Chang M S, Chan K L, Ho B C
Department of Medical and Health Services, Sarawak, Malaysia.
Southeast Asian J Trop Med Public Health. 1993;24 Suppl 2:93-104.
Two field trials in the control of subperiodic brugian filariasis vectors, mainly Mansonia bonneae and Mansonia dives were carried out in Sarawak, East Malaysia. In the first trial, malathion ultra-low volume (ULV) spray was used to control the Mansonia mosquitos in two filariasis endemic villages. Six spray rounds were applied at biweekly intervals at Kampung Rasau and two spray rounds were applied at monthly intervals in Kampung Triboh. ULV malathion spray reduced biting Ma. bonneae population for 3 days after spraying. The biting density decreased to 50% of the pre-treatment level by the 12th - 13th day and reached the pre-treatment level by the 24th - 25th day. Contact bioassay tests on caged Mansonia mosquitos revealed considerable penetration of the malathion aerosol indoors and relatively adequate coverage outdoors. The estimated number of bites per case per day was 1.09 to 4 times less in the sprayed kampung than in an unsprayed control kampung. The parous and daily survival rates of Mansonia mosquitos were not significantly affected by the spraying. In a second trial, chemotherapy with diethylcarbamazine citrate (DEC) was combined with vector control through indoor residual spraying in Kampung Ampungan. The results were compared with the use of only DEC mass treatment in Kampung Sebangkoi and Kampung Sebamban. The combined control measures in Kampung Ampungan reduced the MfD-50 to 44% of the pre-treatment level over a period of 4 years. In the other two kampungs where only mass DEC therapy was applied, the microfilarial rate and MfD-50 declined significantly in the second blood survey but increased gradually in two subsequent follow-up blood surveys. The total insecticidal impact for Ma. bonneae was 3.9 to 1 indoors and 2.7 to 1 outdoors. These results indicated that quarterly pirimiphos-methyl indoor spraying used in integrated control could reduce indoor transmission by 3.9 times. The infective rate from the Ma. bonneae dissected in all three kampungs after the interventions, irrespective of DEC treatment alone or in combination with pirimiphos-methyl residual spraying were reduced by two fold. However the infection rate of brugian filarial larvae in Kampung Ampungan was significantly reduced after the use of DEC and insecticide. Annual Transmission Potential (ATP) showed a high significant reduction in Kampung Ampungan (p > 0.001) compared with Kampungs Sebangkoi and Schambam. In Ampungan, the ATP was reduced by 8.5 times indoors after the MDA and insecticidal application and 3 times outdoors. The reduction rate for Sebangkoi and Sebamban both indoors and outdoors were less than 2 fold.(ABSTRACT TRUNCATED AT 400 WORDS)
在东马来西亚砂拉越开展了两项控制亚周期型布鲁氏丝虫病病媒的现场试验，主要病媒为曼蚊属的博内曼蚊和致倦曼蚊。在第一项试验中，采用马拉硫磷超低容量（ULV）喷雾来控制两个丝虫病流行村庄的曼蚊。在拉绍村每两周进行6次喷雾，在特里博村每月进行2次喷雾。ULV马拉硫磷喷雾使博内曼蚊的叮咬种群在喷雾后3天内减少。到第12 - 13天，叮咬密度降至治疗前水平的50%，到第24 - 25天恢复到治疗前水平。对笼养曼蚊的接触生物测定试验表明，马拉硫磷气雾剂在室内有相当的渗透，在室外覆盖相对充分。与未喷雾的对照村相比，喷雾村估计每人每天的叮咬次数减少了1.09至4倍。喷雾对曼蚊的产蚊率和每日生存率没有显著影响。在第二项试验中，在安蓬甘村将枸橼酸乙胺嗪（DEC）化疗与通过室内滞留喷洒进行的病媒控制相结合。将结果与在塞邦科伊村和塞班班村仅使用DEC群体治疗的情况进行比较。安蓬甘村的联合控制措施在4年期间将微丝蚴密度（MfD - 50）降至治疗前水平的44%。在仅应用DEC群体治疗的另外两个村庄，第二次血液调查时微丝蚴率和MfD - 50显著下降，但在随后的两次随访血液调查中逐渐上升。对博内曼蚊的总杀虫效果在室内为3.9比1，在室外为2.7比1。这些结果表明，综合防治中每季度使用甲基嘧啶磷室内喷洒可使室内传播减少3.9倍。干预后在所有三个村庄解剖的博内曼蚊的感染率，无论单独使用DEC还是与甲基嘧啶磷滞留喷洒联合使用，均降低了两倍。然而，在使用DEC和杀虫剂后，安蓬甘村布鲁氏丝虫幼虫的感染率显著降低。与塞邦科伊村和塞班班村相比，安蓬甘村的年传播潜力（ATP）显著降低（p>0.001）。在安蓬甘村，进行大规模药物驱虫（MDA）和杀虫处理后，室内ATP降低了8.5倍，室外降低了3倍。塞邦科伊村和塞班班村在室内和室外的降低率均小于2倍。（摘要截短至400字）
