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Midnight blood tests for filaria diagnosis could soon be a thing of the past as bioscientists have developed a kit to detect the infection, a first such method in the world.

The kit, developed by a team of bioscientists led by Prof P Kaliraj of Chennai's Anna University, can be used to test blood samples anytime of the day.

In earlier methods, for microscopic observation the blood samples had to be taken at midnight when the microfilaria parasite becomes active.

"Using this method, blood samples can be taken anytime during the day and the test results are known within three minutes," Kaliraj said in New Delhi.

The Rapid Detection Kit for Filariasis, developed in collaboration with Surat-based Span Diagnostics Ltd, has passed stability tests as per the European Pharmacopoeia and is available at medical stores.

The kit has been developed as a part of the Filarial Genome Project of the World Health Organisation in which the Centre for Biotechnology of the Anna University was involved in the process of sequencing the genome of the filarial parasite.

As the post genomic approach, Kaliraj's team has identified more than 20 targets of diagnostic and prophylactic importance from the cDNA libraries of Brugia Malayi and Wuchereria bancrofti, the filaria causing parasital worms.

The US-based Centre for Disease Control has carried out efficacy tests across five countries in different climatic conditions, the results of which were very encouraging, Kaliraj said.

The WHO policy for global surveillance, monitoring and elimination of the disease, the antibody kit is highly recommended for the field application to monitor the exposure to disease in children and travellers.

"The kit is cost effective as each test costs Rs 40. This could be reduced further once we achieve greater volumes," Pradip Desai, Chairman, Span Diagnostics, said.

The kit uses the anti-filarial antibodies detection method, which is considered to be the most sensitive and accurate way of diagnosis of filariasis.

The process provides evidence of the ongoing exposure to filarial infection long before the development of microfilaria, where detectable level of antigen is low due to slow growing nature of the disease.

Filariasis is endemic in tropical regions of Asia, Africa, Central and South America with an estimated 120 million people worldwide being infected by it every year.

An estimated six million case of acute filariasis occur every year in the country.

The most common symptom of lymphatic filariasis is elephantasis that involves thickening of the skin and underlying tissues. The disease affects mainly lower extremities and ears, mucus membranes amd amputation stumps are rarely affected.

The kit was launched by Minister for Science and Technology Kapil Sibal on Monday.