Ndyomugyenyi R, Lakwo T, Habomugisha P, Male B
Vector Control Division, Ministry of Health, PO Box 1661, Kampala, Uganda.
Ann Trop Med Parasitol. 2007 Jun;101(4):323-33. doi: 10.1179/136485907X176355.
The national onchocerciasis-control programme in Uganda successfully eliminated Simulium neavei s.s. from the Itwara focus in 1997, by monthly ground spraying with larvicidal temophos (Abate). Since then, no vectors have been caught in the main Itwara focus or two secondary foci in the same area. After 4 years of intervention, S. neavei s.s. has also been nearly eliminated from the Mpamba-Nkusi focus, and the elimination of this vector from two more foci (West Nile and Wambabya-Rwamarongo) appears quite feasible. There are, however, four isolated foci in Uganda (Budongo, Kashoya-Kitomi, Mount Elgon and Kigezi-Bwindi) which are probably too large and inaccessible to make the elimination of S. neavei s.s. by ground spraying a realistic possibility. Encouragingly, >70% of Ugandans have received an annual dose of ivermectin for at least 10 years, and the national programme of community-directed treatment with ivermectin (CDTI) is thought to be progressing towards sustainability. Despite the good treatment coverages, however, many potential vectors are still found infected with Onchocerca volvulus and many Ugandans have O. volvulus in their skin. There is now evidence that adult O. volvulus can be eliminated, within a period of about 6 years, through semiannual treatment with ivermectin. Together, the isolated foci where vector elimination is not considered feasible have a human population of about 700,000, most of whom (595,000) are eligible to receive ivermectin treatment. The estimated cost of each treatment, via the Ugandan CDTI, is U.S.$0.78 if the salaries of the government-employed personnel and the working time lost by the volunteers who act as community-directed drug distributors (CDD) are taken into account. If these 'expenses' are ignored, however, the cost falls to just U.S.$0.17/treatment, and the total costs for the four isolated foci where vector control is not likely to be successful become about U.S.$101,150/year for annual treatment (for an indefinite period of time) or approximately U.S.$202,300/year for semi-annual treatment (for the 6 years needed to eliminate adult O. volvulus), which would be the more cost-effective option. With the necessary financial support and the continued free supply of ivermectin from Merck, the national onchocerciasis-control programme could eliminate human onchocerciasis from Uganda, through a combination of semi-annual treatment with ivermectin in the isolated foci where S. neavei s.s. elimination is not feasible, and vector elimination in all the other foci.
乌干达的国家盘尾丝虫病控制项目于1997年通过每月地面喷洒杀幼虫剂特莫磷（Abate），成功地在伊特瓦拉疫源地消灭了内氏蚋指名亚种。自那时起，在伊特瓦拉主要疫源地或同一地区的两个次要疫源地均未捕获到病媒。经过4年的干预，姆潘巴-恩库西疫源地的内氏蚋指名亚种也几乎被消灭，在另外两个疫源地（西尼罗河和万巴比亚-鲁马伦戈）消灭该病媒似乎也相当可行。然而，乌干达有4个孤立的疫源地（布东戈、卡绍亚-基托米、埃尔贡山和基盖齐-布温迪），可能面积太大且难以进入，通过地面喷洒来消灭内氏蚋指名亚种不太现实。令人鼓舞的是，超过70%的乌干达人已连续至少10年每年接受一次伊维菌素治疗，而且全国社区导向伊维菌素治疗项目（CDTI）被认为正朝着可持续性发展。尽管治疗覆盖率良好，但仍发现许多潜在病媒感染了盘尾丝虫，许多乌干达人的皮肤中也有盘尾丝虫。现在有证据表明，通过每半年一次的伊维菌素治疗，在大约6年的时间内可以消灭成虫盘尾丝虫。综合来看，不考虑消灭病媒的孤立疫源地共有约70万人口，其中大多数（59.5万）有资格接受伊维菌素治疗。如果将政府雇员的工资以及作为社区导向药品分发员（CDD）的志愿者损失的工作时间计算在内，通过乌干达的CDTI进行每次治疗的估计成本为0.78美元。然而，如果忽略这些“费用”，成本降至每次治疗仅0.17美元，对于病媒控制不太可能成功的4个孤立疫源地，年度治疗（无限期）的总成本约为每年101,150美元，或每半年治疗（消灭成虫盘尾丝虫所需的6年）约为每年202,300美元，这将是更具成本效益的选择。在获得必要的资金支持以及默克公司持续免费供应伊维菌素的情况下，国家盘尾丝虫病控制项目可以通过在无法消灭内氏蚋指名亚种的孤立疫源地每半年进行一次伊维菌素治疗，以及在所有其他疫源地消灭病媒的方式，在乌干达消除人类盘尾丝虫病。
