Eluru (Andhra Pradesh), Dec 10 (IANS): The number of cases of the mysterious illness, in Andhra Pradesh's West Godavari district headquarters Eluru reached 593, but active cases had declined to 46 on Wednesday evening.

The remaining affected of the illness whose symptoms included three to five minutes of epileptic fits, forgetfulness, anxiety, vomiting, headache and back pain have been discharged.

West Godavari Joint Collector Himanshu Shukla, who called the outbreak a "point source epidemic", said 10 more people are ready to get discharged.

Eluru, which is 58 km northeast of Vijayawada, is a coastal paddy cultivation and aquaculture hub.

Until now, 22 water samples have been tested, which showed E Coli to be normal while pesticide, organochlorine, has been found.

Likewise, 10 blood samples examined for heavy metals found a high presence of lead as well as nickel.

"Forty new samples of blood and urine were sent to the All India Institute of Medical Sciences (AIIMS), New Delhi for further investigation," said an official statement.

A total of 35 samples of cerebral spinal fluid, tested for cell count, have emerged normal, and so has their smear test. Their culture report was found to be negative for known viruses and bacteria.

Similarly, 45 CT scans have emerged normal, as well as nine milk samples.

Officials are awaiting results for 20 samples of vegetables sent to National Institute of Nutrition (NIN) at Tarnaka in Hyderabad and 10 cellular and molecular analysis samples sent to Centre for Cellular and Molecular Biology (CCMB), Habsiguda, Hyderabad.

Similarly, results for chemical analysis of 10 more blood serum samples sent to the Indian Institute of Chemical Technology (IICT), Hyderabad are also awaited.

A four-member NIN team has been deputed to Eluru while a two-member World Health Organisation (WHO) team has also arrived.

A joint team with experts from the National Institute of Virology (Pune), National Centre for Disease Control (NCDC) and AIIMS was also expected.

Officials are yet to reach a conclusion on the cause of Eluru's mysterious illness but suspect that lead or organochlorine or a combination of both might have caused the outbreak.