Swine-flu in India - 6

A study of the apparent death rates due to swine-flu for various states of India indicates that Gujarat has the highest rate of about 8% while Delhi has the lowest of about 0.5%. In terms of laboratory confirmed swine-flu cases Gujarat has only about 2.5% compared to about 17% of Delhi. Even in Maharashtra which has about 41% of the total confirmed swine-flu cases the death rate is only about 3.2% which though substantially higher than that of Delhi is also substantially lower than that of Gujarat. It is also interesting to see the difference in the apparent death rates of the two neighbouring states Tamil Nadu and Karnataka. While Tamil Nadu has a death rate of about 0.8% the same for Karnataka is about 5.6%. It is to be noted that both these states has similar number of confirmed cases (Tamil Nadu - 9.3%, Karnataka - 11.1%). I feel the differences in the death rates may be either due to large number of undiagnosed swine-flu cases in some states or may be due late treatment allowing onset of complications. Which one is the correct cause?