Measles Outbreak in Pediatric Hematology and Oncology Patients in Shanghai, 2015 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Despite substantial progress toward measles control are making in China, measles outbreaks in immunocompromised population still pose a challenge to interrupt endemic transmission. This study aimed to investigate the features of measles in pediatric hematology and oncology patients and explore the reasons behind the outbreak.</p><p><b>METHODS</b>We collected demographic, epidemiological, and clinical data of immunocompromised measles children. All suspected measles cases were laboratory-confirmed based on the presence of measles IgM and/or identification of measles RNA. The clinical data were statistically analyzed by t-test for continuous variables and Fisher's exact test for categorical variables.</p><p><b>RESULTS</b>From March 9 to July 25 in 2015, a total of 23 children with malignancies and post hematopoietic stem cell transplantation (post-HSCT) were notified to develop measles in Shanghai. Of these 23 patients with the median age of 5.5 years (range: 11 months-14 years), 20 (87.0%) had received 1-3 doses of measles vaccine previously; all patients had fever with the median fever duration of 8 days; 21 (91.3%) had cough; 18 (78.3%) had rash; 13 (56.5%) had Koplik's spot; 13 (56.5%) had complications including pneumonia and acute liver failure; and five (21.7%) vaccinated patients died from severe pneumonia or acute liver failure. Except the first patient, all patients had hospital visits within 7-21 days before measles onset and 20 patients were likely to be exposed to each other.</p><p><b>CONCLUSIONS</b>The outcome of measles outbreak in previously vaccinated oncology and post-HSCT pediatric patients during chemotherapy and immunosuppressant medication was severe. Complete loss of protective immunity induced by measles vaccine during chemotherapy was the potential reason. Improved infection control practice was critical for the prevention of measles in malignancy patients and transplant recipients.</p>

Clinical characteristics and molecular epidemiology of the novel influenza A (H1N1) infection in children in Shanghai / 中华儿科杂志

<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>