Detection of human herpesvirus 6 and 7 DNA in saliva from healthy adults from Rio de Janeiro, Brazil

In this study, we aimed to evaluate virus shedding in the saliva of healthy adults from the metropolitan region of the city of Rio de Janeiro, Brazil, in order to verify the prevalence of both human herpesviruses 6 and 7 (HHV-6, HHV-7). The studied group comprised 182 healthy individuals at Pedro Ernesto University Hospital, who were being seen for annual odontologic revisions. Saliva specimens were subjected to a multiplex polymerase chain reaction (PCR) to detect the presence of HHV-6A, HHV-6B and HHV-7. The total Roseolovirus DNA prevalence was 22.4 percent. The PCR detected a HHV-6 prevalence of 9.8 percent, with HHV-6A detected in 7.1 percent of the samples and HHV-6B in 2.7 percent. HHV-7 DNA was revealed in 12.6 percent of the studied cases. Multiple infections caused by HHV-6A and 7 were found in 2.1 percent of the samples. No statistical differences were observed regarding age, but for HHV-7 infection, an upward trend was observed in female patients. Compared to studies from other countries, low prevalence rates of herpesvirus DNA were detected in saliva from the healthy individuals in our sample. PCR methodology thus proved to be a useful tool for Roseolovirus detection and it is important to consider possible geographic and populations differences that could explain the comparatively low prevalence rates described here.

Comparação de dois pares de oligonucleotídeos utilizados na reação em cadeia da polimerase para detecção de Papilomavírus Humanos em esfregaços cervicais / Comparison of two pairs of primers used in polymerase chain reaction for the detection of Hunan Papillomaviruses in cervical smears

Introdução: o câncer de colo de útero é a neoplasia mais frequente em mulheres de países em desenvolvimento. Grande parte desses casos é causada por infecção persistente com diferentes tipos de papilomavírus humano (HPV) classificados em alto e baixo risco de acordo com o potencial oncogênico. Atualmente, acredita-se que a melhor rotina de identificação e acompanhamento das lesões por HPV de forma a prevenir o câncer cervical é a combinação da técnica de Papanicolaou com a reação em cadeia por polimerase (PCR) na qual ocorre a amplificação de regiões conservadas do genoma viral, com uso de primers degenerados e em seguida identificação do tipo viral. O primer mais utilizado em todo o mundo é o MY09/11, com boa sensibilidade e especificidade. Recentemente, foi descrito na literatura um novo conjunto de primers consensuais denominado PGMY reformulando o primer MY e adicionando um novo primer HMBO visando diminuir perdas do MY (falso negativo). Objetivo: comparar os dois pares de primers, MY e PGMY, a fim de apontar aquele mais adequado para o rastreamento de infecções causadas por HPV no colo uterino pela técnica de reação em cadeia da polimerase. Métodos: avaliamos 116 amostras de esfregaços cervicais. Após a extração do DNA, a técnica de PCR foi realizada de acordo com os protocolos descritos na literatura. Resultados: através desse trabalho, observamos que o par de primers PGMY apresenta maior sensibilidadee especificidade na detecção do DNA do HPV quando comparado com o par de primers MY, além de melhores valores preditivos negativo e positivo. Conclusão: o novo par de primers PGMY, deve ser usado para substituir o par MY a fim de melhorar a detecção do DNA viral.

Introduction: cervical cancer is the most frequent neoplasia among the women of countries in development. Great part of those cases is caused by persistent infection with different types of Human Papillomavirus (HPV) classified as high and low risk, according to the risk of cervical cancer development. Nowadays, it is believed that the best identification routine and follow up of the lesions in order to prevent the malignant transformation is the combination of the technique of Papanicolaou with the polymerase chain reaction (PCR), in which the amplification of conserved areas of the viral genome occurs, with use of degenerate primers, followed by type identification. The degenerate primers MY 09/11 are used worldwide, presenting good sensibility and specificity. Recently, a new group of consensual primers denominated PGMY was described in the literature reformulating the primer MY and adding a new primer HMBO seeking to reduce losses of MY (false negative). Objective: compare two pairs of primers, MY and PGMY, to discorer the most appropriate for the diagnosis of infections caused by HPV in the uterine cervix for the technique of Polymerase chain reaction. Methods: a hundred and sixteen samples from cervical smears were evaluated. After DNA extraction, the PCR was done according to the protocols described in the literature. Results: we observed that the primers pair PGMY presents better sensibility and specificity in the detection of DNA of HPV when compared to the primers pair MY, it also presents better negative and positive predictive values. Conclusion: the new primers pair PGMY should be used to substitute the pair MY to improve the detection of the viral DNA.