ABSTRACT
<p><b>OBJECTIVE</b>To investigate the epidemiological features, genetic drift in the epitopes of hemagglutinin (HA) of the novel influenza A (H1N1) virus and oseltamivir-resistant variants characterized by H275Y and N295S mutations in children in Shanghai since the outbreak.</p><p><b>METHOD</b>Between June 2009 and May 2012, a prospective surveillance study was carried out in Shanghainese children who attended the outpatient clinic of Children's Hospital of Fudan University for influenza-like illness. One-step real-time fluorescence quantitative RT-PCR was performed to detect seasonal influenza A and influenza B virus and the novel influenza A (H1N1) virus in the respiratory samples. Genetic drift from the vaccine strain in HA epitopes of the novel influenza H1N1 virus and the molecular markers associated with oseltamivir resistance in neuraminidase (NA) were analyzed.</p><p><b>RESULT</b>Out of 3475 enrolled cases, the novel influenza A (H1N1) virus was confirmed virologically in 222 (6.4%) otherwise healthy children with 133 (59.9%) being boys and 89 (40.1%) girls. The median ages of children with the novel influenza A (H1N1) virus infection during the first wave from August 2009 to February 2010 and the second wave from December 2010 to February 2011 were 53.5 months and 32.0 months, respectively (Z = -4.601, P = 0.000); 119 (46.9%) had the close contact with persons suffering from fever or respiratory infection, of whom, 68 (57.1%) contacts were family members and 47 (39.5%) contacts were classmates. During the outbreak in 2009-2010 season, 66 (40.9%) were exposed to primary index cases, school students were the major exposure subjects, accounting for 50.0%. The nucleotide sequences of HA1 gene were highly homologous between the vaccine strain A/California/07/2009 and Shanghai circulating novel influenza A (H1N1) strains and only S83P mutation in epitope E of HA was detected inclusively in the circulating strains. The H275Y and N295S amino acid mutations associated with oseltamivir resistance were not found in the circulating novel influenza (H1N1) strains.</p><p><b>CONCLUSION</b>Two major waves of the novel influenza A (H1N1) outbreaks occurred in Shanghainese children during 2009-2011. Institutional children were the major affected individuals during the 2009 pandemic wave. Households and schools were the main sites of transmission among children during influenza pandemic. Influenza vaccination should be enhanced in children and their close family contacts. The novel influenza A (H1N1) virus in Shanghai has not undergone significant genetic changes. Oseltamivir is effective for the treatment of the novel influenza A (H1N1) virus.</p>
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Amino Acid Sequence , Antiviral Agents , Pharmacology , China , Epidemiology , Drug Resistance, Viral , Hemagglutinins, Viral , Genetics , Influenza A Virus, H1N1 Subtype , Classification , Genetics , Influenza, Human , Drug Therapy , Epidemiology , Pathology , Virology , Molecular Epidemiology , Molecular Sequence Data , Neuraminidase , Genetics , Oseltamivir , Pharmacology , Pandemics , Viral Vaccines , Genetics , Allergy and ImmunologyABSTRACT
<p><b>OBJECTIVE</b>To study the clinical features of children with 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency and review the literature.</p><p><b>METHOD</b>Clinical features and treatment of one Chinese infant with 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency confirmed by HSD3B7 gene mutation analysis were retrospectively reviewed, and 51 cases of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency who were internationally reported since 2000 were also reviewed in this paper.</p><p><b>RESULT</b>(1) A 3-month-old infant with neonatal cholestasis was admitted to our hospital because of hyperbilirubinemia and abnormal liver dysfunction (total bilirubin 110.7 µmol/L, direct bilirubin 74.5 µmol/L, γ-glutamyltransferase 24.4 IU/L, total bile acid 0.1 µmol/L).His jaundice disappeared within a few weeks, serum liver biochemistries improved and his growth in weight and height was excellent after oral cholic acid therapy.HSD3B7 gene analysis using peripheral lymphocyte genomic DNA from the patient identified compound heterozygous mutations. This child was confirmed as the most common inborn error of bile acid metabolism-3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency by molecular analysis.(2) Retrospective review of the literature showed that the clinical features of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency included neonatal cholestasis, some patients progressed to severe liver disease and needed liver transplantation without effective therapy; however, serum biochemical characteristics of normal γ-glutamyltransferase activity, normal or low total bile acid concentrations were not consistent with cholestasis, the replacement treatment with cholic acid produced a dramatic improvements in symptoms, biochemical markers of liver injury; 31 cases were diagnosed by HSD3B7 gene mutation analysis.</p><p><b>CONCLUSION</b>The clinical characteristics of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency include neonatal cholestasis, normal serum γ-glutamyltransferase activity, and normal or low serum total bile acid concentration.Oral cholic acid replacement is an effective therapy; definitive diagnosis of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency can be identified by molecular genetic testing technology.</p>