Implementation of HIV Early Infant Diagnosis and HIV Type 1 RNA Viral Load Determination on Dried Blood Spots in Cameroon: Challenges and Propositions

Abstract

The testing of dried blood spots (DBSs) for human immunodeficiency type 1 (HIV-1) proviral DNA by PCR is a technology that has proven to be particularly valuable in diagnosing exposed infants. We implemented this technology for HIV-1 early infant diagnosis (EID) and HIV-1 RNA viral load determination in infants born of HIV-1-seropositive mothers from remote areas in Cameroon. The samples were collected between December 2007 and September 2010. Fourteen thousand seven hundred and sixty-three (14,763) DBS samples from infants born of HIV-positive mothers in 108 sites nationwide were tested for HIV. Of these, 1452 were positive on first PCR analyses (PCR1), giving an overall infection rate of 12.30%. We received only 475 DBS specimen for a second PCR testing (PCR2); out of these, 145 were positive. The median HIV-1 RNA viral load for 169 infant DBS samples tested was 6.85 log copies/ml, with values ranging from 3.37 to 8 log copies/ml. The determination of the viral load on the same DBS as that used for PCR1 allowed us to bypass the PCR2. The viral load values were high and tend to decrease with age but with a weak slope. The high values of viral load among these infants call for early and effective administration of antiretroviral therapy (ART). The findings from this study indicate that the use of DBS provides a powerful tool for perinatal screening programs, improvement on the testing algorithm, and follow-up during treatment, and thus should be scaled up to the entire nation.

Systematic Review of the Use of Dried Blood Spots for Monitoring HIV Viral Load and for Early Infant Diagnosis

“…DBS samples are regularly used for early infant diagnosis and generally accepted as a sensitive method when venous blood cannot be collected [1], [39]–[41]. Although all studies reviewed here showed good sensitivity, the specificity was slightly less than with fresh blood samples (99–100%).…”

Dried blood spot specimen quality and validation of a new pre-analytical processing method for qualitative HIV-1 PCR, KwaZulu-Natal, South Africa

“…Rates of specimen rejection vary considerably and there is a paucity of data describing the frequency of each specimen quality issue. 15,16 Data such as specimen quality should be analysed in order to review the performance of HIV-1 PCR testing in the field and to standardise DBS specimen collection methods, storage and testing. 14 This study has shown that analysing specimen quality can identify health facilities which require targeted interventions, such as retraining of healthcare workers.…”

Obstetrical, maternal characteristics and outcome of HIV-infected rapid progressor infants at Yaounde: a retrospective study

“…HIV testing of children less than 18 months was done using DNA/RNA PCR. The PCR was done at the Centre Pasteur du Cameroun in the framework of the ANRS Pediacam study (27) and at the Chantal Biya International Research Center (CBIRC) (28). The children were referred to the CME-FCB either for diagnosis of HIV in those suspected to be infected or for further management of the already diagnosed HIV infection.…”