Drug Resistancet Fades Quickly in Key Aids2 Drug
One of the main weapons to prevent mother-to-child transmission of the AIDS virus during birth is the drug nevirapine3. But when nevirapine is used alone just once, HIV4 starts becoming resistant to it. Research in Botswana shows that the resistance is not long lasting and that this affordable drug does not have to be abandoned forever by infected mothers who have already taken it.
International medical guidelines call for5 pregnant women with advanced HIV to get a combination of AIDS drugs including nevirapine to prevent passing their infection on to their newborns during delivery. But in poor countries, combinations have been expensive and nevirapine has often been Used al. one, since studies have shown that a single dose can cut the transmission rate in half.
The problem is that HIV resistance builds against it quickly when used alone just once because other drugs are not present to kill the virus particles that survive nevirapine. This renders the drug less effective in later combinations for treating women after their baby is born. But the new study from Botswana shows that nevirapine can make a comeback for these women if they wait until the resistance subsides.
“The further out you get from that exposure to single dose nevirapine, the less detectable nevirapine resistance is6,” said Shahin Lockman of the Harvard School of Public Health in Boston7. She says waiting period for women who get the single dose of nevirapine at delivery can be as short as six months. “If they started nevirapine-based treatment six or more months after nevirapine exposure, their treatment response8 was just as good, and really quite high, compared to women who did not have the single dose of nevirapine,” she added. “However, the women who started nevirapine-based treatment within six months of that nevirapine exposure were much more likely to experience treatment failure.”
The study published in the New England Journal oJ Medicine9 shows that waiting at least six months means that HIV-positive women are 70 percent more likely to benefit from nevirapine-based drug combinations again than women who get them sooner. An official with the U.S. government health agency that helped fund the study calls it very important.
I.ynne Mofenson is chief of research on child, adolescent, and maternal AIDS at the U. S. National Institute of Child Health and Human Development10. She says the finding supports a World Health Organization (WHO)H recommendation restricting a single dose of nevirapine only to pregnant HIV-infected women who are healthy enough to wait six months after childbirth for more nevirapine-based therapy. Otherwise, they should get other drugs during labor. “It shows the importance of screening women for treatment while they are pregnant and putting them on appropriate therapy while they are pregnant to avoid having to start them too soon after they received preventive therapy,” she explained.
Shahin Lockman in Boston says the problem of nevirapine resistance should diminish now that12 more and more people are receiving combinations of AIDS drugs under expanded U. S. and international programs to deliver them to Africa and other regions hard hit by the virus.
词汇:
fade/feid/v.消失
transmission/ trAnz5miFEn/n.传播;传染;遗传
Botswana/bCt5swB:nE/博茨瓦纳(非洲)
affordable/E5fC:d/adj.负担得起的,能提供的
abandon/E5bAndEn/v.抛弃,放弃
advanced/Ed5vB:nst/adj.晚期的
newborn/nju:5bC:n, 5nju:bC:n/n新生儿
delivery/di5livEri/n.分娩,生产
dose/dEus/n.(一次)剂量,一剂
render/5rendE/vt.使得,致使
comeback/5kQmbAk/n.东山再起;还原;补偿
subside/sEb5said/v.平息;减退
detectable/dI`tektEbl/adj.可查明的;可找出的
positive/5pCzEtiv/adj.阳性的
adolescent/7AdEu5lesnt/adj.青年期的,青春的,2:青少年(12或13至20岁)
maternal/mE5tE:nl/adj.母亲的
restlict//v.限制
pregnant/5pre^nEnt/adj.怀孕的
childbirth/5tFaIldb\:W/v.生孩子,分娩
therapy/5WerEpi/n.疗法,治疗
preventive/pri5ventiv/adj.预防的
diminish/di5miniF/v.减少,缩小
注释:
1.drug resistance:抗药性
2.AIDS(acquired imnmnodeficiency syndrome):获得性免疫缺损综合征,艾滋病
3.nevirapine(NVP):奈韦拉平。一种阻断HIV母婴传播的新药。其品牌名为Viramune。
4.HIV(human immunodeficiency virus):人体免疫缺损病毒
5.call for:要求;提倡;号召
6.The further out you get from that exposure to single dose nevirapine,the less detectable nevirapine resistance is…:你服用一剂nevirapine之后,时间越长越不易发现(HIV)对 nevirapine的抗药性……get out from:从……离开,从……出发(在本句中如直译就是:从……走出去,走得越远就越……)。exposuret。:暴露;接触(在本句中如直译就是:接触一剂nevirapine)。
7.Harvard School of Public Health inBoston:波士顿哈佛公共卫生学院
8.response的原意是“反应。应答”,但在医学文献中常用来指“疗效”,此处treatment response就更加明显。
9.New England Journal of Medicine:《新英格兰医药杂志》。New England是美国东北部 Maine,Vermont,New Hampshire,Massachusetts,Rhode Island和Connecticut六州的总称。
10.U.S.National Institute of Child Health and Human Development(NICHHD):美国国立儿童健康与人类发展研究所
11.World Health Organization(WHO):世界卫生组织
12.now that:既然,因为