[Underdiagnosed asthma in third-grade children]. / Sous-diagnostic de l'asthme chez les enfants en classe de CE2.

Undiagnosed asthma has been poorly studied before adolescence since it can go unnoticed by parents and doctors. Moreover, it is unusual to look for undiagnosed asthma by directly questioning children on the presence of current respiratory symptoms. Epidemiologic studies show that more adolescents quote symptoms suggestive of asthma than the prevalence of doctor-diagnosed asthma, but respiratory symptoms compatible with asthma remain undetected by parents of younger children more frequently than doctors diagnose asthma in their children. We attempted to evaluate the relevance of a questionnaire used since 2011 by school doctors in Paris to detect asthma. In this questionnaire, the family history of atopy and asthma were completed by the parents when they met the school doctor (last year of preschool) and questions on current respiratory symptoms were answered by third-grade children seen alone by the school doctor. One hundred and thirty-one children out of 1135 children questioned had a positive questionnaire for suspected asthma. In three-quarters of the cases, questionnaires were positive based on the children's answers on their respiratory symptoms (without a positive answer on personal or family history being necessary). The outcome of 41 children screened by the questionnaire was known. Twenty (49%) children had received a final diagnosis of asthma, of whom 12 were put on asthma controllers. Among these 20 children, two children underwent lung function testing and two others underwent tests for allergy. In eight children, tests had been requested by the child's GP, but no final diagnosis was reported by the parents. None of the 13 children in whom asthma was ruled out had any test performed. It was concluded that it is possible to detect undiagnosed asthma in children as young as 8 years by directly asking them about their respiratory symptoms. The knowledge of personal and family history can improve screening for asthma in these children. A more thorough evaluation of all children with a positive questionnaire is necessary to better understand the properties of the questionnaire. Finally, the best way to implement this screening program remains to be established (school health, GPs).

Impact of TT virus infection in acute and chronic, viral- and non viral-related liver diseases.

BACKGROUND/AIMS: The prevalence and pathogenicity of TT virus, recently identified in patients with non A-non G post-transfusional hepatitis, are questioned. METHODS: We investigated the impact of this new viral infection in a large series of patients with non A-non G, cryptogenic, non-viral and viral-related, acute and chronic liver diseases (n=577) and blood donors (n=300). TTV DNA was detected in serum by hemi-nested polymerase chain reaction. Phylogenetic analysis was performed in 13 isolates. RESULTS: TTV DNA was detected in 6/25 and 15/127 patients with cryptogenic non A-non G acute and chronic liver disease, respectively. TTV DNA positive subjects with post-transfusional acute hepatitis scored negative before transfusion. TTV prevalence was increased in patients with cryptogenic non A-non G acute and chronic liver disease compared to blood donors (6/300; p<0.001) and non-viral-related chronic liver diseases (6/137; p<0.05). TTV/HBV coinfection was frequently identified (35/147), but this was not the case for HCV-infected subjects (4/77). Transaminase activity or liver histological score was not significantly increased among TTV positive, HBV infected or non A-non G patients. The HBV infection and Mediterranean origin were the risk factors associated with TTV infection. The majority of analysed sequences clustered in genotype 1 (8=1b; 3=1a). Two isolates showed homology to genotype 2. CONCLUSIONS: These results support the view that TTV is a widely spread infectious agent with a weak pathogenicity. It raises the possibility, however, that TTV might be implicated in a few cases of acute and chronic non A-non G hepatitis. TTV-DNA-analysed sequences are related to genotypes 1 and 2 described in Europe.

Prevalence and genetic variants of hepatitis GB-C/HG and TT viruses in Gabon, equatorial Africa.

The distribution of Hepatitis GB-C/HG (GB-C/HG) and TT viruses (TTV) infections was investigated in selected populations from Gabon using Polymerase Chain Reaction (PCR) and Enzyme Linked Immunosorbent Assay (ELISA) for anti-Envelop 2 (anti-E2) GBV-C/HGV antibodies. Among pregnant women, 29 of 229 (12.6%) were Hepatitis GB virus-C and Hepatitis G virus (GBV-C/HGV) RNA positive (+) and 32 of 81 (39.5%) anti-E2 + versus 8 of 39 (20.5%) TTV DNA +. Among sickle cell anemia patients, 9.7% (3/31) were GBV-C/HGV RNA + versus 22.5% (7/31) TTV DNA +. For tuberculosis patients, the figures were 11.5% (4/35) and 0%. A study of hepatocellular carcinoma cases (n = 27) versus controls (n = 66) did not show significant differences for GBV-C/HGV RNA (10.7% versus 12.1%) and TTV DNA (44.4% versus 30.3%). According to phylogenetic analysis, the 15 GBV-C/HGV strains investigated clustered in group 1, the most common in sub-Saharan Africa whereas TTV sequences (n = 4) mostly clustered in genotypes G1 and one close to genotype G3. In the Gabonese populations investigated, GBV-C/HGV and TTV infections were highly endemic. These data are consistent with the low pathogenicity of these agents.

