with ritonavir-boosted nirmatrelvir, 11·6 h (8·6-15·4) with molnupiravir, and 15·5 h (11·9-21·2) with no study drug. Viral rebound occurred more frequently following nirmatrelvir (six [10%] of 58) compared with the no study drug (one [1%] of 84; p=0·018) or the molnupiravir (one [2%] of 65; p=0·051) groups. Persistent infections following molnupiravir had more viral mutations (three of nine patients had an increased number of single nucleotide polymorphisms in samples collected at 7 or more days compared with those at baseline) than after nirmatrelvir (zero of three) or no study drug (zero of 19). There were no adverse events of grade 3 or worse, or serious adverse events in any of the reported treatment groups.

INTERPRETATION

Both molnupiravir and ritonavir-boosted nirmatrelvir accelerate oropharyngeal SARS-CoV-2 viral clearance in patients with COVID-19, but the antiviral effect of ritonavir-boosted nirmatrelvir was substantially greater. Measurement of oropharyngeal viral clearance rates provides a rapid and well tolerated approach to the assessment and comparison of antiviral drugs in patients with COVID-19. It should be evaluated in other acute viral respiratory infections.

FUNDING

Wellcome Trust through the COVID-19 Therapeutics Accelerator.

Clinical Antiviral Efficacy of Remdesivir in Coronavirus Disease 2019: An Open-Label, Randomized Controlled Adaptive Platform Trial (PLATCOV)

BACKGROUND

Uncertainty over the therapeutic benefit of parenteral remdesivir in coronavirus disease 2019 (COVID-19) has resulted in varying treatment guidelines.

METHODS

In a multicenter open-label, controlled, adaptive, pharmacometric platform trial, low-risk adult patients with early symptomatic COVID-19 were randomized to 1 of 8 treatment arms including intravenous remdesivir (200 mg followed by 100 mg daily for 5 days) or no study drug. The primary outcome was the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance (estimated under a linear model fit to the daily log10 viral densities, days 0-7) in standardized duplicate oropharyngeal swab eluates, in a modified intention-to-treat population. This ongoing adaptive trial is registered at ClinicalTrials.gov (NCT05041907).

RESULTS

The 2 study arms enrolled 131 patients (remdesivir n = 67, no study drug n = 64) and estimated viral clearance rates from a median of 18 swab samples per patient (a total of 2356 quantitative polymerase chain reactions). Under the linear model, compared with the contemporaneous control arm (no study drug), remdesivir accelerated mean estimated viral clearance by 42% (95% credible interval, 18%-73%).

CONCLUSIONS

Parenteral remdesivir accelerates viral clearance in early symptomatic COVID-19. Pharmacometric assessment of therapeutics using the method described can determine in vivo clinical antiviral efficacy rapidly and efficiently.

Cost-effectiveness of tenofovir prophylaxis during pregnancy for the elimination of mother-to-child transmission of the hepatitis B virus: real-world analysis from Thailand

OBJECTIVE

Despite implementing hepatitis B immunoglobulin (HBIG) and vaccination, data suggest it would not be sufficient to reach the elimination targets. Tenofovir disoproxil fumarate (TDF) has been added to the Thai national standards of care for prevention of transmission of the hepatitis B virus during birth. To optimise national strategies in Thailand, we assessed TDF's effectiveness for prevention of mother-to-child transmission and conducted cost-effectiveness analyses of different TDF-based strategies.

RESEARCH DESIGN AND METHODS

We retrospectively reviewed medical records of mother and infant pairs whose mothers were positive for hepatitis B e-antigen (HBeAg) and received TDF to prevent maternal transmission of viral hepatitis B during 2018-2020. Based on the available data on transmission rate, we also applied a decision tree to estimate the cost-effectiveness of different TDF-based strategies to eligible mothers. These included: (1) HBIG for all hepatitis B virus (HBV) exposed infants; (2) HBIG for only infants of HBeAg-positive mothers ('HBIG for e-positive') and (3) without HBIG to infants ('HBIG-free'). The incremental cost-effectiveness ratio between the different strategies and baseline intervention without TDF was calculated. The one-way sensitivity analysis was used to adjust prevalence of HBeAg-positive mothers, cost of HBIG, cost of TDF and transmission rate.

RESULTS

Of 223 infants enrolled, 212 (95.0%) received HBIG, while 11 (5.0%) did not. None of the infants had chronic HBV infection. The most cost-saving intervention was 'HBIG-free' followed by 'HBIG for e-positive'. The one-way sensitivity demonstrated that the results were reasonably robust to changes. The cost-saving was greater with a higher hepatitis B virus surface antigen (HBsAg) prevalence. The HBIG-free strategy remained best at 0%-1.4% transmission rates, meeting the additional target for eliminations.

CONCLUSION

The study is the first cost-effectiveness analyses to provide evidence supporting an HBIG-free strategy in an antiviral era. This approach should be considered to prevent mother-to-child transmission in resource-constrained settings, particularly in countries with a high HBsAg prevalence.

Characteristics of Drug-induced Liver Injury in Chronic Liver Disease: Results from the Thai Association for the Study of the Liver (THASL) DILI Registry

BACKGROUND AND AIMS

The impact of drug-induced liver injury (DILI) on patients with chronic liver disease (CLD) is unclear. There are few reports comparing DILI in CLD and non-CLD patients. In this study, we aimed to determine the incidence and outcomes of DILI in patients with and without CLD.

METHODS

We collected data on eligible individuals with suspected DILI between 2018 and 2020 who were evaluated systematically for other etiologies, causes, and the severity of DILI. We compared the causative agents, clinical features, and outcomes of DILI among subjects with and without CLD who were enrolled in the Thai Association for the Study of the Liver DILI registry. Subjects with definite, or highly likely DILI were included in the analysis.

RESULTS

A total of 200 subjects diagnosed with DILI were found in the registry. Of those, 41 had CLD and 159 had no evidence of CLD in their background. Complementary and alternative medicine (CAM) products were identified as the most common class of DILI agents. Approximately 59% of DILI in the CLD and 40% in non-CLD group were associated with CAM use. Individuals with pre-existing CLD had similar severity including mortality. Twelve patients (6%) developed adverse outcomes related to DILI including seven (3.5%) deaths and five (2.5%) with liver failure. Mortality was 4.88% in CLD and 3.14% in non-CLD subjects over median periods of 58 (8-106) days and 22 (1-65) days, respectively.

CONCLUSIONS

In this liver disease registry, the causes, clinical presentation, and outcomes of DILI in subjects with CLD and without CLD patients were not different. Further study is required to confirm our findings.

Pharmacometrics of high-dose ivermectin in early COVID-19 from an open label, randomized, controlled adaptive platform trial (PLATCOV)

Background

There is no generally accepted methodology for in vivo assessment of antiviral activity in SARS-CoV-2 infections. Ivermectin has been recommended widely as a treatment of COVID-19, but whether it has clinically significant antiviral activity in vivo is uncertain.

Methods

In a multicentre open label, randomized, controlled adaptive platform trial, adult patients with early symptomatic COVID-19 were randomized to one of six treatment arms including high-dose oral ivermectin (600 µg/kg daily for 7 days), the monoclonal antibodies casirivimab and imdevimab (600 mg/600 mg), and no study drug. The primary outcome was the comparison of viral clearance rates in the modified intention-to-treat population. This was derived from daily log10 viral densities in standardized duplicate oropharyngeal swab eluates. This ongoing trial is registered at https://clinicaltrials.gov/ (NCT05041907).

Results

Randomization to the ivermectin arm was stopped after enrolling 205 patients into all arms, as the prespecified futility threshold was reached. Following ivermectin, the mean estimated rate of SARS-CoV-2 viral clearance was 9.1% slower (95% confidence interval [CI] -27.2% to +11.8%; n=45) than in the no drug arm (n=41), whereas in a preliminary analysis of the casirivimab/imdevimab arm it was 52.3% faster (95% CI +7.0% to +115.1%; n=10 (Delta variant) vs. n=41).

Conclusions

High-dose ivermectin did not have measurable antiviral activity in early symptomatic COVID-19. Pharmacometric evaluation of viral clearance rate from frequent serial oropharyngeal qPCR viral density estimates is a highly efficient and well-tolerated method of assessing SARS-CoV-2 antiviral therapeutics in vitro.

Funding

'Finding treatments for COVID-19: A phase 2 multi-centre adaptive platform trial to assess antiviral pharmacodynamics in early symptomatic COVID-19 (PLAT-COV)' is supported by the Wellcome Trust Grant ref: 223195/Z/21/Z through the COVID-19 Therapeutics Accelerator.

Clinical trial number

NCT05041907.

