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Vesikari T., Ruuska T., Delem A., Andre F. E., Beards G. M. and Flewett T. H. (Department of Clinical Sciences, University of Tampere, Tampere, Finland, and the Biological Division, Smith Kline RIT Rixensart, Belgium and WHO Collaborating Centre for Reference and Research on Human Rotaviruses, East Birmingham Hospital, Birmingham, U.K.). Efficacy of two doses of RIT 4237 bovine rotavirus vaccine for prevention of rotavirus diarrhoea. Acta Paediatr Scand 80: 173, 1991. Candidate oral bovine rotavirus vaccine RIT 4237 or placebo was given to 252 Finnish infants at birth and at 7 months of age. No vaccine-associated reactions were observed. Primary rotavirus ELISA IgM responses were detected in 36% of the infants after the first vaccination; after the second dose 68% of the vaccinees were seropositive for rotavirus ELISA IgG antibody. The infants remained in clinical follow-up over two rotavirus epidemic seasons (total 28 months). Counted from child years in follow-up the overall vaccine protection rate was 43%. The clinical severity of rotavirus episodes was assessed using numerical score 0–20. Vaccine protection rate for cases with score ≥7 was 57% and for cases with score ≥11 it was 89%. It is concluded that vaccination with bovine rotavirus vaccine at birth and at 7 months of age, with the second dose given shortly before rotavirus epidemic season, protects infants against moderately severe and severe rotavirus diarrhoea in the first 2 years of life.

Rotaviruses (duoviruses) can be found in more than half the cases of acute diarrhoea in children up to the age of six or seven. About that age almost everyone has antibodies to them. Second infections occur and may not be as rare as laboratory findings so far suggest. Very young infants sometimes get subclinical disease-the effect of maternal antibody transmitted across the placenta? Very similar viruses, all possessing a common antigen detectable by immunofluorescence, are known to infect and/or cause diarrhoea in children, calves, piglets, mice, foals and monkeys. The calf virus and the human virus both infect piglets; piglet virus infects calves; we don't know whether any of these can infect children. Other mammals probably have similar diarrhoea viruses. An antigen common to all these viruses is probably in the inner capsid layer, and "species-specific" antigens are probably in the outer capsid layer. A precise test for comparing different strains is bably needed. Adenoviruses possibly cause a smaller proportion of cases of diarrhoea. Coronaviruses, well-known as enteric pathogens of pigs and calves, appear also to infect adults and children. 27 nm particles and 22-23 nm particles of density 1.4 (and other particles) can be found in faeces of children with natural diarrhoea and adults with experimental diarrhoea, sometimes in enormous numbers. It is not yet established whether they cause disease. Rotaviruses, animal coronaviruses and "Norwalk" virus attack the disaccharidase-producing epithelium of the small bowel; adenovirus pathology is unknown.A safe attenuated live vaccine strain of the human rotavirus urgently needs to be developed.

A single oral dose of bovine rotavirus vaccine RIT 4237 or placebo was given to 2 groups of 5-day-old infants, born in October 1984 (n = 244) and June 1985 (n = 245), who remained in follow-up for 2.8 and 2.0 years, respectively. The vaccine had no effect on the total number of detectable episodes of rotavirus diarrhoea: there were 22 cases in the vaccinees and 24 in the placebo recipients in the October group and 18 and 16 respectively in the June group. However, vaccination decreased significantly the clinical severity of rotavirus diarrhoea, as assessed by a numerical score 0-20; this vaccine effect was much greater in the infants born in October. The mean severity scores for vaccine and placebo recipients were 4.55 and 10.75 respectively in the October group (p less than 0.0001, t-test) and 8.2 and 11.6 respectively in the June group (p = 0.010, t-test). Vaccine-induced clinical protection against rotavirus diarrhoea did not correlate well with serological response after vaccination, but showed good correlation to the presence of rotavirus antibodies before the rotavirus epidemic season. It is concluded that bovine rotavirus vaccine is more efficacious when given immediately before the rotavirus epidemic season: the vaccine effect may be amplified by exposure to wild rotaviruses during the season.

