THE Ministry of Health (MoH) started an impromptu, emergency campaign January 30

against an outbreak of mosquitoes breeding as a result of Phnom Penh's sewage

cleanup. The MoH will spray insecticide for at least a week in some of the

city's 76 communes, said Dr Duong Socheat, director of the National Malaria

Center (NMC).

However, the sudden outbreak should prove merely annoying

rather than a health risk, said the World Health Organization's malaria expert

Dr Stefan Hoyer.

"The Culex mosquito has found an ideal breeding ground

in the open sewage canals on Monivong Boulevard," said Dr Hoyer, "but Culex

cannot transmit dengue fever or malaria, and the dengue-carrying Aedes mosquito

cannot breed in sewage water."

The mosquitoes have been plaguing more

than just the citizenry, said Dr Socheat - many government officials had

complained to his department about the problem.

Chanthy is a resident in

the city's Boeung Tumpun commune and lives near the sewage system. He said the

insects had proved an expensive nuisance.

"Every night the mosquitoes

come and bite me. Even though I spray insecticide, they keep flying back," he

said. One bottle of insecticide costing 6,500 riel ($1.60) was lasting him only

three days. "I have already finished four bottles, but still they keep coming

everywhere. You can see my hands are covered with bites."

What is bad

news for Chanthy is good news for the pest-controllers. Huth Daravuth is the

market manager for the Chheng Khieng Import Export Company. He said sales, which

normally dropped in the hot season, had shot up this year.

"I normally

sell 30,000 bottles of insecticides and 3,500 boxes of mosquitoes coils each

month," he said. "This year I have sold 42,000 bottles and 5,000

boxes."

The city's more affluent residents have tried the pest-control

companies. Bora Moeu, general manager of Pestbusters, said he had gained 30 new

customers since December.

"Before there were only foreign clients, but

now Cambodian customers come to us as well," he said. The service comes at a

price: customers pay $60 for a one-time spray that keeps their homes mosquito

free for about four days.

Moeu said sprays and mosquito coils were fine

as a short-term solution, but it was more important to track down the larvae.

WHO's Dr Hoyer said that was exactly what the campaign would do by following the

trail back to the sewers where the insects breed.

"It is much more

efficient to kill the larvae than the adults," he said.

Technical advice

from WHO in Geneva showed the amount of larvacide needed to kill larvae in

sewage would be at least 12 times that needed for clean water.

"That is

not a practical solution because we need to keep enough larvacide to prevent a

[potential] dengue outbreak in May," he said. An outbreak of dengue fever in

January 1998 resulted in 256 cases among Phnom Penh's children, said the NMC. Dr

Hoyer said a better solution would be a light covering of oil on the stagnant

water to suffocate the larvae and breeding mosquitoes.

"The MoH and WHO

have been concerned to find a practical, long term solution because this kind of

sewerage work is likely to continue," he said. The MoH would now keep an eye on

future sewerage work in the city to prevent further outbreaks.

People

should take the war against mosquitoes - which survive for around one month -

into their own homes, said Dr Hoyer. Spraying water outlets in the bathroom with

insecticide, pouring small amounts of non-toxic oil in vases and spraying

insecticide early in the morning are all effective ways of dealing with the

problem.