Severity of COVID-19 in Patients with Diarrhoea: A Systematic Review and Meta-Analysis

COVID-19 patients occasionally present with diarrhoea. Our objective was to estimate the risk of developing the severe disease in COVID-19 patients with and without diarrhoea and to provide a more precise estimate of the prevalence of COVID-19-associated digestive symptoms. A total of 88 studies (n = 67,794) on patients with a COVID-19 infection published between 1 January 2020 and 20 October 2022 were included in this meta-analysis. The overall prevalence of digestive symptoms was 27% (95% confidence interval (CI): 21-34%; I² = 99%). According to our data, the pooled prevalence of diarrhoea symptoms in the 88 studies analysed was 17% (95% CI: 14-20%; I² = 98%). The pooled estimate of nausea or vomiting in a total of 60 studies was 12% (95% CI: 8-15%; I² = 98%). We also analysed 23 studies with eligible individuals (n = 3800) to assess the association between the disease severity and diarrhoea. Individuals who had diarrhoea were more likely to have experienced severe COVID-19 (odds ratio: 1.71; 95% CI: 1.31-2.24; p < 0.0001; I² = 10%). Gastrointestinal symptoms and diarrhoea are frequently presenting COVID-19 manifestations that physicians should be aware of.

Prevalence, Risk Factors, and Prognosis of Liver Involvement in Adult Patients with Chikungunya in Thailand

Chikungunya is a mosquito-borne disease mainly characterized by fever with polyarthralgia. Currently, liver complications of chikungunya remain rarely described. This study assesses the prevalence, severity, and risk factors of liver involvement, and the association between liver involvement severity and prognosis. We conducted a retrospective cohort study at two referral centers for tropical infectious diseases-the Hospital for Tropical Diseases and Bamrasnaradura Infectious Diseases Institute in Thailand-from January 2016 to April 2021. The study included 400 patients diagnosed with chikungunya. Of them, 254 (63.5%) were female with a mean age of 41.5 ± 14.1 years, and 98.5% of them presented with fever with arthralgia. Gastrointestinal presentations included nausea or vomiting (n = 62, 15.5%), diarrhea (n = 33, 8.3%), and abdominal pain (n = 4, 1%). Of 88 patients with available liver function tests, 39.8% had hepatitis (abnormal alanine aminotransferase levels), of whom 5.7% had moderate hepatitis. Nausea or vomiting is a clinical risk factor associated with liver involvement (adjusted odds ratio, 5.17; 95% CI, 1.20-22.34). Liver involvement was usually observed during the first 2 weeks of illness and resolved eventually. None of the patients experienced severe hepatitis, liver failure, or death caused by a liver problem. In conclusion, most of the patients with chikungunya did not have significant liver involvement. In those patients with severe liver injury, coexisting causes should be considered.

Regional Differences in Admissions and Treatment Outcomes for Hepatocellular Carcinoma Patients in Thailand

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the commonest cancers in Thailand. We report the stage and survival of patients who were admitted under the public universal health fund (NHSO) covering 47 million people to determine if there were regional disparities in the treatment outcomes in the country.

METHOD

We used the 2009-2013 Nationwide Hospital Admission Data, Thailand. Patients with hepatocellular carcinoma (HCC) were identified by the ICD10 code C22.0. Procedures were identified by ICD9-CM codes, and deaths were confirmed from the NHSO database and the national citizen registry. Thailand is divided into 6 regions and Bangkok. Hospitals were identified according to their specific reimbursement codes. Survival time started from the day of first admission and was estimated using the Kaplan-Meier method. The statistical method used to compare regions was Chi-squared tests (Pearson, likelihood ratio, linear-by linear association and Mantel-cox).

RESULTS

There were 36,956 HCC patients admitted during the study period. The overall median survival was 36 days. 1.63% of the patients had surgery, 0.96% had radiofrequency ablation (RFA), and 5.24% had trans-arterial chemoembolization (TACE). 90.24% did not have any tumor-specific therapy. The proportion of patients admitted for tumor-specific therapy vs. no tumor-specific therapy was significantly different between regions in all treatment modalities (p<0.01). Each treatment modality showed a wide range of median survival values across the regions (p<0.01). The best survival was seen in Bangkok, the South and the North (for surgery, RFA and TACE) and was often more than twice as long as the regions with the lowest survival, Central, East and West.

CONCLUSIONS

There was a large previously-unreported disparity in admissions and outcomes in Thailand for different treatment modalities for HCC. Bangkok and the South had the best treatment outcomes and often had median survivals more than twice as long as those in the West and East. Public policy to reduce this disparity will need to be implemented in the future.

Safety, pharmacokinetics, and antiviral activity of the capsid inhibitor AB-506 from Phase 1 studies in healthy subjects and those with hepatitis B

AB-506 is a potent, pan-genotypic small molecule capsid inhibitor that inhibits hepatitis B virus (HBV) pregenomic RNA encapsidation. We assessed the safety, pharmacokinetics, and antiviral activity of AB-506 in two randomized, double-blinded Phase 1 studies in healthy subjects (HS) and subjects with chronic HBV infection (CHB). Single ascending and multiple doses of AB-506 or placebo (30-1000 mg or 400 mg daily for 10 days) were assessed in HS. AB-506 or placebo was assessed at either 160 mg or 400 mg daily for 28 days in subjects with CHB. A second follow-up study examined AB-506 or placebo at 400 mg daily for 28 days in 14 Caucasian and 14 East-Asian HS. Twenty-eight days of AB-506 at 160 mg and 400 mg produced mean HBV-DNA declines from baseline of 2.1 log₁₀ IU/ml and 2.8 log₁₀ IU/ml, respectively. Four subjects with CHB (all Asian) had Grade 4 alanine aminotransferase (ALT) elevations (2 at each dose) as HBV DNA was declining; three events led to treatment discontinuation. In the second follow-up study, 2 Asian HS had serious transaminitis events leading to treatment and study termination. No subjects had bilirubin elevations or signs of hepatic decompensation. Conclusion: AB-506 demonstrated mean HBV-DNA declines of >2 log₁₀ ; however, transient but severe ALT flares were observed in 4 Asian subjects with CHB. In the follow-up study in HS, 2 additional Asian HS had Grade 4 flares, suggesting that AB-506 hepatotoxicity contributed to the ALT elevations. The AB-506 development program was terminated because of these findings.

Low Branched Chain Amino Acids and Tyrosine in Thai Patients with Type 2 Diabetes Mellitus Treated with Metformin and Metformin-Sulfonylurea Combination Therapies

Type 2 diabetes mellitus (T2DM) is a growing public health challenge for Thailand (current prevalence ~10.0%). Amino acids offer novel biomarkers to predict risk of T2DM and indicate sub-optimal disease management, which could facilitate earlier treatment. We studied amino acid profiles in a Thai cohort comprising of individuals with T2DM (n = 65 single-drug-treated; n = 38 multi-drug-treated) compared to healthy controls (n = 104) using liquid chromatography-mass spectrometry. Age and BMI were significantly lower in the healthy controls compared to the single or multi-treated T2DM groups. The BCAA (leucine and valine) were significantly lower in the single and multi-treated T2DM groups compared to healthy controls (p < 0.001 and p < 0.001) and isoleucine was significantly lower in the single-treated compared to the healthy controls (p = 0.014). These findings beg the question whether BCAAs supplementation be beneficial in T2DM patients treated with single or multi-drug therapy? Tyrosine was significantly lower in the single and multi-treated T2DM groups compared to healthy controls (p < 0.001 and p = 0.002), whereas phenylalanine was significantly higher in the multi-treated T2DM group compared to the single treated T2DM group (p = 0.045). We provide novel insights into the effects of diabetes treatments on these amino acids in insulin resistant states such as T2DM in a unique but understudied Thai population.

Assessment of the amino acid profile in Thai patients with type 2 diabetes mellitus using liquid chromatography-mass spectrometry

Background

Type 2 diabetes mellitus (T2DM) is a global health problem. Early identification of those at risk is necessary to prevent its onset through lifestyle and pharmacologic interventions. T2DM is characterized by metabolic abnormalities, including protein metabolism. Evaluation of the amino acid profile might be beneficial for early assessment.

Methods

Liquid chromatography-mass spectrometry was performed to separate and quantify plasma amino acids from two groups of Thai individuals, patients with T2DM (n=103) and healthy individuals (n=104). Multivariate analysis was applied to compare free amino acid levels between groups. Subgroup analyses of patients with T2DM were performed to assess the association between amino acid profiles and important T2DM clinical characteristics.

Results

The multivariate analysis showed that glutamic acid was significantly associated with T2DM (OR 1.113, 95% CI 1.006 to 1.231) and results from the subgroup analyses showed that this correlation was significant in all subgroups of patients (p<0.05).

Conclusions

This finding needs to be confirmed in larger groups of patients with T2DM to explore glutamic acid as a biomarker for early prevention in particular at-risk groups. An in-depth understanding of the involvement of glutamic acid in T2DM could enhance our understanding of the disease and potentially provide novel interventions.

Prevalence and clinical manifestations of dengue in older patients in Bangkok Hospital for Tropical Diseases, Thailand

BACKGROUND

The global incidence of dengue has increased with the ageing population. We examined the prevalence, clinical manifestations and risk factors associated with dengue severity among older patients.

METHODS

A retrospective cohort study was conducted at a hospital in Thailand from 2013 to 2018. Data were collected from patient records. Older patients were those aged ≥60 y, whereas adult patients were aged at least 18 y but younger than 60 y.

