Recent decline in hepatitis E virus prevalence among wild boars in Japan: Probably due to countermeasures implemented in response to outbreaks of classical swine fever virus infection.

Previous studies have emphasized the necessity of surveillance and control measures for hepatitis E virus (HEV) infection in wild boars, an important reservoir of HEV. To assess the current situation of HEV infection in wild boars in Japan, this study investigated the prevalence and genetic diversity of HEV among wild boars captured in 16 prefectures of Japan during 2018-2023. Serum samples from 968 wild boars were examined for anti-HEV IgG antibodies and HEV RNA. The prevalence of anti-HEV IgG varied geographically from 0 % to 35.0 %. HEV RNA was detected in 3.6 % of boars, with prevalence varying by prefecture from 0 % to 22.2 %. Genotype 3 was the most prevalent genotype (91.9 %), followed by genotype 4 (5.4 %), with one strain closely related to genotype 6. The prevalence of HEV infection among wild boars decreased from 2018/2019 to 2022/2023 with significant declines in levels of anti-HEV IgG antibodies (14.5 % vs. 6.2 %, P < 0.0001) and HEV RNA (7.6 % vs. 1.5 %, P < 0.0001). Regional analysis showed varying trends, with no HEV RNA-positive boars found in several regions in recent years. A plausible factor contributing to the decline in HEV infection is the application of countermeasures, including installing fences to prevent intrusion into pig farms, implemented in response to the emergence of classical swine fever virus (CSFV) infection in wild boars and domestic pigs, with incidents reported annually since 2018. Further investigation is warranted to explore the association between countermeasures to CSFV infection and the decrease in HEV infection among wild boars.

Successful Recovery from Severe Fever with Thrombocytopenia Syndrome and Hemophagocytic Lymphohistiocytosis with Standard Treatment and a Calcium Channel Blocker of Nicardipine Hydrochloride.

A 67-year-old man was admitted to our hospital with a high fever. Laboratory tests revealed leukopenia, thrombocytopenia, liver dysfunction, rhabdomyolysis, and hyperferritinemia. He was diagnosed with severe fever with thrombocytopenia syndrome (SFTS) complicated by hemophagocytic lymphohistiocytosis and treated with steroid therapy, intravenous calcium channel blocker (CCB), and supportive care, without favipiravir. Serum levels of ferritin and soluble interleukin 2 receptor (sIL2R) were markedly elevated on Day 3 after admission and decreased thereafter, while an SFTS viral load of 6.8×104 copies/µL was detected on Day 2, increasing to 2.9×105 copies/µL on Day 6. Serum ferritin and sIL2R levels may be better indicators of mortality than the SFTS viral load, and CCBs may have a therapeutic effect.

Genomic characterization and the prevalence of a novel copiparvovirus in wild sika deer (Cervus nippon) in Japan.

A preliminary metagenomic analysis of the virome of wild sika deer (Cervus nippon) blood in Japan resulted in the identification of a novel parvovirus. The virus was closest, but only 44.7-60.7% identical to 17 reported strains belonging to the genus Copiparvovirus within the subfamily Parvovirinae, over the near-entire genomic sequence. The sika deer copiparvovirus DNA was detected in 15% (31/206) of sika deer captured in 7 prefectures of Japan, and a region-dependent prevalence of 0-66.7% was noted, with a biased distribution in the southern part of Japan. The observed biased distribution of sika deer copiparvovirus may be due to the habitat density of deer and the number of ticks, which might play a role in the transmission of the virus.

Identification of hepatitis E virus in wild sika deer in Japan.

Hepatitis E virus (HEV) is a zoonotic agent mainly transmitted through the consumption of uncooked or undercooked meat products derived from infected animals. In Japan, domestic pigs and wild boars are the major animal reservoirs, and whether or not deer are an HEV reservoir remains controversial. We analyzed 395 serum and 199 liver samples from 405 sika deer (Cervus nippon) caught in the wild between 1997 and 2020 in 11 prefectures of Japan for markers of HEV infection. Overall, 17 deer had anti-HEV IgG (4.3%), while 1 (0.2%) had HEV RNA (genotype 3b), indicating the occurrence of ongoing HEV infection in wild deer in Japan. An analysis of the complete HEV genome (deJOI_14) recovered from a viremic deer in Oita Prefecture revealed only 88.8% identity with the first HEV strain in sika deer (JDEER-Hyo03L) in Japan, being closest (96.3%) to the HEV obtained from a hepatitis patient living in the same prefecture. Of note, the deJOI_14 strain was 8.7-9.0% different from the wild boar HEV strains obtained in the same habitat and the same year, suggesting that difference in infected HEV strains between boar and deer may be explained by the limited possibility of close contact with each other, although boars are a known source of HEV infection. Increased numbers of hepatitis E cases after consumption of raw or undercooked meat products of wild deer have been reported in Japan. These results suggest a low but nonnegligible zoonotic risk of HEV infection in wild deer in this country.

