Human papillomavirus genotypes and their prevalence in a cohort of women in Trinidad.

OBJECTIVE: Human papillomavirus (HPV) genotypes and their relative prevalences were determined in a cohort of 310 sexually active women in Trinidad, West Indies. METHODS: Cervical samples were collected with Ayre's spatulas and endocervical brushes. Samples were used for the conventional Papanicolaou test and for determining HPV genotypes by amplification of a section of the viral L1 gene, followed by DNA sequencing and probe hybridization. RESULTS: HPV infections were identified in 126 of 310 (40.6%) women. Of them, 83 (65.8%) were infected with high-risk HPV, 16 (12.7%) with low-risk HPV, and 27 (21.4%) with HPV types of unknown risk. HPV 52 (12.7%) was the most frequently occurring high-risk type, followed by HPV 66 (10.3%), HPV 16 (9.5%), and HPV 18 (8.6%). High-risk types HPV 16 and HPV 66 were each found in 3 (20.0%) and HPV 18 was found in 1 (6.6%) of the 15 women with abnormal cytology. CONCLUSIONS: Cervical HPV prevalence and heterogeneity of HPV genotypes are high in this Trinidad cohort. The relative importance of HPV genotypes in the development of cervical lesions needs further investigation in Trinidad in order to better understand the epidemiology of HPV infections as well as to determine the role of HPV testing in the screening, prevention, and control of cervical cancer. This pilot study provided important information on the prevalence of HPV genotypes, which will be used in future nationwide studies.

Genetic diversity between and within the arenavirus species indigenous to western Venezuela.

The results of analyses of Z, RNA-dependent RNA polymerase, glycoprotein precursor, and nucleocapsid protein gene sequence data suggested that Guanarito virus was the most common cause of Venezuelan hemorrhagic fever in a 7-year period in the 1990s and that the evolution of Pirital virus in association with Sigmodon alstoni (Alston's cotton rat) has occurred at a significantly higher rate than the evolution of Guanarito virus in association with Zygodontomys brevicauda (short-tailed cane mouse) on the plains of western Venezuela. The results of analyses of the primary structures of the glycoproteins of the 8 strains of Guanarito virus isolated from humans suggested that these strains would be highly cross-reactive in neutralization assays. Thus, passive antibody therapy may prove beneficial in the treatment of human disease caused by strains of Guanarito virus that are enzootic in the region in which Venezuelan hemorrhagic fever is endemic.

Human papillomavirus genotypes and their prevalence in a cohort of women in Trinidad / Genotipos del papilomavirus humano y su prevalencia en una cohorte de mujeres en Trinidad

OBJECTIVE: Human papillomavirus (HPV) genotypes and their relative prevalences were determined in a cohort of 310 sexually active women in Trinidad, West Indies. METHODS: Cervical samples were collected with Ayre's spatulas and endocervical brushes. Samples were used for the conventional Papanicolaou test and for determining HPV genotypes by amplification of a section of the viral L1 gene, followed by DNA sequencing and probe hybridization. RESULTS: HPV infections were identified in 126 of 310 (40.6 percent) women. Of them, 83 (65.8 percent) were infected with high-risk HPV, 16 (12.7 percent) with low-risk HPV, and 27 (21.4 percent) with HPV types of unknown risk. HPV 52 (12.7 percent) was the most frequently occurring high-risk type, followed by HPV 66 (10.3 percent), HPV 16 (9.5 percent), and HPV 18 (8.6 percent). High-risk types HPV 16 and HPV 66 were each found in 3 (20.0 percent) and HPV 18 was found in 1 (6.6 percent) of the 15 women with abnormal cytology. CONCLUSIONS: Cervical HPV prevalence and heterogeneity of HPV genotypes are high in this Trinidad cohort. The relative importance of HPV genotypes in the development of cervical lesions needs further investigation in Trinidad in order to better understand the epidemiology of HPV infections as well as to determine the role of HPV testing in the screening, prevention, and control of cervical cancer. This pilot study provided important information on the prevalence of HPV genotypes, which will be used in future nationwide studies.

OBJETIVO: Se determinaron los genotipos del papilomavirus humano (PVH) y su prevalencia relativa en una cohorte de 310 mujeres sexualmente activas de Trinidad, en la zona de las Indias Occidentales. MÉTODOS: Se tomaron muestras del cuello uterino con espátula de Ayre y cepillo endocervical. Las muestras se usaron para llevar a cabo la prueba convencional de Papanicolaou y para determinar los genotipos de PVH mediante la amplificación de una sección del gen vírico L1, seguida de secuenciación del ADN e hibridación con sonda. RESULTADOS: Se encontró una infección por PVH en 126 de las 310 mujeres (40,6 por ciento). De ellas, 83 (65,8 por ciento) estaban infectadas con PVH de alto riesgo, 16 (12,7 por ciento) con PVH de bajo riesgo, y 27 (21,4 por ciento) con tipos de PVH de riesgo desconocido. De los PVH de alto riesgo, el más frecuente fue el PVH 52 (12,7 por ciento), seguido por el PVH 66 (10,3 por ciento), el PVH 16 (9,5 por ciento) y el PVH 18 (8,6 por ciento). Entre las 15 mujeres con citología anormal se encontraron los PVH de alto riesgo 16 y 66 en 3 (20,0 por ciento) mujeres cada uno, y el PVH 18 en 1 (6,6 por ciento). CONCLUSIONES: Tanto la prevalencia de PVH en el cuello uterino como la heterogeneidad de los genotipos de PVH son elevadas en esta cohorte de Trinidad. La importancia relativa de los genotipos de PVH en la aparición de las lesiones cervicales requiere de mayor investigación en Trinidad para conocer más a fondo las características epidemiológicas de las infecciones por PVH, así como para determinar el papel del estudio de los PVH en la detección sistemática, la prevención y el control del cáncer del cuello uterino. Este estudio piloto suministró información importante sobre la prevalencia de los genotipos de PVH, que se usará en futuros estudios que se lleven a cabo en todo el país.

Diversity and evolution of the envelope gene of dengue virus type 1.

The genetic diversity and phylogenetic relationships of a collection of strains of dengue virus type 1 (DV-1), isolated from different parts of the world, were investigated. Phylogenetic trees derived from the complete sequence of the E gene of 44 strains suggested the existence of five genetic types defined by a maximum nucleotide divergence within each group of 6%. The 22 strains from America were classified into a single genetic type that included strains associated either with classical dengue or hemorrhagic dengue episodes. Using a maximum likelihood procedure based on a single rate with dated tips model and substitution rates calculated at the third codon position, evolution of the five DV-1 genotypes was shown to conform to a molecular clock. The average rate of evolution was estimated to be approximately 16.2 x 10(-4) substitutions/third codon position site/year. Using this estimate, divergence among the DV-1 genotypes was calculated to have occurred approximately 100 years ago. Very low average value of the ratio of nonsynonymous-to-synonymous nucleotide substitutions, relative to the respective sites (0.046), indicated that the evolution of the E gene of the DV-1 is subject mostly to purifying selection.