The outbreak started in the One-Town area of Eluru and claimed one life on Sunday.
Andhra Pradesh Chief Minister YS Jagan Mohan Reddy on Monday visited the Government General Hospital and interacted with those afflicted by the mysterious disease even as the number of patients rose to 347.
A team of doctors from the All India Institute of Medical Sciences from Mangalagiri visited the hospital and collected blood samples from the patients for a thorough examination.
Close to 200 patients had been discharged from the hospital after treatment.
Most of the victims were in the 20-30 age group while there were about 45 children below the age of 12 years.
There is now a suspicion that anti-mosquito fogging may have caused the disease to spread but nothing has yet been confirmed officially.
It may be recalled that the mysterious disease saw people suddenly falling unconscious after suffering from symptoms of fits and nausea.
The outbreak started in the One-Town area of Eluru and claimed one life on Sunday.
Health authorities could not yet establish the cause of the disease through blood tests and CT (brain) scans were performed. Cerebral Spinal Fluid tests also turned out to be normal.
The probable cause could become evident only after the culture test results came in. E-coli results were also awaited.
Though initially it was suspected that water contamination could have been the cause of the disease outbreak, sample tests ruled that out.
BJP MP G V L Narasimha Rao said, after talking to experts at the AIIMS, New Delhi, that poisonous organochlorine substances could be the most likely cause of the disease.