Saturday, 27 September 2014 00:00
Aquatain and school leavers to the rescue
By Fathima Riznaz Hafi
Taking the battle against dengue to the next level, the Public Health Department has come up with two new lines of attack.
It is embarking on two pilot projects, one being the spraying of marshes with a silicone-based liquid and the other is the involvement of school leavers in their mission.
In an interview with the Weekend FT, Public Health Department Chief Medical Officer Dr. Ruwan Wijayamuni elaborated on their plans and said that he is hopeful that the two pilot projects will bring the numbers down.
Use of marshes
“Now we are embarking on a new project,” Dr. Wijayamuni said. “We are doing a trial with marshes. Marshes are also a big problem. Marshal lands can be found in places like Modera and Mattakuliya. They also contain clear water; so the water is not necessarily dirty and can still breed dengue mosquitoes. We are trying a water-proof environmentally friendly chemical called Aquatain. It’s a silicone-based liquid. It spreads across the surface of water and forms a film.”
When this film is formed, the larvae are prevented from reaching the water surface to breathe, resulting in them drowning.
“In Australia they use it to control mosquitoes as well as to prevent the evaporation of water and to maintain the water level in big water bodies during the dry season because once there is a small thin film the mosquito larva which uses its siphon to come up and take oxygen can’t do that because there’s a surface tension height – they can’t put the siphon up. So they get killed in a couple of hours. 1 ml of Aquatain is enough for one square metre area of water surface. They eventually drown without oxygen. It’s a trial. If that goes well I think we can cover all the marshes,” he said.
The CMC also plans to get school leavers involved in their work, whereby they are selected and trained to find potential breeding places such as yoghurt cups in their environment. They initially planned to engage school children in this project but as they are too small for work of this nature, it has now been decided that it would be more appropriate to engage school leavers as they are around 18 to 20 years of age. Four school leavers per council
“I’m trying to get 200 school leavers from low-income families and will pay them Rs. 200 each per day. They will be paid basically Rs. 1 per potential temporary breeding place that they find. For example, for one discarded yoghurt cup they get Rs. 1, for a bottle Rs. 1, etc. So this goes upto a maximum of Rs. 200 and 200 people are doing this so we can collect 40,000 breeding places per day.
“So with 40,000 containers per day and if we leave out Sundays, it’s 25 days per month, we can collect one million discarded containers for a month. I got the approval from the Council to have a pilot project for six months. I’m going to embark on that particular endeavour this week. Translating it from Sinhala we call this the ‘Dengue birth place detection and destruction’ project.
“This will have a triple effect. The number of discarded containers in the environment will be reduced, the mosquito population will be reduced and if the mosquito population or density goes down it will certainly reduce the number of dengue cases,” he explained.
The main purpose of engaging school leavers, he added, is that it will give knowledge, change the attitudes and inculcate healthy practices among them.
“The school leavers may not be able to collect 200 containers per day as it is a very big task; maybe at first they can but as the project goes on they might have to get their siblings or friends involved; people can get together and help,” he said.
The CMC is discussing the involvement of a Children’s Guild now, whereby the guild selects four underprivileged school leavers from their community and the money that they collect goes to the guild. “It’s a huge amount,” he said. “Rs. 20,000 per month goes to the Children’s Guild which belongs to the Community Development Council (CDC) which is a conglomeration of households in the low income settlements such as those in Modera and Mattakuliya.
“By getting the Children’s Guild involved, rather than developing only one individual, they can start planning the use of the money for the betterment of the society; so that’s how it evolved,” he said.
When asked if the money will be going directly to the guild or the children, he said that the technicalities have not been discussed with the authorities as yet and meetings are still taking place before finalising the best approach.
The ongoing battle
The Public Health Department’s battle against dengue is an ongoing one. The last time the Weekend FT met Dr. Wijayamuni in July, we were informed of some very effective strategies that had been put in place and the situation seemed to be getting under control but presently in September, the numbers are still worrisome.
Giving us an update as at 10 September which is when the Weekend FT met up with him, Dr. Wijayamuni said that in the year 2013, from January to 10 September 2,450 cases were reported and in the year 2014, from January to 10 September there were 2,323 cases.
So there was a slight decrease in the cases reported.
“When you take the total number of cases from 1 January to 10 September there has been a 5.5% decrease overall in Colombo while there was a slight increase in other parts of the country,” he said. “We started reporting with a 60% increase – this was in May; compared to the data in June last year, there was a 60% increase because it was going really very fast.
The cases had started going up since April and every year usually we have the peak in July. We have two peaks – one in June/July and the other is in November/December.
“We are talking about the June/July peak now – we were actually expecting – and if this trend had continued we would have had around 600-700 cases for that month of June. If we compare the June first week data in 2013 the number of cases were in 60% excess but by mid-June we were able to bring it down to a 40% increase (excess) and by end of June we brought it down to 20% and by end of July, compared to last year we were able to bring it down to a 40% increase compared to the number of cases that were reported in July last year.
“But when we look at the past data for four years; in 2012, 2013, 2014 the peak is always in July with the exception of 2011. This year also it meant to be like that – it started going up with that 60% increase and it was going up – we were expecting around 700 cases – but with the change in strategy, it has decreased sharply and we were able to shift the July peak to June. So the July peak compared to all the other years has come down,” he said.
