MANILA, Philippines ? Camanava (cities of Caloocan, Malabon, Navotas, Valenzuela) health officials discourage the use of fogging amid rising number of dengue cases in Metro Manila.

Fogging may kill the mosquitoes that bring the dreaded dengue but it may also create a health backlash to city residents if applied indiscriminately, said city health officials of Camanava.

Caloocan chief health officer Dr. Racquel So-Sayo said in an interview that they preferred the ?smokeless? Hudson sprayer to fogging because it was safer.

The Hudson sprayer is a low-volume sprayer that emits insecticides in small mists instead of heavy smoke produced when fogging.

?It is the same insecticide content but the extent of effect is different,? said So-Sayo.

For one, she said, the low-volume sprays target specifically the mosquito larvae in the area increasing the preventive effect of the process. Fogging, on the other hand, targets the killing of adult mosquitoes which may or may have already fed off some resident at that stage of growth.

The use of Hudson sprayers, So-Sayo added, has very low impact to the residents of the sprayed area because of the low volume of insecticide sprayed.

Fogging, she said, has always resulted to health complaints from residents who experience respiratory problems due to the heavy smoke the procedure created.

Malabon?s chief health officer Dr. Billy Goco likewise recommends that the use of fogging should only be as a last resort to other preventive measures such as maintaining cleanliness in households.

Fogging, he said, was also not environment-friendly as it spewed insecticides into the air.

He said fogging should only be used in areas where a dengue epidemic has been declared and if the number of mosquitoes in the area has reached a dangerous level.