It is well established that rotaviruses of group A are the most important cause of severe diarrhoea in children. The causes of most cases of infectious diarrhoea still remain unidentified, however, and there must be other viruses to be found. 'Novel' rotaviruses have recently been discovered, mainly in animals (serogroups B and C in pigs and humans, D in birds, and one or more further groups in sheep and other mammals). Except for the group B virus which has caused widespread outbreaks of quite severe diarrhoea in adults in China (still not reported from outside China) these novel rotaviruses are rarities in the human and probably represent uncommon zoonotic infections. We speculate that the Chinese virus might have arisen by reassortment of genetic segments of animal group B viruses or perhaps by mutation, and so became infectious for man. The problem of identifying and determining the importance of small round viruses is reviewed. It seems likely that the group of small, round structured viruses, including Norwalk and the viruses of plainly calicivirus morphology, are all representatives of a whole group of enteric caliciviruses. Until they can be more easily cultivated it will be difficult to make diagnostic reagents available to all. Astroviruses and genuine parvoviruses have been found by many people in many countries. Astroviruses are probably more important as pathogens in lambs than in children or calves; parvoviruses can only be established as significant in epidemics. The coronavirus-like particles, first found in Vellore and Bristol, are still enigmatic and their role in diarrhoea is uncertain. Toroviridae, recently discovered as causes of diarrhoea in ungulates, do not seem to be at all important as causes of diarrhoea in humans. Possibly fruitful approaches to future searches are outlined: firstly to make more extensive use of immuno-electron microscopy; and secondly to try to improve existing tissue culture systems to make them more sensitive to enteric viruses.

He was on holiday with his family in the west of Ireland and was breathless. They asked me to see him—it was the 1940s and I had only just got my MD. They asked me …

Virus infections which may cause severe or life-threatening illnesses meriting chemotherapy are surveyed. Experience has shown that effective antiviral chemotherapy must be given early in the illness, and so this paper concentrates on the earliest symptoms of the various diseases and on methods leading to rapid diagnosis. This can be made by recognizing virus particles of characteristic morphology, if they occur in large numbers. e.g. rotavirus in diarrhoea. Sensitivity may be enhanced by using immune serum to trap viruses. A variety of very sensitive immunological methods is now available for detecting virus-specific proteins in secretions of the respiratory and alimentary tracts. Monoclonal antibodies help to make these more specific. Virus nucleic acids can also be detected in secretions and cells in situ by hybridization with purified radio-labelled nucleic acid. Virus diseases specifically surveyed include varicella zoster and measles, both very important in immuno-suppressed patients; epidemic influenza; and the human papilloma viruses, of which 33 different types are now known, and which cause not common warts on hands and feet, but also venereally transmitted inapparent papillomas upon the surface of the uterine cervix, often leading to cervical carcinoma. The problems of diagnosis of acquired immunodeficiency syndrome are reviewed. The aetiology of chronic non-A, non-B hepatitis is still largely obscure, but a retrovirus may be involved. The diagnosis of rabies is also considered.

The subgroups and serotypes of 178 strains of rotavirus isolated from diarrheic and healthy children in Bangui, Central African Republic, during a 27-month period were determined by enzyme-linked immunosorbent assay. The subgroup was determined for 152 of the viral strains, 18.4% being subgroup I and 81.6% being subgroup II. Of the 143 strains which could be serotyped, 71.3% were serotype 1, 15.4% were serotype 2, and 13.3% were serotype 3. Serotypes 1 and 3 were detected throughout the study, while serotype 2 was detected only during 8 months. No serotype exhibited any special epidemiological properties. The serotypes were found to consist of three different electrophoretypes, two long ones (A and B) and a short one (C). All subgroup I, serotype 2 strains presented short electrophoretypes. Strains with identical long electrophoretypes A were either serotype 1 or serotype 3.

