THE government is stepping up the campaign against dengue through various science-and-technology interventions, which include prevention, treatment and diagnostics.
The intensified campaign came in the wake of reported increase in dengue cases. The Department of Health (DOH), over the weekend, said dengue cases in Luzon increased by more than 73 percent compared to last year. In Metro Manila alone, dengue cases increased from 5,416 from January to August last year to 10,487 this year.
Dengue, a hemorrhagic fever, is an acute infectious disease manifested initially with fever. The fatal disease is transmitted by day-biting Aedes aegypti mosquito, which breeds and lays eggs in clear and stagnant water.
The Department of Science and Technology (DOST), in partnership with the Department of Education (DepEd), will distribute within the month free Ovicidal Larvicidal (OL) mosquito trap kits in various schools, where dengue cases have been reported to be high.
The DOST, in partnership with the private sector, is also set to make the OL mosquito-trap kit commercially available next month.
An OL mosquito trap kit, which the DOST has developed, costs around P10 to P15 and the pellet used to make the larvicide solution to extinguish mosquito eggs and larvae costs around P1 to P1.50.
The campaign to stop dengue among schoolchildren will start in Metro Manila, Science Secretary Mario Montejo said in news conference on Friday.
Montejo said, “Our priorities will be schools in hot-spot areas, communities around the schools and barangays.”
Some 34,910 OL mosquito trap kits will be distributed in public and private elementary and secondary schools in the cities of Caloocan, Quezon, Pasay, Valenzuela, Manila, Muntinlupa and Pasig. This will cover a total of 17,454 classrooms.
Also within the month, the DOST and DepEd will extend the distribution to schools in Ilocos Sur, Benguet, La Union and Pangasinan, where about 46,500 OL mosquito-trap kits will be distributed for free.
An OL mosquito-trap kit has three parts: a black container, a small strip of wood locally known as lawanit for mosquitoes to lay eggs on, and a larvicide solution. The scent of the larvicide solution attracts female mosquitoes and encourages them to lay eggs on the immersed lawanit strip. Once exposed to the solution, the eggs and hatched larvae will die.
In effect, the OL mosquito trap prevents the next generation of mosquitoes from reaching adulthood and curbs the Aedes aegypti mosquito population effectively, according to Antonio Ligsay, chief of research and development management division of the Philippine Council for Health Research and Development (PCHRD) of the DOST.
Launched in May last year, 200,000 pieces of OL mosquito-trap kits have been distributed to various barangays nationwide. Recently, the DOST produced and turned over 500,000 additional OL mosquito-trap kits which have been distributed by the DOH.
The larvicide solution is composed of organic solution of water and the DOST pellet for the mosquito trap developed by the PCHRD and the Industrial Technology and Development Institute (ITDI) of the DOST.
The pellet is essentially a byproduct of black pepper, whose active ingredient that attracts mosquitoes when dissolved in water and kills 85 percent of eggs and larvae remains unknown.
According to Ligsay, the DOST is also conducting a whole range of dengue research and development. He said the DOST is embarking on a program to extract the active ingredient from black pepper. He said that a single mosquito is enough to produce the disease. By extending the action of the DOST pellet in the larvicide solution they have developed to prolong the effect from mere 7 days to 15 days or possibly a month using a gram of the DOST pellet dissolved in clean water.
“We want to know what produces the action. We have already asked experts from UST [University of Sto. Tomas], La Salle [De La Salle University] and UP [University of the Philippines] to do research on this together with the DOST,” he said.
He added that if the active ingredient is isolated, there is a big chance that the efficiency of the solution could be enhanced—killing 100 percent of the eggs and larvae in the OL mosquito trap instead of only 85 percent.
He added that there is also a long-term study, in collaboration with the DOH, to determine the effect of the use of OL mosquito trap to dengue.
While there is proof that the DOST’s OL mosquito trap sites show decrease in dengue cases, there is a need to determine whether its continuous use will really curb the mosquito’s population and reduce dengue cases in the long run.
Other research and development initiative includes the use of active ingredients in plants to cure dengue.
“We are currently looking into plants like kamote [sweet potato], bawang [garlic], papaya, tanglad, luyang dilaw and ampalaya. These plants and fruits are effective against certain viruses that’s why we want to know if they are also effective against dengue,” he said.
Meanwhile, to prevent deaths, he said the DOST is embarking on another project to promote the rapid diagnosis of the disease from day one.
Soon, he said persons with fever could be tested using a kit similar to the pregnancy test kit to determine whether the patient is positive or negative to dengue.
The rapid diagnosis of dengue, he said, is important because of reports that dengue is becoming more and more fatal.
“Sometimes, persons with dengue die on the second day. We want to prevent this by developing a DNA-based dengue test kit to determine whether a person is positive with dengue on the first day,” he stressed.
Initial results from various regions revealed decrease in dengue cases after using the OL trap, data from the DOST show.
In Cagayan Valley, five schools in Ballesteros and Claveria towns in Cagayan reported “zero case” as of press time, namely, the Libag Elementary School, North Central School, Caritan Elementary School, Cataggamman National High School and University of Cagayan Valley.
Official reports showed that in 2010, there were 210 cases of dengue among schoolchildren in the four barangays where these schools were located.
Ballesteros and Claveria were declared “hot spots” for dengue cases last year, with the former having 213 cases and the latter, 15 cases. To date, there have been no dengue cases reported since the rollout.
With the decrease in dengue cases reported in the region, Dr. Antonio Labasan, municipal health officer of Solano, Nueva Vizcaya, said that additional OL trap units are needed for other barangays as they found that mosquito eggs and larvae are “killed right there and then.”
“It is the only way to stop the [mosquito] eggs from hatching,” he added.
In the Eastern Visayas where the OL trap was initially launched, results showed that five barangays in Northern Samar, Southern Leyte and Leyte showed zero results after the OL trap was used.
Barangay Dalakit in Catarman, Samar, for example, had 44 cases last year while barangay Airport had 30 cases. Barangay 109-A in Leyte had 64 cases, while its neighbor, barangay 109, also showed significant result having decreased its dengue cases from 122 last year to three this year.
Similar positive results were also seen in Northern Mindanao. Dr. Josephine Ibalo, the DOH dengue coordinator in Bukidnon, noted 36 cases in the whole province as of August 10 this year, a significant decrease from last year’s 1,087 cases and 16 deaths.
In Photo: Ovicidal Larvicidal (OL) mosquito trap kits