First detection and characterization of rat hepatitis E Virus (HEV-C1) in Japan.

Rat hepatitis E virus (HEV-C1) in the Orthohepevirus C species has been reported to cause zoonotic infection and hepatitis in humans. HEV-C1 strains have been detected from wild rats in many countries in Europe, Asia, and North America. However, in Japan, no HEV-C1 strains have been identified. In the present study, 5 (1.2%) of 428 wild rats (Rattus norvegicus or R. rattus) were positive for anti-HEV-C1 IgG. Although all 428 rat sera were negative for HEV-C1 RNA, it was detectable in 20 (19.8%) of 101 rat fecal samples collected on a swine farm, where HEV (genotype 3b, HEV-3b) was prevalent and wild rats were present. In addition, HEV-C1 RNA was detectable in the intestinal contents and liver tissues of 7 (18.9%) of 37 additional rats captured on the same farm. The HEV-C1 strain (ratEJM1703495L) obtained in this study shared only 75.8-84.7% identity with reported HEV-C1 strains over the entire genome but propagated efficiently in cultured cells. HEV-3b strains were detected in the rats' intestinal contents, with 97.3-99.5% identity to those in pigs on the same farm, but were undetectable in rat liver tissues, suggesting that wild rats do not support the replication of HEV-3b of swine origin.

Prevalence and genotype/subtype distribution of hepatitis E virus (HEV) among wild boars in Japan: Identification of a genotype 5 HEV strain.

To further investigate the prevalence of hepatitis E virus (HEV) infection and characterize HEV genomes among Japanese wild boars (Sus scrofa leucomystax), 1880 boars captured in 17 prefectures in Japan from 2013 to 2019 were studied. Overall, anti-HEV IgG was detected in 8.9 % and HEV RNA was detected in 3.9 % of boars, which was comparable with our previous studies during 2003-2013 (10.3 % and 3.5 %, respectively). Among 74 boar HEV strains obtained from infected boars in the present study, 50 (68 %) were classified into genotype 3 (3a and 3b), 23 (31 %) were classified into genotype 4 (4i), and the remaining strain (wbJGF_19-1) was classified into genotype 5. The wbGF_19-1 strain shared 92.7 % identity over the entire genome with the prototype genotype 5 strain (JBOAR135-Shiz09). The identification of the second genotype 5 HEV strain in a place that is located only 100 km from the site at which JBOAR135-Shiz09 was identified, suggests that genotype 5 HEV circulates within a relatively close range in Japan. Genetically similar HEV strains forming a clade were identified from wild boars living in each area during the observation period of 11-13 years, although the nucleotide sequence changed gradually, accounting for up to 3.4-3.6 % within the 412-nucleotide ORF2 sequence. Eight groups of boars with a cluster of HEV infections were observed, consisting of two, three or four infected offspring, presumably born to the same mother or offspring with their mother. These results suggest that wild boars continue to be important reservoirs for HEV infection in humans in Japan.

Virulent strain of hepatitis E virus genotype 3, Japan.

Hepatitis E virus (HEV) genotype 3, which usually causes asymptomatic infection in Japan, induced severe hepatitis in 8 patients. To better understand genetic features of HEV associated with increased virulence, we determined the complete or near-complete nucleotide sequences of HEV from these 8 patients and from 5 swine infected with genotype 3 strain swJ19. Phylogenetic analysis showed that the isolates from the 8 patients and the 5 swine grouped separately from the other genotype 3 isolates to create a unique cluster, designated JIO. The human JIO-related viruses encoded 18 amino acids different from those of the other HEV genotype 3 strains. One substitution common to almost all human HEV strains in the JIO cluster was located in the helicase domain (V239A) and may be associated with increased virulence. A zoonotic origin of JIO-related viruses is suspected because the isolates from the 5 swine also possessed the signature V239A substitution in helicase.

The impact of visceral fat in nonalcoholic fatty liver disease: cross-sectional and longitudinal studies.