Human, piglet, mouse, foal, lamb, calf and rabbit rotaviruses all infected, but could not readily be subcultured in LLC MK2 cells. Cells infected with mouse and calf rotaviruses reacted by indirect immunofluorescence (FA) with convalescent serum from children, piglets, mice, foals, lambs, calves or rabbits, taken after rotavirus infection. Human, calf, piglet, mouse and foal rotaviruses reacted with human, calf, mouse, foal and lamb convalescent serum by complement fixation (CF). It was not possible to distinguish between different rotaviruses by CF or FA. Neutralization tests, however, detected species-specific rotavirus antigens. Any virus was neutralized by a much higher dilution of homologous species convalescent serum than by any heterologous serum. With the exception of the mouse virus there was very little cross reaction. However, in sera with a very high neutralizing titre for the homologous virus the titre was proportionately raised against heterologous virus. It is, therefore, now possible to type to species an unknown rotavirus by a neutralization test in LLC MK2 cells using convalescent serum from each species.

Summary Faeces were examined from one hundred and nine babies, i.e. about a quarter of the annual total, admitted to a special care unit. Thirty-five aged one to 33 days were found to be excreting rotavirus. Of these, 17 had diarrhoea, seven had loose stools and ii were symptomless. There were 41 episodes of diarrhoea in the 109 babies during the study with evidence of rotavirus infection in 59 per cent; no other enteric pathogen was found. Nosocomial infection was evident in five babies whose faeces were first found rotavirus-negative, but later positive. The unit was ‘screened’ on five occasions during the year of this study; up to 41 per cent of the babies were found to be excreting rotavirus. Nine infected infants were examined for their serological response. Two, examined by immunofluorescence, had antibody at less than their mothers' titres; a third, examined 11 days after the onset, had a titre identical to its mother's and a fourth, at 14 days after onset, had no detectable antibody. No specific neutralising activity against three rotavirus serotypes could be shown with the sera from those four babies. Specific IgM was sought in samples from two of the four, but none was found. The remaining five babies, only examined three to five months post-infection, were found to have no detectable antibody by immunofluorescence.

SummaryWe have assessed the effectiveness of flexible-film negative-pressure isolators by physical and biological means. We have found that they afford a high degree of containment and therefore also of safety to hospital staff. We offer some recommendations on the operation of these isolators to ensure the optimum degree of protection.

Summary Faecal filtrates containing rotavirus particles, from children with acute infectious diarrhoea, were inoculated intranasally into gnotobiotic piglets. The piglets developed no symptoms, but virus was readily found by electron microscopy in their faeces during three serial passages. Among 11 piglets tested 3 weeks after inoculation of virus, all had developed fluorescent antibodies against tissue-culture-adapted calf rotavirus but only two had neutralising antibody. Growth of human rotavirus did not occur in either normal or “nude”, thymus-deficient suckling mice.

Summary Extracts of the leaves of Phytolacca americana and partially purified preparations of such extracts caused marked inhibition of the infection of Chenopodium quinoa by cucumber mosaic virus (CMV) and of the infection of monkey kidney cells and embryonated hen eggs by the A2/Hong Kong/1/68 (H3N2) strain of influenza virus. Both viruses became non-infective when mixed with preparations of the extracts but infectivity was regained when the viruses were separated from them by centrifuging.

The Chinese atypical (Group B) rotavirus, previously called the adult diarrhoea rotavirus (ADRV), was examined by transmission electron microscopy using either uranyl acetate or potassium phosphotungstate (PTA) as negative stains. Complete rotavirus particles were seen using uranyl acetate which were indistinguishable morphologically from typical rotaviruses. In the same preparations virus particles with differing degrees of degradation were seen after staining with PTA. This effect was not related to pH of the PTA and could be prevented by fixation of the specimen by 0.1 per cent glutaraldehyde. It is concluded that the use of PTA can give rise to falsely negative results for specimens containing this virus.

A method is described for examining viruses in faeces by direct electron microscopy using negative staining. The particles found in a group of patients with gastroenteritis and a group with other conditions are compared. Small particles in the range of sizes covering parvoviruses and enteroviruses were found about as frequently in each group. Many of these were probably bacteriophages. Many bacteriophages with tails of various sizes and lengths were found. Adenoviruses were found in five of eight patients from whom they were isolated. Reovirus- (or orbivirus-) like particles were found associated with some gastroenteritis patients.

