The steady cold wind got lazy on Thursday and the sun beat down hard to push the Celsius up, an ideal combo to breed viruses and put Calcuttans under the weather.
Critical care expert Subrata Maitra said cases of cough and cold had gone up over the past two weeks.
“We are getting patients with runny nose, fever and sore throats because of viral infections in the respiratory tract. Patients with existing conditions like chronic obstructive pulmonary disease and asthma are suffering from lung congestion. Some of them had to be admitted,” he said.
Doctors say the viral and bacterial attacks are giving rise to flu-like fevers that typically stay for four-five days.
The ticklish throat, body and headache, inflamed tonsil, appetite loss and itchy nose are part of the package.
Doctors say temperature fluctuations favour multiplication of viruses and bacteria, especially those that catch people by their throat. “A spurt in upper and lower respiratory tract ailments is not uncommon in such conditions,” an expert adds.
So the breeze from north India and the wheeze in Calcutta are inter-linked. The wind determines how cold Calcutta would get in winter — a time when the air is thick with dust and pollutants and a slight rise in temperature spawns a virus outbreak.
The Northerly had kept the mercury down for the past couple of days but the city could see a warm phase from Friday.
Various systems had connived to block the wind’s flow this winter, making the minimum temperature yo-yo. The day temperature shot up on Thursday to 27.3 degrees Celsius, a notch above normal and more than three degrees from the day before.
The minimum reading in the early hours of Thursday was 13.2, a notch below normal and marginally less than Wednesday’s.
It is expected to rise to 14 on Friday and settle around 15 degrees over the weekend.
Since New Year’s Day, the minimum has swung on either side of the normal eight times.
The maximum temperature too has fluctuated, with phases where the sun was out of sight for days and the mercury fell more than 5 degrees Celsius below normal.
Meteorologists declared that these fluctuations were unusual. “When there is a cold phase, it stays for at least five days. This year, these periods have been short, mainly because of the trajectory of Western Disturbances that have hit north India and various weather systems that have cropped up closer to the city,” said a senior official of the India Meteorological Department, Calcutta.
At present, a trough of low pressure is hovering over a huge landmass — from the Arabian Sea to north-eastern Madhya Pradesh and beyond. “This diagonal trough is sucking in the North Wind. Between Friday and Sunday, conditions are going to be warm,” the weather expert added.
In keeping with this winter’s trend of fluctuating temperatures, the Celsius will again take a dive but not below the 13-degree mark.
“We are approaching the end of winter and the Northerly has weakened,” said a weather scientist at IMD, Delhi.
Going by Met reading of the thermometer, the doctors would remain busy for a while. ENT specialist Arunava Sengupta said he has got 20 per cent more patients this January than previous years.
“Adenovirus, coronavirus and rhinovirus are affecting the pharynx, while the pneumococcus bacteria are affecting the lungs… causing pneumonia,” said microbiologist Bhaskar Narayan Chowdhury.