Dengue Update

Public warned: Perfume attracts dengue mosquitoes
By Cynthia Balana
Philippine Daily Inquirer
First Posted 05:12:00 09/22/2010

Filed Under: Dengue, Health, Diseases, Health and Beauty Products
MANILA, Philippines—Perfume, which people use to attract the opposite sex, also attracts dengue and malaria-transmitting mosquitoes, according to a medical scientist who studies the behavior and biological life of insects.
Dr. Estrella Cruz, an entomologist at the Research Institute of Tropical Medicine (RITM), Tuesday said mosquitoes were attracted to people who sprayed too much perfume or cologne, who sweated profusely, and who wore dark, sleeveless clothing and shorts.
“Mosquitoes are attracted to hundreds of stimuli. They can smell humans, more so when you spray perfume or when you sweat,” Cruz said at a health forum on “Balancing the Department of Health’s Actions on Dengue” sponsored by the Philippine College of Physicians in Quezon City.
The Department of Health said that dengue, a mosquito-borne disease, has afflicted more than 50,000 people, and has killed at least 500 people.
The disease usually affects children and those whose immune system is weak. A mosquito transmits the disease by biting an infected person and then biting someone else.
2 types of mosquitoes
There are two types of dengue mosquitoes in the Philippines—the Aedes aegypti and the Aedes albopictus. The former dwells inside the house, mostly in dark places like the closet, under the bed and under the table, while the latter lives outdoors, mostly in drums and places with stagnant, clean or rain water, as well as in plants.
Although dengue mosquitoes are day-biting insects, they also bite at night, although at a very low density level, Cruz said.
Peak biting time is early morning between 6 a.m. and 8 a.m. and late afternoon or sunset between 4 p.m. to 6 p.m.
Cruz said it was important to know the peak biting time of mosquitoes for effective control measures like fogging.
She also warned against fogging when it’s raining or during hot days as the chemical used to kill the mosquitoes would not be as effective.
4 strains of dengue
Dr. Hazel Galang, an RITM virologist, or one who studies the viral strains and their activities in a laboratory, said there were four strains of dengue virus in the Philippines.
There were news of a possible fifth strain in the country but Galang said this had not been proven by research as there were not enough samples to date.
Since 2005, the RITM has been trying to determine which specific strain of dengue virus is unique to the Philippines and which is transmitted by mosquitoes from other countries, Galang said.
Blood transfusion
There is no specific treatment for dengue.
Dr. Allan Racho, a pediatric hematologist at St. Luke’s Medical Center, said patients with Grade 1 and 2 dengue should rest, drink plenty of fluids and take a paracetamol. Or they can go to health centers where they can be administered with IV fluids or dextrose.
He said only patients with Grade 3 and 4 dengue should get a blood transfusion.
It’s complicated
“Dengue is primarily a transient disease, meaning it follows its own clinical course. The problem with dengue is the complications,” Racho stressed.
He said the virus can affect the vascular system, the liver and the bone marrow. In some instances, the virus can attack the heart, brain and other parts of the body which could lead to death.
If after three days, the fever does not dissipate, Racho said the patient must go to a doctor for a blood test.
Dark mosquito trap
Nuna Almanzar of the Industrial Development Institute-Department of Science and Technology has developed a dark mosquito trap with a specially formulated solution that attracts female mosquitoes.
Almanzar said in the forum that the trap was being tested in 500 homes in “hot spot” barangays in Marikina City and another 500 homes in Quezon City.
A female mosquito, Almanzar said, can lay eggs three to four times in one cycle, and could breed 200 eggs or 800 eggs in one cycle.
Of these eggs, about 80 percent develop into female mosquitoes.