Title: High Level of HIV-2 False Positivity in KwaZulu-Natal Province: A Region of South Africa With a Very High HIV-1 Subtype C Prevalence
Authors: Singh L, Parboosing R, Manasa J, Moodley P, de Oliveira T.
Journal: Journal of Medical Virology,Advanced Access:doi: 10.1002/jmv.23716 (2013)
Human immunodeficiency virus 2 (HIV-2) is found predominantly in West Africa. It is not unlikely, however, that HIV-2 may also be found in South Africa, due to the influx of immigrants into this country.
It is important to distinguish between HIV-1 and HIV-2 since the clinical courses and treatment responses of these viruses are different. Routine serological methods for diagnosing HIV do not differentiate between HIV-1 and -2 infections, while rapid tests, viral load quantification and PCR are HIV-type specific.
The objective of this study was to describe the seroprevalence and molecular epidemiology of HIV-2 in KwaZulu- Natal, one of the regions with the highest HIV prevalence in the world and home of the two largest harbors in South Africa. HIV-1 positive samples were screened for antibodies against HIV-2, using a rapid test.
The confirmation of HIV-2 positive samples was done by PCR. Of the 2,123 samples screened, 319 (15%) were identified as positive by the rapid test. None of these samples were confirmed positive by PCR. To explore this discrepancy in the results, a subset (n = 52) of the rapid HIV-2 positive samples was subjected to Western blotting. Thirty-seven (71%) of these were positive, yielding an overall HIV-2 seroprevalence of 10.6%. Three out of 28 (10.7%) Western blot positive samples were positive by a Pepti-LAV assay.
This discrepancy between serological and molecular confirmation may be attributed to non-specific or cross-reacting antibodies. The use of rapid tests and Western blots for HIV-2 diagnosis in South Africa should be interpreted with caution.
Citation: Singh L, Parboosing R, Manasa J, Moodley P, de Oliveira T. High Level of HIV-2 False Positivity in KwaZulu-Natal Province: A Region of South Africa With a Very High HIV-1 Subtype C Prevalence Journal of Medical Virology,Advanced Access:doi: 10.1002/jmv.23716 (2013).