RESULTS

In total, 1822 patients were included in the study. The prevalence of older dengue was 7.96%. Older dengue patients were at a higher risk of developing dengue haemorrhagic fever (DHF) than adult dengue patients (40.69% vs 30.71%). Haematuria was significantly more frequent in older patients (24.82% vs 3.58%), whereas other clinical manifestations had similar frequencies between the groups. Multivariate logistic regression indicated that hypertension (adjusted OR [aOR]=3.549, 95% CI 1.498 to 8.407) and abdominal pain (aOR=10.904, 95% CI 1.037 to 114.710) were significantly associated with DHF among older patients.

CONCLUSIONS

Dengue is common in older adults, who also have a higher incidence of developing DHF. Older patients with dengue and comorbid hypertension and abdominal pain should be monitored for their increasing risk of DHF.

Cost-effectiveness and budget impact analyses for the prioritisation of the four available rotavirus vaccines in the national immunisation programme in Thailand

BACKGROUND

Rotavirus is a major cause of diarrhoea in children less than five years old in Thailand. Vaccination has been shown to be an effective intervention to prevent rotavirus infections but has yet to be enlisted in the national immunisation programme. This study aimed to assess the cost-utility of introducing rotavirus vaccines, taking all WHO-prequalified vaccines into consideration.

METHODS

A cost-utility analysis was performed using a transmission dynamic model to estimate, from a societal perspective, the costs and outcomes of four WHO-prequalified rotavirus vaccines: Rotarix®, RotaTeq®, ROTAVAC® and ROTASIIL®. The model was used to simulate the impact of introducing the vaccines among children aged < 1 year and compare this with no rotavirus vaccination. The vaccination programme was considered to be cost-effective if the incremental cost-effectiveness ratio was less than a threshold of USD 5,110 per QALY gained.

RESULTS

Overall, without the vaccine, the model predicted the average annual incidence of rotavirus to be 312,118 cases. With rotavirus vaccination at a coverage of more than 95%, the average number of rotavirus cases averted was estimated to be 144,299 per year. All rotavirus vaccines were cost-saving. ROTASIIL® was the most cost-saving option, followed by ROTAVAC®, Rotarix® and RotaTeq®, providing average cost-savings of USD 32, 31, 23 and 22 million per year, respectively, with 999 QALYs gained. All vaccines remained cost-saving with lower QALYs gained, even when ignoring indirect beneficial effects. The net saving to the healthcare system when implementing any one of these vaccines would be between USD 13 and 33 million per year.

CONCLUSION

Rotavirus vaccines should be included in the national vaccination programme in Thailand. Implementing any one of these four WHO-prequalified vaccines would reduce government healthcare spending while yielding health benefits to the population.

Reverse transcriptase droplet digital PCR vs reverse transcriptase quantitative real-time PCR for serum HBV RNA quantification

Serum hepatitis B virus (HBV) RNA is a novel marker reflecting the activity of covalently closed circular DNA. However, the methodology for detecting HBV RNA has been a technical challenge. In this study, the performance of reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) for quantifying HBV RNA was compared with that of reverse transcription quantitative real-time PCR (RT-qPCR) in serum samples collected from treatment-naïve patients with different phases of chronic hepatitis B (CHB). A total of 417 serum samples, including 136 HBeAg-positive CHB and 281 HBeAg-negative CHB were examined. HBV RNA levels measured by RT-ddPCR and RT-qPCR showed a high degree of linearity and quantitative correlation. The limit of detections of RT-ddPCR and RT-qPCR assays were 102 and 103 copies/mL, respectively. Our results also demonstrated that RT-ddPCR was superior to RT-qPCR in terms of its consistency for quantifying HBV RNA across all concentrations. In the HBeAg-positive group, serum HBV RNA levels based on RT-ddPCR were moderately correlated with HBV DNA (r = 0.591, P < .001) and HBsAg (r = 0.502, P < .001). Among patients with HBeAg-negative CHB, serum HBV RNA levels were moderately correlated with HBV DNA (r = 0.603, P < .001) but had weak correlation with HBsAg (r = 0.203, P = .001). In summary, RT-ddPCR could enhance the sensitivity of serum HBV RNA detection, particularly among the HBeAg-negative group with low viral loads. Thus, RT-ddPCR could serve as an optimal method for HBV RNA quantification in clinical practice.

Towards the elimination of viral hepatitis in Thailand by the year 2030

Viral hepatitis is a global problem with mortality comparable to HIV, tuberculosis and malaria. The WHO aims to eliminate hepatitis B (HBV) and hepatitis C (HCV) by 2030. Improved socioeconomic status of developing countries such as Thailand has reduced the incidence and morbidity associated with hepatitis A. Since the beginning of hepatitis B vaccination in all Thai newborns in 1992, at least 95% of one-year-olds are currently receiving 3–4 hepatitis B doses. The second vaccination of newborns of carrier mothers at 1 month of age has contributed to an effective reduction in mother-to-child transmission. Universal vaccination, blood donation screening, and decreasing needle sharing have reduced hepatitis B infection. Under the test and treat model, cost-effective screening at the point-of-care (health center or village hospital) is recommended for adults >30 years-old. Following referral to a tertiary healthcare center for a treatment plan in developing disease management plan, its implementation by trained healthcare professionals is preferably administered at the point-of-care. Hepatitis C prevalence is also decreasing as a result of blood-borne pathogen awareness. Current hepatitis C infection is highest for adults >35 years who were born prior to 1983, with screening is recommend once in their lifetime. Treatment strategy recommendation follows that of hepatitis B. The availability of direct antiviral agents with high cure rates is expected to contribute to the reduction in hepatitis C transmission and mortality as set forth by the WHO policy. Thus, ensuring the successful planning of hepatitis elimination in Thailand requires pilot regional assessment prior to national implementation.

Incidence of Travelers' Diarrhea among Adult Foreign Travelers in Thailand: A Prospective Study

Travelers' diarrhea (TD) is common among foreign travelers to Thailand. We performed a prospective cohort study to determine the TD incidence among foreign adult travelers to Thailand. We retrieved baseline demographic data, travel plans, and health history on enrolling individuals and collected follow-up questionnaires on days 7, 14, and 28 from the day of arrival. We analyzed data from 349 eligible participants. The mean participants' age was 32.3 years; 55.4% were men. Most of the participants had visited a travel clinic for vaccinations and counseling after arrival in Thailand. The cumulative incidences of the participants developing TD were 14.0% (49/349), 23.5% (82/349), and 33.0% (115/349) at 7, 14, and 28 days, respectively. The median time to develop TD was 9 days (interquartile range 5-18 days) post-arrival. Of 115 participants with TD, 64.3% (74/115) consulted a physician, 1.7% (2/115) were hospitalized, and 11.3% (13/115) had to change their travel plans. We identified young age, eating street food, and not routinely washing hands after using a toilet as risk factors significantly associated with the incidence of TD using the log-rank test in our survival analysis. Up to one-third of foreign travelers developed diarrhea during the first month, and some cases were severe. Although no highly effective TD prevention method exists, the practice of good personal hygiene and avoidance of food and drinks derived from unsanitary sources are still recommended to reduce the risk of travelers' TD.

Thirty-Day Readmission and Cost Analysis in Patients With Cirrhosis: A Nationwide Population-Based Data

Accurate population‐based data are needed on the rate, economic impact, and the long‐term outcomes of readmission among patients with cirrhosis. To examine the rates, costs, and 1‐year outcomes of patients readmitted within 30 days following their index hospitalization for complications of cirrhosis, we conducted a nationwide, population‐based cohort study involving all patients with cirrhosis in Thailand from 2009 through 2013, using data from the National Health Security Office databases, which included those from nationwide hospitalizations. Readmission was captured from hospitals at all health care levels across the country within the Universal Coverage Scheme. For the 134,038 patients hospitalized with cirrhosis, the overall 30‐day readmission rate was 17%. Common causes of readmission consisted of complications of portal hypertension (47%) and infections (17%). After adjusting for multiple covariates, predictors of 30‐day readmission included hepatocellular carcinoma (odds ratio [OR] 1.95, 95% confidence interval [CI] 1.84‐2.06), human immunodeficiency virus–related admission (OR 1.81, 95% CI 1.51‐2.17) and cholangiocarcinoma (OR 1.64, 95% CI 1.3‐2.05). In all, 2,936 deaths (13%) occurred during readmission, and an additional 14,425 deaths up to 1 year (63.5% total mortality among readmitted patients). Causes of death were mostly from liver‐related mortality. Average cost at index admission for those with a 30‐day readmission were significantly higher than those readmitted beyond 30 days or not readmitted. Conclusions: Patients hospitalized with cirrhosis complications had high rates of unscheduled 30‐day readmission. Average hospitalization costs were high, and only 36.5% of patients readmitted within 30 days survived at 1 year.

