[Complement fixation test in the identification of human rotavirus]

Após a eliminação da anticomplementaridade, foi utilizada a reação de fixação do complemento na identificação de rotavírus em 134 amostras de fezes de crianças até um ano de idade, com quadros diarréicos agudos. A percentagem total de positividade foi de 28,7% com percentagens mais elevadas de casos positivos nos grupos etários de 6 meses a 1 ano de idade.

Rotavirus gastroenteritis in the Washington, DC, area: incidence of cases resulting in admission to the hospital

The incidence of rotavirus gastroenteritis in infants and children that required admission to the hospital was estimated for a defined population of approximately 105,000 individuals, including 29,000 children aged 15 years or younger whose primary health care was provided by Group Health Association, Inc, a health maintenance organization in the Washington, DC, area. From January 1977 through March 1979, almost all infants and children in this age group who required hospitalization for gastroenteritis were studied for evidence of infection with human rotavirus (HRV) and other agents. On the average, one in 272 (3.7/1,000) infants less than 12 months old and one in 451 (2.2/1,000) children aged 13 through 24 months were hospitalized for HRV disease each winter. The incidence of rotavirus gastroenteritis requiring hospitalization declined precipitously in children after the second birthday and such illness was not detected in children aged 5 years or older. The role of other agents in acute gastroenteritis requring hospitalization was minimal, compared with that of rotavirus.

Changes of the rotavirus concentration in faeces during the course of acute gastroenteritis as determined by the immune adherence hemagglutination test

Concentrations of rotavirus were studied in serially sampled faecal specimens from 55 patients with acute gastroenteritis, utilizing the immune adherence hemagglutination (IAHA) test. Rotavirus antigen was detected in 45 (82%) out of 55 cases. In the faeces which were positive for rotavirus antigen, the concentrations reached their maximum titer shortly after the onset of the illness and diminished gradually until the 9th day.

Chronic rotavirus infection in immunodeficiency

The characteristics of rotavirus infection in 23 children with a variety of primary immunodeficiency diseases were studied. Stools and sera were tested for rotavirus by means of the enzyme-linked immunosorbent assay and the enzyme-linked fluorescent assay, respectively. Four immunodeficient patients had diarrhea during the study period and all had rotavirus infection; rotavirus was not detected in the stools of the 19 asymptomatic immunodeficient patients. Forty-six control children with diarrhea were tested and 22 had rotavirus infection; rotavirus was not detected in 39 asymptomatic control children. One immunodeficient patient with X-linked agammaglobulinemia and one with severe combined immunodeficiency had chronic, symptomatic rotavirus infection with rotavirus excretion lasting more than six weeks. The other two immunodeficient patients and eight control children eliminated the rotavirus from their stools in periods ranging from two to 12 days. Rotavirus antigen was detected in the sera of three of the four immunodeficient patients; none of the 14 control infants tested had rotavirus antigen detected in their sera. This study indicates that rotavirus may produce a chronic infection in immunodeficient children.

New emerging viral zoonoses

New developments in the field of viral transmission from animal to man can be divided into four areas of study. First are the new viral zoonoses such as diseases caused by rotaviruses, Lassa virus and the animal orthopox viruses which will be more prevalent after the cessation of mandatory vaccination against smallpox. Secondly are the numerous ubiquitous viruses, such as adeno and herpesviruses, which in healthy animals lead only to clinically inapparent infections. A typical example of the third area is the recombination and hybridisation between animal and human influenza type A viruses. The final area is concerned with the transmission of viral zoonoses to man through food of animal origin.

