Government is cutting back on funds for mosquito control services this year by $74,000 compared to last year, with a total budget of $5.6 million.
Despite the financial cutbacks, Health Minister Osbourne Bodden told legislators at a finance committee session last week that he commended the Mosquito Research and Control Unit for their sterling efforts.
Minister Bodden said the cuts are due to “budget constraints,” resulting in the government having to “cut back on some levels of servicing” for the mosquito control unit.
West Bay MLA McKeeva Bush asked if the cutbacks would have an effect on the aerial operations for spraying.
The MRCU aircraft targets adult mosquitos by spraying insecticide and combats mosquito larvae by dropping pellets of larvicide.
The decision about where to spray to combat adult mosquitoes is made on a daily basis, depending on the number of mosquitos, which are checked from around 40 traps set up around the island.
Minister Bodden told legislators that some of the acreage covered by aerial operations that target the larvae population would be reduced, but that the MRCU would “do their best to juggle it in a way that doesn’t negatively impact [operations].”
According to the director of the MRCU, William Petrie, the adult mosquito treatment program that Mr. Bush was inquiring about would not be affected by the reduction in the acreage covered. However, he said the use of aerial applications of pellets to target breeding sites or mosquito larvae would be reduced from 16,000 acres to 12,000 acres of coverage. Pellets of insecticide are dropped in the swamps and pasture lands during the daytime to kill mosquito larvae.
“What we’ve done over the past few years is fine tune the areas that we treat with pellets from the aircraft,” said Mr. Petrie. “Some of [the reduction] is to do with budget constraints, but some of it is also to do with better information on the ground on exactly where there is breeding, what might be a marginal area, so we trimmed the blocks or edges where they weren’t breeding so much.” He added, “We’ve just trimmed some of those blocks down to make the applications more efficient.” Over the next few weeks, the MRCU will carry out pellet treatments over 800 acres on Cayman Brac and Little Cayman. Mr. Petrie said the application was delayed due to rainy weather.
“We need good weather to get the aircraft over there to apply the pellets safely,” he said.
According to the MRCU’s website, “The first campaign of the year is carried out just before the rainy season starts so that when the rains come and the mosquito eggs hatch, the larvicide is waiting for the larvae as they emerge. The pellet formulations are long lasting and break down slowly in the water, releasing more chemical as time passes.”
Mr. Petrie said the pellet treatments can last up to two months, depending on how rainy the weather is and how many times an area gets flooded.
The MRCU carried out its first pellet application for the year on Grand Cayman in May at mosquito breeding sites, and according to Mr. Petrie, some 44,000 pounds of pellets were used.
“This year’s application is always critical as it is the first one of the season and it went very well. We prevented a huge emergence of mosquitos from the swamps and pastor lands,” he said.
The MRCU carries out the treatments on breeding sites three times per year. Breeding sites are uninhabited areas in the mangrove swamps and pastor lands.
Aside from aerial applications, the MRCU also carries out treatments by hand on another type of mosquito, the Aedes aegypti, which is a carrier of dengue fever and chikungunya.
He said the Aedes aegypti only feed on humans so they tend to breed in areas close to humans, often in unattended pools of water left in back yards.
He advises residents to remove standing water, turn over buckets, and empty plant pots, either once or twice a week.
“Our concern is the spread of chikungunya – as it has spread rapidly through the Caribbean. We don’t have reports from Jamaica yet, but there are unofficial reports from Cuba,” said Mr. Petrie.
According to the Caribbean Public Health Agency, since the virus first emerged in the Caribbean in December 2013, it has spread to 23 Caribbean countries with five confirmed cases in Cuba and 4,805 cases overall.
Mr. Petrie said that although the MRCU does not know of any local cases, the team is “concerned as [the virus] will probably reach here quite soon.”
He said to reduce the likelihood of the virus spreading to the Cayman Islands, the MRCU is spending a lot of its efforts on Aedes aegypti control.
Symptoms of chikungunya include a sudden high fever, severe pain in the wrists, ankles or knuckles, muscle pain, headache, nausea and rash. Other symptoms are joint pain and stiffness.