Baseline and kinetics of serum hepatitis B virus RNA predict response to pegylated interferon-based therapy in patients with hepatitis B e antigen-negative chronic hepatitis B

Serum hepatitis B virus (HBV) RNA has emerged as a novel biomarker of treatment response. This study aimed to investigate the role of this marker in predicting long-term outcome of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) receiving pegylated interferon (PEG-IFN)-based therapy. Serial serum samples from 91 patients with HBeAg-negative CHB previously treated with PEG-IFN alone or combined with entecavir in a randomized trial were retrospectively analysed. HBV RNA quantification was examined by droplet digital PCR. At the end of 3 years post-treatment follow-up, maintained virological response (MVR, HBV DNA < 2000 IU/mL), and hepatitis B surface antigen (HBsAg) clearance were achieved in 37.4% (34/91) and 7.7% (7/91), respectively. Baseline serum HBV RNA concentrations correlated with HBV DNA and covalently closed circular DNA but did not correlate with HBsAg levels. Multiple regression analysis showed that pre-treatment HBV RNA and HBsAg were independently associated with MVR and HBsAg clearance. Baseline HBV RNA (cut-off 2.0 log₁₀  copies/mL) had a positive predictive value (PPV) and a negative predictive value in predicting MVR of 80.8% and 80.0%, respectively. At the same cut-off value, PPV and NPV for predicting HBsAg clearance were 30.8% and 95.4%, respectively. At week 12 during therapy, HBV RNA level ≥ 2 log₁₀ copies/mL displayed high NPVs of achieving MVR and HBsAg clearance (95% and 100%, respectively). In conclusion, the measurement of HBV RNA prior to PEG-IFN-based therapy could identify patients with high probability of MVR. In addition, HBV RNA kinetics may serve as a promising "stopping rule" in patients infected with HBV genotypes B or C.

Genetic variation in STAT4 is associated with treatment response to pegylated interferon in patients with chronic hepatitis B

BACKGROUND

Signaling pathways in the STAT4 gene play an essential role in interferon-mediated antiviral effects.

OBJECTIVE

This study was aimed at investigating the role of rs7574865, a single nucleotide polymorphism (SNP) in STAT4, in patients with chronic hepatitis B (CHB) treated with pegylated interferon (PEG-IFN).

METHODS

A total 261 Thai patients (115 HBeAg-positive and 146 HBeAg-negative CHB) treated with 48-week PEG-IFN were recruited. Virological response (VR) at 48 weeks post treatment was defined as HBeAg seroconversion plus HBV DNA < 2,000 IU/mL for HBeAg-positive CHB and HBV DNA < 2,000 IU/mL for HBeAg-negative CHB. The SNP was analyzed by TaqMan PCR assay.

RESULTS

The distribution of GG, GT and TT genotypes of rs7574865 was 41.8%, 42.9% and 15.3%, respectively. There was no different in its distribution according to HBeAg status. Overall, patients with TT genotype, compared with non-TT genotype, achieved higher VR (64.3% vs. 30.5%; P < 0.001) and HBsAg clearance (23.8% vs. 5.0%; P < 0.001). There was the same trend in the HBeAg-positive group (VR, 52.4% vs. 30.9%; P = 0.077; HBsAg clearance, 23.8% vs. 6.4%; P = 0.028) and in the HBeAg-negative group (VR, 68.4% vs. 32.3%; P = 0.004; HBsAg clearance, 21.1% vs. 4.7%; P = 0.026). Multiple regression analysis demonstrated that low baseline HBsAg level and TT genotype were factors independently associated with VR and HBsAg clearance.

CONCLUSIONS

Our data support that SNP rs7574865 is associated with response to PEG-IFN therapy in Thai patients with CHB, regardless of baseline HBeAg status. Thus, the determination of this SNP could maximize cost-effectiveness of PEGIFN in patients with CHB.

Association between Hepatitis B Surface Antigen Levels and the Risk of Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Infection: Systematic Review and Meta-Analysis

Background: The role of hepatitis B surface antigen (HBsAg) levels in predicting the risk of developing hepatocellular carcinoma (HCC) has remained unclear. The aim of this study was to obtain the most up-to-date estimated measure of the association between HBsAg levels and the development of HCC in patients. Methods: We performed a systematic review by searching for relevant studies on PubMed, Scopus, ProQuest and the Cochrane Central Register of Controlled Trials from January 2002 to November 2017. We presented the effects of HBsAg levels at each cut-off value as the odds ratios (ORs) at 95% confidence interval (CI). We also investigated HCC and its potential risk factors including HBeAg, and HBV DNA. We registered our protocol with the International Prospective Register of Systematic Reviews (PROSPERO) with the registration number CRD42018081138. Results: We selected 10 studies representing 12 541 cases. At the 100 IU/ml cut-off, the OR for HCC at the high HBsAg level versus the low level was 4.99 (95% CI, 3.01–8.29) with high inconsistency (I2=79%). At the 1,000 IU/ml threshold, the pooled OR for HCC at the high HBsAg versus the low level was 2.46 (95% CI, 2.15–2.83) with low variance. We also found correlations between the risk of HCC and male gender (OR=2.12), hepatitis B e-antigen positivity (OR=2.99), or hepatitis B (HBV) viral load ≥ 2,000 IU/ml (OR=4.37). Conclusion: Our study revealed that HBsAg levels ≥ 100 IU/ml, and notably >1,000 IU/ ml, are associated with an increased risk of HCC development.

Awareness, knowledge, and practice for hepatitis B infection in Southeast Asia: a cross-sectional study

INTRODUCTION

The prevalence of hepatitis B virus (HBV) infection in Southeast Asia is high. Awareness and early detection are essential for timely prevention and treatment.

METHODOLOGY

We examined the awareness of, knowledge about, practices and views on treatment for HBV infection in Southeast Asia. A cross-sectional survey was conducted from December 2016 to February 2017 among individuals from six nations in Southeast Asia-Myanmar, Thailand, Vietnam, Cambodia, the Philippines, and Singapore. The study population comprised healthcare and non-healthcare personnel.

RESULTS

In total, 799 healthcare personnel and 1079 non-healthcare personnel completed an online survey. The prevalence of the awareness of their own HBV infection status and risk of this regionally endemic infection was 85.6% (684/799) among healthcare personnel and 54.0% (583/1079) among non-healthcare personnel. Similarly, 85.9% of healthcare personnel and 45.5% of non-healthcare personnel had good knowledge about disease transmission, complications, and the need for treatment, and 76.6% of healthcare personnel and 39.8% of non-healthcare personnel followed good HBV infection-prevention practices. Overall, 90.6% found the idea of treatment acceptable. Awareness had a significant impact on both knowledge and practice scores among both healthcare personnel and non-healthcare personnel (p < 0.01) but without statistically significant differences in treatment acceptance between the two groups (p = 0.61).

CONCLUSIONS

Awareness of HBV infection was relatively low among non-healthcare personnel in Southeast Asian populations. The provision of additional hepatitis B awareness campaigns is crucial to eliminating viral hepatitis in the region.

Modeling household dynamics on Respiratory Syncytial Virus (RSV)

Respiratory Syncytial Virus (RSV) is the most common cause of respiratory tract infection in infants and children and shows increasing trend among elderly people worldwide. In many developing country settings, population and household structures have gone through some significant changes in the past decades, namely fewer births, more elderly population, and smaller household size but more RSV high-risk individuals. These dynamics have been captured in a mathematical model with RSV transmission dynamics to predict the disease burden on the detailed population for future targeted interventions. The population and disease dynamics model was constructed and tested against the hospitalization data for Acute Lower Respiratory Tract Infection due to RSV in rural Thai settings between 2005 and 2011. The proportion of extended families is predicted to increase by about 10% from 2005 to 2020, especially for those with elderly population, while the classic nuclear family type (with adults and children) will decline by about 10%. For RSV, infections from extended family type (approximately 60% of all household types) have majorly contributed to the force of infection (FOI). While the model predicted the increase of FOI from the extended family by 15% from 2005 to 2020, the FOI contributed by other household types would be either stable or decrease in the same time period. RSV incidence rate is predominantly high among babies (92.2%) and has been predicted to decrease slightly over time (from 940 to 864 cases per 100,000 population by 2020), while the incidence rates among children and elderly people may remain steadily low over the same period. However, the estimated incidence rates among elderly people were twice than those in children. The model predicts that approximately 60% of FOI for RSV will come from members of the extended family type. The incidence rate of RSV among children and elderly in extended families was about 20 times lower than that in infants and the trend is steady. Targeted intervention strategies, such as health education in some specific groups and targeted vaccination, may be considered, with the focus on extended family type. Target interventions on babies can lessen the transmission to children and elderly especially when transmission within households of extended family type is high.

Evaluation of aspartate aminotransferase to platelet ratio index and fibrosis 4 scores for hepatic fibrosis assessment compared with transient elastography in chronic hepatitis C patients

Background and Aim

Fibrotic stage (FS) assessment is essential in chronic hepatitis C treatment cascade. Liver stiffness measurement (LSM) using transient elastography (TE) is reliable and correlated with liver biopsy. However, TE may not be widely available. This study aimed to evaluate the diagnostic performances of aspartate aminotransferase to platelet ratio index (APRI) and fibrosis 4 (FIB‐4) scores compared with TE.

Methods

We conducted a multicenter, cross‐sectional study, including all chronic hepatitis C virus (HCV) monoinfection patients with successful and reliable LSM, at 10 centers in Thailand from 2012 to 2017. Characteristics and laboratory data within 3 months of TE were retrospectively reviewed. Using TE as a reference standard, the diagnostic performances of APRI and FIB‐4 were evaluated. TE cut‐off levels of 7.1 and 12.5 kPa represented significant fibrosis (SF) and cirrhosis, respectively.

