Bhubaneswar, Feb. 6: Common cold and influenza have been affecting a large number of people in the city lately owing to frequent fluctuations in the weather conditions.

While the elderly, kids and pregnant women are more vulnerable, medical practitioners are of the opinion that people suffering from asthma and chronic obstructive pulmonary disease (COPD) should take adequate precautions.

The day temperature is hovering around the 32°C mark at the moment.

"Northwestern winds and also wind coming from the Himalayan region has brought down the night temperature even though the day time temperature is normal and this pattern will perhaps stay till February 12," said Bhubaneswar meteorological centre director Sarat Chandra Sahoo.

The director of critical care and pulmonology at Amri Hospital, Bhubaneswar, Samir Sahu, said: "The frequent change in the day and night temperature has an effect on the humidity and dust in the air. Hence, the condition can put asthmatic and patients with COPD in trouble."

Saying that the pulmonary distress would be more in case of a patients suffering from fever, the well-known intensive care expert said: "As elderly, diabetic, cardiac patients and people with kidney ailments are more vulnerable, the family members should be on alert and if possible, a vaccination should be done to keep the bad effects of flu at bay."

Prasanta R. Mohapatra, professor and head of department of pulmonary medicine at the All India Institute of Medical Sciences (AIIMS), Bhubaneswar, said: "The temperature fluctuations cannot be directly proportional to the rise in the cases of common cold and flu, but acclimatisation to the rapidly changing environmental situations to people with compromised immunity, elderly or kids may result in such disease prevalence."

However, Mohapatra added that people suffering from the common cold or flu should not fear that each person suffering from cold could be vulnerable to swine flu caused by the H1N1 virus.

The director of Capital Hospital in Bhubaneswar, B.B. Patnaik, says during season change, the hospital sees more patients suffering from common cold. But this year, the number is around 200 in a day out of 1,500 to 1,800 patients visiting the referral facility.

He added that while two samples were sent for tests for swine flu at the laboratory of the Regional Medical Research Centre (RMRC), none was found positive.

RMRC director S.K. Kar said: "Mutations in the genetic content of the viruses causing flu and common cold are the things we are worried about. Frequent changes in the local weather can induce the survival level of the micro-organisms causing diseases."

The RMRC has already set up a state-of-the-art laboratory to test suspected flu samples for H1N1 virus and in a year the laboratory receives 6,000 to 7,000 samples a year.

"This year, till date, we had received 28 suspected samples out of which six were found positive," said Kar.

Joint director, public health, Bikas Patnaik said: "All flu cases are not to be feared as the swine flu (H1N1 virus). The pandemic caused by the H1N1 virus was over by 2010, a year its spread in 2009. Last year, we got a few sporadic cases of swine flu in Odisha and this year again, we are getting some more positive samples."