GB/T 38497-2020Evaluation method of endoscopic disinfection effect (English PDF)

3.1 Endoscope

Endoscope refers to a diagnosis and treatment equipment with image sensor, optical lens, light source lighting and mechanical device; it can enter the stomach through the oral cavity, or, enter the body through other natural orifices.

3.2 Endoscope Disinfectant

Endoscope disinfectant refers to a chemical agent used for disinfection of endoscopes and can achieve the effect of disinfection.

NOTE: it includes commercial disinfectants and ready-to-use disinfectants.

5.3.1 Qualification criteria of disinfectants

Under the shortest action time, the lowest action concentration and the lowest temperature indicated in the instructions of the disinfectants and disinfection machines, the laboratory test and simulated field test result shall all comply with the requirements of 5.2.1.1 and 5.2.1.2. In terms of continuous simulated test, after the longest service time and the maximum number of service times in accordance with the application method indicated in the instructions, the laboratory test result shall comply with the requirements of 5.2.1.1.

5.3.2 Qualification criteria of disinfection machines

5.3.2.1 Disinfection machines with self-produced

Under the shortest action time, the lowest action concentration and the lowest temperature indicated in the instructions of the disinfectants and disinfection machines, the laboratory test and simulated field test result shall all comply with the requirements of 5.2.1.1 and 5.2.1.2.

5.3.2.2 Disinfection machines with external

Under the shortest action time, the lowest action concentration and the lowest temperature indicated in the instructions of the disinfectants and disinfection machines, the disinfectants shall comply with relevant stipulations of our country and the requirements of 5.2.1.1. The disinfection machines shall receive simulated field test and comply with the requirements of 5.2.1.2. In terms of continuous simulated test, after the longest service time and the maximum number of service times in accordance with the application method indicated in the instructions, the laboratory test result shall comply with the requirements of 5.2.1.1.

6.1 Laboratory Test

6.1.1 Reagents, culture media and equipment

6.1.1.1 Test strains

Staphylococcus Aureus (ATCC 6538), Mycobacterium Tortoise Subspecies of Abscess (ATCC 19977), Escherichia Coli (8099), Pseudomonas Aeruginosa (ATCC 15442), Bacillus Subtilis Var. Niger Spore (ATCC 9372) and Poliomyelitis Virus Type-I (PV-I)

Vaccine Strain. In accordance with the special purposes of disinfectants or special demands of the test, other strains may be selected.

6.1.1.2 Test equipment

During the test, firstly, cut the simulated endoscope body at 50 mm, 1,000 mm and 1,950 mm. Take the bacteria-infected carrier, respectively connect it at 50 mm, 1,000 mm and 1,950 mm. Respectively connect the bacteria-infected carrier with the post-disinfection simulated endoscope at 50 mm, 1,000 mm and 1,950 mm; the joints shall be sealed with sealing film.

6.2.2.3 Cleaning and disinfection procedure

6.2.2.3.1 Immersion disinfection procedure

Completely immerse the bacteria-infected simulated endoscope in the disinfectant.

Connect one end of the bacteria-infected simulated endoscope to the peristaltic pump, at a flow rate of 0.1 L/min ~ 0.2 L/min, conduct flow immersion disinfection. In accordance with the stipulations of the instructions of the disinfectant, immerse to the action time.

6.2.2.3.2 Mechanical automatic cleaning procedure

Place the simulated endoscope body in the specified position in the washing and disinfection machine. In accordance with the procedures specified in the instructions provided by the supplier, operate the machine.

6.2.2.4 Bacterial colony count

After the disinfection process is completed, use sterilized tweezers to take out the bacteria-infected carriers. Respectively place them in a test tube containing 10 mL of neutralizer solution; tap for 200 times. Then, respectively draw 1.0 mL of eluent to inoculate plates. For each sample, inoculate 2 plates.

For the positive control group, take 2 bacteria-infected carriers; place them in room-temperature environment without the disinfection treatment. After the experimental group receives treatment to the longest action time, place the bacteria-infected carriers in a test tube containing 10 mL of neutralizer solution; tap for 200 times. Then, use the diluent to make a 10-times serial dilution. Select a suspension with an appropriate dilution. Respectively draw 1.0 mL of the suspension to inoculate plates. For each sample, inoculate 2 plates. Meanwhile, respectively draw 1.0 mL of neutralizer and diluent for the test to inoculate the plates. For each sample, inoculate 2 plates as the negative control group. After the inoculation of plates in each group, pour 15 mL ~ 20 mL of TSA (tryptone soy agar medium). Wait till it solidifies, place it in a 37 °C incubator; culture the bacterial spores for 72 h; culture the bacteria for 48 h. Then, count the number of colonies; repeat the test for 3 times. Calculate the killing logarithm.

6.2.3 Result determination

During the simulated field disinfection with endoscope washing and disinfection machines, within the specified time of action, all 3 tests meet the qualification […]