In a randomized, double-blind, placebo-controlled trial, 331 infants aged 6 to 12 months received orally, at an interval of 1 month, either two doses of live attenuated bovine rotavirus vaccine strain RIT 4237 or equivalent placebo. The vaccinations were carried out during September to November, a non-rotavirus season; only three cases of rotavirus diarrhea occurred in the study group before the vaccinations were completed. During the epidemic season from December to May, 31 patients with clinically significant rotavirus diarrhea required therapy. Five of these were among the 168 vaccine recipients, and 26 among the 160 placebo recipients (P less than 0.001), giving a vaccine protection rate of 82%. The incidence of clinically significant diarrhea from all causes was reduced by 76% in the vaccinees. As determined by an enzyme immunoassay antibody test with homologous virus antigen, seroconversion after vaccination was obtained in 53% of the initially seronegative infants. Clinical protection correlated well with seroconversion, but the vaccinees who failed to seroconvert also had less rotavirus diarrhea than the placebo recipients, suggesting that immunity may be mediated by factors other than serum EIA antibody. Seventeen of the 23 rotavirus isolates in the epidemic season that were typed were of serotype 1, two were of serotype 2, and four were of serotype 3. The protection rates against clinically significant diarrhea were 72%, 100%, and 100% for serotypes 1, 2, and 3, respectively. We conclude that epidemic infantile winter diarrhea associated with human rotaviruses can be significantly reduced by vaccination with the live attenuated RIT 4237 bovine rotavirus vaccine before the epidemic season.

Antenatal screening in the West Midlands during a three-year period identified 297 mothers who were chronic carriers of hepatitis B surface antigen (HBsAg)--a prevalence of about 1 in 850. About half of their infants had HBsAg in the cord blood, but of 122 infants followed up for over three months (mean 8.5 months) only 17 (14%) were still positive for HBsAg. Cord-blood HBsAg-positivity was evenly distributed among different ethnic groups, but the transmission rate was highest among the Chinese, and no carriers were discovered among 39 European infants. Raised serum transaminase concentrations were found in some of the carrier infants who were otherwise healthy. The results suggest that adequate follow-up of HBsAg-positive infants may be achieved by tests at 4 months and 1 year of age, and that the role of breast-feeding in mother-to-infant transmission of HBsAg is unimportant. The Chinese community may be a suitable population in which to test the effectiveness of specific immunoglobulin administration at birth in preventing the development of the HBsAg carrier state.

Pleomorphic virus‐like particles have been observed by electron microscopy in the faeces of children and adults with diarrhoea. Some of these particles were approximately 100 nm in diameter and had a “fringe” of closely applied peplomers approximately 10 nm long; they closely resembled Berne virus of horses and Breda virus of calves, the two representatives of a newly proposed family called the Toroviridae. In one sample a toroidal nucleoprotein‐like structure was observed within the particles. For two samples a buoyant density of 1.14 g/ml was determined by centrifugation through a sucrose density gradient. One sample possessed a haemagglutination for rat erythrocytes. The serological relationship between these different viruses was observed by immune electron microscopy, haemagglutination inhibition, and serum neutralisation. The role of these viruslike particles as candidate pathogens of humans is discussed.

A neutralisation test using cell culture and indirect immunofluorescence was applied to isolates of rotavirus from 55 patients with gastroenteritis, in order to determine serotypes. Frequent cross-reactions were observed, but subsequent statistical analysis confirmed the existence of at least three distinct serotypes. Some results, not sufficient for analysis, suggest that at least five serotypes probably exist. It is suggested that two or more viral polypeptides might be involved in neutralisation, one of which might be common to another serotype(s). This would explain the frequent cross-reactions detected by this neutralisation test. Evidence suggesting that some strains may be hybrids is also presented.