Escherichia coli and rotavirus infections in four-week-old gnotobiotic piglets fed milk or dry food

A haemolytic enteropathogenic E. coli (WG) and pig rotavirus were isolated from a field case of postweaning diarrhoea in pigs. Four-week-old gnotobiotic piglets fed on milk diet were found to be extremely susceptible to infection with WG E. coli. Piglets were less susceptible to the infection immediately after the diet was changed from milk to dry food, and were almost completely resistant 4 days after the change to dry food. There was no difference in the clinical response to infection with WG E. coli when the piglets were fed either a high energy diet or low energy diet. Four-week-old piglets fed milk showed mild symptoms of diarrhoea when inoculated with pig rotavirus. Symptoms were more severe when piglets were inoculated immediately after the change from milk to dry food. Piglets inoculated 4 days after the change of diet showed no symptoms of diarrhoea at all. Under the conditions of these experiments the enteropathogenic E. coli produced a more serious disease than did pig rotavirus. Infection of 4-week-old gnotobiotic piglets with both agents given sequentially produced a diarrhoeal disease that was more severe than that produced by each agent separately.

[Seroepidemiologic survey of the spread of rotavirus infection in a Milan population]

The increasing evidence of involvement of Rotaviruses in the etiology of viral gastroenteritis prompted us to carry on a seroepidemiological survey on the population of Milan. The aim was to get informations on the extension of the circulation of these agents in our population. Utilising a commercial antigen prepared with the "Oslo" bovine strain, c.f.a. were titrated in sera from 575 healthy subjects (age 0 to > 60 years). Of them 232 were children under 4 years of age homogeneously distributed into 6 age classes: at birth, 1 day to 3 months, 4-6 months, 7-12 months, 13-24 months, 2-4 years. Rotavirus infection appears very common. About 80% of the subjects over 10 years have c.f.a. As it is shown by the sharp increase of antibody acquisition after an initial drop in the first 6 months (82% positive at birth and 41% between 4-6 months), the infection seems to occur very early in life, as much as the plateau is reached under 10 years of age. Moreover consistent antibody titers (greater than or equal to 1:32), which could indicate recent infection, first appear in babies 4 to 12 months of age. Such titres are absent in the adults and could be found again in people over 50. Positivity was significantly higher in females than in males (0.01 < P < 0.025). Transplacental c.f.a. passage was studied in paired sera of 37 women at delivery and in cord blood sera of their babies; 28 matched pairs of sera had coincidental titres, but there were additional three cord blood specimens with c.f.a. from newborns whose mothers were negative.

[Serodiagnosis of rotavirus infections in gastroenteritis of infants]

We report the use of the line immunoelectroosmophoresis (LIEOP), a modification of the immunoelectroosmophoresis (IEOP), for the serodiagnosis of rotavirus infection, in comparison with the complement fixation test. We tested 17 paired and 29 single sera from hospitalized children affected by acute gastroenteritis; rotavirus had been searched in the stools both by electron microscopy and IEOP. The LIEOP showed seroconversion in all the 11 cases with positive stools and also in 5 out of 5 patients whose stool sample had been negative. Either we had not been able to detect the virus, or there was an intervening (nosocomial) rotavirus infection. All sera which were reactive by complement fixation with bovine rotavirus were also reactive by LIEOP. Some of the sera which reacted by LIEOP, both with the homologous and the heterologous antigen, were negative by complement fixation.

Oral rehydration therapy for treatment of rotavirus diarrhoea in a rural treatment centre in Bangladesh

In November 1977, an enzyme-linked immunosorbent assay for detecting rotavirus antigen was introduced in the laboratory of a rural treatment centre in Bangladesh. During the next 40 days rotavirus without other pathogens was found in the stools of 216 (45%) of 480 children under age 5 years who visited the centre with a gastrointestinal illness. 188 (87%) of these children were treated with oral rehydration alone, using the solution currently recommended by the World Health Organisation, while 28 (13%) also required some intravenous rehydration; there were no deaths. Oral rehydration treatment was judged successful in 205 (95%) of the rotavirus patients and was not associated with any serious side effects. Oral rehydration treatment, with this solution, has been used extensively and successfully in the treatment of enterotoxin-mediated diarrhoea and can also safely be used for treating rotavirus diarrhoea in infants and young children.

