The vector scare has triggered a race for beds in private hospitals, leading to overbooking and forcing some to turn away even critically ill patients.

When cancer patient Sanghamitra Paul (name changed on request) doubled up in pain on Tuesday evening, her family took her to a leading south Calcutta hospital thinking admission would be just a formality.

But the 36-year-old, who has ovarian cancer, was forced to spend the night in a small nursing home nearby. “We shifted her to the hospital the next morning as soon as a bed was available,” said a relative.

Almost every private hospital has converted day-care and emergency wards into regular ones to accommodate patients with malaria, dengue, encephalitis or fever of unknown origin. There have been instances of people even voluntarily seeking hospitalisation after a bout of fever.

“It is the fear factor. We have had to admit patients with viral fever or influenza because their families insisted on hospitalisation just to be on the safe side,” said Milan Chhetri, a senior consultant in the department of internal medicine at Apollo Gleneagles Hospitals. Not one of the 120 beds in the critical care unit at the Bypass hospital was vacant on Friday, officials said.

Critical care expert Subrata Maitra said the last time vector-borne diseases had hit the city hard was in 2005. “But this year has probably been worse. More than 30 per cent of the patients visiting clinics with high-grade fever and other symptoms of vector-borne diseases are being advised hospitalisation.” At AMRI Hospitals in Dhakuria, patients requiring “normal monitoring” occupy most emergency beds.

“They are being provided treatment in the emergency ward till we can shift them to a regular ward or room. We had not anticipated this rush,” said Suman Ghosh, the hospital’s medical superintendent.

More than 15 per cent of the patients at Ruby General Hospital are being treated for vector-borne diseases. “We have never faced such a situation. The number of critically-ill patients diagnosed with a vector-borne disease is far higher than in previous years,” said S.B. Purkayastha, the CEO of the hospital.

The admission register at the Calcutta Medical Research Institute (CMRI) tells a similar story. “Around 10 per cent of our patients came in with high fever,” said COO Rupak Barua.