Summary Treatment of T3 with various denaturing agents produced distinct components which were identified in the ultracentrifuge. Combining this analysis with electron microscopy made it possible to identify the capsid and nucleocapsid, and a fragment having an s 20, w = 105 ± 10S. This fragment appeared spherical in the electron microscope and had dimensions between 12 nm and 16 nm. It was tentatively identified as the tail. The mol. wt. of the 105S particle and the empty head (200S) were calculated to be 2.3 × 106 and 21.7 × 106, respectively. Adding these weights to the estimated weight for DNA (25 × 106, Lang & Coates, 1968) gave a total weight for the phage of 49 × 106, equal to the mol. wt. obtained by Swaby (1959). In addition to these large fragments, two peptides were examined, one had a mol. wt. of 9300 ± 1400 in 6 m-GuHCl (1.5S) and appeared to be a single chain; the other, released when a suspension of phage was diluted, had a mol. wt. of less than 10000. The origins of the two peptides remain largely speculative, but in view of the marked associative properties of the 1.5S peptide and its detection only when the head was destroyed, it is likely that it was a binding fraction in the head of the phage. The second peptide may be more intimately associated with the DNA of T3.

SUMMARY: The changes in fowl-plague infected tissue cultures have been investigated by the phase-contrast, and electron microscopes. The nucleolus of infected cells first increased in size and then became granular and highly refractile, finally disintegrating into fragments about 64 hr. after infection. After 36– 48 hr., when the inclusions were already developed, filaments were found, usually in bundles, possibly having escaped from the nucleus into the cytoplasm; a few filaments showed segmentation into spherical bodies and shorter filaments. A possible life cycle is suggested for the virus: first, penetration of the nucleus and growth within it, then extension into the cytoplasm in a filamentous form, and eventual segmentation of some of the filaments into elementary bodies.

A case is described of herpetic hepatitis in a pregnant woman with primary herpetic stomatitis. Intranuclear inclusion bodies and virus particles were found in hepatocytes, and herpes virus was isolated from a liver biopsy and from oral swabs but not from blood. From rising titres of neutralizing and complement-fixing antibody it is concluded that the oral infection was a primary one. Factors predisposing to the hepatitis are discussed.

A fatal case of vaccinia necrosum treated with antivaccinial gamma globulin and N-methyl isatin beta-thiosemicarbazone (33T57) is described. Histological abnormalities found at necropsy included intranuclear as well as cytoplasmic inclusion bodies, absence of lymphoid germinal centres, grey hepatization, and bronchiolar epithelial hyperplasia. Virus titres were highest in the original skin lesion; virus was also found in the lymph node draining it and in the kidney and the brain. No toxic effects could be clearly attributed to the drug used in treatment.

Two cases of interstitial pneumonia are described. They were characterized by mononuclear cell infiltration of the alveolar walls and protein-rich exudate into the alveolar cavities, with localized hyaline membrane formation. Coxsackie B5 virus was isolated from the lungs of both patients at necropsy.

1. Polymers of orosomucoid were produced in two molecular shapes, filamentous (‘chain’) and spherical (‘ball’), by heating the sodium salt of the monomer in either water or high concentrations of sodium chloride. An ‘intermediate’ state containing both shapes in various proportions was found in preparations obtained by polymerizing orosomucoid in intermediate concentrations of sodium chloride. 2. The filamentous form of polymer was found to inhibit strongly the haemagglutination of some (‘sensitive’) strains but not of other (‘insensitive’) strains of influenza virus; the ‘intermediate’ form feebly inhibited haemagglutination by ‘sensitive’ strains. 3. The filamentous form agglutinated both ‘sensitive’ and ‘insensitive’ strains of virus; the other forms of polymer did not. It also inhibited multiplication of both ‘sensitive’ and ‘insensitive’ strains when inoculated into embryonated and de-embryonated eggs. 4. The ‘intermediate’ and spherical forms of the polymer had no effect on the virus multiplication. 5. Polymers of orosomucoid from which neuraminic acid had been split off had no detectable effect on influenza viruses.