BACKGROUND: Nonalcoholic fatty liver disease is increasing worldwide, and attention is being paid to its association with obesity and metabolic syndrome. The aim of this study was to elucidate the role of visceral fat accumulation in hepatic steatosis by cross-sectional and longitudinal studies. METHODS: We enrolled 125 patients in a cross-sectional study and 28 patients in a longitudinal study and examined visceral and subcutaneous fat thickness, hepatic steatosis score, and biochemical parameters. In the longitudinal study, the influence of weight change on fat distribution and hepatic steatosis was investigated. RESULTS: In the cross-sectional study, the severity of hepatic steatosis showed a significant positive correlation with body mass index, visceral fat thickness, serum albumin, alanine aminotransferase (ALT), cholinesterase, fasting insulin, and the homeostasis model assessment of insulin resistance. ALT, visceral fat thickness, and serum albumin were independent factors for hepatic steatosis. In the longitudinal study, visceral fat thickness fluctuated closely with changes in body weight, and had the strongest relationship with the change of hepatic steatosis by multivariate analysis. CONCLUSIONS: Visceral fat was the most important factor for the development of hepatic steatosis. Visceral fat thickness can be measured by sonography easily, noninvasively, and repeatedly for assessment of central obesity and monitoring of the efficacy of treatment of nonalcoholic fatty liver disease.

The prevalence of atherosclerosis in cirrhotic patients: assessment of two aspects of atherosis and sclerosis.

AIM: In general, cirrhotic patients are known to have a low prevalence of cardiovascular disease. Cirrhosis is often accompanied by diabetes mellitus, while blood pressure and serum cholesterol levels are low in liver cirrhosis. We examined the atherosclerosis of patients with chronic liver disease by two phases of atherosis "lipid deposition" and sclerosis "arterial fibrosis." METHODS: Atherosis was assessed by carotid intima-media thickness and the ratio of the systolic blood pressure at the ankle to the average systolic blood pressure at the right arm (ankle brachial pressure index), while sclerosis was evaluated by brachial ankle pulse wave velocity. RESULTS: There were no significant differences in intima-media thickness and ankle brachial index among grades of cirrhosis. Brachial ankle pulse wave velocity decreased closely as the severity of cirrhosis progressed (F = 4.90, P < 0.05). In univariate analysis, brachial ankle pulse wave velocity was correlated with systolic blood pressure, age, total bilirubin, albumin, prothrombin time, retention rate of indocyanine green at 15 min, blood ammonia, branched chain amino acids/tyrosine molar rate and fasting blood sugar. Multiple regression analysis showed that systolic blood pressure and total bilirubin were independent factors for the inhibition of vascular sclerosis progression. CONCLUSION: Although no difference in atherosis between cirrhotic patients and healthy controls was found, vascular sclerosis was decreased with the severity of cirrhosis through hypotension and hyperbilirubinemia.

Full-length genomic sequences of new subtype 1g hepatitis E virus strains obtained from four patients with imported or autochthonous acute hepatitis E in Japan.

Hepatitis E virus (HEV) causes acute or chronic hepatitis in humans worldwide and can be transmitted via the fecal-oral route. Four HEV strains (HE-JA14-2173, HE-JA15-1335, HE-JA15-1920 and HE-JA16-0610) obtained from patients with imported (from Pakistan or India) or autochthonous acute hepatitis E in Japan were most closely related to the Nepalese and Mongolian genotype 1 HEV strains of unassigned subtype within the partial ORF2 sequence. To investigate whether a putative novel subtype (1g) of genotype 1 can be assigned, full-length genomic sequences were determined for the four HEV strains. They shared 95.4-99.2% nucleotide identity over the entire genome, and differed by 6.3-11.7% from the reported HEV strains of subtypes 1a-1f and by only 0.6-4.7% from a Mongolian genotype 1 HEV strain (MNE15-072) of unassigned subtype. A phylogenetic analysis showed that the four HEV strains obtained in the present study formed a cluster with MNE15-072, with a bootstrap value of 100%. Although the p-distance between subtypes 1a and 1f was 0.048-0.083, these five strains showed a higher nucleotide p-distance value of 0.068-0.138 with the genotype 1 HEV strains of subtypes 1a-1f. A BLAST search revealed the presence of candidate members of subtype 1g HEV in at least five other countries, including France, Israel, the Netherlands, Portugal, and the UK, sharing identities of 95.4-99.6% with the HE-JA16-0610 strain within the common sequence of 294-867 nucleotides. These results support the assignment of a new subtype 1g within genotype 1 and suggest a global distribution of subtype 1g strains. Subtype 1g strains found in Europe can be imported from Asia. Further studies are needed to confirm the global distribution of HEV subtype 1g.

