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J O Arrobio

Publications and source records attributed to J O Arrobio.

10 recordsLinked to original sources

Common exposure outbreak of gastroenteritis due to type 2 rotavirus with high secondary attack rate within families.

A sharp outbreak of gastroenteritis associated with human rotavirus type 2 involved not only all of nine infants and young children in a playgroup but also seven of 10 parents and grandparents studied. The source of the outbreak appeared to be two non-playgroup siblings. Six of 11 individuals studied shed human rotavirus type 2, and each of seven from whom paired sera were obtained developed a type 2 sero-response. Overall, evidence of infection with rotavirus type 2 was demonstrated in 10 of 11 individuals by detection of virus in stools and/or a serologic response in an enzyme-linked immunosorbent assay.

Antibodies, Viral

Influenza A and B virus infection in infants and young children during the years 1957-1976.

Influenza A virus activity was demonstrated in infants and young children from metropolitan Washington, DC during each of 19 successive August-July respiratory disease years, and during 17 of these years at least 2% of hospitalized respiratory disease patients yielded an influenza A or B virus and/or showed an influenza A or B serum complement-fixing (CF) antibody response. Between October 1957 and July 1976, 14.3% of 860 croup patients and 5.3% of a total of 5655 hospitalized respiratory patients, including croup patients, showed evidence of influenza A or B infection. The mean period of hospitalization with either virus was about 8 days, though serious infection with influenza A virus was 4.5 times more common than with influenza B virus. Both influenza viruses were detected more frequently in respiratory disease outpatients than in respiratory disease inpatients. Patients with serious influenza A virus infections were especially likely to have croup (particularly during the H3N2 era), to be seen during December through February, and to be black male infants. During the peak month of a composite of 13 consecutive influenza A virus outbreaks, influenza A virus infection was demonstrated in 67.6% of croup patients and in 35.6% of all hospitalized respiratory patients including croup patients. During the peak month of a composite of 6 consecutive influenza B virus outbreaks, influenza B virus infection was demonstrated in 36.0% of croup patients and in 10.8% of all hospitalized respiratory disease patients including croup patients.

Antibodies, Viral

Comparative epidemiology of two rotavirus serotypes and other viral agents associated with pediatric gastroenteritis.

Human rotavirus (HRV) type 1 or 2, adenovirus, or non-cultivatable 27 nm virus-like particles were demonstrated by electron microscopy and/or rotavirus ELISA in fecal samples from 45.5% of 604 gastroenteritis inpatients, 25.0% of 200 gastroenteritis outpatients and 6.0% of 812 control subjects, all sampled at Children's Hospital National Medical Center. Washington, DC. Rotaviruses were the most common pathogens detected as 39% and 22% of gastroenteritis inpatients and outpatients, respectively, shed HRV. About three-fourths of the rotaviruses were type 2, which was prevalent during five successive epidemic years from January, 1974, through June, 1978. HRV type 1 was detected in the last four successive epidemic years and represented nearly half of the HRV infections observed among gastroenteritis inpatients during the year 1977--1978. Both rotavirus serotypes were detected most often in the month of January, when 71% of 123 gastroenteritis inpatients and 62% of 34 gastroenteritis outpatients shed one of these viruses. Uncultivatable adenoviruses were detected significantly more frequently in stools from patients with gastroenteritis (3.9%) than from control subjects (0.6%), suggesting that these viruses played a role in acute enteric disease. The frequency of detection of 27 nm particles was not significantly different in gastroenteritis and control patients. Numerically, HRV infection was detected most often in gastroenteritis inpatients who were 10 through 12 months of age. The group of gastroenteritis inpatients with the highest percentage of HRV infection was 13 through 15 months of age. The excess of type 2 HRV infection relative to type 1 infection was especially large in those aged 7 through 24 months. Lower socioeconomic status or greater crowding appeared to be associated with the occurrence of rotavirus infection earlier in life and earlier in the epidemic year.

Adenoviridae

Human reovirus-like agent infection. Occurrence in adult contacts of pediatric patients with gastroenteritis.

Sixty-four adult family contacts of 61 young patients with gastroenteritis were included in a study for evidence of concurrent infection with the human reovirus-like agent (HRVLA) of infantile diarrhea. Evidence of infection was detected in 26 (41%) of the adult contacts. The HRVLA infection occurred significantly more often among adult contacts of pediatric patients infected with HRVLA (55%) than among contacts of young patients not infected with the agent (17%). Mild cases of gastroenteritis developed in only three of the contacts infected with HRVLA.

Adolescent

Clinical features of acute gastroenteritis associated with human reovirus-like agent in infants and young children.

