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S Grinstein

Publications and source records attributed to S Grinstein.

371 records · Page 21Linked to original sources
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[Rotavirus laboratory network: results after one year of observation].

Rotavirus is the most common cause of severe diarrhea in children and it has been estimated that in Argentina Rotavirus is responsible for 21,000 hospitalizations, 85,000 medical attentions and an annual medical cost of US$ 27 millions. Given that a Rotavirus vaccine is about to be approved, a laboratory network based surveillance system was organized. Herein, we present the results after one year of study. Severe diarrhea was responsible for 9% of pediatric hospitalizations and rotavirus was detected in 42.1% of the diarrhea cases. We estimated that Rotavirus causes 3.8% of pediatric hospitalizations. The number of diarrhea and Rotavirus diarrhea hospitalizations was greater during the first year of life (62% and 71.3%, respectively). The number of diarrhea hospitalizations during the December-May semester was significantly higher than the rest of the year. A Rotavirus diarrhea peak was detected between April and June. These results indicate that Rotavirus is the most important etiological agent of severe diarrhea in Argentine children and show the importance of performing Rotavirus diagnosis in every pediatric hospital. The additional costs will be compensated by many benefits such as better use of antibiotics, improved nosocomial spread control, better handling of hospital beds and of laboratory resources and of the hospitalized patient.

Argentina↗
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[Evaluation of an ELISA technique for detection of antigens and circulating immune complexes of Trypanosoma cruzi by a field study in an endemic zone of Argentina].

The ELISA technique for detection of T. cruzi circulating antigens (cAg) and immune complexes (CIC) in the sera of chronic chagasic patients was field-tested in a well-known endemic area of Argentina (San Luis province). Of 215 individuals screened, 51 were positive for ELISA-CIC and 45 for ELISA-cAg. Seventy four subjects were considered por T. cruzi-infected, as they showed serologic reactivity at least by two different techniques. In this group, 49 (66.21%) were ELISA-CIC positive, whereas in 43 (58.11%) of them cAg was found by ELISA. Unspecific reactions were observed in only 2 cases with reactive serology for Chagas disease. Within the group considered as noninfected, a false-positive outcome was obtained at low dilution by one of the serologic tests in 16 (11.35%) of 141 individuals. These sera yielded consistently negative results by ELISA-CIC and cAg, showing the utility of antigen detection in situations of conflictive serology. While antibody determination merely provides an indirect proof of infection, our ELISA tests for demonstration of T. cruzi-specific antigenic fractions in the host's circulation allow a parasitologic diagnosis in chronic patients, with higher sensitivity than that exhibited by traditional methods for detection of the whole parasite.

Adolescent↗
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[Seroepidemiology of human rotaviruses in a community of the Avellaneda district, Province of Buenos Aires].

The results obtained during a prospective study performed in 49 families of the Avellaneda District, Buenos Aires Province, in order to known the seroepidemiology of human rotaviruses under natural conditions were described. Families which included a pregnant woman, were voluntarily recruited. The newborn was studied together with its family until two years of age, in order to assess the moment of the primary rotavirus infection. Feces from every person with gastrointestinal symptoms were obtained for rotavirus diagnosis. Blood samples from every member of the family were obtained since their recruitment and each 6 months until the newborn reached two years of age. Rotavirus infections were established by determining the amount of circulating rotavirus IgG antibodies in paired serum samples using ELISA. In all, 502.2 six-month periods with paired serum samples were studied. Most of the infections detected during the first year of life were primary infections (0.64 cases per child-year; 91.3% in seronegative children; p less than 0.005). The peaks of rotavirus diarrhea incidence were observed at the same age (0.25 cases per child-year; p less than 0.01). It must be stated that 51.9% of the newborns presented circulating anti-rotavirus IgG antibodies transmitted by the mother; 72% were breastfed for a mean period of 9.7 months. The total incidence of rotavirus infections was 0.63 cases per person-year, without significant variations for each age group. Most of them were asymptomatic cases and 61.6% were reinfections. These results show the high endemicity of human rotavirus in our population where siblings and adults act as reservoirs of the infection. Finally we found a significant relation between the level of circulating anti-rotavirus antibodies and the resistance to infection and illness caused by rotavirus during the six-month periods studied with paired serum samples (p less than 0.005 for infection; p less than 0.03 for diarrhea). The incidence of rotavirus infection did not seem to be statistically different among all the age groups. As we found a high incidence of reinfections and we were able to determine the total decrease in the level of serum anti-rotavirus IgG antibodies in 5% of the infections one year after the seroconversion was detected, we postulate a short duration of high antibody levels and protection associated with circulating anti-rotavirus antibodies.

Adult↗
PubMedDate not supplied

[Counterimmunoelectrophoresis in the diagnosis of Bordetella pertussis].

The serum of 50 patients between 25 days to 15 years old who were admitted with the diagnosis of pertussis syndrome were investigated for precipitating antibodies by means of discontinuous counterimmunolectrophoresis (CIED). The presence of antibodies for Bordetella pertussis antigen was shown in 28 cases. All samples were taken within the first 24/48 hours of admission and at convalescence. The technique is easy to carry out, quick and of low cost. This test offers an adequate and fast means to differentiate a Bordetella pertussis syndrome form others produced by different viral etiologies. Besides, this serologic technique shows earlier results and of lower cost than classic techniques such as agglutination and complement fixation which are more difficult to apply.

Adolescent↗