Evaluation of the sensitivity and specificity of rapid human immunodeficiency virus (HIV)1 and 2 test kits commonly used in Nigeria

The sensitivity and specificity of five rapid HIV antibody test kits commonly used in Nigeria were evaluated. The kits were selected based on their high percentage frequency of use as compared to others. A total of 100 EIA HIV-1and RNA HIV-1 positive sera were used as positive gold standard; while 100 EIA HIV-1 and RNA HIV-1 negative sera were used as negative gold standard. The positive gold standard sera were pooled; serially diluted and analysed to determine the sensitivities of the kits. The methods used were strictly as provided by the manufacturers. Of the 100 positive gold standard serum samples used; Immunocomb-II gave false negative results with 10 (Sensitivity = 90); while HIV-SAV; Hexagon; Determine and SD-Bioline were false negative with 12 specimens; representing 88 sensitivity for each. On the other hand; of the 100 negative gold standard sera; Immunocomb-II gave 6 false positive results (Specificity = 94); HIV-SAV 12 (Specificity = 88); Hexagon 2 (Specificity = 98); Determine 12 (Specificity = 88); while SD-Bioline had no false positive result (specificity = 100). In analytical sensitivity; Immunocomb-II detected the highest serum titre of 30 000; making it the most sensitive. Two of the five test kits (Immunocomb and SD-Bioline) demonstrated excellent analytical sensitivity and specificity respectively. The two could be recommended for use as combination test algorithms instead of EIA/Western Blot algorithm; which is time-consuming; expensive and often not technically feasible in a developing country like ours. This study shows that not all the analytical performance indices cited in the literature from the manufacturers of diagnostic kits are necessarily reproducible in end-user laboratories

Infection à VIH-2 au Sénégal: échecs virologiques et résistances aux antirétroviraux (ARV)

Introduction: le VIH-2, endémique en Afrique de l'Ouest, est naturellement résistant aux inhibiteurs non nucléosidiques de la rétro transcriptase, ce qui rend difficile la prise en charge dans les pays en développement. Objectifs: déterminer la prévalence de l'échec virologique au 12éme et 24éme mois (M12 et M24) de traitement antirétroviral de première ligne chez les patients infectés par le VIH-2 et d'en décrire les résistances génotypiques associées.Méthodes: il s'agit d'une étude descriptive longitudinale et prospective, durant la période de Novembre 2005 à Juin 2017. L'échec virologique a été défini comme toute charge virale supérieure à 50 copies/ml après 6 mois de traitement ARV à deux reprises. La recherche de mutations de résistance a été réalisée dans les régions codantes de la protéase et de la transcriptase inverse. Résultats: au total 110 patients ont été colligés, d'âge médian de 46 ans (Extrêmes 18-67) avec un ratio F/H de 2,54. A l'inclusion, la charge virale était détectable dans 44% des cas avec une médiane de 935cp/ml (Extrêmes 17-144038). Le schéma antirétroviral associait 2 INTI à 1IP dans 94% des cas. La durée médiane de suivi était estimée à 1200 jours (Extrêmes 1-3840). 94 puis 76 patients ont respectivement complété leur bilan à M12 et M24. Au suivi M24, 39 patients étaient en échec virologique soit une prévalence de 39% estimée à 33% à M12 et 11% à M24. 45% des patients avaient des résistances aux INTI, 41% des résistances aux IP et 30% des multi résistances aux INTI et IP.Conclusion: il est impératif de rendre accessibles les nouvelles classes thérapeutiques pourle traitement de sauvetage des patients infectés par le VIH-2 dans les pays à ressources limitées

Inconclusive results with HIV serodiagnosis algorithms, and HIV-1 and HIV-2 co-infection in North-eastern Democratic Republic of Congo

Background:Inconclusive serodiagnosis of HIV infection is particularly frequent in Central Africa. The aims of this study were to: (i) determine the rate of inconclusive results with the two-test algorithm that the WHO proposed in 1997 (WHO II) versus the three-test algorithm (revised in 2012 and consolidated in 2015 by WHO) for HIV testing, and (ii) determine the prevalence of HIV-1 and HIV-2 co-infection in the north-eastern region of the Democratic Republic of the Congo (DRC).Methods:A multicentre cross-sectional study was performed between March and June 2016 in Kisangani and Bunia, the capital cities of Tshopo and Ituri provinces respectively. Alere Determine HIV-1/2 (Alere Medical Co. Ltd., Japan), Uni-GoldTM HIV (Trinity Biotech Manufacturing Ltd., Ireland) and recomLine HIV-1 and HIV-2 IgG (Biosynex, France) were the first, second and third tests in the serial algorithm.Results : The rate of inconclusive results was 1.1% (95% CI: 0.4 to 3.1) with the two-test algorithm and 0.4% (95% CI: 0.1 to 2.1) with the three-test algorithm (p less than 0.001). The prevalence of HIV-1 and HIV-2 co-infection among HIV positive sera was 16.7% (95% CI: 4.7 to 44.8).Conclusion:The three-test algorithm HIV testing strategy significantly reduces the rate of inconclusive results. In addition, the prevalence of HIV-1 and HIV-2 co-infection is higher in a context where HIV-2 infection is poorly documented. Large-scale research is essential to clarify these results

Diagnosis and Monitoring of HIV Infection

The latest statistics indicate that the number of people infected with human immunodeficiency virus type 1 (HIV-1) worldwide is 40.3 million; 25.8 million of whom live in sub-Saharan Africa. In 2004; 29.5 of South African women attending antenatal clinics were infected. The virus infects people of all ages and social classes. A diagnosis of HIV has serious physical; emotional and social implications for the patient. HIV-infected patients are susceptible to numerous opportunistic and other infections; as well as to non-infectious backdiseases such as tumours. They eventually require lifelong treatment with potentially toxic medication. It is therefore essential that a timeous and correct diagnosis be made. An understanding of the tests available for the diagnosis and monitoring of HIV is essential for all clinicians working in South Africa. Tests available for the diagnosis of HIV in patients older than 18 months include HIV-specific antibody assays; fourth-generation combination antibody-antigen assays and Western Blot. The diagnosis of HIV infection in infants younger than 18 months requires detection of the virus itself by means of p24 antigen detection or HIV DNA PCR. The CD4+ T lymphocyte count and HIV viral load are used for monitoring disease progression and response to therapy