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Exposure with person of unknown HIV status. How accurate is 15 for pcr ? - Online Doctor Chats

Date : 26-Mar-2013
User rating for this question
Very Good Posted in: HIV and AIDS
Answered by

General & Family Physician
Practicing since : 2003
Answered : 1560 Questions
User:hello doctor ..
User:This s XXXXXXX
Doctor:How can I help you?
User:good morning sir
User:i need about inf. about hiv dna pcr
User:15 days after exposure they resulted NON-DETECTED
User:HOW accurate is 15 for pcr ?
Doctor:HIV DNA PCR test is the most sensitive test of all the HIV tests.
Doctor:It's accuracy is most when done after 2 weeks following exposure.
Doctor:If the test is negative after 15 days of exposure, then the chances that you will be positive is less than 1%
User:in low risk cases is dna pcr is not advisible
Doctor:DNA PCR can be done in any cases if you wish to rule out infection at the earliest.
Doctor:Other tests that are available though are accurate, but are less sensitive than this test,
User:ok doctor
Doctor:I mean, the senstivity of those is between 90-95%
User:i wil tel u about my exposure
User:I am not done sex like vaginal , anal , and oral sex
User:But while in foreplay i am UN-PROTECTIVE , that time the females vaginal fluids are in leakeage ,I am worrying that fluids had contacted with my penis a bit
Doctor:The risks of transmission depend on the HIV status of your partner, amount of fluid transmitted, the viral load of the partner and the area of contact.
Doctor:based on what you say,
User:unknown status of partner
User:the area is top of my penile in foreplay
Doctor:your chances of getting HIV even if your partner was positive for HIV is very, very less.
Doctor:Have you followed what I have suggested?
User:ya doctor
Doctor:Do you have any other query?
User:many labs saying u have repeat the tests untill 3 months - 6 momths
Doctor:The repeat tests are needed for antibody testing.
Doctor:I mean antibody test such as ELISA / westernblot / P24 antigen tests that are done to diagnose HIV needs to be repeated after 3-6 months time.
Doctor:HIV DNA PCR test need not be repeated as it is extremely sensitive.
Doctor:Have you followed what I suggested?
Doctor:Do you have any other query?
User:so i am free of hiv sir
Doctor:the chances that you are positive is very, very unlikely.
Doctor:You need not worry about HIV, if you do not involve in another risky exposure.
Doctor:Avoid exposure with any unknown partner, this is the best way to prevent HIV.
Doctor:Hope it is clear.
Doctor:Do you have any other query?
User:no need of repeatin pcr again in 28 days ?
Doctor:You need not repeat the test.
User:so what dna pcr detects and elisa detects
User:pcr only in 15 days
User:elisa about 6
Doctor:PCR detects DNA fragements of HIV
Doctor:while ELISA looks for antibodies
Doctor:It seems you have moved out of the chat window.
Doctor:Kindly login again if you have any more queries.
Doctor:Are you there?
User:sorry doctor my chat was ended
User:i came back now
Doctor:Welcome back
Doctor:Dr. XXXXXXX here
User:yes sir
Doctor:You wish to know about HIV DNA PCR and ELISA Test;
User:yes sir
User:i am confuseing bcaz dna pcr in 15 days
User:but why in elisas 3 -6 momths
Doctor:As I mentioned earlier, PCR test looks for DNA the fragments which are specific to HIV.
User:ah ok
Doctor:The DNA particles are found from the day one and increases day by day.
Doctor:It would disappear only when all the HIV particles are destroyed or killed.
Doctor:So if a test is negative at 2nd week, it would be the same when repeated again.
Doctor:However ELISA tests looks for antibodies against HIV,
Doctor:sometimes depending on the immune status of the individual, the antibodies may not be secreted at 2 weeks
Doctor:further, HIV infections are associated with window period during which time antibodies are absent.
Doctor:This window period lasts between 2 weeks to 3 months in most individuals
Doctor:Hence if ELISA test is negative before 2 weeks of exposure, we recommend the test to be repeated after 3-6 months.
User:ok doctor
Doctor:In simple words, ELISA test may not pick up any thing (even if one is infected) between 2 weeks to 3-6 months
Doctor:so it has to be repeated to confirm again.
Doctor:Have you followed what I have suggested?
User:my lab person take my blood sampel in my town
User:ya doctor
User:he said we send this mumbai to test dna pcr
User:its about he said 2 days it reaches the labaratory
User:the blood is active
Doctor:Do you mean is the test valid?
Doctor:PCR test is a recent test introduced in the last century.
Doctor:It is a highly sophisticated test programmed to pick up any minute traces of DNA in a sample.
User:that s ok doctor
User:what i am saying is
User:the taken blood sampel today assume
User:if blood sampel taken today
User:after 2 days the examination is doing
Doctor:Further, the blood before being transported is preserved using chemicals so as to lose any viral particles.
User:yes yes that i mean
Doctor:so you need not worry about the validity or status of the report.
Doctor:Again, this test is only available at selected centres and most laboratories send samples to higher centres after preservation techniques.
User:yes thats my question
Doctor:The validity of the test is known after taking this fact into consideration.
Doctor:Have you followed?
Doctor:Do you have any other queries?
User:after transportation 2 or 3 days is the blood loses the viral p[article
Doctor:it doesn't
User:thankq doctor
Doctor:My pleasure.
Doctor:Is there any other query that you wish to discuss?
User:i can move my life happily
User:free of hiv
User:what if i take anothre test after 30 days pcr ?
Doctor:You can carry on with your life.
User:nothing happen
Doctor:There is no actual need for repeating,
Doctor:but if you are still anxious,
Doctor:you can get the test done to allay your fear.
User:ok ok
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