The Body: The Complete HIV/AIDS Resource
Follow Us Follow Us on Facebook Follow Us on Twitter Download Our App 
Professionals >> Visit The Body PROThe Body en Espanol
Ask the Experts About

Understanding Your LabsUnderstanding Your Labs
Rollover images to visit our other forums!
Recent AnswersAsk a Question
  • Email Email
  • Glossary Glossary

Southern Africa

Jul 19, 2004

Dumela (Hello!),

In some parts here, 40% of adults are infected with HIV and C subtype is the main one. Many do not know they are infected and there is a question if tests designed for B subtype are as accurate for C and some other rare subtypes.

I am sorry to ask a few questions, but no one seems to know the answers.I will be very grateful if you can help -

a. How sensitive are blood samples for ELISA tests to delays in processing specimens? In one of your answers last year, you talked about how delays in separating plasma and cells causes breakdown of antibodies and virus in whole blood (less sensitivity therefore?). Do the 99.8 % sensitivity numbers for ELISA's anticipate perfect handling of specimens?

b. Nutrition is a problem for many here - could that mean, if some have low numbers for chemicals or enzymes that are important for the ELISA to work as well, that the test is less reliable? (for example, maybe abnormally low alkaline phosphotase or B cells)....or is low normal enough for reliable ELISA's?

c. I live in a hot climate where the local Clinic stores blood specimens all day until they are sent to the laboratory at 5pm. Will the delays reduce sensitivity of ELISA?

d.Here, they sometimes use an ELISA with viral lysate from B subtype and other times may use one with synthetic peptides. Yet C is predominant in South Africa and Zimbabwe. Is the 99.8% sensitivity for B antibodies the same for C or is there some reduction the more the subtypes depart from B?

Thank you.

Response from Dr. Holodniy

a. this pertains more to viral load tests than to antibody testing. b. this should not affect the test. c. labs should be running quality control tests to make sure the tests in their hands are working properly. d. Many commercial tests are available that can adequate test for subtypes A and C.

these #'s are making me crazy
Is this possible

  • Email Email
  • Glossary Glossary

 Get Email Notifications When This Forum Updates or Subscribe With RSS



This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.

Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.

Review our complete terms of use and copyright notice.

Powered by ExpertViewpoint