Summary: The nuclear changes leading to spore formation in Bacillus anthracis were investigated in 35 strains. Fusion of four chromatinic bodies into one mass and its subsequent break up into four bodies was observed. One of these became incorporated in the spore; the other three disintegrated. Some cells showed no fusion before spore formation; in these one chromatinic body was incorporated in the spore and the other three disintegrated. The percentage of cells in which fusion occurred varied with the strain. Rough colony strains showing a high incidence of fusion tended readily to throw smooth colony variants. Strains showing a low incidence of fusion were stable in this respect. The incidence of variants of other types bore no relation to the incidence of nuclear fusion in the strain.

Summary The reticular structure previously described on the original taylor 1233 strain of influenza C was found on two further strains of influenza C. In negatively stained preparations of influenza C three kinds of particles with different surface morphology have been found: particles with ‘spikes’ typical of myxovirus, particles with a hexagonal reticular surface and ‘naked’ particles with no reticular structure. The fine structures of influenza viruses A and C as seen in thin sections were compared. In walls of influenza A the structures encountered from the surface inwards were: a layer of spikes hollow and open at both ends; an electron-transparent layer of uniform width; and a finely granulated layer. The electron-transparent layer of influenza C virus was much less prominent; the spikes were irregularly placed and often absent. On sectioned influenza C filaments a hexagonal pattern was seen. The internal component of influenza A virus measured about 6 nm. in diameter and sometimes appeared to be hollow. The internal component of influenza C measured about 9 nm. across and appeared to be helical. On the basis of these results the taxonomic position of influenza C has been questioned.

SummaryThe cytoplasmic inclusion bodies produced by fowl-pox virus in the chorioallantoic membrane of the egg consist of a mass of virus particles, frequently surrounding an apparently normal component of the cytoplasm. Finely granular or filamentous material is seen in the centre of the inclusion and round the more central virus particles into whose structure it appeared to be incorporated. The inner virus bodies consisted of a granular core surrounded by a single membrane. The outer virus bodies consisted of a cortical layer 20 mμ thick, enclosing a space in which lay a core with a granular centre.

The reovirus-like particles present in faeces of young children with acute gastroenteritis and the virus causing acute diarrhœa in newborn calves were found to be indistinguishable from each other in size and shape. The human and calf viruses were agglutinated by sera from convalescent calves. Some adult human sera neutralised infectivity of the calf virus in tissue-cultures. Sera from convalescent children agglutinated both human and calf viruses and gave a positive immunofluorescent reaction with calf virus in cell-cultures. Since these viruses differ morphologically both from reoviruses and orbiviruses, the name " rotavirus " is suggested for them.

Pleomorphic virus-like particles about 100 nm in diameter with a fringe of closely applied peplomers (7-9 nm in length) were observed by electron microscopy in the stools of 20 children and adults with gastroenteritis. In most of the samples no other viral or bacterial pathogens were detected. In form and under immune electron microscopy these virus-like particles resembled the Breda virus isolated from diarrhoeic calves. These objects may be a viral pathogen of humans.

During 1974 in the West Midlands of England, 38% of children less than 6 years old with enteritis were excreting rotaviruses. Children aged from 6 months to 3 years were those most commonly infected. Rotavirus infections were most common during winter with only a few sporadic cases during summer. A possible pathogen was detected in 59% of patients examined.

Intrahepatic cholestasis is manifested by an obstructive type jaundice but the exact mechanism which cause failure of bilirubin secretion because of drugs is not known. It is recognized as a benign complication of oral contraceptive agents. This paper describes the case report of 2 sisters who were using contraceptive agents where the common component was norethisterone. Both sisters were well built with auburn hair and hazel eyes. Both were 0 rhesus -positive. In each case pruritis was severe and the most unbearable symptom. It was treated successfully with intravenous ACTH and oral prednisone and the itching was relieved but the jaundice continued over many months. One sister had severe pruritis during the latter part of her 3 pregnancies. The mother of these women had no problems during her 3 pregnancies. The other sister in this family was taking Anovlar 21 which she had used for 2 years without problems. This sister presented a totally different physical appearance and is A rhesus-positive. The strong similiarity between these 2 sisters and their common reaction to this steroid causes speculation that the jaundice may be due to a genetic abnormality and possibly a single enzyme defect.

