Virus-specific IgM antibodies in acute gastroenteritis due to a reovirus-like agent (rotavirus).

62 serum samples from 24 patients with rotavirus gastroenteritis were tested for IgM antibodies against a bovine rotavirus by an indirect fluorescent antibody technique. IgM antibodies were detected in one or more of the serum samples from all but one of the patients. IgM antibodies were not detected in samples obtained from 11 of the patients after the 5th week of illness. Absorption of sera for IgG with Staphylococcus aureus increased the sensitivity of the IgM antibody test. It is concluded that the presence of IgM antibodies against bovine rotavirus in a patient's serum, as measured by the present technique, does suggest a recent rotavirus infection. On the other hand, the lack of IgM antibodies in the serum of a child with acute gastroenteritis between the second and the 5th week of illness tends to exclude rotavirus as a cause of the disease.     

Reovirus-like agent in acute epidemic gastroenteritis in Japanese infants: fecal shedding and serologic response.

The reovirus-like agent, sometimes referred to as duovirus or rotavirus, was visualized by electron microscopy in stool extracts from Japanese infants and young children with acute epidemic gastroenteritis. The virus particles measured 70 nm in diameter and had double-shelled capsids. One hundred ten (89%) of 124 patients with the gastroenteritis had such virus particles in stools obtained during the acute phase. The virus particles were excreted in the stools usually during the first eight days of illness. Agglutination of virus particles by antibody present in convalescent-phase sera was demonstrated by immune electron microscopy. Complement-fixing antibody was detected as early as day 3 of illness, and antibody titers peaked during the second and third weeks of the disease. The antibody appearing in the acute and early convalescent phases was sensitive to 2-mercaptoethanol. Antibody resistant to 2-mercaptoethanol was produced approximately 10 days after the onset of the symptoms. The serologic evidence suggests that a primary infection with the reovirus-like agent was responsible for the clinical attack of acute gastroenteritis.     

A long-term survey of rotavirus infection in Japanese children with acute gastroenteritis.

Human rotavirus was detected by electron microscopic examination of the stools of 320 (63%) of 506 infants and young children hospitalized with acute gastroenteritis between December 1974 and March 1977. Serologic responses to infection with the rotavirus were revealed by the complement-fixation test in 130 (70%) of 185 patients examined. During the study period three epidemics of human rotavirus infection occurred during the winter months. The peak incidences occurred in January 1975 (88% of patients positive by serologic analysis or electron microscopy of stools), January 1976 (92%), and February 1977 (96%). Rotavirus was detected in the stools of 288 (79%) of 365 patients tested during the cooler months (December to March) and 35 (25%) of 141 during the rest of the year. In the summer (June to August), rotavirus infection occurred rarely. The frequency of human rotavirus infection was highest among patients aged six to 11 months. These results indicate that human rotavirus can be regarded as a major etiologic agent of acute gastroenteritis in infants and young children, of which wintertime epidemics are common in Japan.     

Rotavirus-associated gastroenteritis in two adults probably caused by virus reinfection.

Rotavirus infection was diagnosed by virus detection and by serological methods in 2 women with acute gastroenteritis, aged 22 and 29 years, respectively. Both patients had been in close contact with children with rotavirus gastroenteritis. Rotavirus-specific antibodies were detected in serum specimens obtained prior to the illness in one of the patients, and the serological response in both patients suggested a reinfection with rotavirus as cause of the disease.     

Norwalk virus in Norway: an outbreak of gastroenteritis studied by electron microscopy and radioimmunoassay

An outbreak of acute gastroenteritis affected approximately half of 40 children staying at a holiday centre in Southern Norway. By direct electron microscopy Norwalk-like viruses were demonstrated in 4/8 available stool specimens. No other pathogens were detected. Antibody against these viruses was demonstrated by immune electron microscopy in all of 7 convalescent phase sera but in none of 11 acute phase sera collected. Radioimmunoassay examination showed a rise in titre of Norwalk virus antibody in 6 available paired sera. This outbreak of Norwalk virus gastroenteritis in Norway was thus documented by a combined use of direct and immune electron microscopy and radioimmunoassay.     

Central nervous system involvement in patients with rotavirus gastroenteritis.

