tailieunhanh - báo cáo hóa học:" Concurrency revisited: increasing and compelling epidemiological evidence"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : Concurrency revisited: increasing and compelling epidemiological evidence | JOURNALOF THE INTERNATIONAL AIDS SOCIETY Mah and Shelton Journal of the International AIDS Society 2011 14 33 http content 14 1 33 COMMENTARY Open Access Concurrency revisited increasing and compelling epidemiological evidence Timothy L Mah and James D Shelton Abstract Multiple sexual partnerships must necessarily lie at the root of a sexually transmitted epidemic. However that overlapping or concurrent partnerships have played a pivotal role in the generalized epidemics of sub-Saharan Africa has been challenged. Much of the original proposition that concurrent partnerships play such a role focused on modelling self-reported sexual behaviour data and ethnographic data. While each of these has definite merit each also has had methodological limitations. Actually more recent cross-national sexual behaviour data and improved modelling have strengthened these lines of evidence. However heretofore the epidemiologic evidence has not been systematically brought to bear. Though assessing the epidemiologic evidence regarding concurrency has its challenges a careful examination especially of those studies that have assessed HIV incidence clearly indicates a key role for concurrency. Such evidence includes 1 the early and dramatic rise of HIV infection in generalized epidemics that can only arise from transmission through rapid sequential acute infections and thereby concurrency 2 clear evidence from incidence studies that a major portion of transmission in the population occurs via concurrency both for concordant negative and discordant couples 3 elevation in risk associated with partner s multiple partnering 4 declines in HIV associated with declines in concurrency 5 bursts and clustering of incident infections that indicate concurrency and acute infection play a key role in the propagation of epidemics and 6 a lack of other plausible explanations including serial monogamy and non-sexual transmission. While other factors such as sexually transmitted .