HealthCareMagic is now Ask A Doctor - 24x7 | https://www.askadoctor24x7.com

How Accurate Is Pcr Test At 18 Days Post Exposure?

Posted on Mon, 11 Mar 2013

Question: how accurate will a pcr test be of the 18th day? after incident

Answered by Dr. Sankaranantham Murugan (8 hours later)

Hi XXXXXXX,
Welcome back.

HIV DNA PCR starts to become reactive (if infected with HIV) 72 after the entry of the virus. In certain individuals it may get delayed. It is almost 90% reliable after 18 days even though it becomes more conclusive after 3-4 weeks. It is a very specific and sensitive test.
Good luck to you.
Dr S XXXXXXX

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (16 hours later)

72 days and thats 2 months? ...... what if in totals is 28 days because i learnt after a month is cant really detect it

Answered by Dr. Sankaranantham Murugan (6 hours later)

Hi, XXXXXXX.

I am very sorry. Mistakenly not mentioned the measure. It is 72 hours after the entry of the organism, not 72 days.
More conclusive after 3-4 weeks and thereafter it will be reactive for ever almost. Antibody test like ELISA, Western blot , Rapid tests will become positive after 12 weeks.
Are you satisfied with these information?
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (7 hours later)

so after this test shud i go for elisa in 2 months times?

Answered by Dr. Sankaranantham Murugan (6 hours later)

Hi,
Welcome back.

It is not so. If you are able to do either P24 or DNA PCR test and if these tests become nonreactive then further tests are not necessary. If you are not able to do Antigen tests either due to nonavailability or due to high cost, then alternatively you have to wait and go for antibody tests.

I hope that I made it clear to you.

Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (22 minutes later)

Ok thanks so much.. God bless you

Answered by Dr. Sankaranantham Murugan (8 hours later)

Hi,

I am also quite thankful to for your interest in my answers. If you have no further discussion let us close the conversation.

Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (5 hours later)

I have knee aches but its mostly on my friend knee and my arm joints too aches but rarely any cause ? and my wrist too

Answered by Dr. Sankaranantham Murugan (4 hours later)

Hi,

Welcome back.

Your joint pain has nothing to do with HIV. Similar type of joint pains may likely to occur with Rheumatic fever, Rheumatoid arthritis or due to some reactive arthritis following any type of bacterial infection etc. If consult your physician he/she will help in this regards.
Wish you a speedy recovery.
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (23 hours later)

Thanks so much

Answered by Dr. Sankaranantham Murugan (3 hours later)

Hi,
You are most welcome.
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (4 hours later)

Ok last question cos im being scared now....... my muscle joint aches, my chest hurts, and my abdomen lightly hurts and i dunno if its because of my waist problem (cos my waist hurts at times due to the position of my sleep).... cos my wrist aches.....I got headache, feel tired easily, no fever cos my temperature always below 37.... and i have had cold and block nose for more than a month now...... and before then my encounter my penis was inching ( which i knew was cos of condom allergies ).... in 21 days of my incident what do u think it happening.... any of this related to my incident ? or is it cos of anxiety, panic or fear ?

Answered by Dr. Sankaranantham Murugan (9 hours later)

Hi XXXXXXX,
The earliest HIV manifestations, due to acute infection can occur only after 4 weeks. That is a typical FLU like symptoms, not chest ache. Generalized body pain, tiredness may be due common cold as you have already cold and blocked nose.

As it already over three weeks it is better for you have tested for HIV with P24 antigen test or DNA PCR which will be sensitive and conclusive by now and a negative result will relieve all your anxiety.
Good luck to you.
Dr S. Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (4 hours later)

what is flu like symptoms ?

Answered by Dr. Sankaranantham Murugan (28 minutes later)

Hi,

Fever, head ache, body pain , sore throat, mild rashes and lymph node enlargements are FLU like symptoms. Few or all may be present. In HIV this stage usually go unnoticed or undiagnosed, as it is thought to be an ordinary viral fever.

Even if all symptoms are there, only with a reactive HIV test only can confirm the disease as HIV.
So don't get confused unnecessarily and go for a HIV test and rule out the possibility completely and remove the same from your mind too.
I hope, you got the point.
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (10 minutes later)

sure thank you

Answered by Dr. Sankaranantham Murugan (19 hours later)

Hi,
You are welcome once again.
Dr.S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (2 days later)

Ok I did Elisa around 3rd week and it still came Negative but the PCR they said results be out next week thursday but when i do the days calculation its gonna be 32 days after incident ... so how can i rely of the results please

Answered by Dr. Sankaranantham Murugan (3 hours later)

Hi,

ELISA after 3 weeks is not so reliable as it may take at least 8-12 weeks to become reactive.

But DNA PCR is highly reliable after 3 weeks and it is more conclusive. If it becomes nonreactive after 3 weeks or 32 days ELISA need not be repeated.

Wish you a negative HIV DNA PCR .
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (27 minutes later)

Thanks so much

Answered by Dr. Sankaranantham Murugan (7 hours later)

If you have no more questions to ask let us close this conversation.
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (6 hours later)

Sure thanks so much
please check the picture attached cos this morning i woke up and found some blisters at the top left corner of my upper lips... and beside that I had a lip bump which I taught was cos of saliva distraction because of my block nose .... and under my tongue too being a very little hurting

Answered by Dr. Sankaranantham Murugan (1 hour later)

Hi,

I saw the picture.

You are having HSV 1 infection called as Herpes Labialis. It is mostly not venereal origin even though it can occur with kissing or oral sex.
Even without any sex contact, sometimes children, also can have this lesion. Following a high fever or extreme exhaustion also anybody one can have a recurrence. Recurrence is very common. 90 % nonvenereal origin caused by HSV . It is self limiting condition and heal with or without treatment within a weeks time. Not necessarily associated with HIV.
Dr S.Murugan

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Sankaranantham Murugan (3 minutes later)

Also last question I am having a discomfort in my pelvic region .... I just dont know whats going on with me
so are blisters not a flu like symptoms ?

Answered by Dr. Sankaranantham Murugan (7 hours later)

Hi,

These blisters are not coming under early HIV symptoms and not related to HIV at this stage. So don't correlate this to HIV Acute infection and not to worry.

Good luck to you.
Dr S.Murugan

Note: Get personalized answers to your HIV related queries You can choose to talk face to face with your doctor. Book a Video Call now.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar