Resistance test tells what medications is resistant to the virus. Not all viruses respond the same way to all medications, by what this test will allow the medical provider, knowing which are the correct medication for each case. Unlike CD4 and viral load counts, resistance tests not sorted on a regular basis, they are only recommended for two reasons: to find out whether the patient is infected with a viral strain resistant or to find out if resistance developed in the course of treatment and it is not as effective as expected. Resistance test should be taken after confirming the diagnosis of HIV, even if no treatment is needed immediately. A baseline of resistance testing is less accurate the further postponement. The health service provider should sort test, where the treatment is not having the expected result to determine than drugs stop prescribing and which can be used here.
There are two types of resistance tests; of genotypes (search the) mutations or changes in the genes that generate the drug resistance) and of phenotypes (measures the ability of the virus replicated or multiply in the presence of drugs). The test of genotypes is quick and economic, but difficult to interpret when there are many mutations; While proof of phenotypes is more expensive and takes longer, but is more accurate and is more accurate for determining the degree of resistance that has the virus to a drug. Resistance tests are not perfect. The lab cannot get results if the viral load is less than 1,000 and they can only prove that drugs do not work, rather than those that whether they would be effective. The bad news (evidence of resistance) are accurate, but the good news (sensitivity to the drug evidence) should be taken with caution. These can provide reliable information about drugs that were used previously, since the resistant virus may be present but not be detectable at the time of the test. Previous results of tests can not be ignored in resistance, because if the resistance was detected for 5 years, will still be there, even only appears on the test. For more information about the HIV AIDS virus visit: original author and source of the article