The influence on liver parenchymal function and complications of radiofrequency ablation or the combination with transcatheter arterial embolization for hepatocellular carcinoma.

Objectives: We investigated how radiofrequency ablation (RFA) alone or the combination with transcatheter arterial embolization (TAE-RFA) for hepatocellular carcinoma (HCC) affects the liver parenchymal function of underlying chronic liver disease to find a predictive factor for selecting appropriate candidates for RFA. Methods: In 53 HCC patients (RFA alone, 25; TAE-RFA, 28), liver laboratory tests and development of complications were monitored until 6 months after treatments. Serum albumin deteriorated within 1 month and recovered after 6 months in both groups, whereas the elevation of the Pugh score continued in RFA alone group and that of serum bilirubin continued in TAE-RFA group until 6 months. The elevation of Pugh score 6 months after RFA was significantly more frequent in patients with a high pre-treatment Pugh score (>/=8 points) than in those with a low pre-treatment Pugh score (<8 points). Complications after RFA were observed in 11 of the 53 patients: temporary complications in 5, refractory ascites in 6. Refractory ascites developed in only patients with a high pre-treatment Pugh score. Conclusion: Liver parenchymal functions in patients with a low pre-treatment Pugh score were transiently deteriorated by RFA or TAE-RFA. However, in patients with a high Pugh score, RFA or TAE-RFA induces long-term deterioration of the liver parenchymal functions and causes serious complications. Therefore, patients with a Pugh score >/=8 points would not be good candidates for RFA or TAE-RFA.

Molecular characterization of a novel hepatitis E virus (HEV) strain obtained from a wild boar in Japan that is highly divergent from the previously recognized HEV strains.

Although a consensus classification system for hepatitis E virus (HEV) genotypes is currently unavailable, HEV variants (JBOAR135-Shiz09 and wbJOY_06) from wild boars (Sus scrofa leucomystax) have provisionally been classified into two novel genotypes (5 and 6). While performing a survey of HEV infections among 566 wild boars that were captured in Japan between January 2010 and August 2013, we found 24 boars (4.2%) with ongoing HEV infections: 13 had genotype 3 HEV, 10 had genotype 4 HEV and the remaining boar possessed a novel HEV variant (designated wbJNN_13). The entire wbJNN_13 genome comprised 7247 nucleotides excluding the poly(A) tail, and was highly divergent from known genotype 1 to 4 HEV isolates derived from humans, swine, wild boars, deer, mongoose and rabbits by 22.4-28.2%, JBOAR135-Shiz09 and wbJOY_06 by 19.6-21.9% and rat, ferret, bat and avian HEV isolates by 40.9-46.1% over the entire genome. Phylogenetic trees confirmed that wbJNN_13 is distantly related to all known HEV isolates. A Simplot analysis revealed no significant recombination among the existing HEV strains. These results indicate the presence of at least three genetic lineages of presumably boar-indigenous HEV strains. Further studies to fully understand the extent of the genomic heterogeneity of HEV variants infecting wild boars are warranted.

Isolated metastases of hepatocellular carcinoma in the right atrium: Case report and review of the literature.

The aim of this study was to clarify the clinical features of patients with isolated HCC metastases to the heart. A 66-year-old female hospitalized with a hepatocellular carcinoma (HCC) ranging from the right to the left lobe and with a tumor thrombus in the main portal vein, was treated with intraarterial cisplatin, 5-fluouracil, adriamycin and mitomycin. Computed tomography (CT) one month later revealed that the HCC had progressed with multiple lung metastases and moderate ascites. The patient had no symptoms. Magnetic resonance imaging (MRI) and echocardiography revealed a round, movable tumor with a diameter of 2 cm in the right atrium (RA). The patient succumbed to HCC five months later. An autopsy revealed HCC with portal tumor thrombi and metastases to the lungs, inferior vena cava (IVC) and RA. The metastases in the RA and IVC were not continous with the intrahepatic tumor and were histologically attached to the endocardium and endothelium, respectively. An isolated metastasis of a HCC of the RA and IVC is extremely rare. In conclusion, although the majority of isolated metastases of HCC to the heart were diagnosed by echocardiography and were treated with mainly surgery, they had poor prognosis. The echocardiography should be performed for patients with advanced HCC. A novel treatment including molecular targeted drugs is required.

