**5. Transmission — Based additional precautions**

These include airborne precautions, droplet precautions and contact precautions. These are taken when patients having or suspected of having infection with highly transmissible / epidemiologically important organism for which additional precautions are needed in addition to standard precautions [65].

**Air borne pracautions :** These are to be taken when patients with disease spread by droplet nuclei (<5 μm) in diameter or suspected cases are taken care of. Diseases like open/active tuberculosis, measles, chicken pox, pulmonary plague and haemorrhagic fever with pneumo‐ nia can be spread by droplet nuclei. Alongwith standard precautions the patients should be placed in a single room with negative pressure which receives ≥12 air changes per hour (≥ 12 ACH after 2001 construction). The air flow in a negative pressure room should be from outside and also should be exhausted outside but may be recirculated if the air is filtered through a High Efficiency Particulate Filter. The rooms should be closed and patients transport and movement is to be limited i.e. only when necessary. During transportation, patient must use a surgical mask to prevent dispersal of droplet nuclei. Anyone who enters the room must wear a special high filtration particulate respirator (N 95) mask.

**Droplet Precautions :** These are taken for large particles droplets (>5 μm diameter) and the diseases transmitted are pneumonias, pertusis, diphtheria, influenza type B, mumps and meningitis. The patient is placed in a single room or in a room with another patient infected by same agent. Surgical mask should be used by HCWs and during transportation patient should put a surgical mask.

**Contact precautions :** These are used to prevent transmission of antibiotic resistant bacteria, enteric infections and skin infections. HCWs must use gloves and gowns. The movement and transportation of patient should be limited.

**Patient placement :** Adequate spacing is required to prevent transmission of HAI. Optimum spacing between beds is 1 – 2 meters. Single room with hand washing facilities with attached toilet and bathroom is preferable to reduce transmission.

**Environmental Management Practices :** Safe drinking water supply, appropriate cleaning practices, housekeeping practices, laundry, pest control (mice, rodents etc) appropriate waste management facilities must be ensured to reduce HAIs. In isolation rooms, food should be served on disposable crockery and cutlery.
