kala-azar is spreading. Two cases of the disease, usually found in eastern parts of India, have been reported from Gujarat and Madhya Pradesh. The pathogen could spread in the area because sandflies, which transmit it, are already present in the region. The treatment for kala-azar is generally expensive and has been found ineffective in some cases.

Analysing the cases, researchers at aiims, New Delhi, found the patients had no exposure to endemic regions like Bihar and Assam. Neither had they undergone blood transfusions, a source of infection. Given this, there is a possibility that the disease could be emerging and spreading to new areas, says Sarman Singh one of the researchers.

Researchers suggest these random occurrences could have been triggered by increased ecological disturbances such as deforestation forcing sand flies to move to urban areas.Though the flies were widely destroyed during the malaria elimination programme in the 1980s, reasearchers suggest its population could be growing again.

The study was published in the Journal of Vector Borne Diseases (September 2007) and the American Journal of Tropical Medicine and Hygiene (July 2007).

Researchers say migrant workers from eastern parts could have taken the disease west. In western India, kala-azar treatment is not available easily. Disease-specific care is absent. "These are sporadic case reports but could be early signals of focal outbreaks, and may indicate ecological changes conducive for disease transmission,' says Shyam Sundar of the Kala-azar Medical Research Centre, Institute of Medical Sciences, Banaras Hindu University, Uttar Pradesh.

Scientists fear more cases of kala-azar might be going unreported. P K Sinha of the Rajendra Memorial Research Institute of Medical Sciences in Patna, Bihar, says: "Aspects like ecology and climate, and presence of conditions like hiv need to be considered to understand the spread of the disease.'