Doctors say tests for various infectious diseases come up negative for patients with the fever, so it has been difficult to prescribe medication, The Times of India reported Saturday.
"Since we don't know the reasons for the ailment, we are forced to treat the symptoms. We prescribe medicines for the fever and painkillers for the joint aches. The symptoms are the almost the same -- fever, followed by severe body pain which could last up to two weeks or a month," said Dr. T. N. Ravishankar, head of Deepam Hospital.
"The fever shows symptoms of chikungunya and at times of dengue, but the tests are negative for both. Most of the patients come in with really high fever which lasts up to three days following which they have intense pain in the joints," said Dr V Ramasubramaniam, infectious disease specialist at Apollo Hospitals.
Meanwhile, patients, leery after not getting a concrete answer from doctors about what's making them sick, have been discontinuing treatment and switching between doctors.
"At first I thought it was the routine seasonal flu. But when my temperature rose and my body ache became unbearable, I knew it was more than that. I couldn't even place my feet on the floor," said Susan Philip, of Nungambakam. "Doctors said it was some viral fever and gave me painkillers. I was apprehensive about taking them so I switched treatment."
Health officials say the fever is not life-threatening.
"We had an intermittent spell of rain before and we've had cloudy conditions over the past few weeks. This is has created a conducive environment for such infections. We have stepped up vigilance," said Chennai Corp. health officer P Kugananthan.