Dengue is one of the most prevalent infectious tropical diseases in the world, with high incidence in over 100 countries. Rapid and reliable diagnosis of dengue is of great importance for public health. To simplify molecular diagnostics, isothermal amplification techniques have recently emerged as an alternative to conventional methods of deoxyribonucleic acid (DNA) amplification. Here, we developed a one-step method for dengue virus detection from real sample based on RT-LAMP (reverse transcription-loop mediated isothermal amplification) in a disposable microdevice. The reaction was thermally controlled with a thermoblock for 15 min at 72 ºC. At the end of the incubation time, we either removed the solution for detection of fragments by gel electrophoresis or added DNA intercalator for visual detection on-chip. Our results demonstrated that it is possible to detect dengue virus through RT-LAMP directly from a serum sample, without previous ribonucleic acid (RNA) extraction. The success of RT-LAMP was confirmed in reactions initiated with 0.8 fg µL-1 of RNA, which represents 200 copies of RNA per µL. RT-LAMP in a polyester-toner (PeT) microdevice is a simple and inexpensive method that allows for rapid detection of dengue virus with high reliability and great potential for point-of-care applications.

In an effort to detect West Nile virus (WNV) in Brazil, we sampled serum from horses and chickens from the Pantanal region of the state of Mato Grosso and tested for flavivirus-reactive antibodies by blocking ELISA. The positive samples were further confirmed for serological evidence of WNV infection in three (8%) of the 38 horses and one (3.2%) of the 31 chickens using an 80% plaque-reduction neutralisation test (PRNT80). These results provide evidence of the circulation of WNV in chickens and horses in Pantanal.

OBJETIVOS: Identificar e caracterizar os vírus respiratórios que acometeram crianças de creche que apresentavam sintomas de infecção respiratória e avaliar a associação dos dados clínicos e epidemiológicos da doença com os vírus identificados. MÉTODOS: O estudo foi realizado entre os anos de 2003 e 2005 com 176 crianças que apresentavam sintomas de infecção respiratória e frequentavam uma creche municipal. Amostras de secreção nasofaríngea foram testadas por meio da técnica de reação em cadeia da polimerase com transcrição reversa e as amostras positivas para picornavírus foram sequenciadas. RESULTADOS: Todas as 782 amostras coletadas foram analisadas, e 31,8% foram positivas para algum dos vírus respiratórios estudados. As infecções respiratórias foram caracterizadas pela presença de sintomas moderados do trato respiratório superior, sendo os mais comuns coriza e tosse. Em 2 anos de estudo, a maioria dos casos de infecção ocorreram no outono e no inverno, mas vírus respiratórios foram detectados ao longo de todo o período de estudo. CONCLUSÕES: Vírus respiratórios e as infecções respiratórias causadas por eles fazem parte do cotidiano de crianças que frequentam creches. Nossos resultados mostram o grande impacto gerado pelas infecções respiratórias nessas crianças e sugere que uma maior atenção deve ser dispensada aos patógenos virais.

OBJECTIVES: To identify and characterize respiratory viruses that infect children from daycare centers with symptoms of respiratory infection and to evaluate the association of clinical and epidemiological disease data with the identified virus. METHODS: We conducted a study between 2003 and 2005 in 176 children with respiratory infection symptoms attending a municipal daycare center. Samples from nasopharyngeal secretion were tested by reverse transcriptase polymerase chain reaction and positive samples for picornavirus were sequenced. RESULTS: All 782 collected samples were analyzed and 31.8% were positive for at least one of the studied respiratory viruses. Respiratory infections were characterized by the presence of mild symptoms of the upper respiratory tract, the most common of which were runny nose and cough. In the 2 years of study, most cases of infection occurred in autumn and winter, but respiratory viruses were detected throughout all the study period. CONCLUSIONS: Respiratory viruses and respiratory infections caused by them are part of the daily life of children attending daycare centers. Our results show the great impact that respiratory infections have on these children and suggest that more attention must be paid to viral pathogens.

As infecções herpéticas são complicações comuns em pacientes com AIDS. As manifestações clínicas podem ser incomuns e o tratamento antiviral é imperativo. Um método diagnóstico rápido pode previnir abordagens e tratamentos incorretos. A reação em cadeia da polimerase (PCR) é um método rápido, sensível e específico para a amplificação de DNA e para o diagnóstico de doenças infecciosas, especialmente as de etiologia viral. Esta abordagem tem vantagens quando comparada com os métodos convencionais de diagnóstico virológico. Recentemente nós relatamos um novo protocolo de PCR para o diagnóstico rápido de infecções herpéticas com supressão da etapa de extração de DNA. Neste trabalho nós apresentamos um caso de paroníquea herpética com diagnóstico através de PCR específico para Herpes Simplex tipo 1 usando o referido protocolo.

Herpetic infections are common complications in AIDS patients. The clinical features could be uncommon and antiviral chemotherapy is imperative. A rapid diagnosis could prevent incorrect approaches and treatment. The polymerase chain reaction is a rapid, specific and sensible method for DNA amplification and diagnosis of infectious diseases, especially viral diseases. This approach has some advantages compared with conventional diagnostic procedures. Recently we have reported a new PCR protocol to rapid diagnosis of herpetic infections with suppression of the DNA extraction step. In this paper we present a case of herpetic whitlow with rapid diagnosis by HSV-1 specific polymerase chain reaction using the referred protocol.