Molecular HIV screening

Abstract

Nuclear acid testing is more and more used for the diagnosis of infectious diseases. This paper focuses on the use of molecular tools for HIV screening. The term ‘screening’ will be used under the meaning of first-line HIV molecular techniques performed on a routine basis, which excludes HIV molecular tests designed to confirm or infirm a newly discovered HIV-seropositive patient or other molecular tests performed for the follow-up of HIV-infected patients. The following items are developed successively: i) presentation of the variety of molecular tools used for molecular HIV screening, ii) use of HIV molecular tools for the screening of blood products, iii) use of HIV molecular tools for the screening of organs and tissue from human origin, iv) use of HIV molecular tools in medically assisted procreation and v) use of HIV molecular tools in neonates from HIV-infected mothers.

Keywords::

• blood safety
• HIV
• HIV mother-to-child transmission
• medically assisted procreation
• molecular biology
• nucleic acid testing
• organ and tissue safety
• point-of-care diagnosis

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• • HIV molecular screening relies on three types of nucleic acid testing (NAT) technologies: HIV qualitative nucleic acid assays, RNA viral load testing and molecular point-of-care (POC) testing.

• • Different platforms are in development and will be available soon for the detection/quantification of HIV nucleic acids in POC with excellent sensitivity and specificity and without need of molecular training for technicians.

• • By using the most sensitive tests, the window period for HIV can be reduced from 17–22 days with standard serological tools to 7–16 days with 4th generation or combined antibody-antigen tests and 5–6 days with NAT for HIV.

• • In the era of NAT screening, the residual risk for HIV transmission by labile blood products was estimated to 1:1,800,000 (minipools) and 1:2,800,000 (single donor) in the USA, 1:4,300,000 in Germany and 1:2,400,000 in France.

• • There is no consensus on the clinical benefit for testing organ donors with HIV NAT. The present techniques are not well fitted for a rapid diagnosis 24/24, 7/7 but new technologies are coming soon. In contrast, tissue donors must be submitted to HIV NAT screening as blood donors.

• • In assisted reproductive techniques in which the male partner is infected by HIV, a screening for HIV RNA is recommended in seminal plasma. In case of low positivity, NAT is performed on the germ cells used for antiretroviral therapy (ART). If positive, ART is delayed.

• • Concerning the mother-to-child transmission (MCT), HIV molecular screening plays an important part in the rise of an ‘HIV-free generation’. It permits to identify rapidly the few neonates that escaped to the benefit of anti-retroviral prophylaxis.

• • HIV molecular screening needs also to be implemented in resource-limited settings, notably to monitor MCT. This implies the development of simplified technologies that necessitate low maintenance and rudimentary technical training.

Notes