Findings Confirm Anopheles Mosquito Resistant to Insecticide


Findings from resistance testing of the Anopheles mosquito to insecticide by two malaria consultants from the Centre for Disease Control (CDC), has confirmed that there is significant resistance from the pest to the traditionally used insecticide.
The result supports the preliminary tests conducted recently by local experts Trevor Castle and government entomologist, Sherine Huntley, which indicated that there was some degree of resistance from the vector to malathaion, the main insecticide used by health personnel in the Malaria Prevention and Control Programme.
In an interview with JIS News, Acting Head of the Malaria Prevention and Control Programme, Dr. Eva Lewis-Fuller disclosed that the experts conducted some other tests on mosquito samples taken from the Duhaney River in Kingston 19, with insecticides other than malathaion and that the results were quite positive.
“Tests with Permitherin, for example, were very promising as both aedes aegypti that causes dengue fever and the anopheles that causes malaria showed sensitivity to permitherin, which is another relatively safe insecticide, although it will be more expensive than malathaion,” she explained.
As part of its response to the findings, the Ministry will conduct more tests because the samples of mosquito larvae used previously were taken from outside of Kingston 11, 12, 13 and 14, the areas mostly affected by the malaria outbreak.
“We now need to get the mosquitoes from within those areas to test, although we think it is a good correlation, regardless of the fact that the mosquitoes came from the Duhaney River,” she informed.This process, which is expected to commence in earnest next week, will see health personnel collecting larvae from certain breeding sites to take to the laboratory, where they will be allowed to go through their life cycle and develop as adults, then be tested.
“We have been left with the technology by the CDC consultants and that test will continue in those areas by our local entomologists,” Dr. Lewis-Fuller noted.
In addition to carrying out more tests for resistance, the Ministry will also review the usage of the current insecticide for vector control in the affected areas.
“We have to look at the insecticide that we will use in the future. We do not know that malathaion cannot be used because it is still killing a fair amount of mosquitoes. It is just that, it is not killing 100 per cent,” she pointed out.
“We have to select the areas in which we will use it and use some more effective insecticide within the affected areas to kill the mosquitoes more quickly and decisively, so that we can bring this outbreak to an end,” Dr. Lewis-Fuller continued.
The Ministry invited the consultants with the assistance of the United States Agency for International Development (USAID) and the Pan American Health Organisation (PAHO). This move was triggered by the fact that the Ministry had been doing intensive work in vector control, active surveillance and treatment of persons in affected areas, yet the vector was behaving contrary to expectation, in that some were resistant to the insecticide being used.

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