Characterisation of complete high- and low-risk human papillomavirus genomes isolated from cervical specimens in southern Brazil

The classification of human papillomavirus (HPV) intratypic lineages by complete genome sequencing is a determinant in understanding biological differences in association with this disease. In this work, we have characterised complete HPV genomes from southern Brazil. Fifteen cervicovaginal Pap smear negative samples previously categorised as HPV-positive were sequenced using ultradeep sequencing, and 18 complete genomes from 13 different HPV types were assembled. Phylogenetic and genetic distance analyses were performed to classify the HPV genomes into lineages and sublineages. This is the first report describing the distribution of HPV intratype lineages of high and low oncogenic risk in asymptomatic women from southern Brazil.

Bonafide, type-specific human papillomavirus persistence among HIV-positive pregnant women: predictive value for cytological abnormalities, a longitudinal cohort study

This study investigated the rate of human papillomavirus (HPV) persistence, associated risk factors, and predictors of cytological alteration outcomes in a cohort of human immunodeficiency virus-infected pregnant women over an 18-month period. HPV was typed through L1 gene sequencing in cervical smears collected during gestation and at 12 months after delivery. Outcomes were defined as nonpersistence (clearance of the HPV in the 2nd sample), re-infection (detection of different types of HPV in the 2 samples), and type-specific HPV persistence (the same HPV type found in both samples). An unfavourable cytological outcome was considered when the second exam showed progression to squamous intraepithelial lesion or high squamous intraepithelial lesion. Ninety patients were studied. HPV DNA persistence occurred in 50% of the cases composed of type-specific persistence (30%) or re-infection (20%). A low CD4+T-cell count at entry was a risk factor for type-specific, re-infection, or HPV DNA persistence. The odds ratio (OR) was almost three times higher in the type-specific group when compared with the re-infection group (OR = 2.8; 95% confidence interval: 0.43-22.79). Our findings show that bonafide (type-specific) HPV persistence is a stronger predictor for the development of cytological abnormalities, highlighting the need for HPV typing as opposed to HPV DNA testing in the clinical setting.

Determinants of HIV-1 mother-to-child transmission in Southern Brazil

Diferentes subtipos do virus da imunodeficiência humana do tipo 1 (HIV-1) podem ter propriedades biológicas, imunológicas e patogênicas distintas. A eficiência da transmissão materno-infantil (TMI) pode estar entre estas propriedades, porém resultados escassos e controversos foram descritos até o momento. Neste estudo, 102 crianças nascidas de mães infectadas pelo HIV-1 entre 1998 e 2004 na cidade do Rio Grande, Brasil, foram analisadas para fatores de risco potenciais associados à TMI. Aquela região geográfica é caracterizada por uma alta proporção de indivíduos infectados pelo subtipo C do HIV-1, permitindo a comparação entre os subtipos B e C e sua influência na transmissão vertical do vírus. A análise também incluiu parâmetros clínicos, obstétricos e imunológicos. Análises de regressão multivariada foram conduzidas para avaliar a influência daqueles parâmetros na TMI, e as razões de prevalência (RP) e intervalos de confiança de 95% (IC95) foram também calculados. Um prevalência surpreendentemente alta do subtipo C acima dos 70% foi encontrada. Somente a carga viral do HIV e o uso de protocolo ACGT 076 maternos forma preditivos de TMI. O subtipo do HIV-1 e a contagem de células T CD4+ não foram associados a um risco aumentado de transmissão. Embora uma clara expansão do subtipo C seja evidente no sul do Brasil, esta não parece estar correlacionada com risco aumentado de transmissão vertical.