Absence of hepatitis C virus and detection of hepatitis G virus/GB virus C RNA sequences in the semen of infected men.

The identification of hepatitis C virus (HCV) in semen remains controversial and that of hepatitis G virus (HGV) or GB virus C (GBV-C) has never been investigated. Serum and semen from 90 anti-HCV-positive drug users were tested (27 infected with HIV) for HCV and HGV/GBV-C RNAs by polymerase chain reaction (PCR) assay, hybridization, and sequence analysis. Semen was processed into round cells, seminal plasma, and spermatozoa. Fifty-six patients were HCV-viremic, but HCV-RNA was not identified in their seminal fractions. However, PCR inhibitors were found in the semen of 34 of these men. Twenty-eight patients had HGV/GBV-C RNA in their blood and for 24 of them, ejaculates were available for analysis. HGV/GBV-C RNA was found in the seminal plasma of 6 of 12 samples free from PCR inhibitors. These results agree with the low risk of sexual transfer of HCV and provide preliminary evidence for the presence of HGV/GBV-C in semen.

Development of a simple restriction fragment length polymorphism (RFLP) based assay for HCV genotyping and comparative analysis with genotyping and serotyping tests.

The distribution between the different hepatitis C virus genotypes and subtypes has potentially important clinical and epidemiological implications. With this view a simple restriction fragment length polymorphism (RFLP) based assay was developed to identify the three major genotypes, 1, 2 and 3 and distinguish subtype 1a from 1b. This RFLP test uses a combination of three restriction endonuclease digestions, BstN1, BstU1 and Sau3a, respectively. Comparison with a 5'UTR based assay (LiPA), showed a 98% concordance with the RFLP based assay. In addition, good concordance is shown between these data and those obtained with a serological assay based on NS4 peptides.

Hepatitis C virus genotypes in French haemophiliacs: kinetics and reappraisal of mixed infections.

The distribution and kinetics of hepatitis C virus (HCV) genotypes and the prevalence of mixed infections were studied in a group of 45 French patients with haemophilia A or B or von Willebrand's disease, 21 of them being anti-human immunodeficiency virus (HIV) positive; genotyping was carried out by three methods based on the core, 5' untranslated region (5'UTR), and the detection of type-specific NS4 antibodies. Genotyping of the 5'UTR revealed genotypes 1a (n = 10), 1b (n = 13), 2a (n = 3), 2b (n = 4), 2NC (n = 3), 3a (n = 10), and two mixed infections (1a + 1b and 3a + 2). Five of 33 patients showed a change from one HCV genotype to another. The core genotyping assay showed 8 of 45 mixed infections: 6/8 1a + 1b and 2/8 3a + 2. Sequencing of core polymerase chain reaction (PCR) products showed that mixed infection 1a + 1b could be explained by nonspecific annealing of the 1b primer to type 1a sequence. By designing new primers whose sequence was more specific to HCV types 1a and 1b, we could confirm 1a + 1b mixed infection in only one of six cases. Serotyping assay showed for 17 of 21 anti-HIV negative patients a concordance with the 5'UTR genotype; however, only 6 of 19 anti-HIV positive patients showed detectable serological reactivity. In summary, we have observed a similar HCV genotype distribution between our haemophilic group and the French anti-HCV positive patients. The study demonstrates the difficulties of assessing with the presently available genotyping and serotyping assays the real prevalence of mixed infections in multiply transfused patients.

Transmission of hepatitis C virus in allografted patients: use of viral genotyping as an epidemiological marker.

One hundred and ninety-two allografted patients were tested for hepatitis C virus (HCV) RNA from 1992 to 1995 in Saint-Louis Hospital (Paris). They received blood products and intravenous immunoglobulins (IVIG) and more particularly Gammagard IVIG suspected of transmitting HCV (batches distributed in France between January 1993 and February 1994). The presence of serum HCV RNA was tested by polymerase chain reaction (PCR) in 86 patients who received Gammagard IVIG during the critical period and in 106 patients treated with IVIG other than the suspected batches of Gammagard (negative controls). HCV RNA positive sera were HCV genotyped. Ten out of 86 patients who received Gammagard IVIG during the exposed period vs 0 out of 106 negative controls were HCV RNA positive showing a higher prevalence of HCV infection in the exposed patients that in the negative controls (P = 0.001). The link between HCV transmission and IVIG infusion was reinforced by the high frequency of genotype 2b (70%) in the exposed patients because genotype 2b is an underrepresented subtype in France (< 1%).