Results

The distribution of FS by TE in 2000 eligible patients was as follows: no SF 28.3%, SF 31.4%, and cirrhosis 40.3%. APRI ≥ 1 provided 70.1% sensitivity and 80.6% specificity, with an area under the receiver operator characteristics curve (AUROC) of 0.834 for cirrhosis. The specificity increased to 96.3% when using a cut‐off level of APRI ≥ 2. FIB‐4 ≥ 1.45 provided a sensitivity, specificity, and AUROC of 52.4%, 91.0%, and 0.829 for cirrhosis, respectively. For SF, APRI performed better than FIB‐4, with an AUROC of 0.84 versus 0.80 (P < 0.001). APRI score < 0.5 and FIB‐4 score > 1.45 yielded sensitivities of 82.3% and 74.4% and specificities of 65.4% and 69.8%, respectively.

Conclusions

APRI and FIB‐4 scores had good diagnostic performances for FS assessment compared with TE, especially for cirrhosis. APRI may be used as the noninvasive assessment in resource‐limited settings for HCV patients’ management.

Modelling population dynamics and seasonal movement to assess and predict the burden of melioidosis

BACKGROUND

Melioidosis is an infectious disease that is transmitted mainly through contact with contaminated soil or water, and exhibits marked seasonality in most settings, including Southeast Asia. In this study, we used mathematical modelling to examine the impacts of such demographic changes on melioidosis incidence, and to predict the disease burden in a developing country such as Thailand.

METHODOLOGY/PRINCIPAL FINDINGS

A melioidosis infection model was constructed which included demographic data, diabetes mellitus (DM) prevalence, and melioidosis disease processes. The model was fitted to reported melioidosis incidence in Thailand by age, sex, and geographical area, between 2008 and 2015, using a Bayesian Markov Chain Monte Carlo (MCMC) approach. The model was then used to predict the disease burden and future trends of melioidosis incidence in Thailand. Our model predicted two-fold higher incidence rates of melioidosis compared with national surveillance data from 2015. The estimated incidence rates among males were two-fold greater than those in females. Furthermore, the melioidosis incidence rates in the Northeast region population, and among the transient population, were more than double compared to the non-Northeast region population. The highest incidence rates occurred in males aged 45-59 years old for all regions. The average incidence rate of melioidosis between 2005 and 2035 was predicted to be 11.42 to 12.78 per 100,000 population per year, with a slightly increasing trend. Overall, it was estimated that about half of all cases of melioidosis were symptomatic. In addition, the model suggested a greater susceptibility to melioidosis in diabetic compared with non-diabetic individuals.

CONCLUSIONS/SIGNIFICANCE

The increasing trend of melioidosis incidence rates was significantly higher among working-age Northeast and transient populations, males aged ≥45 years old, and diabetic individuals. Targeted intervention strategies, such as health education and awareness raising initiatives, should be implemented on high-risk groups, such as those living in the Northeast region, and the seasonally transient population.

The incidence, etiologies, outcomes, and predictors of mortality of acute liver failure in Thailand: a population-base study

BACKGROUND

Acute liver failure (ALF) is uncommon but progresses rapidly with high mortality. We investigated the incidence, etiologies, outcomes, and predictive factors for 30-day mortality in patients with ALF.

METHODS

We conducted a population-based study of ALF patients hospitalized between 2009 and 2013 from the Thai Nationwide Hospital Admission database, which comprises 76% of all admissions from 858 hospitals across 77 provinces in Thailand. ALF was diagnosed using ICD-10 codes K72.0 and K71.11. Patients with liver cirrhosis were excluded.

RESULTS

There were 20,589 patients diagnosed with ALF during the study period with 12,277 (59.6%) males and mean age of 46.6 ± 20.7 years. The incidence of ALF was 62.9 per million population per year. The most frequent causes of ALF were indeterminate (69.4%), non-acetaminophen drug-induced (26.1%), and viral hepatitis (2.5%). Acetaminophen was the presumptive cause in 1.7% of patients. There were 5502 patients (26.7%) who died within 30 days after admission. One patient (0.005%) underwent liver transplantation. The average hospital stay was 8.7 ± 13.9 days, and the total cost of management was 1075.2 ± 2718.9 USD per admission. The most prevalent complications were acute renal failure (ARF)(24.2%), septicemia (18.2%), and pneumonia (12.3%). The most influential predictive factors for 30-day mortality were ARF (HR = 3.64, 95% CI: 3.43-3.87, p < 0.001), malignant infiltration of the liver (HR = 3.37, 95% CI: 2.94-3.85, p < 0.001), and septicemia (HR = 1.96, 95%CI: 1.84-2.08, p < 0.001).

CONCLUSIONS

ALF patients have poor outcomes with 30-day mortality of 26.7% and high economic burden. Indeterminate etiology is the most frequent cause. ARF, malignant infiltration of the liver, and septicemia are main predictors of 30-day mortality.

Characteristics and associated factors of acute kidney injury among adult dengue patients: A retrospective single-center study

Severe dengue cases have been increasingly reported in Thailand, and the under-reporting of acute kidney injury (AKI) in cases of dengue viral infection has become an obstacle in obtaining an accurate description of the true nature and epidemiology of AKI. Because AKI may lead to patient morbidity and mortality, an early diagnosis is important in preventing its onset in dengue patients. This study aimed to determine the prevalence, clinical and laboratory characteristics, and associated factors of AKI among adult dengue patients. This retrospective study reviewed admission data from the medical records of adult dengue patients admitted to the Bangkok Hospital for Tropical Diseases between January 2012 and November 2017 and stratified these patients into AKI and non-AKI groups using the Kidney Disease Improving Global Outcomes criteria (KDIGO). A total of 1,484 patients were included in the study, with 71 categorized into the AKI group. The prevalence of AKI was 4.8%. In the AKI group, the predominant age range was 18–40 years (71.8%), with a female to male ratio of 1:2.7. These patients showed significantly (P < 0.05) higher proportions of altered consciousness, dyspnea, low mean arterial blood pressure, high-grade fever, major bleeding, severe thrombocytopenia, hypoalbuminemia, severe transaminitis, coagulopathy, metabolic acidosis, rhabdomyolysis, proteinuria, hematuria, and pyuria. Our study established that older age, male sex, diabetes mellitus, obesity, severe dengue, and coexisting bacterial infection were significant associated factors for AKI in dengue by multivariate analysis. A total of 10 (14.1%) patients with AKI received dialysis, among which 9 (12.7%) patients from the AKI group died. Our findings suggest that an awareness of AKI, its early diagnosis, and evaluation of clinical and laboratory characteristics of dengue patients will help clinicians to initiate appropriate therapy for dengue-associated AKI.

Birth-cohort HCV screening target in Thailand to expand and optimize the national HCV screening for public health policy

The World Health Organization aims to eliminate HCV infection worldwide by 2030. A targeted HCV screening policy is currently unavailable in Thailand, but a decrease in HCV infection has been observed in the country. However, a previous study showed that there was a higher HCV seroprevalence in adults aged between 30–64 years in the Phetchabun province (15.5%), as compared to the Khon Kaen province (3.6%). It was hypothesized that young adults had a lower rate of HCV seropositivity; this was determined by the age distribution of anti-HCV in Phetchabun and with the identification of high seroprevalence birth cohorts. In order to compare the provincial findings to the national level, anti-HCV birth cohorts were further analyzed in Khon Kaen (averaged-HCV prevalence) as well as the Thai data set that was derived from the previous literature. Thai individuals aged between 18–30 years residing in Phetchabun (n = 1453) were recruited, tested for the presence of anti-HCV antibodies and viral RNA and completed questionnaires that were designed to identify HCV exposure risks. Data was collected and compiled from previously published articles (n = 1667, age 30–64 years). The HCV seropositivity in Phetchabun by age group (18–64, at 5-year intervals) and the birth year were tabulated parallel to the Khon Kaen data set (n = 2233) in conjunction with data from the national survey 2014 (n = 5964) representing the Thai population. Factors such as age, male gender, agricultural work, blood transfusion, intravenous drug use and having a tattoo were associated with anti-HCV positivity in Phetchabun. HCV seroprevalence was less than 4.0% (ranging from 0.0–3.5%) from the age of 18–34 years. A dramatic increase of 15.1% was found in adults aged greater than or equal to 35 years, whereas, the age group in Khon Kaen and the national population with increasing prevalence of HCV were older (≥40). The HCV seropositivity cohort accumulated for those born between 1951–1982 accounted for 71.4–100.0% of all seropositive individuals. Subsequently, new cases occurred sporadically. This finding provides evidence that there is a disproportionately high HCV seroprevalence among people born before 1983 (or aged ≥35). This cohort should be targeted for priority screening as part of the national HCV screening policy. Incorporating this birth cohort with other risk factors could improve HCV diagnostic rates, resulting in overall improvements in parallel to those given by novel antiviral treatment.

Characteristics and outcomes of cholangiocarcinoma by region in Thailand: A nationwide study

AIM

To identify the potential risk factors of cholangiocarcinoma, we determined the characteristics of cholangiocarcinoma patients among 5 different regions of Thailand.

