Rabies. FAQ: 1) Expiration of the test results; 2) Time validity of the sample after extraction; 3) Need to separate serum from the collected blood; 4) How to separate serum if you do not have a centrifuge?; 5) What to do if the results indicate that is not protected?.
1) Expiration of the test results
The results of a test that has given protection (greater than or equal to 0.5 IU / mL value), do not expire, ie are valid indefinitely, periodic booster shots are made, on the dates indicated by the vaccine have him administered to the animal. This revaccination should be included in the documentation animal. If you have not revaccination within the time indicated by the vaccine, you are given a new dose, and after at least one month after this new dose should perform the test again. So if you are traveling with the animal, it is very important to revaccination within the dates indicated to avoid having to retake the test. We have received information from a client in a border not he allowed to pass the animal because there was a difference of one day between the deadline for administering the dose of revaccination and the day that revaccination was carried out , so we recommend not miss the deadline, or should have been, repeat the test.
2) Time validity of the sample after extraction prior to testing
The blood sample once removed, must be processed to separate the serum. Separated serum must be deposited in a tube, preferably sterile, and kept refrigerated (in a refrigerator). If serum is kept in a refrigerator it can be kept quite some time, about a week. If it is anticipated that the shelf life will be higher, it is recommended to freeze (never whole blood, if not separate blood serum). Do not freeze and thaw sera more than once. If you move personally or through a messaging a maximum transfer time of 48 hours, it can be sent without cooling, but if the transfer time will be greater, should be placed the tube in an isothermal container, for example box white cork, small refrigerator type, or the like beach with a cold pack (pack, frigolín ... frozen). Sometimes we wonder what to do if you have in the refrigerator and will be traveling with the sample personally. In this case stored in the refrigerator, keep at room temperature during the journey and upon arrival at home, replace in the refrigerator until sent to the laboratory.
3) Need to separate serum from the collected blood
After withdrawal of the blood sample should leave her serum. The purpose of this separation is to prevent blood hemolyzed, ie erythrocytes (RBCs) are broken, as this may alter test results. If it is certain that the full blood drawn, until it is received in our laboratory, will be maintained at room temperature about 20-25 ° C or lower, for example refrigerated (not frozen), and for up 24 hours , serum separation would not be necessary. However, this is impossible to guarantee when sent by courier. For this reason it is necessary to separate the serum.
4) How to separate serum if you have no centrifuge?
In this case, there are two alternatives: a) extracting blood and placed in a clean dry tube, without any additives, leaving at room temperature until the next day to the blood clot and then retract the clot. Once retracted clot can be aspirated serum that is above or around the clot with a suction pipette, for example plastic for suction bulb; b) extracting the blood and placed in a tube containing EDTA so that blood does not clot, allowing to stand at room temperature overnight, to erythrocytes (RBCs) are deposited by sedimentation on the bottom and the plasma remaining in the upper part. Once formed the two phases, taking care not to move can suck the plasma from the top (plasma) with a suction pipette, for example plastic bulb to suction, making it slowly so as not to move sediment erythrocytes, without approaching the pipette tip to the erythrocyte layer vacuuming not.
5) What to do if the results indicate that is not protected?
When the results indicate that is not protected (less than 0.5 IU / mL), it is because the vaccine did not induce sufficient antibody production in the animal with the rabies vaccine. This may occur by one of the following reasons: a) the blood sample is taken too early, within 30 days after administering the vaccine; b) the serum sample is adequately preserved not from extraction, after having separated from the blood, before shipment to the laboratory or during transport to the laboratory; c) the vaccine has been administered to a young animal that does not have an immune system capable of responding adequately to vaccination; d) the vaccine is administered to an elderly animal whose immune response is poor; e) the vaccine was not under suitable conditions; f) the vaccine is not properly managed; g) Sometimes if the animal has a disease, or is receiving treatment when vaccine, the immune response may be lower.
Consider which of the reasons is the most likely to have been given, and according to them, if you think you may be the reasons a) or b) make a new drawing blood. If you think the reasons may be c), d), e), f) or g), give a new dose of vaccine, and after 30 days, extract a new blood sample, separate the serum, properly retain and send to repeat the test.