To spray or not to spray?

Spray of DDT for malaria vector control is discontinued all over the world except in India particularly in the North East. The WHO has objected to its use but the Indian government has argued that Indoor Residual Spray (IRS) needs to be continued due to its effectiveness and disease endemicity in the region. Should it be continued in Nagaland? Here are some pros and cons:

 

Pros:

• It is effective in vector control. UMS Dimapur study shows that vectors in the State are still susceptible to DDT although resistance does exist.
•  There is no good alternative. Long Lasting Insecticide-treated bed Nets (LLINs) are costly and difficult to procure. 
• It is safe if technical guidelines are followed during spraying.

Cons: 

• DDT is a bio-hazard. If it is sprayed outside and enters the food chain, its concentration increases through Bio-magnification. 
• Acceptance is low. There is reluctance to have it sprayed indoor. People prefer to have it sprayed outside which is counter-productive (chases the mosquitoes inside the house). 
• Technical guidelines are difficult to follow in the ground: Villagers ask for their share of DDT rather than having it sprayed in their houses.

 DDT will be used for a number of years to come. It is very necessary that people are made aware of the risks and benefits, and technical guidelines be strictly followed whenever and wherever used.