Viral fever is back in the city. For the past three weeks, clinics across Calcutta are receiving a steady stream of patients with medium to high fever, body ache and headache.

The temperature of the patients is varying between 102 and 104 degrees Celsius. Muscle and throat pain, cough and cold and weakness are the other symptoms. The fever is typically persisting from four days to a week.

“Viral fever is common during the onset of monsoon. But this year, more people are being affected. Those with very high fever and chest infection have to be admitted to hospitals,” said Subrata Maitra, a city-based critical care specialist. Viral and bacterial infections like hepatitis and typhoid are also spreading in the city, he added.

Children, especially school-going ones, are particularly vulnerable to viral fever, said Apurba Ghosh, the director of Institute of Child Health (ICH).

More than 20 per cent of the children in the ICH outpatients department are suffering from viral fever. Temperature up to 105 degrees Celsius, a running nose and cough are the symptoms.

“The fever generally subsides after three or four days but could relapse within 24 hours. The temperature is much lower the second time,” added Ghosh.

The virus is causing secondary infection in the throat, according to ENT specialists.

“Patients are feeling more sick because of blocked nose and throat infection,” said Arunabha Sengupta, the head of ENT department of SSKM Hospital. “More than 30 per cent” of the visitors to the outpatients department are complaining of “nasal and throat infections”.

Doctors are prescribing paracetamol for bringing down the fever and painkillers for the head and body ache. If there are secondary infections, antibiotics are prescribed.

Infections can be avoided by not eating outside food and drinking only purified water.