The center lists the parameters of the states to mark zones

NEW DELHI: Parameters such as active cases, doubling and fatality rates, and cases per lakh population were listed on Sunday for Union states and territories to follow when classifying areas into red, orange, or green zones.

It also issued guidelines for the delimitation of buffer and containment zones and described the actions that must be implemented in those areas to break the chain of transmission of the disease.

In a letter to union states and territories, the Union's secretary of health, Preeti Sudan, said states can classify districts or municipal corporations into critical zones, red zones, orange zones and green zones.

However, they may also choose to classify the subdivision, neighborhood, or any other appropriate administrative unit in color-coded areas after detailed analysis at the end, taking due account of the geographical distribution of cases, contacts, and their area of ​​influence in Los Terms of the disease were extended, the letter said.

This comes after the ministry of internal affairs issued guidelines for the fourth phase of the national closure, empowering union states and territories to delineate red, green and orange zones based on the Covid-19 situation taking into account the parameters shared by the union Ministry of health.

In its letter, Sudan explained that the demarcation of the areas would be based on the total number of active cases, cases per lakh population, doubling rate calculated over a period of seven days, case fatality rate, evidence index (number of tests per lakh population) and shows positivity rate

The reference points or thresholds for critical and desirable levels for the total of active cases would be more than 200 and zero or no case reported in the last 21 days, respectively.

For the active cases per lakh population, the critical threshold would be when more than 15, while for the calculated doubling rate over a period of seven days, the critical level would be less than 14 days and desirable when more than 28 days.

As for the case fatality rate, more than six percent would be considered critical and less than one percent desirable. The critical threshold for the test ratio (number of tests per lakh population) would be less than 65, while the desirable level would be more than 200, according to the letter.

The sample positivity rate would be considered critical if it is more than six percent, while less than two percent is desirable.

However, the Ministry of Health stressed that the benchmarks or thresholds for critical and desirable levels are dynamic and can be reviewed for the evolving situation at the field level.

The letter mentions that the guidelines are issued after the Prime Minister's video conference Narendra Modi with the chief ministers on May 11 and taking into account the comments received from them.

The most important task once zones are identified is field action in terms of implementing the containment action plan. This implies the identification of the buffer and containment zones within the red, orange and green zones from where the cases have been mainly reported.

A containment operation (large outbreak or group) is considered successful when no cases are reported in the last 28 days from, the letter said.

According to the guidelines, the containment zones are delineated based on the mapping of cases and contacts, the geographical dispersion of cases and contacts, the area that has a well-defined perimeter and the enforceability of perimeter control.

It is reiterated that this is the main area where intensive actions will be carried out with the aim of breaking the transmission chain. Therefore, this area should be adequately defined by the district administration/local urban agencies with technical input at the local level.

Effective containment, it is advisable to err on the side of caution, the letter said.

The guidelines established that once the containment area is delineated, the perimeter will be defined and there will be strict control of the perimeter with the establishment of clear entry and exit points.

No movement should be allowed, except for medical emergencies and essential goods and services, an uncontrolled influx of population and the registration and monitoring of people in transit through the Integrated Disease Surveillance Program (IDSP) should not be allowed.

Strict action must be initiated within these containment zones in terms of an active case search through house-to-house physical surveillance by special teams trained for this purpose, testing all cases according to sampling guidelines and contact location , identification of the local community. Volunteers to assist in surveillance, locating contacts and communication of risks and the strict application of social distancing, among others, he said.

Sudan said a buffer zone should also be delineated around each containment zone.

The buffer zone will primarily be the area where additional, focused attention is needed to ensure that the infection does not spread to adjacent areas. For effective containment, it is of utmost importance that the damper be large enough, the letter stated.

The main areas of action in the buffer zone include extensive case surveillance through monitoring of ILI/SARI cases in health centers, among others, according to the guidelines.

Consequently, all states are requested to initiate the necessary actions in terms of categorization of red/orange/green zones, delimitation of containment and buffer zones and their notification, he said in his letter.