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Anti-dengue bacteria: medical experts at odds
By Sachitra Indivara Mahendra
A government appointed committee to look into the possibility of importing a bacteria variety to fight dengue, has opposed the move and insists it is better to keep the environment clean rather than use the bacteria.

"We can't put it in every small container where water collects. The best option is to see that containers do not retain water that invites mosquito-related diseases, rather than introduce bacteria into every little container. It appears to be expensive as well as impractical," said Science and Technology Minister Tissa Vitarana, who chaired the Health Ministry appointed committee.

The committee report was handed over to Health Minister Nimal Siripala de Silva this week. Prof. Vitarana, a former director of the Medical Research Institute, said the role of the bacteria (BTI) in controlling the present dengue epidemic would be limited.

"The use of BTI in water storage tanks is not valid since they play only a small role in carrying mosquito-related diseases. The main breeding grounds of the dengue mosquito are tins, bottles, plastic cups, coconut shells, husks and rubber tyres. Studies done at the MRI have indicated that about ninety per cent of dengue mosquitoes breed in such containers during the rainy season. Therefore, we believe priority should be given to preventing rainwater collecting in such containers," Prof. Vitarana said.

He said Cuba had got rid of the mosquito menace not only by using BTI but also through an intense campaign to get rid of small breeding spots. The bacteria has already been imported by the Colombo Municipal Council for use in the city.

"We are using the bacteria while urging the people to keep the environment clean," Chief Medical Officer Dr. Pradeep Kariyawasam said. When told of the Health Ministry appointed committee's views, Dr. Kariyawasam said: "The committee may say that it is not practical. But I have been to Singapore and have seen how effectively the bacteria works there. Even in some other countries it has proved effective. The World Health Organization also has recommended it. Many scientists are trying to produce the bacteria locally. So we are continuing to import it though the views of the committee differ. The CMC is not under the Health Ministry. I have recommended importing the bacteria and I am doing it on my own."

Meanwhile Dr. Kariyawasam referring to last week's news item in The Sunday Times, said that the CMC had not imported Bacillus Thuringiensis Isarelensis (Bti) H 14 formulation from Cuba, as mentioned.

"We have never imported any bacteria from Cuba although we made efforts to do so. However, we have BTi 12 AS from Germany. This was imported after following tender procedures. This is now used to spray the waterlogged areas and marshes in the city. Preliminary work has shown good results but spraying BTi is playing a minor role in our dengue control work which is spearheaded by a cleanup and awareness creation campaign. However dengue continues to spread in the city unabated with 190 cases reported last month - an all time record for the city," Dr. Kariyawasm said.

"Some years ago we received some Bacillus Sphericus (BS), which had been imported by the Health Ministry from Cuba and donated to us. That was used to spray the canals in the southern part of the city and yielded good results. We were since then trying to import these bacteria from Cuba but due to some reasons it never worked out," Dr. Kariyawasam said.

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