By Sfoorti Mishra New Delhi, May 3 : To contain coronavirus effectively, the government has demarcated the country into three zones -- red, orange and green. There are more coronavirus cases in western region than the eastern region. There are more red zones in prosperous states, like Maharashtra, than states considerably less advanced, like Bihar and Odisha. The number of cases in metros, like Mumbai and Delhi, is more than smaller cities in the eastern region. In Maharashtra, there are 14 red, 16 orange and 6 green zones. In Bihar, there are 5 red, 20 orange and 13 green zones. There are 130 red, 284 orange and 319 green zones in the country, according to the letter written by Health Secretary Preeti Sudan to the state secretaries on April 30. Explaining these zones, the government said the green zones comprised districts with either zero confirmed case or no confirmed case in the last 21 days. The classification of districts as red zones takes into account number of active cases, doubling rate of confirmed cases, extent of testing and surveillance feedback from there. The districts, which are neither defined as red nor green, are classified as orange zones. As of 8 a.m. on May 3, Maharashtra reported 12,296 coronavirus cases and 521 fatalities. Bihar had 481 cases and 4 deaths; and Odisha 157 cases and one death, according to the Health Ministry. Among the the other western states, Gujarat reported 5,054 cases and 262 deaths, followed by Rajasthan with 2,770 cases and 65 fatalities. In the eastern region, West Bengal reported 922 cases and 3 deaths, and UP 2,487 cases and 43 deaths. Speaking to IANS, K. Srinath Reddy, president of the Public Health Foundation of India (PHFI), said, "The pattern reflects difference in economic development, indicated by the size of the international airports, number of international and domestic flights operating from those airports, foreign-returned travellers arriving and spreading out from there." "Western India is more urbanised, with greater mobility of people with whom the virus hitch hikes to spread fast. Eastern India has lower foreign returnees to initiate the spread," Reddy said. According to him, the rural India has less mobility. "This too has protected eastern parts. That's why the more urbanised western countries too have seen a rapid spread. Similar phenomenon in India has occurred," he said. Dr Manoj Goel, Director (Pulmonology), at Fortis Memorial Research Institute, told IANS attributed this distribution of infection to the population density in different parts of India. "India is a large country. It's like a subcontinent with over 17 per cent of the world population. So there is likely to be no uniformity in distribution of cases in the different regions," he said. Stating that the densely populated places in the west are the worst hit, he said, "Dense population makes it difficult for the virus to contain as social distancing can be difficult to manage. The states with large number of immigrants from abroad could also been witnessing more Covid-19 cases." The government has said the classification of districts into red, green and orange zones will be shared by the MoHFW with states and Union Territories on a weekly basis, or earlier, as required. While states and UTs can include more districts in the red and orange zones, they may not lower the classification of a district included by the MoHFW. India reported 39,980 coronavirus cases, and 1,301 deaths as on Sunday morning. (Sfoorti Mishra can be contacted at sfoorti.m@ians.in) /IANS