Between January, 1974, and June, 1975, infection with a human reovirus-like agent was detected in 47% of 152 infants and children hospitalized with acute gastroenteritis. Certain epidemiologic, clinical, and laboratory findings appear to be helpful in distinguishing gastroenteritis due to HRVLA from other causes in those children sick enough to require hospitalization. Age: 76% of infants and children seven through 12 months of age and 76% of those 13 through 24 months of age had infection with the HRVLA, whereas such infection was found in only 21% of infants under six months of age and 23% of children 25 through 60 months of age. Time of Year: 61% of patients studied during the cooler months had HRVLA infection and such infection was not found from June to October. Frequency of vomiting and dehydration: Twice as many patients infected with HRVLA as those who were not had vomiting (92%) and significant dehydration (83%).

Acute Disease

Safety and antigenicity of inactivated influenza virus vaccines in children: trials with monovalent and bivalent A/New Jersey/76 (HswN1) and A/Victoria/75 virus vaccines in Washington, D.C..

Safety and antigenicity of monovalent and bivalent A/New Jersey/NJ)/76 (HssN1) and A/Victoria/75 inactivated influenza virus vaccines were studied in 125 children aged three to 18 years. In recruitment, families who knew the study team, who were professionally involved, and/or who were under close continuing care were more likely to volunteer for such studies than those who were unfamiliar with the team or institution. Antibody responses and systemic reactions occurred more often after administration of inactivated whole-virus vaccine than after split-virus vaccine. Significant titers (greater than or equal to 1:40) of hemagglutination-inhibiting antibody to A/NJ/76 virus occurred in 95% of normal children three to 18 years of age who received two doses of the same vaccine (whole or split). However, insufficient numbers of children achieved a reasonable antibody titer (greater than or equal to 1:40) after one dose of vaccine.

Adolescent

Human reovirus-like agent as the major pathogen associated with "winter" gastroenteritis in hospitalized infants and young children.

We found a human reovirus-like agent in the stools of 42 per cent of 143 infants and young children hospitalized with acute gastroenteritis between January, 1974, and June, 1975. Half the patients studied by electron microscopy and serologic technics had evidence of infection with the agent. The infection had a seasonal pattern: 59 per cent of those admitted during the cooler months (November to April) shed the agent, with a peak of 78 per cent in December, 1974, and January, 1975, combined. None of the patients admitted during the warmer months (May to October) shed the agent. None of 275 Escherichia coli isolates from 32 patients with diarrhea produced heat-labile enterotoxin, whereas 17 of the 32 had evidence of infection with the reovirus-like agent. In addition, 14 of 40 parents of 37 patients with diarrhea associated with the reovirus-like agent were also infected, but most infectious were inapparent. This agent appears to be the major cause of diarrheal illness in the young during the cooler months.

Acute Disease

Recent advances in the aetiology of viral gastroenteritis.

Studies with the human reovirus-like (HRVL) agnet, also designated rotavirus and duovirus, have revealed that it is a major aetiological agent of diarrhoea of infants and young children in many parts of the world. In a study of patients admitted with a diarrhoeal illness to the Children's Hospital of the District of Columbia in the United States from January 1974 to June 1975, it was found that half of the patients studied by both virus shedding (by electron microscopy) and serological (complement-fixation) techniques demonstrated evidence of infection with the HRVL agent. The temporal distribution of infections with the HRVL agent followed a seasonal pattern with this agent being shed exclusively by patients admitted during the cooler months of the year. Electron microscopic examination of stools was as efficient as serological methods for detecting infection with the HRVL agent. We also initiated studies to determine the possible mode of transmission of the HRVL agent by studying contacts of hospitalized patients. We found that 35% parents of patients with HRVL infections were also infected with the HRVL agent. Serological studies revealed that the HRVL agent was antigenically related to the Nebraska Calf Diarrhoea Virus, the epizootic diarrhoea of infant mice virus, the SA-11 virus, and the "O" agent.

Animals

Temperature-sensitive mutants of influenza A virus: response of children to the influenza A/Hong Kong/68-ts-1(E) (H3N2) and influenza A/Udorn/72-ts-1(E) (H3N2) candidate vaccine viruses and significance of immunity to neuraminidase antigen.

One of two slightly different influenza A/ts-1[E] recombinant candidate live vaccines was given intranasally to each of 23 young children. Twelve of 15 children who had no serum HI antibody but who did have serum ANAB at the time of administration became infected and 1 had mild rhinitis. All eight who lacked both types of antibody became infected and they shed virus in higher titer and for longer than the former group; five had rhinorrhea and five had mild fever. These findings suggest that serum ANAB plays a part in modulating influenza virus infection and that the full expression of virulence of these or other attenuated influenza vaccines may be manifest only in individuals lacking both HI antibody and ANAB. These particular candidate vaccine strains appear to be attenuated for older children (who have some prior experience with influenza A as demonstrated by serum ANAB), but the occurrence of fever in over half who had no prior experience indicates that they would not be acceptable for a vaccine in wide-spread use.

Antibodies, Viral