Made available in DSpace on 2022-04-29T08:42:13Z (GMT). No. of bitstreams: 0 Previous issue date: 1981-01-01 Pathologic changes induced in the small intestine of suckling mice by rotavirus infection were studied by conventional histology, immunofluorescence, scanning electron microscopy, and electron microscopy of ultrathin sections. Infection could be detected within 24 hours in a few mice, but after 2 days it was well established. Swollen, often vacuolated infected cells were found on the sides and tips of villi from which they rapidly became detached; microvilli showed variable irregularity. Immature enterocytes from crypts replaced lost infected cells. By the tenth day very few infected cells could still be found. Both tubular structures and spherical particles occurred in the infected cells. Only tubular structures were found in nuclei. © 1981 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted. Departamento de Patologia Faculdade de Medicina, 18600, Botucatu Sao Paulo

The reovirus-like particles present in the feces of young pigs and foals with acute enteritis and the virus causing epizootic diarrhea of infant mice were found to be indistinguishable morphologically from each other, from the South African SA. 11 and "O" viruses, and from the rotaviruses of children and calves. The inner capsid layer of each of these viruses reacted seriologically with sera of children, calves, mice, piglets, and foals convalescent from infection with their respective rotaviruses. These sera reacted by immunofluorescence with human, bovine, porcine, and murine rotaviruses, SA.11, and "O" viruses in tissue cultures and with human bovine, procine, nad murine viral antigens by complement fixation and gel diffusion. However, the antisera differed in their ability to react serologically with the outer capsid layer of the viruses investigated and in their ability to neutralize tissue culture-adapted calf virus. These two tests may demonstrate strain or host specificity among rotaviruses. Since the porcine, murine, and equine viruses are closely related serologically to and are morphologically identical to the human and bovine viruses, they should be included in the group of viruses for which the term "rotavirus" has been suggested. All known members of this proposed group of viruses share a common antigen, probably situated within the inner capsid layer; thus, any one of the viruses may be used for the preparation of antigen or antibody for diagnostic tests, and this will aid in the diagnosis of virus infection in those species from which a rotavirus has not been cultured.

An attempt is made to answer 2 questions: is it possible to develop a vaccine capable of preventing acute infectious diarrhea; and would this rotavirus vaccine make a significant impression on the number of fatal cases of acute infectious diarrhea. The isolation of rotaviruses in tissue culture to develop less powerful strains for use as a live oral vaccine has been accomplished. At least 4 serotypes exist which can be distinguished from each other by specific antibody. No one knows yet as to whether infection by 1 serotype can provide immunity against infection by a different serotype. The techniques of genetic engineering suggest new possibilities for vaccine development. Rotavirus antigen could be implanted in common bacteria which normally colonize the small bowel. They would reproduce the antigen and thus immunize the patient. Alternatively, the strain of typhoid bacillus, Ty21a, used in the new antityphoid vaccine might carry the rotavirus antigen. The effectiveness of such vaccines is unknown, but the technology to conduct the experiment exists. Recently, new kinds of rotavirus have been identified. 2 serotypes of "standard" piglet rotavirus are well established and share a common group antigen with the rotaviruses commonly found in children, and, of late, 2 new piglet rotaviruses have been discovered. Additionally, recent reports describe new human rotavirus strains in Australia, China, Brazil, France, and Britain, and these are serologically distinct but cannot be detected by current ELISA tests. Prior to marketing a diarrhea vaccine, fully adequate field trails need to guarantee its effectiveness. It will be necessary to conduct these field trials over several years because of the variation in viruses and the periodic nature of viral diarrhea. As reliable vaccination against viral diarrhea seems technically unlikely to become available in the near future, the availability of the inexpensive, simple, and life-saving technique of oral rehydration must be universally publicized and applied.