Hepatitis A outbreak associated with a revolving sushi bar in Chiba, Japan: Application of molecular epidemiology.

AIM: The number of hepatitis A cases in Japan as well as in other developed countries has been progressively decreasing during the last several years. There is no universal hepatitis A vaccination program in Japan, and a hepatitis A virus (HAV) epidemic in Japan is not unlikely. In 2011, a hepatitis A outbreak associated with a revolving sushi bar occurred in Chiba, Japan. We aimed to analyze this outbreak. METHODS: Twenty-seven patients associated with this outbreak were admitted to the National Hospital Organization Chiba Medical Center. Molecular epidemiologic investigations were conducted. RESULTS: Twenty-six of the 27 patients had gone to the same revolving sushi bar, and then clinical symptoms appeared. HAV RNA was detected by reverse transcription polymerase chain reaction in 23 of the 27 (85.1%) patients whose sera had tested positive for anti-HAV immunoglobulin M. All isolates from this outbreak were clustered within subgenotype IA, displaying 100% sequence homology with each other in 232 bp from all 23 patients. All isolates belong to the IA-1 sublineage, which is endemic to Japan. CONCLUSION: A revolving sushi bar was associated with a hepatitis A outbreak, and molecular epidemiological investigations proved useful.

How to characterize non-hypervascular hepatic nodules on contrast-enhanced computed tomography in chronic liver disease: feasibility of contrast-enhanced ultrasound with a microbubble contrast agent.

BACKGROUND AND AIM: Although hypervascular appearance is characteristic in hepatocellular carcinoma (HCC), hepatic nodules without hypervascular appearance are sometimes found in patients with chronic liver disease (CLD). The aim of the present study was to clarify the efficacy of contrast-enhanced ultrasound (CEUS) with Levovist to characterize small, non-hypervascular hepatic nodules on contrast-enhanced computed tomography (CECT) in patients with CLD. METHODS: The subject was 41 hepatic nodules (<30 mm, 18.5 +/- 5.6 mm) which showed non-hypervascular appearance on CECT in 35 patients with CLD; their histological results were 31 HCC (15 well, 14 moderate, and two poor) and 10 regenerative nodules (RN). CEUS with Levovist was performed under intermittent scanning (1-s interval) using APLIO at the early phase and the liver-specific phase, and the contrast enhancement of the nodule was assessed in comparison to that of the surrounding liver parenchyma. The contrast-enhanced findings with the time-intensity analysis were compared with the histological results. RESULTS: Twelve nodules with weak enhancement in the liver-specific phase were HCC, regardless of their early-phase appearances. The other 29 nodules with equivalent or weak enhancement in the early phase and equivalent enhancement in the liver-specific phase were 19 HCC and 10 RN. Among them, the maximum-intensity ratio of tumor to non-tumor in the early phase was significantly higher in HCC than in RN (P < 0.01, n = 16), and the receiver-operating characteristic analysis showed a sensitivity of 1.0 and a specificity of 0.83 for their characterization. CONCLUSION: CEUS with Levovist may be an alternative to biopsy to characterize small, non-hypervascular hepatic nodules on CECT in patients with CLD.

Doppler study of hepatic vein in cirrhotic patients: correlation with liver dysfunction and hepatic hemodynamics.

AIM: To elucidate the significance of Doppler measurements of hepatic vein in cirrhotic patients and to correlate with liver dysfunction and hepatic hemodynamics. METHODS: One hundred patients with liver cirrhosis and 60 non-cirrhotic controls were studied. Doppler waveforms were obtained from right hepatic vein and flow velocity measured during quiet respiration. Doppler measurements were also obtained from portal trunk, right portal vein and proper hepatic artery. RESULTS: Hepatic vein waveforms were classified into three classical patterns. Flat waveform was uncommon. Mean hepatic vein velocity was significantly higher in cirrhotic patients (12.7 +/- 6.4 vs 5.1 +/- 2.1 and 6.2 +/- 3.2 cm/s; P<0.0001). The poorer the grade of cirrhosis, the higher was the mean velocity. Maximum forward velocity was never greater than 40 cm/s in controls. Degree of ascites was found to be highly correlated with mean velocity. "Very highq group (>=20 cm/s) presented clinically with moderate to massive ascites. Correlations between right portal flow and mean velocity was significant (P<0.0001, r = 0.687). CONCLUSION: Doppler waveforms of hepatic vein, which is independent of liver dysfunction, should be obtained during normal respiration. Mean hepatic vein velocity reflects the change in hepatic circulation associated with progression of liver cirrhosis. It can be used as a new parameter in the assessment of liver cirrhosis.

Magnetic resonance images of the globus pallidus in patients with idiopathic portal hypertension: a quantitative analysis of the relationship between signal intensity and the grade of portosystemic shunt.

