VOA常速英语2013--及早杀灭蚊虫预防疟疾（在线收听）

Killing Mosquitoes Early On 及早杀灭蚊虫预防疟疾

Targeting mosquitoes in their early stages of life has the potential to greatly boost malaria control efforts and prevent thousands of new infections every year. A new study looks at the effectiveness of – what’s called -- larval source management or LSM. It’s estimated malaria causes 660,000 deaths every year, mostly in sub-Saharan Africa and Asia.

在蚊子生命早期进行灭杀，有可能极大地促进疟疾控制工作，并预防每年数千新感染病例。一项新研究评价了所谓幼虫源管理(LSM)的效果，估计疟疾每年造成66万人死亡，大多在撒哈拉南部非洲和亚洲。

Currently, the main malaria preventive measures are long-lasting insecticide-treated mosquito nets and the indoor spraying of homes. But mosquitoes are building up resistance to the chemicals. That’s one reason why researchers reviewed 13 studies of LSM from Eritrea, Kenya, The Gambia, Mali, Tanzania, the Philippines, Sri Lanka and Greece.

目前，预防疟疾的主要措施是耐用的用杀虫剂处理过的蚊帐，以及在家中室内喷洒药剂。但蚊子对这种化学品正产生抗性，这也是研究者审视来自厄立特里亚、肯尼亚、冈比亚、马里、坦桑尼亚、菲律宾、斯里兰卡和希腊的13个研究的一个原因。

Lucy Tusting -- an epidemiologist at the London School of Hygiene and Tropical Medicine -- is the lead author of what’s called The Cochrane review.

Lucy Tusting是伦敦卫生和热带医学学校的流行病专家，也是所谓的Cochrane评价的首席作者。

“This research was important because a number of malaria endemic countries in sub-Saharan Africa and elsewhere are currently using larval source management. But there’s a real lack of consensus on how effective the method can be and in which settings it’s appropriate. And few studies have so far been conducted to rigorously evaluate the intervention,” she said.

“这项研究之所以很重要，是因为撒哈拉南部非洲等地的诸多疟疾流行国家目前使用幼虫源管理办法，但很缺乏对这种方法适当使用有效性的一致意见，到目前为止在着力评估这种干预上进行的研究很少。”

Eliminating mosquitoes before they’re able to transmit the parasite would – on the surface – appear to be a valuable addition to any control program. But Tusting said it’s not a simple decision.

在蚊子能传播寄生虫之前就将之杀灭，从表面上看来是任何控制项目的不错补充。但Tusting说这并不是个简单的决定。

“First of all, we do have very, very effective existing methods of malaria control. Long-lasting insecticide treated nets and indoor residual spraying are both highly effective, rolled out in a vast scale across Africa and elsewhere. And they’ve been undoubtedly a major reason for the successes in malaria control in the last decades. So I think with that in mind there’s been less need to look at other alternative interventions.”

“首先，我们确实有疟疾控制的非常有效的现有办法，耐用的用杀虫剂处理过的蚊帐，以及在家中室内喷洒药剂，这两种办法在整个非洲等地得到大规模的推广，也无疑是过去几十年来疟疾控制成功的主要原因。所以我想有了这些办法，也几乎没有必要去用其他的干预措施。”

The World Health Organization has issued guidelines on the use of LSM. Currently, the WHO does not recommend using the larvicides in rural sub-Saharan Africa, unless there are particular circumstances that limit the habitats of mosquito larvae. The guidelines say, “Larviciding should be considered for malaria control -- with or without other interventions -- only in areas where the breeding sites are few, fixed and findable.”

世界卫生组织发布有关幼虫源管理使用的指导方针，世卫组织并未推荐在撒哈拉南部非洲使用杀幼虫剂，除非在能限制蚊子幼虫栖息地的特别的环境。指导方针称，“不管有没有其他干预办法，只有在那些繁殖地很少、固定且容易发现的地区，杀幼虫剂才能被视为疟疾控制的办法。”

The guidelines add, “In most endemic settings, the appropriate way to use larviciding is as a supplement” to nets and spraying. The WHO says, “Larviciding measures may be effective as the leading method of vector control in urban areas.”  However, it says “more good quality evidence is needed to support this view.”

指导方针称，“在大多数传染病环境下，适当使用杀幼虫剂的办法都只能作为蚊帐和喷洒办法的补充。世卫组织称杀幼虫剂措施作为主要的传病媒介控制办法可能在城市地区才很有效。不过，这种观点还需要更多可靠的例证来说明。”

Tusting explained how larval source management works.

Tusting解释了幼虫源管理运作的办法。

“Malaria is transmitted by mosquitoes,” she said, “The mosquitoes lay their eggs in standing water and the eggs then hatch and develop into larvae, which then develop into flying adult mosquitoes, which are capable of transmitting malaria. So, larval source management is a method of controlling malaria that works by targeting those immature mosquito stages that are found in standing water.”

“疟疾通过蚊子传播，蚊子在静水中产卵，卵孵化成幼虫，幼虫发育成能飞能传播疟疾的成年蚊子。因此，幼虫源管理是通过杀灭静水中不成熟的幼虫来控制疟疾的办法。”

Long-lasting insecticide treated nets and residual indoor spraying take aim at adult mosquitoes. Tusting said that LSM would be used in combination with these methods, not in place of them. There are several ways of using larval source management, which could be especially effective in urban areas.

耐用的用杀虫剂处理过的蚊帐和室内喷洒办法都针对成年蚊子，Tusting说LSM将和其他方法相结合来使用，而不是代替其他方法。有几种使用幼虫源管理的办法，这些办法在城市地区特别有效。

“So, for example, by permanently removing standing water – by draining or filling land – or by making temporary changes to mosquito habitats to disrupt their breeding, for example, by clearing drains to improve water flow. Another common method is larviciding in which chemicals or biological larvicides are added to standing water to kill larvae,” she aid.

“比如，通过排水或填地的办法永久性地移去静水，或暂时改变蚊子的栖息地来打乱其繁殖过程，比如可以清理排水管来使水流动。另一个常见的办法是用杀幼虫剂，用化学品或生物杀幼虫剂添加到静水中来杀灭幼虫。”

Tusting said some research indicates the cost of LSM would be comparable to that of nets and spraying. According to the Roll Back Malaria Campaign, the total cost of the global strategy against the disease is between five and six billion dollars a year.

Tusting说，有的研究表明，LSM的成本相当于用蚊帐和喷洒的成本。击退疟疾行动表明，全球对付疟疾策略的全部成本为每年50到60亿美元。

Her colleague and co-author, Durham University Professor Steve Lindsay, called the review a “landmark publication demonstrating that in many places larval source management should be used as a supplementary weapon against malaria.”

她的同事兼合著者、英国杜伦大学的史蒂夫·林赛教授称这次评价是“里程碑式的出版物，表明在许多地区幼虫源管理应该被视为抗击疟疾的补充办法。”

The review says LSM, in appropriate settings, could reduce malaria cases by up to 75 percent and the proportion of people infected with the malaria parasite by 90 percent.

这次评价称，LSM在适当的使用条件下能将疟疾病例减少75%，感染疟疾寄生虫的患者比例能减少90%。