RESUMO
Infections with influenza virus type A and B present serious public health problems on a global scale. However, only influenza A virus has been reported to cause fatal pandemic in many species. To provide suitable clinical management and prevent further virus transmission, efficient and effective clinical diagnosis is essential. Therefore, we developed multiplex PCR assays for detecting influenza types A and B and the subtypes of influenza A virus (H1, H3 and H5). Upon performing multiplex PCR assays with type-specific primer sets, the clearly distinguishable products representing influenza A and B virus were separated by agarose gel electrophoresis. In addition, the subtypes of influenza A virus (H1, H3 and H5), which are most common in humans, can be readily distinguished by PCR with subtype-specific primer sets, yielding PCR products of different sizes depending on which subtype has been amplified. This method was tested on 46 influenza virus positive specimens of avian and mammalian (dog and human) origins collected between 2006 and 2008. The sensitivity of this method, tested against known concentrations of each type and subtype specific plasmid, was established to detect 10(3) copies/microl. The method's specificity was determined by testing against other subtypes of influenza A virus (H2, H4 and H6-H15) and respiratory pathogens commonly found in humans. None of them could be amplified, thus excluding cross reactivity. In conclusion, the multiplex PCR assays developed are advantageous as to rapidity, specificity, and cost effectiveness.
Assuntos
Vírus da Influenza A Subtipo H1N1/metabolismo , Vírus da Influenza A Subtipo H3N2/metabolismo , Virus da Influenza A Subtipo H5N1/metabolismo , Vírus da Influenza A/metabolismo , Vírus da Influenza B/metabolismo , Reação em Cadeia da Polimerase/métodos , Animais , Análise Custo-Benefício , Primers do DNA/química , Cães , Eletroforese em Gel de Ágar , Humanos , Influenza Humana/diagnóstico , Reação em Cadeia da Polimerase/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Swine have been known to be a suitable host for influenza A virus. In Thailand, phylogenetic analysis on swine influenza virus (SIV) has as yet not been attempted. The present report presents molecular and phylogenetic analysis performed on SIV in Thailand. In this study, 12 SIV isolates from the central and eastern part of Thailand were subtyped and the molecular genetics of hemagglutinin and neuraminidase were elucidated. Three subtypes, H1N1, H1N2 and H3N2, are described. Phylogenetic analysis of the SIV hemagglutinin and neuraminidase genes shows individual clusters with swine, human or avian influenza virus at various global locations. Furthermore, amino acid substitutions were detected either at the receptor binding site or the antigenic sites of the hemagglutinin gene.
Assuntos
Vírus da Influenza A/genética , Infecções por Orthomyxoviridae/virologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Genes Virais/genética , Hemaglutininas Virais/genética , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A/classificação , Dados de Sequência Molecular , Neuraminidase/genética , Filogenia , Alinhamento de Sequência , Suínos/virologia , Tailândia , Proteínas Virais/genéticaRESUMO
An 8-month-old girl presented with fever, rash, and diarrhea. Physical examination revealed multiple well-circumscribed, brownish-black, purpuric-like rashes on the face, arms, and legs with cervical and suboccipital lymphadenopathy. Laboratory findings showed mild anemia with thrombocytopenia and positive polymerase chain reaction for parvovirus 819 DNA in the serum. The patient recovered uneventfully with symptomatic and supportive treatment. Since the infection can manifest in many dermatological patterns, it should also be included in the differential diagnosis of febrile illness with purpuric rash in children.
Assuntos
Eritema Infeccioso/diagnóstico , Parvovirus B19 Humano , Feminino , Humanos , LactenteRESUMO
Anemia in HIV-infected patients is a common clinical manifestation. We report on a 31-year-old Thai male, who had been HIV positive for 6 years, did not harbor any opportunistic infection, and had been receiving Highly Active Anti Retroviral Therapy (HAART) for one month, and who developed severe anemia. Investigation revealed pure red cell aplasia, suspected secondary to parvovirus B19 infection. This diagnosis was confirmed by the detection of parvovirus B19 DNA in his serum. He received blood transfusions for supportive treatment and continued on HAART to improve his immune status and to resolve the anemia. This case suggests that parvovirus B19 infection should be considered as a possible cause of anemia in HIV-infected individuals.