RESUMO
Respiratory infections positive for human respiratory syncytial virus (RSV) subtype A were characterised in children admitted to hospitals in Rome and Ancona (Italy) over the last three epidemic seasons. Different strains of the novel RSV-A genotype ON1, first identified in Ontario (Canada) in December 2010, were detected for the first time in Italy in the following 2011/12 epidemic season. They bear an insertion of 24 amino acids in the G glycoprotein as well as amino acid changes likely to change antigenicity. By early 2013, ON1 strains had spread so efficiently that they had nearly replaced other RSV-A strains. Notably, the RSV peak in the 2012/13 epidemic season occurred earlier and, compared with the previous two seasons, influenza-like illnesses diagnoses were more frequent in younger children; bronchiolitis cases had a less severe clinical course. Nonetheless, the ON1-associated intensive care unit admission rate was similar, if not greater, than that attributable to other RSV-A strains. Improving RSV surveillance would allow timely understanding of the epidemiological and clinicopathological features of the novel RSV-A genotype.
Assuntos
Epidemias , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Adolescente , Criança , Pré-Escolar , Feminino , Variação Genética , Genótipo , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Itália/epidemiologia , Masculino , Dados de Sequência Molecular , Filogenia , RNA Viral/química , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano/classificação , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/epidemiologia , Estações do Ano , Análise de Sequência de DNARESUMO
The aim of this study is to monitor type I interferon (IFN) activation in the cervical mucosa of Human Papillomavirus (HPV)-infected and uninfected women attending a routine gynaecologic clinic. The expression of three IFN-induced genes (MxA coding for human Mixovirus resistance protein A, ISG15 Interferon Stimulated Gene coding for a 15 kDa ubiquitin-like protein and UBP43 coding for the ISG15 isopeptidase) was determined as the mRNA copy number in cervical cells, normalized to the mRNA ones of the beta-glucuronidase gene. Type-specific HPV-DNA load was concurrently determined in the HPV-positive samples. Out of 127 samples tested, 54 were sufficient for both DNA and RNA extraction. The type-specific HPV-DNA copy numbers in the 34 HPV-positive samples varied widely. No significant association was found between copy numbers of MxA, ISG15, UBP43 and HPV status or viral load. However, despite a marked inter-individual variability, ISG15 expression was significantly higher when low-risk HPV infections were compared with HPV-negative samples, while high-risk HPV infections had very low ISG15 levels. The lack of ISG15 activation in high-risk HPV-infected cervical cells could be due to the lack of p53-mediated induction or to HPV-directed specific inhibition of type I IFN pathways. This study approach might be of value in clarifying the role of type I IFN activation in determining the clearance or persistence of HPV infections.
Assuntos
Colo do Útero/imunologia , Interferon Tipo I/fisiologia , Mucosa/imunologia , Infecções por Papillomavirus/imunologia , Adolescente , Adulto , Colo do Útero/virologia , Citocinas/genética , DNA Viral/análise , Endopeptidases/genética , Feminino , Proteínas de Ligação ao GTP/genética , Regulação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Mucosa/virologia , Proteínas de Resistência a Myxovirus , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/virologia , RNA Mensageiro/análise , Ubiquitina Tiolesterase , Ubiquitinas/genética , Carga ViralRESUMO
To evaluate the performance of different commercial assays for the detection of recent cytomegalovirus (CMV) in pregnancy, the sensitivity and specificity of assays for CMV-specific IgM antibodies were compared. Routine specimens from pregnant women were screened for CMV IgM using the Abbott AxSYM assay. Sera that were reactive according to AxSYM were further tested for IgM by other commercial assays. In selected IgM positive samples a CMV IgG avidity assay (Radim) and virus isolation from urine (shell vial) were also performed. The positivity rate for IgM anti-CMV by AxSYM was relatively high (140 out of 492, combining reactive and grayzone results). Only 26 of the 140 samples were positive for IgM according to Radim. The IgG avidity was low in 16 of the 43 samples tested, and the Radim and DiaSorin IgM assays were negative in 5 of them; 2 of the latter cases were also positive for viral isolation according to a shell vial method. There are differences in the sensitivity of the commercially available tests for CMV antibodies. CMV screening in pregnancy is performed as a first step by immunoassays and the choice of highly sensitive IgM test associated with further serological and virological methods could help to identify early primary infections.