METHODS

All patients diagnosed with cholangiocarcinoma between 2008 and 2013 were identified using the Nationwide Hospital Admission Data registry (n = 39421). Baseline characteristics, comorbidities and survival were abstracted.

RESULTS

The annual incidence during the study period was stable in all regions. Most patients lived in the Northeast (62.8%), followed by the North (16.9%), Central (12.3%), Bangkok (5.4%), and South (n = 2.6%) regions (P < 0.0001). Significantly more cholangiocarcinoma patients had diabetes, cirrhosis, and chronic viral hepatitis B/C infection than non-cholangiocarcinoma participants (diabetes: 11.42% vs 5.28%; cirrhosis: 4.81% vs 0.92%; hepatitis B: 0.74% vs 0.12%; and hepatitis C: 0.50% vs 0.10%, P < 0.0001 for all, respectively). The overall 1-year mortality rate was 81.7%, with a stable trend over time.

CONCLUSION

Diabetes and chronic liver diseases may be associated with cholangiocarcinoma in the Thai population.

Factors affecting mortality and resource use for hospitalized patients with cirrhosis: A population-based study

Hospitalizations for advanced liver disease are costly and associated with significant mortality. This population-based study aimed to evaluate factors associated with in-hospital mortality and resource use for the management of hospitalized patients with cirrhosis.Mortality records and resource utilization for 52,027 patients hospitalized with cirrhosis and/or complications of portal hypertension (ascites, hepatic encephalopathy, variceal bleeding, spontaneous bacterial peritonitis, or hepatorenal syndrome) were extracted from a nationally representative sample of Thai inpatients covered by Universal Coverage Scheme during 2009 to 2013.The rate of dying in the hospital increased steadily by 12% from 9.6% in 2009 to 10.8% in 2013 (P < .001). Complications of portal hypertension were independently associated with increased in-hospital mortality except for ascites. The highest independent risk for hospital death was seen with hepatorenal syndrome (odds ratio [OR], 5.04; 95% confidence interval [CI], 4.38-5.79). Mortality rate remained high in patients with infection, particularly septicemia (OR, 4.26; 95% CI, 4.0-4.54) and pneumonia (OR, 2.44; 95% CI, 2.18-2.73). Receiving upper endoscopy (OR, 0.29; 95% CI, 0.27-0.32) and paracentesis (OR, 0.93; 95% CI, 0.87-1.00) were associated with improved patient survival. The inflation-adjusted national annual costs (P = .06) and total hospital days (P = .07) for cirrhosis showed a trend toward increasing during the 5-year period. Renal dysfunction, infection, and sequelae of portal hypertension except for ascites were independently associated with increased resource utilization.Renal dysfunction, infection, and portal hypertension-related complications are the main factors affecting in-hospital mortality and resource utilization for hospitalized patients with cirrhosis. The early intervention for modifiable factors is an important step toward improving hospital outcomes.

Health problems among Thai tourists returning from India

BACKGROUND

The number of Thai tourists visiting India is increasing each year. Most studies investigating health problems among international travellers to India have focused on travellers from Europe or North America, and the applicability of these studies to Asian travellers is unknown.

METHODS

This cross-sectional study used data collected from Thai tourists who had recently completed a trip to India. A questionnaire on demographic data, travel characteristics, pre-travel health preparation, and health problems during the trip to India was administered. All participants were also invited to answer a follow-up questionnaire 15 days after their arrival.

RESULTS

The study included 1,304 Thai tourists returning from India between October 2014 and March 2015. Sixty-two percent were female. Overall median age was 49 years, and the median length of stay was 10.6 days. Most were package tourists, and 52% (675) reported health problems during their trip. Common health problems were cough, runny nose, and sore throat (31.1%), followed by musculoskeletal problems (21.7%), fever (12.7%), diarrhea (9.8%) and skin problems (6.6%). Other reported problems were related to the eyes/ears (2.1%), animal exposure (1.9%) and accidents (0.8%). We found that several factors may be associated with the incidence of health problems among these tourists, including travelling style and travel health preparation. In the follow-up questionnaire, 16.8% of the participants reported new or additional symptoms that developed after their return to Thailand. Respiratory symptoms were still the most common health problems during this 15-day period.

CONCLUSIONS

Over half (52%) of Thai tourists experienced health problems during their trip to India. The most common health problem was not travellers' diarrhoea, as would be expected from published studies. Rather, respiratory and musculoskeletal problems were common symptoms. This information will be useful in pre-travel assessment and care. Our findings may indicate that health risks among travellers vary by nationality.

Assessment of hepatitis C virus infection in two adjacent Thai provinces with drastically different seroprevalence

Improved awareness of the hepatitis C virus (HCV) transmission has contributed to the overall decline in the HCV infection rate in some developing countries including Thailand. Chronic HCV infection in some rural Thai communities, however, presents a challenge in the efforts to treat and manage HCV-related diseases. Published and unpublished studies have suggested an unusually high incidence of HCV infection in a Thai province of Phetchabun compared to elsewhere in Thailand. To determine the magnitude of HCV infection and identify potential factors contributing to the higher rate of HCV infection in this province, we performed a population-based study in Phetchabun (n = 1667) and the neighboring Khon Kaen province (n = 1410) where HCV prevalence is much lower. Individuals between 30 and 64 years old completed detailed questionnaires designed to identify HCV risk factors and provided blood samples for anti-HCV antibody screening. The anti-HCV seropositive rates were 15.5% (259/1667) in Phetchabun and 3.6% (51/1410) in Khon Kaen. Positive samples were subsequently genotyped for HCV core gene sequence and assessed for the hepatitis B virus surface antigen (HBsAg) and human immunodeficiency virus antigen/antibody (HIV Ag/Ab). More individuals in Phetchabun possessed the combined presence of HBsAg (5.0%) and HIV Ag/Ab (0.4%) than those in Khon Kaen (3.9% HBsAg and 0.0% HIV Ag/Ab). While male gender, intravenous drug use (IVDU) and tattoos were significant HCV risk factors in both provinces (p <0.05), education less than high school and agriculture-related occupation were additionally associated with HCV in Phetchabun. HCV genotypes 6, 3, and 1 were identified in similar frequency in both provinces. We estimated that prevalence of HCV seropositivity and viremic carriers were higher in Phetchabun (143 and 111 per 1000) than in Khon Kaen (34 and 22 per 1000). Finally, we derived a simple risk factor-based scoring system as a useful preclinical tool to screen individuals at risk of chronic HCV infection prior to intervention. Knowledge gained from this study will assist in HCV screening and promote access to anti-viral treatment in high-risk groups.

A significant cancer burden and high mortality of intrahepatic cholangiocarcinoma in Thailand: a nationwide database study

BACKGROUND

We aimed to examine the burden of intrahepatic cholangiocarcinoma (ICC) in Thailand and identify the prognostic factors for all-causes of death.

METHODS

We conducted a population-based study of ICC patients admitted during 2009-2013 using the Nationwide Hospital Admission Database, the National Health Security Office (NHSO). There was an average of 1,051,146 patients/year with diagnosis of gastrointestinal diseases (GI). All patients with a diagnosis of ICC (ICD10- C221) were included from a total of 72,479 admissions from 858 hospitals. The surgical resection procedures such as the radical pancreaticoduodenectomy, subtotal and partial hepatectomy were analyzed. Data for all patients were censored 1 year post-study or death, whichever came first.

RESULTS

A total of 34,325 patients with ICC during a 5-year study period (on average, 6865 patients/year, with the incidence rate of 14.6 per 100,000 population, per year. The ICC patients had a mean age of 63.8+/-11.6 years and 63% were males. The mean length of hospital stay was 6.4+/-7.3 days with a mean+/-SD cost of hospitalization of $595+/-$1160 USD per admission. There were 659 patients (1.9%) underwent surgical resection. The overall survival of ICC patients with surgery was significantly better than those patients without surgery. Hazard ratio of death for patients without surgery was 2.5 (95% CI of 2.3-2.7). Approximately 14% of the ICC patients died during hospitalization. The median overall survival of all patients after the first admission was 53 +/-0.6 days. From the multivariate analysis, factors related to all-causes of death were: patients' age >60 years (OR = 1.2, 95% CI; 1.1-1.3), length of hospital stay of >7 days (OR = 1.1, 95% CI; 1.02-1.2), male (OR = 1.3, 95% CI; 1.2-1.4), living in the northern part of Thailand (OR = 1.5, 95% CI; 1.3-1.8) and presence of complications during admission (OR = 1.3, 95% CI; 1.1-1.5).

CONCLUSION

The disease burden of patients with ICC in Thailand is significant with the incidence rate of 14.6 per 100,000 population, per year during 2009-2013 and showed high mortality rate of 14%.

The incidence, presentation, outcomes, risk of mortality and economic data of drug-induced liver injury from a national database in Thailand: a population-base study

Background

Toxic liver diseases are mainly caused by drug-induced liver injury (DILI). We assessed incidences and outcomes of DILI including associated factors for mortality.

Methods

We performed a population-based study of hospitalized patients with DILI. Information was retrieved from the Nationwide Hospital Admission Data using ICD-10 code of toxic liver diseases (K71) and additional codes (T36–T65). The associated factors were analyzed with log-rank test, univariate and multiple cox regression analysis.

