key: cord-0986034-dov56otn
authors: O'Neill, H J; Connolly, J H; Redmond, A O B; Dermott, E
title: An Otofuke-like virus associated with diarrhoea. Case report and electronmicroscopic study
date: 1985-04-03
journal: Ulster Med J
DOI: nan
sha: 5aa57e5b1bd469a113ff95bcb989f1ebcef3299f
doc_id: 986034
cord_uid: dov56otn

Virus particles similar to Otofuke virus have been found, together with rotaviruses and astroviruses, by electronmicroscopy in faeces from an infant with diarrhoea in Northern Ireland. Previously Otofuke virus has been found only in Japan whence it may have been carried to this country by a businessman.

Several types of viruses may be seen by electronmicroscopy in faeces from childhood diarrhoea. These include rotaviruses, adenoviruses, coronaviruses and reoviruses. In addition there are small round viruses which may be classified into two groups. I The first, which includes enteroviruses and parvoviruses, comprises viruses with no surface structure and a smooth entire outer edge; the second, which includes astroviruses, caliciviruses and the Norwalk group of viruses comprises viruses with a structured surface and/or ragged edge. We report the occurrence of a small round virus (34-36 nm) with a surface structure, in association with smaller particles (15-17 nm), in faeces from a child with diarrhoea. We consider this virus to be similar to the Otofuke agent which to date has been reported only in Japan.

A six-month-old boy from Downpatrick, Northern Ireland, was admitted to hospital in December 1982 for investigation of screaming after feeds associated with passage of foul smelling stools. The symptoms had started at the age of four weeks, but despite this he gained weight and was thriving. There were three other The Ulster Medical Journal children in the family who were asymptomatic. On admission the child was put on clear fluids orally. The diarrhoea quickly subsided and he was discharged after one week as his bowel movements had returned to normal. While in hospital, urea, electrolytes, sweat test and chest x-ray were normal and bacteriology of faeces revealed no pathogens. At review, six weeks after discharge the baby remained asymptomatic. Virus was not isolated from faeces in baboon kidney or HEp2 cells. The supernatant fluid from a 10% faecal suspension previously centifruged at 4,500 g for 1 hr was re-centrifuged at 180,000 g for 1 hr. The resultant pellet was resuspended in 25 pl distilled water, transferred to a carbon/formvar coated grid, stained with 2% phosphotungstic acid pH7 and examined in a Philips 301 electron microscope. Clusters of astroviruses measuring 28 nm and rotaviruses were seen. On the same grid an aggregate of two sizes of particles, the appearance of which suggested that they were bound by antibody, was seen ( Fig. 1 a) . All the smaller size particles were 'empty' and measured 15-17 nm. The larger particles measured 34-36 nm, had obvious icosahedral structure and surface projections. One particle (Fig. 1 b) when subjected to Markham rotation2 showed enhancement of 10 surface projections only when n = 5 (Fig. 1 c) . 

The size and structure of the larger particle described here is similar to the Otofuke virus3 which also has been shown to have an antigenically related smaller particle.4 The Sapporo virus in human diarrhoea 5 and the Newbury agent in calf diarrhoea6 also have been shown to have smaller 'empty' particles associated with larger structured virus particles, but the published illustrations of these show a different structure from the virus described here and the Otofuke virus.

The Otofuke virus was found in faeces from children and adults with gastroenteritis in institutional outbreaks in Japan, but since rotaviruses and astroviruses are both capable of causing diarrhoea, the contribution of the Otofuke-like virus to the diarrhoea in this child is unknown. It is unlikely that the father brought the virus from Japan and infected the child, since his last visit was more than a year before the child's birth. It is possible, however, that the virus was carried by a Japanese businessman to this family. Undoubtedly similar contacts are made elsewhere and therefore it would be worthwhile looking for this virus in outbreaks of gastroenteritis in the United Kingdom.

The electronmicroscopical and physical characteristics of small round human fecal viruses: an interim scheme for classification

Methods for the enhancement of image detail and accentuation of structure in electronmicroscopy

Virus-like particle, 35-40 nm, associated with an institutional outbreak of acute gastroenteritis in adults

Further studies of 35-40 nm virus-like particles associated with outbreaks of acute gastroenteritis

The 33-39 nm virus-like particles, tentatively designated as Sapporo agent, associated with an outbreak of acute gastroenteritis

Isolation of small viruses resembling astroviruses and caliciviruses from acute enteritis of calves

We thank Dr E 0 Caul, Public Health Laboratory, Bristol, and Dr A M Field, Central Public Health Laboratory, London, for helpful comments on identification of the virus.