Cerebral pulsatility index by transcranial Doppler sonography predicts the prognosis of patients with fulminant hepatic failure.

AIM: Cerebral hemodynamic derangement is well known in patients with fulminant hepatic failure. The advent of transcranial Doppler sonography (TCD) enabled noninvasive observation of cerebral hemodynamics. To evaluate its clinical usefulness, we examined longitudinal cerebral hemodynamic parameters in patients with fulminant hepatic failure and severe acute hepatitis. METHODS: The six subjects were four patients with fulminant hepatic failure, one with severe acute hepatitis and one with severe acute exacerbation on chronic hepatitis. The pulsatility indices of the right middle cerebral artery were used as parameters of cerebral hemodynamics. RESULTS: The pulsatility indices of the two patients with a deteriorating course had elevated to >1.00, whereas those of the two patients undergoing recovery were within normal limits, as well as of the patients with acute hepatitis or acute exacerbation on chronic hepatitis. CONCLUSION: Cerebral pulsatility measured by TCD may be a real-time and useful tool to assess and monitor patients with fulminant hepatic failure.

FibroIndex, a practical index for predicting significant fibrosis in patients with chronic hepatitis C.

UNLABELLED: Diagnosis of the stage of liver fibrosis in chronic hepatitis C is essential for making a prognosis and deciding on antiviral therapy. In the present study a simple model consisting of routine laboratory tests was constructed and then validated in cross-sectional and longitudinal investigations. Consecutive treatment-naive patients with chronic hepatitis C who had undergone liver biopsy were divided into 2 cohorts: an estimation set (n = 240) and a validation set (n = 120). A longitudinal set consisted of 30 patients who had undergone a liver biopsy twice, before and after IFN treatment. The FibroIndex was derived from the platelet count, AST, and gamma globulin measurements in the estimation set. The areas under the ROC curves of the FibroIndex for predicting significant fibrosis were 0.83 and 0.82 for the validation set, better than those of the Forns index and the aminotransferase-to-platelet ratio index (APRI). Using the best cutoff values, whether significant fibrosis was present was diagnosed with high positive predictive values, and 35% of patients could avoid liver biopsy. In the longitudinal set, there was a significant decrease in the FibroIndex of 14 patients whose fibrosis stage improved, and a significant increase in that of 5 patients whose fibrosis stage deteriorated. Change in the FibroIndex correlated significantly with variation in fibrosis stage. There was no such correlation with the Forns index or the APRI. CONCLUSION: The FibroIndex is a simple and reliable index for predicting significant fibrosis in chronic hepatitis C and could also be used as a surrogate marker during antifibrotic treatment for chronic hepatitis C.

Percutaneous sonographically guided radiofrequency ablation with artificial pleural effusion for hepatocellular carcinoma located under the diaphragm.

OBJECTIVE: Sonographically guided radiofrequency ablation is usually one of the most effective treatments for hepatocellular carcinoma. However, the localization of the tumor is a major limiting factor in the use of a sonographically guided procedure. In our experience, sonographic examination with artificial pleural effusion has improved the visualization of hepatocellular carcinomas under the diaphragm. We investigated the safety, benefits, and local efficacy of radiofrequency ablation with artificial pleural effusion. SUBJECTS AND METHODS: Twenty-five lesions in 23 patients were treated using radiofrequency ablation with artificial pleural effusion, for which 5% glucose solution was injected into the pleural cavity. RESULTS: Artificial pleural effusion allowed us to visualize the whole tumor on gray-scale sonography in 22 lesions that were not detectable or were poorly visible and to obtain a safer and easier puncture line in 14 lesions. In 23 (92%) of the 25 lesions, artificial pleural effusion was helpful in performing percutaneous radiofrequency ablation. Complete necrosis after radiofrequency ablation was obtained in 22 (88%) of the 25 lesions. During a mean (+/- SD) follow-up period of 10.6 +/- 6.5 months, local recurrence at the ablation site was diagnosed in only one (4.5%) of the 22 lesions. Mild cough in three patients and mild dyspnea in two patients were observed as adverse effects of artificial pleural effusion, but these effects were temporary. Oxygen saturation of the blood during artificial pleural effusion was slightly decreased. CONCLUSION: Radiofrequency ablation with artificial pleural effusion is a safe and beneficial treatment option that offers excellent local control through visualization of hepato-cellular carcinomas under the diaphragm.