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                  UTARC Standard Operating Procedure for
			"Clean - Dirty" Concept

The  process of maintaining a disease free colony of rodents 
is  very  complicated  and costs  expand  geometrically  as  that 
process intensifies.   UTARC,  in order to maximize contamination 
control and minimize associated costs,  uses a practical approach 
to this ever-present problem.  

Our infection control program involves the indoctrination of 
the  staff  and researchers in a "clean - dirty"  concept.   This 
concept attempts to instill conscientiousness about which animals, 
areas,  and  equipment  are "clean";  which are  "dirty";  and  about 
procedures   to   keep  the  two  separated  from   each   other.  
Essentially,  personnel  are  trained to keep "clean"  virus-free 
animals and their associated environments away from suspected 
virus infected or immuno-compromised animals and their associated 
environment.   

For example, one  elevator  in the main facility is  called the "clean" 
elevator,  and is  used  to transport clean cages and equipment.   The 
other elevator is  the "dirty" elevator and is used for transporting  dirty 
material.   Certain animal rooms  are  designated "dirty" when even 
one animal is  found  to have a common rodent virus, or when animals 
in a room are being stressed enough to possibly compromise their 
immune system.  Any attendant working in these rooms should not 
work in a "clean" disease-free room within twenty-four hours.  It is 
anticipated that, whenever possible, this procedure would be followed 
by researchers and their assistants.

 On the first floor, there are two outside hallways and  an inner hallway 
down the middle of the floor.   The  middle hallway  is  designated 
"clean" and the outer  hallways  "dirty".  This is done for the purpose of 
changing out dirty cages.   Clean cages  go down the "clean" inner 
hallway and into the animal room through  a  door  on that side of  the  
animal  room.   When  the attendant  finishes changing out cages,  
they are transported out of  the  room  through the door opening into  
the  "dirty"  outside corridor,  and  down  to the "dirty" side of the  
cagewash  area.  Here  the  cages  are sent through a cage washer  
where  they  are sanitized with 180 F.  water.   The cages come out on 
the "clean" side  of the cage wash area,  are refilled with bedding,  and 
then sent back to the area of origin by way of the "clean" corridor.


In general terms, and from an animal housing perspective, the new 
ARC Annex is considered "cleaner" than the main facility.  Personnel 
should therefore always attempt to complete animal related work in 
the annex before working with animals in the main facility.


The  above are some examples of the "clean - dirty" concept, 
and  demonstrate the overall practical concept of simply  keeping 
"clean" animals, equipment, and surfaces as far away from "dirty" 
ones as possible within our facility and operating budget.   This 
method depends on the good will and cooperation of all  personnel 
who use and work in our facility.