Results

During 2009–2013, a total of 159,061 (average 21,165 per year) admissions were related to liver diseases. 6,516 admissions (1,303 per year) were due to toxic liver diseases. The most common type of toxic liver disease was acute hepatitis (33.5 %). In-hospital and 90-day mortality rates were 3.4 % and 17.2 %. DILI with cirrhosis yielded the highest in-hospital and 90-day mortality rates (15.8 % and 47.4 %). Acetaminophen, cirrhosis and age ≥ 60 years were seen in 0.5 %, 8.3 % and 50.1 % of patients who died versus 5 %, 2.3 % and 32.4 % of survivors. Factors associated with mortality were cirrhosis (HR 2.72, 95 % CI: 2.33–3.19), age ≥60 years (HR 2.16, 95 % CI: 1.96–2.38), human immunodeficiency viral infection (HR 2.11, 95 % CI: 1.88–2.36), chronic kidney disease (HR 1.59, 95 % CI: 1.33–1.90), chronic obstructive pulmonary disease and bronchiectasis (HR 1.55, 95 % CI: 1.17–2.04), malnutrition (HR 1.43, 95 % CI: 1.10–1.86) and male (HR 1.31, 95 % CI: 1.21–1.43). Acetaminophen DILI yielded lower risks of mortality (HR 0.24, 95 % CI: 0.13–0.42). The most common causes of DILI were acetaminophen (35.0 %) and anti-tuberculous drugs (34.7 %).

Conclusions

DILI is an uncommon indication for hospitalization carrying lower risks of death except in patients with non-acetaminophen, cirrhosis, elderly or concomitant diseases.

Incidence and Clinical Outcome of Acute Liver Failure Caused by Dengue in a Hospital for Tropical Diseases, Thailand

Acute liver failure is an atypical manifestation of dengue with a high mortality. We performed a retrospective cohort study at the Hospital for Tropical Diseases, Bangkok, Thailand. In total, 1,926 patients with serologically confirmed dengue were enrolled in the study from 2011 to 2015. Of these, six patients presented with acute liver failure, four died, and two survived. The incidence of dengue-associated acute liver failure was 0.31%. Dengue-associated acute liver failure was most common among young adults (median age, 29 years). The median duration from onset of fever to development of acute liver failure was 7.5 days. Patients with the severe stage of dengue had a higher risk of developing acute liver failure (P < 0.001). The baseline risk factors associated with the development of acute liver failure were an age of ≤ 40 years (odds ratio [OR] = 1.5, 95% confidence interval [CI] = 1.1-2.0, P < 0.05), a > 10% ratio of atypical lymphocytes (OR = 2.3, 95% CI = 1.8-3.0, P < 0.001), and a platelet count of < 50,000 mm³ (OR = 2.8, 95% CI = 2.2-3.6, P < 0.001). The incidence of acute liver failure in patients with dengue was quite low, but its impact on morbidity, mortality, and poor clinical outcomes was significant. In summary, this study indicates that various baseline risk factors are associated with acute liver failure in patients with dengue.

Hepatitis B vaccination for international travelers to Asia

There is a wide range in prevalence of hepatitis B virus (HBV) infection and HBV immunization programs between different regions. Hepatitis B is a vaccine preventable disease yet is still endemic in the majority of countries in Asia. Despite the decreasing global prevalence of chronic HBV infection, there is still considerable risk of HBV infection among international travelers to high endemic areas. Numbers of international travelers are expected to increase year by year; thus immunization among this cohort is a crucial preventive measure. Among international travelers to Asia, HBV immunization should be recommended for those without previous HBV vaccination who plan to travel to countries with intermediate to high prevalence of HBV, and especially for those individuals at greater risk of HBV infection; including travelers engaging in casual sex, getting a tattoo or piercing, and those having dental surgery or other medical procedures. Longer duration of travel is also associated with a greater risk of HBV infection. Travelers from low HBV prevalence countries, especially those born before implementation of universal HBV vaccination, might benefit from HBV vaccination during long-term traveling to HBV intermediate to high endemic country.

The burden of cirrhosis and impact of universal coverage public health care system in Thailand: Nationwide study

BACKGROUND AND RATIONALE

Cirrhosis is responsible for significant health-care costs and morbidity. This study aims to evaluate the burden of illness associated with cirrhosis, its impact on the universal coverage public health care system in Thailand.

MATERIAL AND METHODS

We used data from the 2010 Nationwide Hospital Admission Data, the National Health Security Office (NHSO), Thailand. Their baseline characteristics, hospital costs, and outcomes were analyzed according to national health insurance categories including medical welfare scheme (MWFS), social security scheme (SSS) and civil servant medical benefit scheme (CSMBS).

RESULTS

92,301 admissions were eligible for analysis. The mean age was 55 ± 12.8 years, and 63.3% of patients were above 50 years old. The majority of patients (79%) belonged to the MWFS group. The MWFS group incurred the lowest medical expense and had the shortest hospital stay compared to the SSS and CSMBS groups. Overall in-hospital mortality was 10.7%. Cirrhosis complications include bleeding esophageal varices, spontaneous bacterial peritonitis, hepatic encephalopathy, hepatorenal syndrome, and hepatocellular carcinoma. These complications significantly increased mortality rates compared to patients without complications (26 vs. 8.9%, p < 0.001). In-hospital mortality of patients with cirrhosis complications did not differ among the three national health insurance groups. Respiratory failure and septicemia were associated with the highest risk of death (HR 5.4; 95% CI: 4.8-5.9 and HR 5.2; 95% CI: 4.9-5.6 respectively; P < 0.001).

CONCLUSIONS

Illness associated with cirrhosis is a significant public health problem in Thailand. Outcomes of cirrhosis complications did not differ between universal public health care coverage systems in Thailand.

Evaluation of Efficacy of Chloroquine for Plasmodium Vivax Infection Using Parasite Clearance Times: A 10-Year Study and Systematic Review

INTRODUCTION

Chloroquine, in combination with primaquine, is used as the firstline treatment for uncomplicated P. vivax malaria in Thailand. In view of the declining efficacy of chloroquine in many P. vivax endemic areas, the possibility of emergence of chloroquine- resistant P. vivax in Thailand is a concern. The aim of this study was to assess the trends in therapeutic efficacy of chloroquine and primaquine for the treatment of uncomplicated P. vivax malaria and to assess the utility of parasite clearance times as a measure of efficacy.

MATERIALS AND METHODS

This study consisted of: 1) review of medical records of patients who were hospitalised for a period during their treatment for uncomplicated P. vivax malaria at the Hospital for Tropical Diseases, Bangkok, Thailand between 2004 and 2013. Treatment consisted of chloroquine (1500 mg base administered over 3 days) or chloroquine (as before) plus primaquine (15 to 30 mg base/daily for 14 days from day 2); and 2) systematic review of the literature in English to assess current standards in the reporting of parasite clearance times.

RESULTS

The 28-day cure rate was 99.1%. The range of median parasite clearance time over the 10-year period was 46 to 59 hours, and there was statistical evidence for an increasing trend in parasite clearance times between 2009 and 2013. Heterogeneity was noted among previous chloroquine efficacy studies in the measurement and reporting of parasite clearance.

CONCLUSION

The treatment of P. vivax infection with a combination of chloroquine and primaquine has remained efficacious in Thailand. Increasing rates of parasite clearance in a population over time may be a useful early warning mechanism for the emergence of chloroquine resistance. The utility of monitoring time-trends in parasite clearance to detect resistance may be enhanced if parasite clearance measurements are standardised.

Burden of Liver Abscess and Survival Risk Score in Thailand: A Population-Based Study

In Thailand, the burden of liver abscess, a life-threatening infectious disease, has not been thoroughly evaluated. We developed a predictive scoring system to estimate survival of patients with liver abscess using information from the 2008-2013 Nationwide Hospital Admission Data to evaluate the burden of liver abscess in Thailand. All patients with primary diagnosis of pyogenic liver abscess (PLA) and amoebic liver abscess (ALA) were included. Epidemiological data, baseline characteristics, hospital course, and survival were analyzed. Overall, 11,296 admissions comprising 8,423 patients from 844 hospitals across Thailand were eligible for analysis. The mean age was 52 ± 17 years and 66.1% of patients were male. ALA was significantly prevalent in southern and western border regions of Thailand, and PLA occurred nationwide. The highest incidence of liver abscess occurred in the rainy season (June-November, P < 0.01). The median length of hospital stay was 8 days (interquartile range = 4-13 days), and mean direct cost of hospitalization was 846 ± 1,574 USD. The overall inhospital mortality rate was 2.8%. Incidence of ALA decreased over the 5-year study period, whereas PLA incidence increased (P < 0.01). Using multivariable Cox regression methods with stepwise variable selection, we developed a final model with five highly significant baseline parameters associated with increased 60-day mortality: older age, PLA, underlying chronic kidney disease, cirrhosis, and human immunodeficiency virus infection. Range of estimated probability of 60-day survival was 95-16% at cumulative risk score 0-13. This simplified score is practical, and may help clinicians prioritize patients requiring more intensive care.

