As calls con­tin­ue to be made for the In­sect Vec­tor Con­trol Di­vi­sion to in­crease spray­ing mos­qui­toes as con­firmed dengue cas­es rise, the head of the di­vi­sion says they have the re­sources to meet the grow­ing de­mand.

Speak­ing at a me­dia con­fer­ence at the Min­istry of Health Head Of­fice, Queen’s Park East, yes­ter­day, Dr Os­afo Fras­er, Med­ical Of­fi­cer of Health, said spray­ing was just one method used to fight against dengue.

Asked if they had enough re­sources as some re­gion­al cor­po­ra­tions de­mand more spray­ing, Fras­er said, “Once there is a case, a re­port­ed case, whether sus­pect­ed or con­firmed, we will re­spond, and that re­sponse is done per coun­ty. Each coun­ty has an In­sect Vec­tor Con­trol Di­vi­sion of­fice, and that of­fice is staffed with both peo­ple and per­son­nel to re­spond to those cas­es. We have been do­ing that from the be­gin­ning, so yes.”

Dr Fras­er added that spray­ing for mos­qui­toes is done when two con­firmed cas­es are re­port­ed with­in a quar­ter-mile ra­dius. He warned that over­spray­ing can lead mos­qui­toes to de­vel­op im­mu­ni­ty.

He said the ul­tra-low-vol­ume chem­i­cal used works very well in large ar­eas to kill adult mos­qui­toes. “Over-spray­ing is a prob­lem; spray­ing every day, every­where, all the time in­creas­es mos­qui­to re­sis­tance to the ac­tu­al in­sec­ti­cide we are us­ing, which re­sults in in­ef­fec­tive con­trol when we do need to spray. So, if we are al­ways spray­ing and we do end up with a dengue case where the mos­qui­to is re­sis­tant and we go in­to that area and we try to use our ULV spray, it will not work.”

He added that over­spray­ing will hurt the en­vi­ron­ment and the sup­port­ing ecosys­tem, in­clud­ing peo­ple. Asked about the use of mod­i­fied mos­qui­toes as an­oth­er form of com­bat­ing dengue, Health Min­is­ter Ter­rence Deyals­ingh said the sci­ence does not sup­port that just yet. He said mod­i­fied mos­qui­toes can pos­si­bly cre­ate a mu­tat­ed virus, and there is no da­ta on how that will im­pact the ex­ist­ing ecosys­tem.