BACKGROUND AND AIM: To elucidate a quantitative relationship between hyperintensity of the globus pallidus on T1-weighted magnetic resonance images (MRI) and portosystemic shunt (PSS) in portal hypertension. METHODS: Fifteen patients with idiopathic portal hypertension (IPH) and 44 patients with liver cirrhosis (LC) underwent brain MRI to asses signal intensity at the globus pallidus and Doppler sonography to examine the blood flow volume of PSS. Blood manganese (Mn) levels were examined in 36 patients and neuropsychological tests were performed in 15 patients without overt hepatic encephalopathy. RESULTS: Pallidal hyperintensity on MRI was more prominent in patients with IPH than in patients with LC. There was no correlation between MRI pallidal hyperintensity and the severity of liver dysfunction or hepatic encephalopathy. The grade of hyperintensity correlated well with the grade of PSS. The correlation was stronger in patients with IPH than in patients with LC. The plasma ammonia level and whole blood Mn level significantly correlated with MRI pallidal hyperintensity, but blood Mn level showed a stronger correlation than plasma ammonia. CONCLUSION: Hyperintensity of the globus pallidus on T1-weighted MRI correlated with the development of PSS independent of liver cell function. This brain image should be an index of the grade of PSS rather than a landmark of chronic liver failure.

Study of hemodynamic changes in portal systemic shunts and their relation to variceal relapse after endoscopic variceal ligation combined with ethanol sclerotherapy.

BACKGROUND: Among the factors influencing variceal relapse after endoscopic treatment, portal hemodynamic changes, especially in portal systemic shunts, could be the most important factor because hemodynamics are directly related to the development of esophageal varices. We aimed to clarify the influence of endoscopic treatment for esophageal varices on portal systemic shunts as well as its predictive value for variceal relapse. METHODS: Fifty patients who underwent combined endoscopic variceal ligation and injection sclerotherapy were examined with sonography and portography. RESULTS: Decrease of diameter, hepatopetal flow direction in the left gastric vein, or the presence of non-varices portal systemic shunt were sonographic findings related to a low incidence of variceal relapse. The presence of blood flow in and around the esophagus on venograms was highly predictive for variceal relapse. In patients with such venograms, non-varices portal systemic shunts did not develop. CONCLUSIONS: Sonographic assessment of hemodynamic changes in portal systemic shunt could be useful for estimating the results of endoscopic treatment for esophageal varices.

Study of portal vein thrombosis in patients with idiopathic portal hypertension in Japan.

BACKGROUND/AIMS: The aim of this study was to elucidate the incidence and clinical manifestations of portal vein thrombosis (PVT) in patients with idiopathic portal hypertension (IPH) in Japan during long-term follow-up. PATIENTS AND METHODS: Twenty-two patients with IPH were examined for PVT by sonography during a follow-up of 12+/-6 years. Clinical manifestations and patient outcome related to PVT were studied. Seventy patients with liver cirrhosis were examined by sonography as an incidence control of thrombosis. RESULTS: Nine IPH patients had portal thrombosis (9/22, 41%), a higher incidence than in liver cirrhosis patients (7/70, 10%). Those with thrombosis showed ascites, marked hypersplenism, and low serum albumin. Four patients with thrombosis died. Patients without thrombosis showed less clinical problems after long-term follow-up. Plasma antithrombin III and protein C activity decreased in almost half of the patients. However, there were no differences in these parameters between patients with and without thrombosis. CONCLUSIONS: In Japan, IPH patients had a high incidence of portal thrombosis, a significant factor for poor prognosis. Whether the management of PVT contributes to an improvement of a clinical course of IPH or not should be clarified in further study.

Portal-systemic encephalopathy in two patients without liver cirrhosis and portal hypertension.

The portal-systemic venous shunt is uncommon in patients without portal hypertension. We present two cases of portal-systemic encephalopathy due to extrahepatic shunt without liver cirrhosis and portal hypertension. Two women in their seventies were admitted to our hospital because of recurrent episodes of altered sensorium, drowsiness, slurred speech, disorientation, asterexis and high blood ammonia levels. There was no history of abdominal surgery or abdominal trauma. Clinical examination revealed no signs of portal hypertension or stigmata of chronic liver diseases. Brain CT and MRI scanning were unremarkable except for a high intensity signal in the basal ganglia on T1 weighted MRI images. Laboratory tests were almost normal except for the hyperammonemia occurring on several occasions. There was no evidence of liver cirrhosis by imaging. However, color Doppler showed an extra-hepatic shunt in both patients and pulsed Doppler showed decreased velocity and volume of the portal venous flow. These sonographic findings were confirmed during percutaneous transhepatic portography (PTP). Portal pressures measured during PTP were 9 and 11 mmHg. Needle biopsy ruled out idiopathic portal hypertension and liver cirrhosis. The diagnosis was portal systemic encephalopathy due to extra-hepatic portosystemic venous shunting. Both patients were treated by embolization of the shunting vessel with metallic coils.