LABORATORY DIAGNOSIS OF DUAL HIV-1/HIV-2 INFECTION IN GHANAIAN PATIENTS

Abstract

Objective: To determine the true prevalence of HIV dual infections in a previously

characterised HIV seropositive patient group due to inconsistencies between different

diagnostic methods.

Design: A cross-sectional study of an HIV seropositive group with different diagnostic

methods.

Setting: Noguchi Memorial Hospital for Medical Research.

Subjects: Venous blood aseptically collected from 145 HIV infected individual from

June to September.

Main outcome measures: Using serological and molecular methods, the seropositive

status of HIV-infected patients, previously determined by a preliminary screening

process, was confi rmed and discrepancies noted. The data was used to propose a more

accurate laboratory diagnosis of HIV dual infections involving HIV-1 and HIV-2.

Results: HIV-1 infections were mostly accurately detected, but diffi culties were

encountered in diagnosing HIV-2 infections. To achieve a positive detection on

confi rmatory immunoblots, antibody concentration in some samples tested was

enhanced by using larger volumes. In other cases, diagnosis of HIV infections by

PCR, especially HIV-2, was possible only after increasing the DNA template or MgCl2

concentrations. Such samples would otherwise have been inaccurately scored for HIV

infections.

Conclusion: Based on the results of this study, we propose that the accurate diagnosis

of HIV dual infections, especially HIV-2 component, must use an algorithm that

involves PCR. Our results however underscore conclusions of a previous study that

most dually seroreactive samples are predominantly HIV-1 infections with crossreactivity

to HIV-2 antigens.