Biomedical subjects

A Sánchez-Fauquier

Publications and source records attributed to A Sánchez-Fauquier.

9 recordsLinked to original sources

PubMed2004

[Nosocomial gastroenteritis and asymptomatic rotavirus and astrovirus infection in hospitalized children].

BACKGROUND: Nosocomial gastroenteritis is frequent in pediatric hospital wards. Between 20% and 50% of gastroenteritis cases caused by rotavirus and astrovirus are of nosocomial origin. OBJECTIVE: To determine the incidence of nosocomial rotavirus and astrovirus gastroenteritis in our environment, the incidence of asymptomatic infection with these viruses, and to identify the G serotypes of the rotaviruses detected. METHODS: We performed a prospective study of all children under 2 years of age admitted to a neonatology unit over a 1-year period who were followed-up for the presence of diarrhea and periodic study of feces to detect the presence of rotavirus and astrovirus antigens by enzyme immunoassay (EIA). Patients with gastroenteritis also underwent bacteria stool culture, adenovirus detection by EIA, calcivirus detection by polymerase chain reaction, and analysis of rotavirus G serotypes by EIA with monoclonal antibodies. RESULTS: Of 666 children admitted without diarrhea, 60 presented nosocomial gastroenteritis (9 % of patients admitted and 1.75 per 100 days of hospital stay): 34 presented rotavirus (5 % of patients) and two presented astrovirus (0.3 % of patients). Of the 329 patients without diarrhea who were studied, viral elimination was detected in 27: rotavirus in 23 patients and astrovirus in four. Viral infection was detected on admission in 13 patients (4 %) and after 72 hours in 14 patients (4.2 %) (asymptomatic nosocomial infection). No differences in the distribution of rotavirus G serotypes were observed between community-acquired and nosocomial gastroenteritis. CONCLUSIONS: These data confirm the importance of viral etiology in nosocomial gastroenteritis and allow us to evaluate asymptomatic fecal elimination of rotavirus as one of the factors in the transmission of this infection.

Algorithms↗

PubMed2003

First detection of group C rotavirus in children with acute diarrhea in Spain.

Group C rotavirus causes sporadic cases and outbreaks of acute diarrhea in children and adults in many countries, but has never been detected among children in Spain. In a recently conducted surveillance study to screen fecal specimens for bacteria and viruses from a cohort of 822 young children who were treated for acute diarrhea in Madrid, no pathogens were detected in fecal specimens from 238 (29%) children. In this study, we examined 147 of those specimens for group C rotavirus by EIA and PCR and found 22 (15%) were positive. Our findings demonstrate that group C rotavirus is an important cause of childhood diarrhea in Spain.

Child↗

PubMed2003

Viruses causing gastroenteritis.

Acute gastroenteritis is one of the most common diseases in humans worldwide. Viruses are recognized as important causes of this disease, particularly in children. Since the Norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. Rotavirus is the most common cause of severe diarrhea in children under 5 years of age. Astrovirus, calicivirus and enteric adenovirus are also important etiologic agents of acute gastroenteritis. Other viruses, such as toroviruses, coronaviruses, picobirnaviruses and pestiviruses, are increasingly being identified as causative agents of diarrhea. In recent years, the availability of diagnostic tests, mainly immunoassays or molecular biology techniques, has increased our understanding of this group of viruses. The future development of a safe and highly effective vaccine against rotavirus could prevent, at least, cases of severe diarrhea and reduce mortality from this disease.

Acute Disease↗

PubMed2002

Molecular detection of human calicivirus among Spanish children with acute gastroenteritis.

A survey was conducted among Spanish children with gastroenteritis treated in an emergency room. Reverse transcription-PCR with specimens negative for other enteric pathogens was used. The minimum incidence of human calicivirus infection was 7.7%, with Lordsdale as the predominant genotype. The clinical features and severity of calicivirus and rotavirus were similar.

Acute Disease↗

PubMed2001

New immunochromatographic method for rapid detection of rotaviruses in stool samples compared with standard enzyme immunoassay and latex agglutination techniques.

Three different commercial immunologic tests for rapid detection of group A rotavirus (an immunochromatographic method, latex agglutination, and enzyme immunoassay) were used to evaluate 228 faecal specimens obtained from Spanish children with acute gastroenteritis. After resolution of 30 (13.2%) discordant results by reverse transcription-polymerase chain reaction for rotavirus, the statistical values of the enzyme immunoassay, latex agglutination, and immunochromatographic method were respectively 96%, 68%, and 99% for sensitivity; 99%, 99%, and 96% for specificity; 98%, 96%, and 92% for positive predictive value; and 98%, 88%, and 99% for negative predictive value. The immunochromatographic technique showed high sensitivity and specificity and was rapid and easy to perform in the routine clinical laboratory.

Child, Preschool↗

PubMed1999

[The molecular epidemiology of the rotavirus in Spanish children. The Rotavirus Study Group (GER)].