Passive immunity in calf rotavirus infections: maternal vaccination increases and prolongs immunoglobulin G1 antibody secretion in milk

Ten heifers were inoculated on two occasions with an inactivated preparation of tissue culture-grown calf rotavirus, and a further ten heifers received a placebo vaccine. Serum anti-rotavirus antibody titers were significantly increased throughout pregnancy in the vaccinated group. After calving, the mean neutralizing antibody titer of colostral whey in control cows was 100, associated with immunoglobulins A and G1. No antibody was detected in the milk of these cows after the 4th day postpartum. The colostral whey from the vaccinated cows had a mean antibody titer of 20,452; 28 days after calving, the mean milk antibody titer was 320, associated mainly with immunoglobulin G1. Calves were challenged with a large oral inoculum of calf rotavirus at the 7th day of age. There was significant lengthening of the incubation and prepatent periods in calves born to vaccinated dams, but rotavirus-associated diarrhea of equal severity occurred in both groups. Evidence is presented which suggests that rotavirus antibody in milk can protect against a smaller challenge dose. Maternal immunization against rotavirus may be a practical proposition.

The first year of life. Diarrhoea

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An outbreak of rotavirus infection in a long-stay ward of a geriatric hospital

An outbreak of rotavirus infection in elderly patients in a long-stay ward of a geriatric hospital is described. Virus was detected in 7/15 (47%) symptomatic individuals. Four members of staff were among those affected. The findings emphasise the need for electron microscopy to be used in the initial investigation of outbreaks of diarrhoea in all age groups.

Course of rotavirus gastroenteritis in a closed community

There were 3 outbreaks of rotavirus gastroenteritis accompanied by milky-white stools in a closed community of 21 children in Japan during a 2-year period. Several different clinical courses were observed as a result of clinical, serological, and virological observations.

Oral fluid replacement by a glucose glycine electrolyte formulation in E coli and rotavirus diarrhoea in pigs

A glucose glycine electrolyte solution (GGES) was investigated to determine its suitability for oral rehydration in diarrhoea in pigs. Piglets with diarrhoea following experimental infection with eneteropathogenic Escherichia coli were given access in cube drinkers to either GGES or water. The mortality in the GGES group (11.6 per cent) was significantly (P less than 0.05) less than in the controls (24.0 per cent), and weight gain in severely diarrhoeic piglets was greater in the GGES group. Gnotobiotic piglets were challenged with pig rotavirus and either given access to GGES or milk. The GGES was either in restricted volume or ad lib. Restricted access to GGES prevented much of the weight loss due to the diarrhoea and ad lib access to GGES allowed relatively uninterrupted weight gain in comparison with controls. In naturally occurring cases of diarrhoea on farms, access to GGES reduced mortality to weaning from 19.7 per cent to 7.2 per cent (P less than 0.05). Weight gain per day was also greater in piglets which scoured for three days or more, indicating the rehydrating effect in reducing net fluid loss. Thus GGES treatment was of value in treatment e&ects of diarrhoea due to either E. coli or rotavirus.

An epidemic of gastroenteritis in Auckland 1978

During an epidemic of gastroenteritis which spread throughout New Zealand in 1978, 372 cases of nonbacterial illness were documented in children in Auckland during the months of June and July. A brief account is given of the clinical picture observed. Evidence from virological techniques suggests that some if not all cases were due to rotavirus. The severity of illness may have been greater than most observers to date have noted. From our observations we raise the possibility of air-borne spread, perhaps in addition to faecal-oral. We wish to emphasise that drugs play no part in the treatment of viral gastroenteritis, that home-made electrolyte solutions can be hazardous and that early intravenous therapy can be life-saving.

[Rota virus infection in the newborn and infant -- epidemiological aspects (author's transl)]

In a total of 406 sera an age-dependent pattern of complement fixing antibodies against Rotavirus (Nebraska calf diarrhea virus) was found: 85% of the adults had antibodies, infants in the second half-year of life had the lowest percentage (42%). Thereupon a Rotavirus survey was carried out in a newborn ward by means of electron microscopy, enzyme-linked immunosorbent assay and complement fixation test during three weeks in January/February 1978. A chronically high infection rate was discovered. Children acquired intestinal infection despite of complement fixing serum antibodies and very few showed a rise in antibody titer.

