Mosquitoes around the home can be reduced significantly by minimizing the amount of standing water available for mosquito breeding. Residents are urged to reduce standing water around the home in a variety of ways.
The best way is to avoid being bitten by mosquitoes.This can be accomplished using personal protecting while outdoors when mosquitoes are present. Treated bed nets should be used sleeping. Mosquito repellent should be used when outdoor.
The malaria control programme of the Obuasi-based mining company is driven by an entomology laboratory and research unit, situated just outside the main offices of the AngloGold Ashanti Malaria Control Limited (AGAMal).
A walk through the ultra-modern entomology department reveals gadgets, slides, microscope, and other equipment needed to scientifically measure the density of the malaria vector, the number of mosquitoes with the malaria parasite and the effectiveness of the insecticides used in the indoor residual spraying (IRS) programme among other key issues.
The department also houses an ultra-low temperature freezer (worthy of a mortuary) in which 12,000 to 15,000 mosquitoes have been kept at minus-80 degree Celsius for the past four to five years.
Another interest ing “ tour ist attraction” at this facility is the artificially-created breeding room, where nature is simulated by creating a warm tropical climate in which mosquitoes can be grown from the egg stage to maturity for entomological studies.
Mr Kwame Desewu, the entomologist at AGAMal, explained that the department carries out quality control work which includes testing to see if the sprayers are doing a good job.
He said the laboratory breeds two types of mosquitoes for the studies. These are made up of mosquitoes that have never been exposed to insecticides, which can pass for “virgins,” and those that have been exposed to insecticides, known as wild mosquitoes. The virgin mosquitoes are brought in from a community in Kisumu in Kenya, for breeding and in terms of resistance to insecticide, they have none.
He said the team conducting the studies at the laboratory is made up of an entomologist, a biologist, technicians and other supporting staff. Work is done in collaboration with other research sites such as the Kintampo Health Research Centre and the Noguchi Memorial Institute for Medical Research.
Mr Desewu said their IRS activities are done in partnership with the National Malaria Control Programme and the Malaria Vector Control Oversight Committee. The entomological studies, which are operated in four entomological sentinel sites, are generally to assess the impact of the IRS programme on malaria transmission in 10 districts in the Ashanti and Upper West regions.
According to Mr Desewu, a baseline study is conducted to know if the IRS is actually reducing the mosquito population and malaria transmission every month, enabling them to know the trend before and after spraying, as impact indicators.
He said various studies are conducted to help gauge the malaria vector density, the proportion of mosquitoes that have the malaria parasites, the number of infective mosquito bites per night and the accompanying biting rates of these mosquitoes.
One of the methods used to check the malaria vector density is the pyrethrum spray collection (PSC), which involves selecting rooms to spray after which the windows and doors are closed for some minutes.
The floors of these structures are covered with materials to aid the collection of mosquitoes that have This serves as a sort of mosquito baseline study to help the monitoring activity and to assess how the IRS activity is faring within the communities.
Mr Desewu explained that the other method used for the monitoring and evaluation exercise is the human landing collection for the malaria vector density studies. Here, the exercise is carried out from 6pm to 6am, and it involves trained vector collectors who sit outside and inside to collect mosquitoes that land on them.
This helps to assess how many mosquitoes will bite per night. These collections are brought to the laboratory to see if the mosquitoes have the malaria parasites.
He also spoke on the monitoring and evaluation of the insecticides used for their IRS programme, and said this is also done to assess the right amount of insecticide being used for the exercise and how it is impacting on mosquitoes in terms of their density before the start of the IRS programme and after the activity is carried out.
This is because the IRS programme can only be effective if the biting rates of mosquitoes go down, and when they are destroyed by a potent insecticide.
Mrs Rosemary Ampofo-Bekoe, a biologist at the entomology department, said the laboratory carries out various studies to assess if sprayers engaged for the IRS activities are using too much or too little spray on structures and houses targeted for the exercise.
They, additionally, conduct insecticide susceptibility tests using mosquitoes in Obuasi and those the Upper West region, where they operate to assess how mosquitoes in these different ecological environments respond to different types of insecticides.
Mr Ignatius Williams, in charge of monitoring and evaluation at AGAMal, said before embarking on an IRS programme, an insecticide susceptibility study is conducted to determine the most efficacious insecticide for use. This always informs all insecticide procurement decisions.
He said the work carried out on the monitoring and evaluation of their IRS malaria control programme begins from checks on quality control from the manufacturer's end, facilitated by an external body and the Global Fund, which has invested in the programme.
According to him, when the insecticides are delivered to them at AGAMal, samples of the insecticides are again tested to ascertain if the active ingredients are present in the chemical.
Mr Williams explained that during the IRS exercise itself, apart from tests being carried out to ensure that each IRS spray operator delivers the right quantity of spray on the surfaces of structures and houses, checks are also conducted on the techniques used in spraying for efficiency.
After the spraying exercise, monthly assessments are done to test how efficacious the insecticide is over the time it remains on the wall. He said different techniques are used to spray different surfaces, houses and structures.
By Eunice Menka