Two children with rotavirus gastroenteritis are presented. The first case developed a fatal Reye's syndrome and the other one encephalitis with slow recovery. The rotavirus diagnosis was made in both cases by electron microscopy and a significant rise in antibody titres to Nebraska calf diarrhea virus was seen in one of the two patients.     

An epidemic of rotavirus-associated gastroenteritis in a nursing home for the elderly

92 cases of acute gastroenteritis were registered among 256 individuals during an outbreak in a nursing home for the elderly, the majority of patients being between 70 and 90 years of age. Most cases appeared in 4 of the 8 wards; 66% of the inmates of these wards became ill. Characteristic symptoms were initial nausea and vomiting followed by diarrhoea and low fever. A number of patients were severely ill. One patient died. Rotavirus infection was diagnosed by virus detection and/or antibody titre rise during the acute phase of the illness in 13 of 16 patients examined. At the end of the outbreak, high titres of complement-fixing antibodies against rotavirus (greater than or equal to 64) were detected in serum from 21/22 patients convalescing from the disease, as compared to only 5/45 individuals with no signs of disease. It is tentatively suggested that the outbreak became extensive and rather severe because of lowered immunity against rotavirus infection among the elderly.     

Parasitologic and serologic observations of infection with Pneumocystis in humans.

More than 500 specimens of lung tissue were examined for Pneumocystis. Of the 38 infections detected, most were in immunodeficient patients. Samples of serum from approximately 600 healthy normal subjects and 117 children with acute lymphatic leukemia were examined by an indirect fluorescent antibody test. The age-related data from the normal children suggested that nearly 100% of children are infected with Pneumocystis during the first two years of life. Groups of patients with leukemia who had symptoms of pneumocystis pneumonia had significantly higher titers of IgG antibody than groups of patients with leukemia who did not have clinical symptoms and normal subjects. Nevertheless, the diagnostic value of the indirect fluorescent antibody test is limited, but serologic follow-up study can be useful. Groups of children with leukemia had lower mean titers of IgM antibody regardless of their clinical condition.     

Gastroenteritis in Auckland: An aetiological and clinical study

Faecal specimens from 60 patients (under six years old), most of whom were Maoris and Pacific Islanders admitted to Auckland Hospital with gastroenteritis during the months of June and July 1977, were examined for the presence of faecal viruses, bacterial pathogens and parasites. Faecal specimens from 18 non-diarrhoeal control patients were also examined, of which three contained rotavirus. Forty-three (72 per cent) gastroenteritis patients had rotavirus detectable in stools by electron microscopy or immune electron microscopy. Of the remainder, 17 patients were regarded as having non-rotavirus diarrhoea. Enterotoxigenic Esch. coli. was isolated from seven patients of whom six yielded stable toxin producers (ST+), four labile toxin producers (LT+) and two dual toxigenic strains (ST+/LT+). All ST+ isolates appeared to be of low enterotoxigenicity as indicated by low gut weight/carcass weight ratios in the infant mouse assay. Rotavirus was the commonest aetiological agent (72 per cent), bacterial pathogens (alone) accounted for only five per cent and no enteric pathogens were found in 15 per cent of cases. Non-agglutinable rotavirus, presumably a different serotype, was seen in both gastroenteritis and control patients. Rotavirus ‘satellite’ particles previously undescribed were demonstrated in a number of stool samples.     

Epidemiological study of group C rotavirus

By electron microscopy survey of acute gastroenteritis of children in Matsuyama, rotaviruses were detected in 561 of 2479 fecal samples obtained between October, 1984 and September, 1988, in which 60 atypical and 259 typical rotaviruses, so far tested, were detected by polyacrylamide gel electrophoresis (PAGE) of viral RNA. Out of 60 atypical rotaviruses, 5 were observed in 1985, 7 in 1986, none in 1987 and 48 in 1988. These atypical rotaviruses were morphologically indistinguishable from typical ones and showed very similar RNA migration patterns of PAGE to those of group C rotavirus. Furthermore, one atypical virus (86-542) reacted with antiserum against a porcine group C rotavirus in immune electron microscopy, while it did not react with anti-group A rotavirus serum. On the other hand, hyperimmune guinea pig antiserum against 86-542 reacted with a couple of atypical rotavirus including viruses isolated in 1988, so far tested, but did not react with any of the typical viruses. These findings showed that atypical rotaviruses which were endemic in Matsuyama city in 1988 were defined as group C rotavirus. Moreover, these group C rotaviruses showed two kind of RNA migration patterns in PAGE, which clearly discriminated the virus were isolated before and after 1987. Epidemiological features of group C rotavirus were as follows. Children from whom group C rotavirus was isolated were older than those from of whom group A rotavirus was isolated. The epidemic season was in February through April, compared to December through March in group A virus. Retrospective seroepidemiological study by immune adherence hemagglutination test (IAHA) using the purified 86-542 virus as antigen indicated that 15 of 78 sera of children obtained in 1971 already possessed IAHA antibody against group C rotavirus.     

