Bengaluru, Grappling with spiking Coronavirus infections and consequent multiplicity of containment zones in closely located houses, the Karnataka health department is finding it difficult to conduct surveillance activities and perimetre control around them, an official said on Thursday.

"There are a large number of cases reported in houses and apartments which are closely located. This has led to too many containment zones, thus making it difficult for authorities to conduct surveillance activities and ensure perimetre control," said Additional Chief Secretary Jawaid Akhtar.

As a result, the health department took a relook at containment zones for individuals and clusters, highlighting that such places are well-defined areas around the residences of a Covid positive persons, where the most intensive measures to prevent the viral spread need to be implemented.

In case of individuals Covid infections in an apartment complex, the entire floor will be treated as a containment zone.

Similarly, in case of an independent house or villa, the entire house will be treated as a containment zone.

"For a slum area, notified or otherwise, the street which has the residence of the Covid positive person. For rural areas, the complete habitation where the Covid positive person resides or a small contiguous area as deemed appropriate," he said.

Pasting a notice in front of the house, informing neighbours, apartment owners association, identifying contacts, testing and home quarantining of contacts will be as usual with individual cases.

However, Akthar pointed out that there is no necessity for hard barricading and hand stamping in such cases.

In case of cluster of cases where more number of cases are reported from the same area, the containment zone shall be bigger in size and cover the cluster of closely located patients.

Health officials will decide the size and boundary of such a cluster containment zone by mapping the cases and contacts, geographical dispersion of cases and contacts, well demarcated perimetre and enforceability of perimetre control.

Cluster containment zones should be demarcated with technical inputs at the local level, identifying roads, drains, parks or other features for clear geographical segregation for effective perimetre control.

Cost-effective hard barricading for better perimetre control is allowed in case of cluster containment zones.

Likewise, a buffer zone around a containment zone has been defined as an area where new cases are more likely to appear, which will be 200 metres around the perimetre of a containment zone in both rural and urban areas.

Ramping up surveillance in containment zones, Akhtar said active house to house surveillance should be done daily while it should be twice a week in the buffer zones.

According to the senior officer, a containment zone will return to normal only when no new case is reported for at least a fortnight and all the contacts of confirmed cases have been followed up.

A village, city, district or the entire state will be declared Covid free only after 28 days have been passed since the last confirmed Coronavirus case has been discharged from hospital or home isolation.

On Wednesday, Karnataka registered the highest single day rise of Coronavirus infections, 8,642, increasing the state tally to 2.49 lakh.