10 Dec 2012
Kala–azar, known to claim a few lives every year in North and East India, including West Bengal, may soon be a thing of the past, courtesy an effective vaccine developed by acity scientist.
Nahid Ali, a scientist at the Indian Institute of Chemical Biology (IICB) who worked on the vaccine for 10 years, has published a paper on her successful research in an international medical journal last month.
Successfully tried on an animal model, the vaccine is now being further modified to increase its potency. While several other organizations and scientists have been working on kala–azar vaccines, Nahid’s paper claims it is the first and the most advanced one so far.
Transmitted by sandflies, kala–azar is caused by the Leishmania Donovani parasite, named after its discoverers. Epidemics were common till 1946. One had even resulted in 7,500,00 people dying in three years in India.
Even though the malaria eradication programme had almost wiped out the disease from 1954 till 1974, outbreaks were reported from West Bengal and Bihar again in the Seventies. Ever since, sporadic outbreaks have been recurring. It is widespread in as many as 48 districts across Bihar, Jharkhand, West Bengal and Uttar Pradesh and around 165 million people are believed to be at risk.
"I worked independently like so many others did. The extent of parasite–level reduction in my animal model trial was substantially more than other experiments have managed. I am still involved in developing the vaccine further. Certain modifications are needed to increase its effectiveness. I expect to do it in the next few months," said the scientist.
WHAT ARE THE SIGNS OF KALA–AZAR?
Recurrent fever – intermittent or remittent with often double rise, loss of appetite, pallor and weight loss with progressive emaciation
Kala–azar is caused by a protozoan parasite of genus Leishmania. In India, Leishmania donovani is the only parasite causing the disease
The parasite primarily infects reticuloendothelial system and may be found in abundance in the bone marrow, spleen and liver SYMPTOMS 1 Splenomegaly – spleen enlarges rapidly and usually becomes soft and non–tender 2 Liver – enlargement not to the extent of spleen but organ develops a sharp edge 3 Lymphadenopathy or swollen lymph nodes – not common in India 4 Skin – dry, thin and scaly and hair may be lost. People with light skin colour show greyish discolouration of the skin on hands, feet, abdomen and face. Disease called Kala–azar meaning "Black fever" in India because of this. 5 Anaemia – develops rapidly and further adds to the weakness