The Indian Council of Medical Research (ICMR) will soon commercialise its newly developed technology which is a process for diagnosis of infective (L3) stage larvae of Wuchereria bancrofti in vector mosquito Culex quinquefasciatus. To commercialise this newly developed technology, the ICMR has invited proposals from companies interested in commercializing this process.
The infective (L3) stage of Wuchereria bancrofti is the one that initiates infection in human after getting itself transmitted through the bite of infective mosquitoes. Detection/ diagnosis of presence of L3 stage of the filarial parasite is important for monitoring the transmission of infection in a filariasis endemic area, delimiting filariasis endemic areas and monitoring control operation such as recently launched Global Programme for Elimination of Lymphatic Filariasis in all the endemic countries.
Senior ICMR officials said that currently it is being done by conventional technique of dissection of vector mosquitoes followed by examination under microscope. Alive mosquito brought from field for examination of infection is knocked down using ether and then dissected in a saline solution with the help of needles and forceps. The skilled technician will then observe under microscope for the presence of parasite stage and records the observations.
This technique is cumbersome, needs experienced person to observe the infection, subjective and not amenable for large-scale screening of vectors. Therefore, an alternative diagnostic technique, RT-PCR, has been developed by VCRC which is not cumbersome, does not require live mosquito sample, and is amenable for large scale screening of mosquito vectors, unlike the conventional technique.
Salient features of the newly developed technology are: Indian patent application has been filed; the process is 90-100 per cent sensitive and specific for the diagnosis of infective stage (L3) larva of filarial parasite in vector mosquito in pools of vector mosquitoes; the kit has been developed based on Reverse Transcription (RT)- PCR; the kit includes a pair of primers to amplify W. bancrofti L3 stage specific fragment of 111 bp; and it can be applied for monitoring filariasis elimination programmes such as Global Programme for Elimination of Lymphatic Filariasis (GPELF) and National Vector Borne Disease Control Programme (NVBDCP).