The Public Health Department has tried various tactics to bring the numbers down. One of the tactics used was indoor fogging. They started indoor fogging as they found that to be more effective than outdoor fogging. Less fog is needed and the mission is accomplished within 10 seconds. This was started towards the end of May and numbers started coming down. “We completely changed the dengue control strategy and the indoor fogging was started; open air fogging was completely forbidden and the spraying of Aicon commenced, then the number of cases showed a decline straight away,” he said.
“We were able to kill the infected mosquitoes efficiently by indoor fogging. In the past it was done in the vicinity, but we found that it was a waste of chemical, energy and money. That only has a mosquito referral effect where the mosquitoes only fly away. So we can’t really kill them. Also they can get adapted or resistant to the chemical. But when we spray indoors, there’s only a small amount of fog that we require and if we just fog the small household for 10 seconds that’s enough!
“Then you close the doors and windows and leave it like that for half an hour and within that time all the mosquitoes are dead, along with the cockroaches and other pests in the house. So we have double or triple effects by doing that,” he said.
High Risk Strategy
“Starting June, we had programs together with the Health Ministry and the presidential task force on dengue control; we embarked on the national dengue control program. We had a meeting with the President and he gave very clear instructions to the Ministry of Health. All this time we were working on our own so I thought that we should open up because being in Sri Lanka and trying to be separate from the rest of the island was not practical as mosquitoes do not identify or recognise borders.
“So it was opened up and we started working on a common strategy – the High Risk Strategy was adopted, where out of 47 wards, 21 were selected first and those were focussed well,” he said. He was referring to the program he had talked about to the Weekend FT during our last visit – they had embarked on a comprehensive dengue control program where they selected the high risk wards or the geographical areas that were producing the highest number of cases so that they could focus and place their resources more efficiently.
“We had basically five main programs where we deployed nearly 19,500 people, mostly the troops – mostly from the tri-forces; the police, health personnel from the Health Ministry and also our own people. We were able to cover the entire housing lot within the city of Colombo for the first time in history. In the past we had only covered around 10,000 or 20,000 houses. We have about 1,118 households, 124 schools, around 15 international schools, private premises, government institutions, etc.
“Then later we embarked on the entire city – we went for a blanket cover. When we did the blanket cover, at the high risk areas, houses were re-inspected twice or thrice. We were able to bring it down very sharply,” he continued.
“We completed six phases. The number of cases has come down. With the rains, there has been a very slight increase – about 15 cases have been reported in excess. In August this year we have recorded a 40% decrease compared to the August of 2013. There is a very slight increase in the first week of September. This month so far we are almost parallel to the number of cases that were there in September 2013, probably because of the rain pattern. Last year it was 83 cases and as per yesterday there were 84,” he said.
Potential breeding places at 16%
After several strategies have been put in place and improvements being made, Dr. Wijayamuni remains concerned about the numbers. “My biggest problem is, we have done so many programs – where we have inspected all the schools, pre-schools, tuition classes, higher education levels, houses, hostels – we have inspected 1,643 institutions and out of that we found 263 premises with breeding places. So our potential breeding places are 16%. That means despite all our health education, the pressure that we were putting on, still when we inspect 100 places, we can see 16 places out of 100 potential breeding places!” Dr. Wijayamuni exclaimed. This is when they realised the necessity to do more and decided to embark on the two pilot projects.
Dr. Wijayamuni said that the number of places with larva has actually come down to 1.5 out of 1,643 and that they only found the larva in 25 houses/premises. It’s not bad, he said, but if it is to be kept at endemic level, we have to keep fighting.
“We are fighting a war; it’s not only the health authorities, we all have to pitch in. It’s a gigantic task; I think we have been able to bring some changes but this 16% is still my biggest worry,” he said and added, “Again with the rain, it might go up because when it rains water collects, so this is what we have to get rid of – actually if we can bring down the number of premises with larva, bring the index positive for larva to 1% ie if out of 100 houses that we inspect if we find mosquito larva in only one place, then we can suspect that there won’t be any outbreak or epidemic – it won’t go beyond endemic proportions.”
“There are a few things that we have to do. The very first thing is, in an epidemic situation we have to knock down the adult infected mosquitoes. They are the fellows who can infect people. So you have to really do something about the adult mosquitoes. That’s why we sprayed inside houses and the walls because when they go and rest, they will get killed.”
“In the meantime we have to focus on temporary breeding places – we have to find and destroy them and permanent breeding places like slabs should also be attended to,” he said.
Keep the grip and pressure on
Contrary to what has happened in the previous years, this time they have decided not to loosen the grip! “All this time what happened was when the cases are there everyone is waking up and going and attending to that and then they forget it. Then they wait again and when again some cases are coming up then again they start to do something, Dr. Wijayamuni said.
“But this time we decided not to loosen the grip, we have to keep the pressure on but now of course, on soft pedal when there are fewer cases because you can’t keep the momentum all the time – it’s the same set of people who go from house to house – it’s a tedious process and it gets stale. It’s not something fancy that you’re really interested in – going into someone else’s backyard – it’s someone else’s work but we are doing it because they aren’t. So it’s not a very interesting game,” he concluded.