 From:  Supply and Services Canada
 R&D Bulletin - Science and Technology
 No. 234, September 1992

 Better blood sterilization with ozone.


 Ozone may soon be used to destroy viruses in donated blood, 
 thanks to researchers at the Department of National Defence 
 (DND) and the Canadian Red Cross Society (CRCS).

 Under a $303.943 contract with the Surgeon General Branch of 
 DND's National Defence Headquarters, researchers from the 
 National Reference Laboratory at the CRCS are investigating two 
 ozone sterilization technologies to confirm their reported 
 efficacy in deactivating a variety of potential viral 
 contaminants of blood, including HIV-1 and hepatitis.

 Many developing countries cannot afford blood-screening, which 
 costs about $45 for each unit of blood and requires a trained 
 technician.

 "If the Canadian military is operating in an underdeveloped part 
 of the world and is cut off from its supplies, we may have to 
 resort to local blood sources," says Major Brian Crowell, Health 
 Services Research Coordinator at DND.

 "We're looking for a sterilization technique that can be taken 
 to the field, put together on the tailboard of a truck or in a 
 tent, and used to sterilize donated blood quickly and 
 effectively."

 Once developed, such a sterilization technique would have 
 applications beyond the military.  Dr. Peter Gill, Director of 
 the CRCS's National Reference Laboratory, says ozone 
 sterilization technology could be used in disasters to aid 
 civilian populations.

 Ozone gas is produced by passing electricity through pure 
 oxygen.  Although ozone is toxic when inhaled over time, at the 
 right concentrations it is highly effective as an antimicrobial.  
 Over 2,000 water-purification plants worldwide, including those 
 in Moscow and Montreal, use ozone to decontaminate water.

 Researchers are investigating two methods of sterilizing blood 
 with ozone that have been patented by Medizone (Canada) Inc. and 
 Mueller Medical International Inc.

 One of these methods exposes 10 cm(3) of blood to heat (42.5 C) 
 and ultraviolet light.  Ozone gas is bubbled in through a tube.  
 The blood foams up alongside the vial, exposing more blood 
 surface area to the light, heat and ozone.  Following treatment, 
 the container is spun to force the blood down.

 The other method uses a hollow fibre system between the ozone 
 and the blood.  The membrane separates the blood from the ozone 
 and oxygen.  Over time, a pre-determined amount of ozone is 
 absorbed into the blood.  The amount of ozone absorbed is 
 measured by subtracting the amount of ozone going back into the 
 machine from the amount that left the machine.

 These ozone sterilization methods are easy to operate, quick to 
 perform (from three to 60 minutes), and chap (no more than $15 
 for each unit of blood).

 Researchers will also investigate ways to combine ozone 
 sterilization and filtration technologies.  Filtering the blood 
 to reduce the number of white cells, the site of most intra-
 cellular viral infections, means viruses can be deactivated 
 using low levels of ozone.  This is preferable to using high 
 levels of ozone, which could change the molecular structure of 
 the blood.  For example, the haemoglobin structure may be 
 altered so that it no longer acts as an oxygen carrier.

 At low doses, however, there are no known adverse or toxic side 
 effects of ozone sterilization.  In Europe, an estimated 350,000 
 people were treated with ozone between 1980 and 1985.  The 
 university of Bonn reviewed these cases in 1986 and reported 
 virtually no side effects of ozone therapy when properly 
 administered.

 Test results so far indicate that even low concentrations of 
 ozone are extremely effective at deactivating extra-sterilized 
 10 cm(3) of blood containing enough HIV to infect the entire 
 world population 10 times.

 Results from Bethesda Naval Hospital in Bethesda, Maryland, 
 indicate that ozone can also be effective against intra-cellular 
 viruses when used in higher concentrations.  The ozone seems to 
 destroy only infected cells, exposing the viral material to the 
 gas and ultimately deactivating the virus, all without creating 
 toxicity problems.

 HIV research using similar technologies may lead to an 
 "autovaccine" for AIDS patients in which a patient's blood would 
 be treated with ozone and re-introduced.  A cure would be 
 unlikely, but the autovaccine may be able to control the 
 infection by boosting the immune system, suppressing virus 
 replication, and re-introducing deactivated samples of all 
 mutant forms of the HIV-1 virus.

 Researchers hope that ozone sterilization for blood fractionates 
 such as Factor VIII, a clotting agent given to haemophiliacs, 
 will be available soon.  Technologies for sterilizing whole 
 blood may be on the market in a few years.  Ozone sterilization 
 technologies may be approved only for emergency blood supplies 
 at first, but if evidence is found that some viruses are not 
 being screened, the treatment may be extended to all blood 
 collections.

 "The products of this research have worldwide applications," 
 says DND's Capt. (N) Shannon.  "In the right concentration, 
 ozone sounds almost too good to be true.  We're trying not to be 
 overly enthusiastic, but the data so far is very compelling."