[Virological and serological study of rotavirus gastroenteritis]

Cases of acute gastroenteritis with negative bacteriological analyses were examined. Preparations of feces collected from patients in the acute stage of the disease were found by immune electron microscopy to contain typical rotavirus particles forming specific aggregates in the presence of convalescent sera. Examinations of paired acute and convalescent sera of the patients revealed the presence in convalescent sera of specific antibodies neutralizing simian rotavirus SA 11 antigenically related to human rotavirus. The specificity of the antibody was confirmed by their titrations by immune electron microscopy and HI test. Thus, rotavirus etiology of cases of gastroenteritis in various parts of the country was confirmed, and the possibility of specific laboratory diagnosis of such cases using simian rotavirus SA 11 was demonstrated.

[Rotavirus gastro-enteritis in infants (author's transl)]

Deviation of complement antibodies were studied in 630 hospitalized infants aged from 0 to 4 years suffering from rotavirus gastro-enteritis, over a period of one year. Seroconversion was observed in 30 cases out of the 256 infants in whom 2 serological samples were taken. In 29 cases out of 30, these rotavirus infections occurred in infants under 18 months of age, and they were all seen during ther period from november to march, rotavirus being responsible for one third of the gastro-enteritis cases. A serological study according to age-group in 640 infants gave positive results in 75 per cent (1st semester), 68 per cent (2nd semester), 75 per cent (2nd year), 78 per cent (3rd and 4th years).

Canine viral enteritis. Recent developments

Two apparently novel viral gastroenteritides of dogs were recognized in 1978: one caused by a parvo-like virus (CPV) and one by a corona-like virus (CCV). A rotavirus has also been tentatively associated with neonatal pup enteritis. Canine viral enteritis is characterized by a sudden onset of vomiting and diarrhea, rapid spread and high morbidity. Treatment is only supportive but must be initiated promptly. Infected animals should be isolated immediately; the extremely contagious nature of these diseases makes them difficult to contain. Feces from infected dogs appear to be the primary means of transmission. Sodium hypochlorite solutions (eg, Clorox) are recommended for disinfection. The development of effective vaccines is an immediate and pressing problem.

Gradual reintroduction of full-strength milk after acute gastroenteritis in children

46 children (26 boys and 20 girls) admitted with mild acute gastroenteritis were randomly allocated to a regimen of continuing on full-strength milk, or to one of taking clear fluids until the diarrhoea settled before full-strength milk was reintroduced either immediately, or gradually in quarter-strength steps. There was no difference in length of hospital stay between the three groups.

Rotaviral diarrhea in pigs: brief review

Rotavirus is a name given to a group of viruses that have similar characteristics and are generally capable of causing diarrhea in the young. Infection of pigs with porcine rotavirus is common and widespread and can result in diarrhea, especially in 1- to 4-week-old pigs. This virus is frequently associated with a diarrheal syndrome popularity known as "white scours," "milk scours," or "3-week-old scours." Pigs less than 1 week old are infrequently infected, presumably because of adequate passive immunity. The infection resembles enzootic transmissible gastroenteritis. Diagnosis can be made by immunofluorescent staining of mucosal scrappings from the small intestines.

Quantitative observations on experimental reo-like virus (rotavirus) infection in colostrum-deprived calves

Ten calves were challenged with one of two strains of reo-like virus (rotavirus). Changes in the daily faecal and urinary outputs were monitored and packed cell volume, plasma sodium, potassium and urea levels were measured. Faeces were examined for the presence of rotavirus by direct electron microscopy and immunofluorescence in cultures of PK(15) cells. All calves excreted rotavirus in the faeces for several days. Two calves remained clinically normal throughout the experiment, but in the remaining calves, faeces became mucoid in consistency and yellow-white in colour. In only two calves did the daily faecal output exceed 500 g with a fall in the dry matter content to less than 10 per cent. Slightly elevated blood urea levels and hyperkalaemia were the only changes observed in blood chemistry and these quickly returned to normal. Virus antigen was observed in the epithelial cells by immunofluorescence in the proximal and middle small intestine of calves. Pathological lesions occurred predominantly in the proximal small intestine of nine calves examined.

