Collaboration in Civic Spheres

Seattle-Nairobi Team Has Better HIV Test For African Infants

by Matt Rosenberg March 15th, 2011

SUMMARY: Early detection of the HIV-1 virus in infants in Africa is a pressing global health concern but current testing tools are too expensive. A team of researchers from the University of Washington and Fred Hutchinson Cancer Research Center in Seattle and institutions in Nairobi, Kenya, has validated a new and far less costly in-house testing tool involving the detection of HIV-1 nucleic acids from filter papers used to collect samples of whole blood or dried blood spots. The researchers recommend the new infant HIV-1 diagnostic tool be developed for integration into “rapid point-of-care” African settings “where the HIV epidemic prevails and resources are limited.”

BACKGROUND:

  • Mothers who have HIV-1, an infection which can lead to the AIDS virus, may pass that infection along to their in-utero infants. An estimated 1,000 new cases of pediatric HIV-1 occur daily, 90 percent in Sub-Saharan African nations. Reliable early detection is crucial so that anti-retroviral drugs to combat the infection can be administered to patients as soon as possible.
  • Because of antibodies passively acquired from the mother, detection of HIV-1 infection in an infant can be more complicated if medical staff are using conventional testing methods.
  • A more suitable and potentially cost-effective molecular testing method incorporating polymerase chain reaction or PCR has been identified. It involves the detection of HIV-1 nucleic acids, using filter papers to collect samples of whole blood or dried blood spots (FP-DBS). But this type of approach has been mainly limited to commercial products which cost $20 to $50 per test, too expensive.
  • The study team devised a simple-to-administer, in-house version of the “PCR FP-DBS” infant HIV-1 testing tool, which costs just a few dollars per round. They then assessed its performance by seeing if it returned correct results on archived HIV-1 positive infant test results from dried blood spots on filter paper, and on samples of recently-collected dried blood spots on filter papers from infants in Nairobi, Kenya who had already been diagnosed as HIV-1 positive using the commercially-produced diagnostic tool.

KEY LINK: Evaluation Of A Single Round Polymerase Chain Reaction Assay Using Dried Blood Spots For Diagnosis Of HIV-1 Infection In Infants In An African Setting, BioMedCentral Pediatrics, February 18, 2011. (Authors include: Bhavna H. Chohan, Dept. of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle; Grace John-Stewart, Dept. of Epidemiology, University of Washington, Seattle; and Sandra Emery, Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle.)

KEY FINDINGS:

  • The study has demonstrated the reliability of a cost-effective in-house DNA-based infant HIV-1 test based on analysis of dried blood spots on filter papers, that compares quite favorably to earlier more labor-intensive versions of the product, and a more expensive commercial product. It’s full official name is the HIV 1 pol FP-DBS PCR assay.
  • “HIV-1 was detected with high sensitivity using both archived and more recently collected samples. This suggests that this in-house HIV assay can provide an alternative cost-effective, reliable and rapid method for early detection of HIV-1 infection in infants.”
  • The results of the study point to the need to integrate the new infant HIV-1 testing tool more broadly into “rapid point-of-care” environments including Africa “Ă«specially where the HIV epidemic prevails and resources are limited.”

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