HPV detection and genotyping as an earlier approach in cervical cancer screening of the female genital tract.

Human papillomavirus (HPV) infection is the leading risk factor for cervical intraepithelial neoplasia (CIN) and cervical cancer. More than 100 virus genotypes have been identified so far, some of them strongly associated with the development of neoplasia. The aim of this study was to evaluate the prevalence of the different HPV genotypes in women presenting no cytological alterations in cervical cells, in women presenting light alterations, and in women presenting severe alterations at routine gynecological examination. We retrospectively analyzed 97 HPV results of women submitted to cervical cancer screening compared to their Papanicolaou and colposcopy examinations. Data were analyzed individually and within groups to correlate the HPV genotypes identified by polymerase chain reaction (PCR) and the respective alterations in cervical cells. Among the nine cases diagnosed as CIN I (9.3%), two were positive for low-risk HPV genotypes (22%), and the other seven were negative for HPV by PCR (78%). CIN II or CIN III diagnoses were associated with positive HPV results by PCR in four cases (36%), for high-risk as well as low-risk genotypes. There were two patients with severe cytological alterations in cervical cells, but with an indeterminate HPV genotype (18%), and one case with a negative HPV result (9%). Among the 57 cases without cytological alterations, seven were positive for low-risk HPV (12%) and two for high-risk HPV genotypes (3.5%). In the 48 remaining cases, we observed one with an indeterminate HPV genotype (2%), and the other 47 were negative for HPV by PCR (47%). Our study demonstrates an important prevalence of high- and low-risk HPV genotypes in our population, including those not present in the commercially available vaccine, even in patients with no evidence of cytological alterations in cervical cells. These results highlight the usefulness of HPV detection and typing as an early approach for cervical cancer screening and prevention.

Evaluation of methods for detection and identification of Mycobacterium species in patients suspected of having pulmonary tuberculosis.

Tuberculosis control is a priority for the Ministry of Health policies in Brazil. In the present work, the detection of Mycobacterium tuberculosis by the Polymerase Chain Reaction (PCR) was standardized, and the laboratory diagnosis of pulmonary tuberculosis was evaluated comparing baciloscopy, culture and PCR tests. The study was carried out with 117 sputum samples from different patients suspected of having pulmonary tuberculosis, for whom physicians had ordered a baciloscopy test. Baciloscopy was performed using the Ziehl-Neelsen method, and culture was performed by incubation of treated samples in Lowenstein-Jensen's medium at 37°C for eight weeks. For PCR, DNA was amplified with a specific pair of primers to the M. tuberculosis complex, with a resulting product of 123 bp from the insertion element IS6110. Three (2.56%) samples presented a positive baciloscopy result and a positive PCR result (100% agreement), and nine (7.69%) presented Mycobacterium sp. growth in culture (P= 0.1384). Among six samples with positive results in culture, one was identified by PCR-RFLP as belonging to the M. tuberculosis complex and one was identified as a non-tuberculosis mycobacteria. Sensitivity and specificity of PCR compared to culture were 33.3% and 100%, respectively.

Evaluation of methods for detection and identification of Mycobacterium species in patients suspected of having pulmonary tuberculosis / Avaliação de métodos para detecção e identificação de espécies de Mycobacterium em pacientes com suspeita de tuberculose pulmonar

Tuberculosis control is a priority for the Ministry of Health policies in Brazil. In the present work, the detection of Mycobacterium tuberculosis by the Polymerase Chain Reaction (PCR) was standardized, and the laboratory diagnosis of pulmonary tuberculosis was evaluated comparing baciloscopy, culture and PCR tests. The study was carried out with 117 sputum samples from different patients suspected of having pulmonary tuberculosis, for whom physicians had ordered a baciloscopy test. Baciloscopy was performed using the Ziehl-Neelsen method, and culture was performed by incubation of treated samples in Lowenstein-Jensen's medium at 37ºC for eight weeks. For PCR, DNA was amplified with a specific pair of primers to the M. tuberculosis complex, with a resulting product of 123 bp from the insertion element IS6110. Three (2.56 percent) samples presented a positive baciloscopy result and a positive PCR result (100 percent agreement), and nine (7.69 percent) presented Mycobacterium sp. growth in culture (P= 0.1384). Among six samples with positive results in culture, one was identified by PCR-RFLP as belonging to the M. tuberculosis complex and one was identified as a non-tuberculosis mycobacteria. Sensitivity and specificity of PCR compared to culture were 33.3 percent and 100 percent, respectively.

A tuberculose é um dos agravos prioritários para as políticas do Ministério da Saúde. No presente trabalho, o método de detecção de Mycobacterium tuberculosis pela Reação em Cadeia da Polimerase (PCR) em amostras de escarro foi padronizado e o diagnóstico laboratorial da tuberculose pulmonar foi avaliado, comparando-se as metodologias de baciloscopia, cultura e PCR. Foram analisadas 117 amostras de escarro de diferentes pacientes com suspeita de tuberculose pulmonar, com solicitação de baciloscopia. A baciloscopia foi realizada com a coloração de Ziehl-Neelsen e a cultura pela semeadura das amostras em meio de Lowenstein-Jensen, incubadas a 37ºC por oito semanas. Para realização da PCR, o DNA foi amplificado com um par de oligonucleotídeos específicos para o complexo M. tuberculosis, resultando em um produto de 123 pb do elemento de inserção IS6110. Das 117 amostras analisadas, três (2,56 por cento) apresentaram baciloscopia positiva e PCR positiva para M. tuberculosis (concordância de 100 por cento), e nove (7,69 por cento) tiveram crescimento de Mycobacterium sp. na cultura (P= 0,1384). Das seis amostras que tiveram resultado positivo somente por cultura, uma foi identificada ainda como pertencente ao complexo M. tuberculosis por PCR-RFLP, e outra foi identificada como micobactéria não tuberculosa. A sensibilidade e a especificidade da baciloscopia e da PCR em relação à cultura foram 33,3 por cento e 100 por cento, respectivamente.