Injection drug use and HIV/AIDS transmission in China

After nearly three decades of being virtually drug free, use of heroin and other illicit drugs has re-emerged in China as a major public health problem. One result is that drug abuse, particularly heroin injection, has come to play a predominant role in fueling China‘s AIDS epidemic. The first outbreak of HIV among China‘s IDUs was reported in the border area of Yunnan province between China and Myanmar where drug trafficking is heavy. Since then drug-related HIV has spread to all 31 provinces, autonomous regions and municipalities. This paper provides an overview to HIV/AIDS transmission through injection drug use in China. It begins with a brief history of the illicit drug trade in China, followed by a discussion of the emergence of drug related AIDS, and a profile of drug users and their sexual partners who have contracted the virus or who are vulnerable to infection. It ends by summarizing three national strategies being used by China to address both drug use and AIDS as major health threats.     

Bean dwarf mosaic virus: a model system for the study of viral movement

Taxonomy: Bean dwarf mosaic virus‐[Colombia:1987] (BDMV‐[CO:87]) is a single‐stranded plant DNA virus, a member of the genus Begomovirus of the family Geminiviridae. Physical properties: BDMV virions are twinned incomplete isosahedra measuring 18 × 30 nm. The viral particle is composed of 110 subunits of coat protein, organized as 22 pentameric capsomers. Each subunit has a molecular mass of ～29 kDa. BDMV possesses two DNA components (designated DNA‐A and DNA‐B), each ～2.6 kb in size. Host range: The natural and most important host of BDMV is the common bean (Phaseolus vulgaris). Nicotiana benthamiana is often used as an experimental host. Common bean germplasm can be divided into two major gene pools: Andean materials, which are mostly susceptible to BDMV, and Middle American materials, which are mostly resistant to BDMV. Disease symptoms: The symptom intensity in common bean plants depends on the stage of infection. Early infection of susceptible bean seedlings will result in severe stunting and dwarfing, leaf distortion and mottling or mosaic, as well as chlorotic or yellow spots or blotches. BDMV‐infected plants usually abort their flowers or produce severely distorted pods. Late infection of susceptible plants or early infection of moderately resistant genotypes may show a mild mosaic, mottle and crumpling or an irregular distribution of variegated patches. Biological properties: As a member of the Begomovirus group, BDMV is transmitted from plant to plant by the whitefly Bemisia tabaci. BDMV is a nonphloem‐limited virus and can replicate and move in the epidermal, cortical and phloem cells. As a nonphloem‐limited virus, it is sap‐transmissible.