'It is coming. It comes with the monsoon,' Dr Chusak Prasittisuk, WHO's coordinator for communicable diseases here, told The Straits Times on Wednesday.

India's neighbouring countries, however, are in no immediate danger as no cases of the disease had been reported, he said.

According to India's National Vector Borne Disease Control Programme (NVBDCP), as of June 19, a total of 17,059 suspected cases of chikungunya had been reported from 16 states across the country.

Of these, 1,797 blood samples had been sent for testing and 414 had been confirmed as positive.

Though the figure is considerably lower than last year's figure of 1.39 million, Dr Prasittisuk said 'the worst is yet to come'.

He said the disease is not fatal but it could lead to health complications resulting in death.

WHO is assisting the government by providing technical information regarding the disease and the guidelines for combating it.

The disease is spread by the bite of the Aedes Aegypti mosquito and the symptoms are fever, chills, headache, nausea, vomiting, joint pain and rash.

The highest incidence of the disease had been reported from the southern coastal state of Kerala (12,900), followed by Gujarat (2,900) and Karnataka (750).

The figure quoted by the WHO official for Kerala is higher than the 7,000 given out by Kerala Health Minister P.K. Sreemathi earlier this month, indicating a rapid spread of the disease.

Dr Prasittisuk described chikungunya as an 'ecological disease' created by man.

He said the 'artificial breeding places created by man' for mosquitoes are causing the disease to spread.

Because of the tropical wet climate of states like Kerala, rain water often accumulates in coconut shells, discarded tyres, cans and other items that collect water.

The Kerala government earlier this month sought the help of the army in checking the spread of the disease and launched a week-long clean-up campaign across the state.

Dr Prasittisuk described the chikungunya situation in Kerala and Karnataka as 'unique'.

That was because besides the Aedes Aegypti mosquito, the usual carrier of the virus, the Aedes Albopictus or Asian Tiger mosquito had also become a vector.

Indian cities have witnessed a sharp increase in mosquito population, according to NBVDCP, and this has resulted in an increase in chikungunya, dengue and malaria cases in recent years.

Movement of people between states and across the borders has also contributed to proliferation of the disease, experts said.

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