A randomized clinical trial of peginterferon alpha-2b with or without entecavir in patients with HBeAg-negative chronic hepatitis B: Role of host and viral factors associated with treatment response

Combining peginterferon (PEG-IFN) and a potent nucleoside/nucleotide analogue might improve treatment response in patients with chronic hepatitis B (CHB). The aims of this study were to compare the efficacy of PEG-IFN alpha-2b with or without entecavir in HBeAg-negative CHB and to investigate predictors of response. A total of 126 treatment-naïve patients were randomly assigned to receive monotherapy (n = 63) or combination therapy (n = 63) for 48 weeks. Virological response (VR) was defined as HBV DNA level <2000 IU/mL at week 96. Baseline factors including polymorphisms in the IFNL3 (rs12979860) and HLA-DPA1 (rs3077) genes and on-treatment viral kinetics were determined. At week 48, rates of undetectable HBV DNA were lower in the monotherapy than combination groups, but rates of HBsAg clearance and decline were comparable. At week 96, there was no difference between the corresponding groups regarding virological response (41.3% vs 38.1%, P = 0.856), HBsAg clearance (9.5% vs 4.8%, P = 0.491) and HBsAg decline. Baseline HBsAg level [odds ratio (OR): 3.14 (1.34-7.69), P = 0.012] and rs3077 polymorphism [OR: 2.78 (1.27-6.11), P = 0.011] were independent predictors of response. Patients carried GG genotype of rs3077 with low baseline HBV (<1000 IU/mL) had high probability of achieving VR (76.5%) and HBsAg clearance (29.4%). None of the patients without decrease in HBsAg combined with <2 log10 HBV DNA decline at week 12 achieved a virological response. In conclusion, the combination therapy lead to greater on-treatment HBV DNA suppression but did not improve virological response and HBsAg clearance/decline over monotherapy. Host and viral factors could help optimize decision-making at baseline and during PEG-IFN-based therapy.

Influence of Host and Viral Factors on Patients with Chronic Hepatitis C Virus Genotype 6 Treated with Pegylated Interferon and Ribavirin: A Systematic Review and Meta-Analysis

OBJECTIVES

We conducted a systematic review and meta-analysis of the influence of host and viral factors on the sustained virologic response (SVR) in hepatitis C virus genotype 6 (HCV-6) patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV).

METHODS

Data were retrieved from Medline, Embase, PubMed and the Cochrane Library for 'genotype 6' studies published up to December 2014 and for abstracts from international scientific meetings. Inclusion criteria were efficacy of PEG-IFN+RBV based on SVR, 24- or 48-week therapy and treatment-naïve patients. Patients with hepatitis B, D and E and HIV coinfection or another concurrent liver disease were excluded. Pooled standard difference, odds ratio and confidence intervals (CIs) were calculated using a random-effect model with STATA 11.

RESULTS

Fourteen studies were included in the meta-analysis. The pooled SVR rate was 80% (95% CI: 0.78-0.83, p < 0.0001; I2 = 71.2%). SVR of the PEG-IFN+RBV-treated HCV-6 patients was markedly higher than that of HCV-1 patients (80.1 vs. 55.3%). The SVR rate was significantly higher for the 48- than the 24-week treatment, but not different among HCV-infected patients with rs12979860 and ss469415590 polymorphisms of the ILFN4 gene (80.6% CC vs. 66.7% non-CC, p = 0.593; 81.1% TT/TT vs. 60% non-TT/TT, p = 0.288). Gender and type of PEG-IFN did not affect SVR rates.

CONCLUSIONS

Treatment outcomes for HCV-6 patients are superior to those for HCV-1 patients and comparable to those of HCV-2 and HCV-3 patients, especially at 48 weeks. The level of fibrosis affects treatment outcome, but SVR rates are not significantly different between genders. IL28B and IFNL4 polymorphisms are not significantly associated with HCV-6 treatment outcome.

HEPATIC LYMPHOMA AND SPLENIC ASPERGILLOSIS MIMICKING HEPATOSPLENIC ABSCESSES FROM MELIOIDOSIS IN THAILAND

We report here a case of hepatic lymphoma and splenic aspergillosis in an elderly patient with diabetes mellitus, exhibiting hepatosplenic abscesses mimicking melioidosis. Immunohistochemistry confirmed the diagnosis of a diffuse hepatic large B-cell lymphoma. Biopsy of the spleen revealed a clump of fungus with a slender shape and dichotomous branching, morphologically consistent with aspergillosis. Hepatosplenic abscesses are a common presentation in melioidosis, but this case reveals this assumption can lead to misdiagnosis. Histological and microbiological confirmation are required, especially in patients with hepatosplenic lesions.

Nephrotoxicity caused by oral antiviral agents in patients with chronic hepatitis B treated in a hospital for tropical diseases in Thailand

BACKGROUND

There is increasing concern about the potential for nephrotoxicity in patients with chronic hepatitis B (CHB) treated long-term with nucleotide analogs.

METHODS

We examined renal dysfunction and its associated risk factors in patients with CHB treated with antiviral regimens containing either nucleosides or nucleotide analogs. We undertook a retrospective cohort study from 2006 to 2014 at the Hospital for Tropical Diseases, Bangkok, Thailand, and analyzed the data of 102 patients with a median follow-up time of 44.5 months (range 4-101 months).

RESULTS

Seventy-three patients were treated with an antiviral regime containing a nucleoside analog, and 29 with a regime containing a nucleotide analog. Abnormally elevated serum creatinine concentration was observed in 12 patients (11.8 %) after 8 years of treatment. Thirty one percent of patients treated with nucleotide analogs had elevated serum creatinine levels and three of these patients (10.3 %) developed nephrotoxicity. In contrast, serum creatinine concentrations were elevated in three of the 73 patients treated with a nucleoside analog (4.1 %), and none developed nephrotoxicity. The incidence of renal dysfunction by the nucleotide analog regimen was cumulative, with 11.1, 21.0, 26.5 and 47.6 % of patients affected after 2, 4, 6 and 8 years, respectively. Univariate and multivariate analysis indicated that a nucleotide analog-based regimen significantly predicted renal dysfunction (odds ratio 10.5, 95 % confidence intervals 2.6-42.4, P <0.001).

CONCLUSION

The long-term use of nucleotide analogs increased the risk of nephrotoxicity in patients with CHB. Thus, the regular assessment of renal function is recommended for all patients with CHB, particularly those treated with a nucleotide analog.

Hepatitis E virus infection: Epidemiology and treatment implications

Hepatitis E virus (HEV) infection is now established as an emerging enteric viral hepatitis. Standard treatments in acute and chronic hepatitis E remain to be established. This study undertakes a review of the epidemiology, treatment implication and vaccine prevention from published literature. HEV infection is a worldwide public health problem and can cause acute and chronic hepatitis E. HEV genotypes 1 and 2 are primarily found in developing countries due to waterborne transmission, while the zoonotic potential of genotypes 3 and 4 affects mostly industrialized countries. An awareness of HEV transmission through blood donation, especially in the immunocompromised and solid organ transplant patients, merits an effective anti-viral therapy. There are currently no clear indications for the treatment of acute hepatitis E. Despite concerns for side effects, ribavirin monotherapy or in combination with pegylated interferon alpha for at least 3 mo appeared to show significant efficacy in the treatment of chronic hepatitis E. However, there are no available treatment options for specific patient population groups, such as women who are pregnant. Vaccination and screening of HEV in blood donors are currently a global priority in managing infection. New strategies for the treatment and control of hepatitis E are required for both acute and chronic infections, such as prophylactic use of medications, controlling large outbreaks, and finding acceptable antiviral therapy for pregnant women and other patient groups for whom the current options of treatment are not viable.

Swine is a possible source of hepatitis E virus infection by comparative study of hepatitis A and E seroprevalence in Thailand

Hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in developing countries are associated with contaminated food or water. Although Thailand is non-endemic for HEV, sporadic infections may occur from zoonotic transmission. Individuals between 7 months to 69 years (mean age = 32.8) from predominantly Islamic Narathiwat (n = 305) and swine farm-dense Lop Buri (n = 416) provinces were screened for anti-HEV and anti-HAV antibodies by commercial enzyme-linked immunosorbent assay and automated chemiluminescent microparticle immunoassay, respectively. Seroprevalence and relative antibody titers were analyzed according to age groups. HAV IgG antibody positive rates in Lop Buri and Narathiwat residents were 39.9% and 58%, respectively (p < 0.001). Greater than 90% of individuals >50 years old in both provinces possessed anti-HAV IgG. In contrast, seroprevalence for anti-HEV IgG was much higher in Lop Buri (37.3%) than in Narathiwat (8.9%) (p < 0.001). Highest anti-HEV IgG prevalence was found among 21-30 year-olds (50%) in Lop Buri and 41-50 year-olds (14.1%) in Narathiwat. In summary, fewer individuals possessed anti-HEV IgG in Narathiwat where most residents abstained from pork and fewer swine farms are present. Therefore, an increased anti-HEV IgG seroprevalence was associated with the density of swine farm and possibly pork consumption. Adults were more likely than children to have antibodies to both HEV and HAV.