New Delhi, Nov 19 (IANS) With the winter chill now in the air, swine flu cases in the national capital have recorded a sudden jump in the past two days. Doctors Thursday warned that H1N1 infections could see a rise as the virus spreads faster during winter.

The capital Wednesday reported 63 swine cases while on Tuesday 62 people reported positive for H1N1. This is a sharp increase from the 16 and 23 cases reported Monday and Sunday, respectively.

'The temperature has dipped in the northern parts of the country in the past few days. With the onset of winter, swine flu cases will increase but as of now the infection is mild and the morbidity is not much,' Randeep Guleria, head of medicine at the All India Institute of Medical Sciences (AIIMS), told IANS.

Guleria said people need to be more vigilant and take precautions during the winter.

'People should visit a designated health facility if they notice flu-like symptoms. Those in the target group like the elderly, children, pregnant women, heart and diabetic patients should take extra care during the winter,' said Guleria.

S. Chatterjee, senior consultant internal medicine at the Indraprastha Apollo Hospital, said people should avoid crowded places and take necessary precautions while stepping out.

'Cover your face while sneezing and wash hands after regular interval - these are a must to prevent the spread of the H1N1 infection,' said Chatterjee.

The Delhi government said necessary measures are in place to check the increase of swine flu cases.

'The situation is under control and the government is doing its best to provide treatment to H1N1 patients in government hospitals. People should visit a doctor at the earliest on noticing symptoms of swine flu,' said Delhi Health Minister Kiran Walia.

Delhi with 3,900 swine flu cases tops the list of people affected with H1N1 in the country. India has so far reported 534 swine flu deaths.