An outbreak of gastroenteritis associated with acute rotaviral infection in schoolchildren

In April 1988 a large outbreak of group C rotavirus infection associated with acute gastroenteritis occurred among schoolchildren and their teachers simultaneously at seven elementary schools in Fukui city, Japan. Of 3,102, 675 (21.8%) became ill. Clinical symptoms were mild, predominantly abdominal pain and vomiting, with diarrhea reported in only 27.6%. The outbreak subsided within 2 d. No pathogenic bacteria were found in fecal specimens; the virus particles detected by electron microscopy were morphologically indistinguishable from conventional infantile rotavirus. Immune electron microscopy showed that these virions formed large aggregates with convalescent serum and with the reference serum specific to group C rotavirus. Polyacrylamide gel electrophoresis showed similar RNA patterns for virus from this outbreak and typical group C rotavirus.     

Epidemiological aspects of rotavirus infection in hospitalized Venezuelan children with gastroenteritis.

The prevalence of rotavirus infection in hospitalized Venezuelan children with gastroenteritis was studied during the period November 1975 to December 1976. Rotaviruses were the pathogens most frequently associated with gastroenteritis, being found in 121 of 293 (41.3%) patients and in only 3 of 66 (4.5%) controls. Other viruses (adenoviruses, enteroviruses, and small icosahedrical viruses) were detected at a lower frequency both in cases and controls. Rotaviruses were detected at a lower frequency both in cases and controls. Rotaviruses were readily detected throughout the year, which may correspond to the absence of seasonal temperature variation in a tropical country such as Venezuela. Children of all age groups examined (0-5 yr) were susceptible to rotavirus infection. The frequency of infection was slightly higher in the age group 13-24 mo, and significantly lower in children younger than 6 mo old. Rotaviruses were readily detected even after 12 days from the onset of illness. These results indicate that rotaviruses may be a major cause of infantile acute gastroenteritis in Venezuela.     

Impact of rotavirus infection at a large pediatric hospital

Information is limited about national patterns of rotavirus infection throughout the USA. Discharge records and laboratory rotavirus detection for 1979-1989 at the Texas Children's Hospital, Houston, were evaluated to determine the impact of rotavirus gastroenteritis at a large children's hospital. The availability since 1983 of diagnostic assays less expensive than electron microscopy was associated with increased rotavirus detection. Only 67% of rotavirus-positive samples came from children likely to have had community-acquired acute gastroenteritis. Combined laboratory results and ICD-9 discharge diagnosis codes (008.6, 008.8, and 558.9) measured rotavirus activity better than either alone. A case definition for hospitalization for rotavirus infection resulted in an estimate that an average of 473 children were hospitalized for rotavirus infection at Texas Children's Hospital each year over the 10-year period. These cases accounted for 3.0% of all hospital days and $1.5 million per year in bed costs at this hospital. Hospitalization rates and the impact of hospital costs for the USA were estimated by extrapolation.     

Presence of two distinct types of rotavirus in infants and young children hospitalized with acute gastroenteritis in Mexico City, 1977.

Between December 1976 and January 1978, infection with rotavirus was detected by electron microscopy in 61 (25%) of 242 infants and young children hospitalized with acute gastroenteritis at two hospitals in Mexico City. This type of infection was more frequent in autumn than in winter. The presence of virus could also be detected by the electrophoretic pattern of its segmented, double-standed ribonucleic acid (RNA) in the stool samples taken from 52 (85%) of the 61 patients who were shown by electron microscopic examination to excrete rotavirus. Two distinct patterns, previously called 2s and 21, were observed, which were distinguishable by the relative migration of the second, 10th, and 11th viral RNA segments in gel electrophoresis; the 21 pattern was observed much more frequently than with the 2s pattern.     

