Hideyasu Nara

Winter seasonality and rotavirus diarrhoea in adults

We investigated the aetiological role of group A rotavirus in adults with acute diarrhoea in a 4-year prospective study. Of 683 patients with acute diarrhoea, 97 (14%) shed rotavirus as a sole agent, whereas six (5%) of 115 patients without diarrhoea shed rotavirus. Half of patients with rotavirus diarrhoea required admission to hospital. Unlike rotavirus diarrhoea in children, the occurrence of rotavirus-positive cases did not show a significant winter seasonality. Rotavirus infection should be included in the differential diagnosis of diarrhoeal diseases in adults.

ASYMPTOMATIC COLONIC ANISAKIASIS IDENTIFIED DURING COLONOSCOPY

A 66‐year‐old‐man had received colonoscopy periodically as a follow up since endoscopic polypectomy of the colon in February 1997. In March 2001, periodic colonoscopy revealed a worm penetrating the mucosa of the sigmoid colon. This worm was caught with biopsy forceps, and it was identified parasitologically as an Anisakis simplex larva (Anisakis larva type I). However, the patient had no complaint before or after the examination. The patient ingested lavage solution, including polyethylene glycol for the preparation of colonoscopy. Therefore, Anisakis larvae might be flushed quickly to the distal colon by an oral colon‐wash without penetration of worms into the gastric or intestinal mucosa. In the present paper, we report on asymptomatic colonic anisakiasis treated successfully by endoscopic removal of the worm. In some cases, penetration of the worm causes cramp of the colon or immediate mucosal huge edematous change and results in intestinal obstruction. Colonoscopic removal of the worm would be most effective and safe if possible.

Studies on the outbreak of hepatitis A in an institute for mentally retarded children.

SummaryThe authors encountered an outbreak of acute hepatitis in a public institute for mentally retarded children in Aomori Prefecture, Japan.Studies revealed that the probable vehicles of transmission of infection were contaminated water, contaminated meals, and close contact. From the clinical manifestations and epidemiological investigations of 41 affected children and staff members, an outbreak of hepatitis A was strongly suspected.Immune electron microscopy disclosed hepatitis A virus antigen particles in the stool specimens collected during the few days before and after peak transaminase elevation.Hepatitis A antigen was further extracted and purified. This antigen was the first reported recovery of the virus from a natural outbreak of hapatitis A in Asia. Subsequently, with the immune adherence hemagglutination test, using this extracted antigen, an increase in titer of antibody to hepatitis A antigen was demonstrated. Thus, this epidemic was serologically established as an outbreak of hepatitis A.Human immune serum globulin for the protection against hepatitis A was administrated to the 80 individuals concerned, and it was effective in preventing the clinical manifestation of hepatitis.

3430 Endoscopic assessment of diarrhea in an adult rotavirus positive population.

Background: Rotavirus infection in young children often manifests with the typical signs or symptoms of winter vomiting and diarrhea. But there may be no established consensus on adult infection except in mass outbreak or travelers. Besides there have been no reports about endoscopic assessment of rotavirus gastroenteritis.We report our preliminary results with the colonoscopic findings and diagnosis of rotavirus infection in adults. Patients and Methods: Rotavirus was evaluated by ELISA method (Cambridge Biotech Co.) in adult diarrhea patients. Rotavirus infection was diagnosed in 97 patients and colonoscopy with biopsy was carried out in 62 ( 23M; 18F, age range 13- 91 [mean 43]) out of them. Endoscopic findings were analyzed as to the characteristics of mucosal changes. The biopsy specimens were prepared for HE staining, electron microscopy, and immunostaining use. Results: We found macroscopic change of colon mucosa in 41(66%) out of 62 rotavirus positive patients. Endoscopic findings included various changes such as erythema, longitudinal ulcer , aphthoid ulcer, and pseudomembranous lesion. Erythema was most frequently observed, in 31 patients (76%) and others were minor in prevalence. Conclusion:Rotavirus infection has been supposed to damage the small intestine mucosa and cause diarrhea. It was suggested rotavirus possibly invade not only small intestine but also colon.We have gotten a small clue about it from colonoscopic findings.

Epiological study of an outbreak of hepatitis A in Aomori prefecture.

昭和58年1月から4月にかけて青森県全域に632例のA型肝炎の流行をみた.この流行は血清学的にIgM-HA抗体検索により確定診断し得たA型肝炎では国内外の報告のうちで最も大規模な流行であった.患者の性別では1.7:1と男性に多く,年齢別では0歳から74歳に及んだが20～30歳代が75%と多く,50歳代以上は2.0%と少数であった.劇症肝炎が5例あり3例が死亡したが,いずれも男性であった.全発症者の74.8%が発症前に生ガキを摂取しており,同時期の非発症者対照群の摂取の率より有意に高く,青森県むつ湾内産のカキが感染経路として強く疑われた.生ガキ摂取から発症までの期間は平均29日であった.青森県内のHA抗体保有についての検診を行った.20歳以下でHA抗体保有率は0%で,30歳から50%を越え,36歳以上では80%以上と国内の疫学調査の結果と同じ傾向であった.