RESUMEN
BACKGROUND: The association between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV) and the development of HSV vaccines have increased interest in the study of HSV epidemiology. OBJECTIVES: To estimate the age and sex specific seroprevalence of HSV-1 and HSV-2 infections in selected populations in Brazil, Estonia, India, Morocco, and Sri Lanka. METHODS: Serum samples were collected from various populations including children, antenatal clinic attenders, blood donors, hospital inpatients, and HIV sentinel surveillance groups. STD clinic attenders were enrolled in Sri Lanka, male military personnel in Morocco. Sera were tested using a common algorithm by type specific HSV-1 and HSV-2 antibody assay. RESULTS: 13,986 samples were tested, 45.0% from adult females, 32.7% from adult males, and 22.3% from children. The prevalence of HSV-1 varied by site ranging from 78.5%-93.6% in adult males and from 75.5%-97.8% in adult females. In all countries HSV-1 seroprevalence increased significantly with age (p<0.001) in both men and women. The prevalence of HSV-2 infection varied between sites. Brazil had the highest age specific rates of infection for both men and women, followed by Sri Lanka for men and Estonia for women, the lowest rates being found in Estonia for men and India for women. In all countries, HSV-2 seroprevalence increased significantly with age (p<0.01) and adult females had higher rates of infection than adult males by age of infection. CONCLUSIONS: HSV-1 and HSV-2 seroprevalence was consistently higher in women than men, particularly for HSV-2. Population based data on HSV-1 and HSV-2 will be useful for designing potential HSV-2 vaccination strategies and for focusing prevention efforts for HSV-1 and HSV-2 infection.
Asunto(s)
Herpes Simple/epidemiología , Adolescente , Adulto , Brasil/epidemiología , Niño , Preescolar , Estonia/epidemiología , Femenino , Herpesvirus Humano 1/inmunología , Herpesvirus Humano 2/inmunología , Humanos , India/epidemiología , Lactante , Recién Nacido , Masculino , Marruecos/epidemiología , Oportunidad Relativa , Prevalencia , Estudios Seroepidemiológicos , Sri Lanka/epidemiologíaRESUMEN
Genome sequences of three Wheat streak mosaic virus (WSMV) strains were compared. The Type and Sidney 81 strains of WSMV from the American Great Plains were closely related, with sequence identities of 97.6% (nucleotide) and 98.7% (amino acid). In contrast, the El Batán 3 strain from central Mexico was divergent, and shared only 79.2-79.3% (nucleotide) and 90.3-90.5% (amino acid) sequence identity with Type and Sidney 81. All three WSMV strains were serologically related, however the El Batán 3 capsid protein (CP) had 15 fewer amino acid residues. Phylogenetic analysis of the CP cistron indicated that Type, Sidney 81, and nine other American isolates of WSMV were closely related and distinct from the El Batán 3 sequence. Nucleotide substitutions among the WSMV strains were not randomly distributed across the genome with more variation within P1, HC-Pro, and CP, and less within P3. One 400-nucleotide region of the genome, corresponding to the 3'-end of P3, was strikingly deficient in silent substitutions. Nonetheless, the ratio of synonymous to non-synonymous substitutions throughout the genome was essentially the same for all three WSMV strains. Collectively, our data indicate that both genetic drift and negative selection have contributed to the evolution of WSMV strains.
Asunto(s)
Genoma Viral , Potyviridae/genética , Triticum/virología , Sustitución de Aminoácidos , Evolución Biológica , Cápside/genética , Frecuencia de los Genes , Genes , Variación Genética , México , América del Norte , Potyviridae/clasificación , Selección Genética , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido NucleicoRESUMEN
Cross-protection and vector transmission bottlenecks have been proposed as mechanisms facilitating genetic isolation of sympatric viral lineages. Molecular markers were used to monitor establishment and resolution of mixed infections with genetically defined strains of wheat streak mosaic virus (WSMV). Two closely related WSMV strains from the U.S. (Type and Sidney 81) exhibited reciprocal cross-protection in wheat, confirming this classic phenomenon as a mechanism of genetic isolation. In contrast, cross-protection between either U.S. strain and the divergent El Batán 3 strain from Mexico was unilateral, erratic, and only partially effective. Distribution of WSMV strains within individual leaves of plants supporting a mixed infection of Type and Sidney 81 was spatially nonuniform. Strain distribution among individual tillers of coinfected plants also was heterogeneous, with some containing either Type or Sidney 81 alone and some containing both. Transmission by wheat curl mites, acquiring virus from source plants simultaneously infected with both Type and Sidney 81, often resulted in test plants bearing only a single WSMV strain. Spatial subdivision of virus strains within coinfected plants likely contributed to vector transmission bottlenecks during acquisition. Collectively, these three distinct mechanisms enhance genetic isolation of individual viral lineages, and together with stochastic processes, may explain generation and maintenance of genetic diversity in field populations.
Asunto(s)
Virus del Mosaico/genética , Triticum/virología , Animales , Evolución Biológica , Genotipo , México , Ácaros/virología , Virus del Mosaico/clasificación , Virus del Mosaico/fisiología , Enfermedades de las Plantas/parasitología , Enfermedades de las Plantas/virología , Hojas de la Planta/parasitología , Hojas de la Planta/virología , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Triticum/parasitología , Estados UnidosRESUMEN
The Test of Gross Motor Development was administered to 300 children, ages 5 to 7 yr., attending public schools in Puerto Rico. Statistical comparisons indicated that the test-manual norms for US children were applicable to Puerto Rican children except for 7-yr.-old girls. A 2 x 3 x 2 factor analysis of intercorrelations of Puerto Rican scores indicated no significant difference between rural and urban children, expected age group differences, and sex differences favoring boys.