Estimating hospital admissions due to rotavirus gastroenteritis from hospital episode statistics

OBJECTIVES: To determine the proportion of hospital admissions, in children < 5 years old, coded for intestinal infectious disease or non-infectious gastroenteritis, using ICD-10 codes, that were due to rotavirus infection. To assess how many children admitted with rotavirus gastroenteritis were given the specific ICD-10 code (A080) for this disease. METHODS: Sixteen-month prospective, observational study of children < 5 years old, admitted to district general hospital with: acute gastroenteritis (> or =3 loose stools/day), proven rotavirus infection and those coded as intestinal infectious disease or non-infectious gastroenteritis. RESULTS: Four hundred and twenty children < 5 years old were admitted with acute gastroenteritis. Rotavirus was detected in 170 children's stools. Acute rotavirus gastroenteritis accounted for 81/397 (20%) children coded as having non-infectious gastroenteritis and 32/81 (40%) coded for intestinal infectious disease. Only 18 children were coded for rotavirus gastroenteritis. Potentially preventable rotavirus gastroenteritis occurred in 122 children; 78 coded as non-infectious gastroenteritis (20%) and 26 coded for intestinal infectious disease (34%). CONCLUSIONS: The proportion of children coded with diarrhoeal diseases and found to have rotavirus is less than previously estimated. Using the specific code for rotavirus infection to estimate hospital admissions would be a gross underestimate. Hospital episode statistics cannot reliably estimate the burden of disease due to rotavirus.     

Rotavirus infection in children in Saudi Arabia.

Three hundred sixty-three fecal specimens were collected from infants and young children with gastroenteritis over a 13-month period in Jeddah, western Saudi Arabia. Rotavirus was detected in 46% of the 363 specimens tested using an enzyme-linked immunosorbent assay (ELISA), and in 40.7% of 113 specimens using a latex agglutination test. One hundred nine of the 113 specimens that were positive by the latex agglutination test were also positive by ELISA. Electron microscopy was used to examine some specimens to demonstrate the presence of the virus. Rotavirus was detected throughout the 13-month study period, with an increase in the frequency of infection in the cooler months. Infection with this virus was more frequent among infants and children less than two-years old, with a maximum incidence among children 13-15 months old. In the 363 stool specimens tested, rotavirus was found in mixed infections with bacteria in 0.44%, with parasites in 1.31%, and with yeast in 0.66%.     

Detection by immune electron microscopy of 26- to 27-nm viruslike particles associated with two family outbreaks of gastroenteritis.

Viruslike particles 26-27 nm in size were detected by immune electron microscopy in stools of volunteers who were ill after administration of bacteria-free fecal filtrates derived from two separate family outbreaks of acute epidemic nonbacterial gastroenteritis. Fluorocarbon treatment and concentration of the filtrates were necessary to provide enough antigen to test sera by immune electron microscopy. Serum antibody responses were detected in both naturally occurring and experimentally induced cases of illness. The Montgomery County viruslike particle appeared to be related to the previously described Norwalk particle, whereas the Hawaii particle appeared to be unrelated to the Norwalk particle.     

Detection by immune electron microscopy of 27-nm viral particles associated with community-acquired diarrhea in children

The proportion of diarrheal illnesses of unknown origin that were associated with small round virus (SRV, 23-38 nm) particles among children less than 2 years old attending an outpatient clinic in Baltimore was determined. During a 9-month period, stool specimens from 188 patients with acute diarrhea and 108 healthy age-matched control children were examined for enteric bacterial pathogens, protozoa, enteric adenovirus, and rotavirus. An enteropathogen was identified in 75 patients (40%) and in 21 controls (20%). A random sample of specimens without an identifiable pathogen was then examined for SRV particles by immune electron microscopy (IEM) using commercial human gamma globulin. Viruses of 26-30 nm diameter that were not enteroviruses were detected in specimens from 9 (12.5%) of the 72 patients and 1 (1.8%) of the 53 control subjects (P less than .04). Of 6 patients with available acute and convalescent sera, 4 demonstrated a significant immune response when tested by IEM. All patients experienced a mild, self-limited (1-3 days) illness. These findings suggest that SRV may be endemic in the Baltimore community and may result in clinically significant diarrheal illnesses.