New Delhi, Aug 27 - Swine flu claimed three more lives Thursday, taking India's toll to 78, as health officials maintained that most of the deaths occurred because the patients reported late for treatment.

R.K. Srivastava, director general of the Directorate General of Health Services (DGHS), said one death each was reported from Bangalore, Nashik and Pune.

At least 123 people tested positive for the Influenza A (H1N1) virus Thursday, taking the total number affected with the contagious disease to 3,396, he added.

'We decided to do a limited analysis of death cases. So we collected case sheets of 30 random victims from seven affected states and did a medical analysis on them. The prime reason for death is people are coming late for treatment. The study has reasserted it,' Srivastava told reporters.

He said the study also showed that most of those who died were in the age group of 14 to 44 years. 'Most of these deaths are in the young productive age.'

'Most of the people who have died came late to the hospitals and died on the fifth day of treatment. The most common symptoms were excessive cough and breathlessness,' he added.

Srivastava said in most of the deaths, the infection had spread widely in the chest and H1N1 pneumonitis had kicked in.

Swine flu cases are bracketed in three categories - those who had mild flu-like symptoms, those with high fever, and those with chest congestion and other flu-like symptoms.

'Most deaths are of those who fall in the last category,' Srivastava added.

He said those falling in the second and third categories should immediately go to the identified health facility, while those in the first category could go to a private hospital.

'The best way is to report it early so there is better redressal and treatment chance,' he added.

However, he clarified that the study was in its nascent stage.

'Analysis will have to be compared with other positive cases before ascertaining a clear trend because the sample size is still small,' Srivastava added.