Diarrhea associated with rotavirus in rural Guatemala: a longitudinal study of 24 infants and young children

A population of 24 infants and young children followed prospectively during the first 3 years of life was studied for the occurrence of rotavirus infection by using enzyme-linked immunosorbent assay to detect virus in stools. Infection with rotavirus was associated with 26 (14.2%) of 183 selected diarrheal episodes. Twenty of the 24 infants and young children had diarrhea associated with rotavirus on at least one occasion and six had two such episodes. Rotavirus infection was documented in over 50% of the dehydrating episodes studied, thus further indicating the importance of rotavirus in this population.

Structural and functional abnormalities of the small intestine in infants and young children with rotavirus enteritis

Structural and functional alterations in duodenal mucosa from 17 children with rotavirus enteritis were assessed. Structural changes were found in specimens from all patients. Patients with the most severe mucosal damage were more likely to require intravenous therapy to correct dehydration. Depression of one or more mucosal disaccharidases was found in 14 of 16 patients. Repeat duodenal biopsy three to eight weeks later in six patients showed marked improvement. The study clearly shows that rotavirus can cause a marked structural and functional lesion in the upper small intestine which is rapidly reversible.

Small intestinal morphology and epithelial cell kinetics in lamb rotavirus infections

Morphologic changes in the small intestine of rotavirus-infected gnotobiotic lambs were investigated by measurement of villi and crypts in histologic sections of jejunum, midgut, and posterior ileum. In midgut, villus atrophy developed within 12 hr of infection and was apparent until 72 hr after infection. Crypt hypertrophy was evident from 42 hr after infection until the end of the observation period (6 days after infection). Changes in posterior ileum were similar in extent, but jejunal changes were much less marked. The relatively mild effect in the jejunum is in accord with reports from other species, and provides a basis for questioning the assumption that human rotavirus affects mainly the foregut. Studies of epithelial cell kinetics were made on midgut using a microdissection and metaphase accumulation technique on sequential samples from anesthetized lambs. An increase in the cell production rate per crypt per hour from the overall control level of 5.8 was detected by 48 hr after infection. The maximum level of 21.2 was reached 8 days after infection, and this had returned to near normal by 15 days after infection. This large and sustained increase in crypt cell production probably underlies other previously described functional abnormalities.

Rotavirus gastroenteritis in infants and young children

The electronmicroscopic examination of stool samples from 18 infants and young children with gastroenteritis, hospitalized at the Clinic of Infectious Diseases in Prague, was carried out. In ten children rotavirus was found in the faeces and the bacteriological findings were negative. Rotavirus particles were aggregated by convalescent child sera and by normal human gamma globulin. The clinical picture was characterized by the sudden onset of vomiting and fever, in one case with febrile convulsions. Diarrhoea was watery and yellow-green, and usually persisted for four to five days. The condition of the children improved rapidly after rehydration and a special diet. Older siblings, and in one family also adult members, were frequently affected.

Viral intestinal infections of animals and man

The extensive use of negative staining techniques and electron microscopy in diagnostic centers has resulted in a dramatic increase in the number of reported viral enteric infections in man and animals in the last 10 yr. Enteric infection due to adenoviruses, astroviruses, coronaviruses, paramyxoviruses, parvoviruses, picornaviruses (caliciviruses), rotaviruses as well as some unidentified viral particles are described. The brief literature review on each of these virus families is supplemented with clinical cases submitted to the Texas Veterinary Medical Diagnostic Laboratory. Comparative aspects of viral infections between different animal species as well as man are discussed wherever possible.

[Rotavirus infections in children (author's transl)]

In 43 out of 90 children suffering from acute gastroenteritis Rotaviruses could be identified in stool-specimens by electronmicroscopy. Symptoms were watery diarrhoea (100%), vomiting (88%), fever (77%), dehydration (47%) and upper respiratory tract infection (21%). In 3 out of 9 patients liver involvement could be documented. In 29 children i.v.-fluid therapy for 1-2 days was necessary. Only in 1 patient severe diarrhoea persisted for 11 days.