Table 1 Options for housing high-risk persons into designated ‘green zones’

1. Household-level shielding

Each household demarcates a room or shelter for high-risk members. If necessary, a carer from the household is isolated with them.

Settings with multi-shelter compounds or multi-room houses.

Likely preferable to families with space available but also more likely to be ‘leaky’ if isolation is not strictly enforced.

2. Street- or extended family-level shielding

Neighbouring households (e.g. 5–10) or members of an extended family within a defined geographic locale (neighbourhood, district) voluntarily ‘house-swap’ and group their high-risk members into dedicated houses / shelters.

All, but especially urban settings.

Infection control and physical distancing measures would also have to be strictly observed within each green zone.

3. Neighbourhood- or sector-level isolation

Sections of the settlement are put aside for groups of high-risk people (e.g. 50–100).

High density camps/settlements (e.g. refugee/IDP camps, slums, informal settlements for migrants where humanitarian actors can provide supportive services and smaller scale isolation is not possible.

Ideally located at the periphery of camps to facilitate such measures.

Infection control and physical distancing measures would also have to be strictly observed within each green zone.

We have discounted this option due to likely high cost, potential lack of acceptance of elders being separated from families, and the risk of large-scale harm if transmission is seeded within such a concentrated ‘green zone’.