BACKGROUND: Rotavirus are the most common etiologic agent of acute gastroenteritis in childhood. The knowledge of the circulating antigenic types is important in development of future vacunes. METHODS: Faeces from children (age < 4 years) with acute gastroenteritis admitted in the two hospitals (Hospital Severo Ochoa-Madrid and Hospital General Vic-Barcelona) have been studied prospectively during one year (October-1996 to October-1997). The detection of rotavirus was performed by ELISA (IDEIA, Dako). All samples were G-serotyping by EIA-Mabs (Silenius Laboratories) and the indeterminate or non-serotypable samples were G-genotyping by RT-PCR. P genotypes were identified by RT-PCR. RESULTS: 322 (45%) patients with acute diarrhoea causing for rotavirus were confirmed, 242 coming from the Madrid metropolitan area and other 80 from the Barcelona area. The EIA-Mabs technique made it possible to identify the G serotypes in 287 cases (89%), corresponding 207 to G1 serotype, 70 to G4 serotype and 6 to G3 serotype. In 4 patients both G1 and G4 serotypes were detected. The EIA-Mabs could not determined the serotype in 35 (11%) patients, all of whom were confirmed by RT-PCR (12 belonged to serotype G1 and 23 to serotype G4). Analysis of P genotypes was carried out in 25 patients obtained from Madrid and 17 from Barcelona; all cases were classified in the P[8] genotype. CONCLUSIONS: The most frequent serotype in both hospitals was G1. The EIA-Mabs technique were showed a high sensitivity, however, the RT-PCR technique used were even more efficient, making it possible for us to identify all the non-serotypable EIA-Mabs cases. The temporal study of circulating serotypes/genotypes of rotavirus is necessary to evaluate the efficiency of vaccines.

Acute Disease↗

PubMed1995

Ultrastructure of human astrovirus serotype 2.

The ultrastructure of human astrovirus serotype 2 (H-Ast2) grown in cell culture was analysed by electron microscopy of thin sections and negatively stained preparation. Infected LLCMK2 cells, as visualized in thin sections, contained cytoplasmic aggregates of dense or hollow-cored particles that aggregated in quasicrystalline arrays and were specifically labelled using a rabbit polyclonal anti-Ast2 antiserum. H-Ast2 particles from the supernatant of infected LLCMK2 cells in thin sections after flat- embedding were similar in size to intracellular virions. In negatively stained preparations, these virus particles had an external diameter of 41 nm and exhibited a well defined layer of surface spikes. Pentagonal and hexagonal contours were occasionally visible, and probably correspond to the projections of icosahedral structures. Star-like morphologies and particles with surface triangular hollows were seen in dark areas of the preparations only after a short treatment of the viruses of pH 10. Incubation of the viruses at pH 10.5 induced a rapid disassembly of the virus particles. The finding that the particles with icosahedral geometry and surface spikes are fully infective allows an alternative morphological model to the traditional one for astroviruses to be proposed.

Cell Line↗

PubMed1995

Type- and subtype-specific detection of influenza viruses in clinical specimens by rapid culture assay.

A rapid culture assay which allows for the simultaneous typing and subtyping of currently circulating influenza A(H1N1), A(H3N2), and B viruses in clinical specimens was developed. Pools of monoclonal antibodies (MAbs) against influenza A and B viruses and MAbs HA1-71 and HA2-76, obtained by immunizing mice with the denatured hemagglutinin subfragments HA1 and HA2 of influenza virus A/Victoria/3/75, were used for immunoperoxidase staining of antigens in infected MDCK cells. MAb HA1-71 reacted exclusively with influenza A viruses of the H3 subtype, while MAb HA2-76 reacted with subtypes H1, H3, H4, H6, H8, H9, H10, H11, and H12, as determined with 78 human, 4 swine, and 10 avian influenza virus reference strains subtyped by the hemagglutination inhibition test. To determine if the technique can be used as a rapid diagnostic test, 263 known influenza virus-positive frozen nasal or throat swabs were inoculated into MDCK cells. After an overnight incubation, the cells were fixed and viral antigens were detected by immunoperoxidase staining. Influenza A viruses of the H1 and H3 subtypes were detected in 31 and 113 specimens, respectively. The subtypes of 10 influenza A virus-positive specimens could not be determined because they contained too little virus. Influenza B viruses were detected in 84 specimens, and 25 specimens were negative. We conclude that this assay is a rapid, convenient, non-labor-intensive, and relatively inexpensive test for detecting, typing, and subtyping influenza viruses in clinical specimens.

Animals↗

PubMed1987

Isolation of cross-reactive, subtype-specific monoclonal antibodies against influenza virus HA1 and HA2 hemagglutinin subunits.

The large (HA1) and small (HA2) subunits of influenza virus A/Vict/3/75 hemagglutinin were purified in denatured form by preparative electrophoresis. Both polypeptides were used to immunize mice from which monoclonal antibodies were obtained. These antibodies reacted not only with the corresponding hemagglutinin subunit but also with purified virions. When tested by radioimmunoassay against a panel of human viruses, most anti-HA1 and -HA2 antibodies behaved as subtype-specific, whereas anti-HA antibodies, raised against purified virus, were more restricted. The anti-subunit antibodies were negative in hemagglutination-inhibition and neutralization tests. The interest of these antibodies as reagents for research and diagnosis is discussed.

Animals↗