Our Lady of the Lake University

About: Our Lady of the Lake University is a education organization based out in San Antonio, Texas, United States. It is known for research contribution in the topics: Social work & Supply chain. The organization has 222 authors who have published 341 publications receiving 7153 citations. The organization is also known as: OLLU.

Genome-Scale Phylogenetic Analyses of Chikungunya Virus Reveal Independent Emergences of Recent Epidemics and Various Evolutionary Rates

Abstract: Chikungunya virus (CHIKV), a mosquito-borne alphavirus, has traditionally circulated in Africa and Asia, causing human febrile illness accompanied by severe, chronic joint pain. In Africa, epidemic emergence of CHIKV involves the transition from an enzootic, sylvatic cycle involving arboreal mosquito vectors and nonhuman primates, into an urban cycle where peridomestic mosquitoes transmit among humans. In Asia, however, CHIKV appears to circulate only in the endemic, urban cycle. Recently, CHIKV emerged into the Indian Ocean and the Indian subcontinent to cause major epidemics. To examine patterns of CHIKV evolution and the origins of these outbreaks, as well as to examine whether evolutionary rates that vary between enzootic and epidemic transmission, we sequenced the genomes of 40 CHIKV strains and performed a phylogenetic analysis representing the most comprehensive study of its kind to date. We inferred that extant CHIKV strains evolved from an ancestor that existed within the last 500 years and that some geographic overlap exists between two main enzootic lineages previously thought to be geographically separated within Africa. We estimated that CHIKV was introduced from Africa into Asia 70 to 90 years ago. The recent Indian Ocean and Indian subcontinent epidemics appear to have emerged independently from the mainland of East Africa. This finding underscores the importance of surveillance to rapidly detect and control African outbreaks before exportation can occur. Significantly higher rates of nucleotide substitution appear to occur during urban than during enzootic transmission. These results suggest fundamental differences in transmission modes and/or dynamics in these two transmission cycles.

Meta-analysis of the effects of behavioral HIV prevention interventions on the sexual risk behavior of sexually experienced adolescents in controlled studies in the United States.

Abstract: To estimate the effect of behavioral and social interventions on sexual risk of HIV among sexually experienced adolescents in the United States and to assess factors associated with variation in outcomes, we selected studies from the HIV/AIDS Prevention Research Synthesis project database. Twenty studies published or reported during the years 1988 through 1998 met criteria: 16 presented sufficient data; of these, 15 evaluated behavioral interventions and 1 a social intervention. Summary odds ratios (ORs) and 95% confidence intervals (CIs), weighted by study precision, indicated significantly less sex without condoms (number of studies, k, 13; OR, 0.66; CI, 0.55-0.79) and lower behavioral risk (k, 2; OR, 0.66; CI, 0.50-0.88), but no difference in number of partners (k, 8; OR, 0.89; CI, 0.76-1.05) or STDs (k, 2; OR, 1.18; CI, 0.48-2.86). A composite sexual risk behavior variable (k, 16; 1 outcome per study; preferred order, sex without condoms, number of partners, risk index) was used for heterogeneity and publication bias tests and stratified analyses. Overall, these interventions had a significant protective effect on sexually experienced adolescents (k, 16; OR, 0.65; CI, 0.50 - 0.85), although there was a suggestion of publication bias. Study design and intervention variables did not explain outcome variation. An exploratory finding may merit investigation: interventions tested with single ethnic groups out-of-class (k, 5) had larger effects than in-class interventions with mixed ethnic groups (k, 11), whether the mixed groups were in- (k, 6) or out-of class (k, 5).