Saturday, 28 January 2017

Dichloro Diphenyl Trichloroethen (DDT) Vs. Synthetic Pyrethroid (SP)


DDT (50%)
In order to reduce the incidence rate of Vector Born Diseases, the Govt adopted dual strategies like Reduction of Vector growth as well as Reduction of Parasitic growth. The reduction of the vector growth can be achieved through effective use of insecticides. Generally, this happens in 02 different ways: 1. Release into air in the form of Vapour (Fogging) 2. Application to the surface in form of spray/deposit. In case of Kala Azar, though the vector is found inside the room, hence the second strategy is found to be more effective than the first one. In public health when we choose any insecticide for Residual spray, few things have been taken in

Synthetic Pyrethroid


to account i.e Toxicity to the targeted vector, Longevity on given surface, Lethal effect/not repellent, Acceptance in the community, Safe for Human as well as Domestic Animals, Suitability in storing and transportation, Cost effectiveness.
Stencilling
During the initial period DDT has been used for IRS in Kala Azar elimination program implemented in all the 33 Kala Azar affected districts of Bihar. Over a period of time it has been observed that the rate of reduction in the incidence rate is very slow. It was suspected that due to continuous use of DDT leads to resistance in sand-flies which reduces the lethal effect and the second major cause was reduction of community acceptance due to white stains on the wall & bad odour.


Spray using Stirrup Pump
In order to speed up the reduction rate, Govt.of Bihar has taken initiative to change the insecticide i.e shifting from DDT to Synthetic Pyrethroid. This not only overcome the above drawbacks but also more effective in terms of storage & transportation, Water solubility & longevity etc. Though SP (Synthetic Pyrethroid) is water soluble, doesn’t leave any stains on the wall/surface and odourless, hence easily accepted by almost all communities irrespective of caste, class, race & religion.