[Comparison of the performance of viral load screening from plasma and from the oneblotting paper (Oudried Blood Spot), protocol in people living with the human immunodeficiency virus (PLHIV) in Bamako]

INTRODUCTION

The use of blotting paper as a support for quantification of viral load could improve the virological monitoring of patients on Human Immunodeficiency Virus treatment in Mali. The urgency is obvious to us that the coverage in charge is only 10% for the achievement of the 3rd 90.

OBJECTIVE

To assess the performance of viral load screening (sensitivity, specificity, concordance) of DBS from the one spot DBS protocol according to plasma in people living with the human immunodeficiency virus (PLHIV) in Bamako.

METHODS

A total of 130 blotting papers were made from blood samples received from five sites for monitoring live persons with HIV. These blotting papers thus made were analyzed with the Abbott m2000 apparatus for the purpose of quantifying the viral load with plasma as reference sample. The extraction was done with the m2000SP automatic extractor, following the protocol 1.0 mL HIV-RNA DBS Protocol for paper. Furthermore, the extraction of plasma RNA on the m2000SP was done according to the 0.6 mL HIV-1 RNA protocol.

RESULTS

With 130 samples with detectable viral loads, we obtained a correlation of r = 0.837 (p <0.001). In addition, the average difference between the viral load on blotting paper and plasma was 0.512 log / virological copies with a kappa coefficient = 0.708. The threshold of 1000 copies / mL defined as virological success in our study allowed us to obtain a sensitivity of 87% and a specificity of 100%.

CONCLUSION

Decentralized zones or virological plasma monitoring is not accessible, the new Protocol one spot of Abbott laboratory offers an interesting opportunity for the follow-up of these patients with good performance at the threshold of 1000 copies. The use of DBS as a virological support can contribute effectively to the achievement of the 3rd 90.

Validation of the Viral Load Testing Criteria - an algorithm for targeted viral load testing in HIV-positive adults receiving antiretroviral therapy

OBJECTIVES

Restricted capacity for viral load (VL) testing is a major obstacle for antiretroviral therapy (ART) programmes in high-burden regions. Algorithms for targeted VL testing could help allocate laboratory resources rationally. We validated the performance of the Viral Load Testing Criteria (VLTC), an algorithm with satisfactory performance in derivation (sensitivity 91%, specificity 43%).

METHODS

HIV-positive adults who had been receiving first-line ART for ≥12 months at three Ethiopian public ART clinics were included. Healthcare providers collected data on variables of the VLTC: current CD4 count, mid-upper arm circumference (MUAC) and self-reported treatment interruption. VL testing was performed in parallel. Performance of the algorithm for identification of patients with VL ≥ 1000 copies/ml was evaluated.

RESULTS

Of 562 patients (female 62%, median ART duration 92 months), 33 (6%) had VL ≥ 1000 copies/ml. Sensitivity for the VLTC was 85% (95% CI, 68-95), specificity 60% (95% CI, 55-64), positive predictive value 12% (95% CI, 10-14) and negative predictive value 98% (95% CI, 97-99). Use of the algorithm would reduce the number of VL tests required by 57%. Misclassification occurred in 5/33 (15%) of subjects with VL ≥ 1000 copies/ml.

CONCLUSION

In validation, the VLTC performed similarly well as derivation. Use of the VLTC may be considered for targeted VL testing for ART monitoring in high-burden regions.

How to achieve the global 90-90-90 target by 2020 in sub-Saharan Africa? A mathematical modelling study

OBJECTIVES

The 90-90-90 target states that by 2020, 90% of people living with HIV should be diagnosed, 90% of those diagnosed treated, and 90% of those treated virally suppressed. We assessed the actions needed in each country of sub-Saharan Africa to achieve the 90-90-90 target.

METHODS

We developed a mathematical model to assess the number of patients needing to start antiretroviral therapy (ART) between 2017 and 2020 to achieve 81% coverage by 2020 in each country, and the proportion of treated patients who are virally suppressed in four scenarios, combining two scenarios of retention (current-level or perfect), and routine viral load monitoring (current or universal coverage). We performed two separate simulations, one using observed failure rates from cohort studies, and one with considerably lower failure rates to set a theoretical lower limit.

RESULTS

Our model projected that 2.9 million people started ART in 2017 in sub-Saharan Africa. If, depending on scenario, at least 2.2-2.7 million patients continue to start ART annually, 81% ART coverage will be reached in 2020 in sub-Saharan Africa on average. In 37% of the countries, a multiple-fold increase in annual number of patients starting ART is needed. Virological suppression >90% in 2020 could be reached only in the best-case scenario assuming low probability of treatment failure, elimination of treatment interruptions, and universal routine viral load monitoring.

CONCLUSION

The 90-90-90 target is realistic in sub-Saharan Africa on average, but not necessarily in all individual countries. Each country should identify and focus on the specific gaps needing attention.

Secondary dengue virus infections during the 2009 outbreak in Buenos Aires

OBJECTIVES

To evaluate the occurrence of secondary dengue virus (DENV) infections during the 2009 outbreak in a non-endemic area. Viral loads were evaluated in serum from acute-phase patients, comparing primary and secondary infection.

METHODS

Serum samples from patients with clinical diagnosis of suspected dengue were referred to the Virology Laboratory at 'Ricardo Gutiérrez' Children's Hospital. Dengue-positive samples were classified as primary or secondary DENV infections through serological methods (anti-DENV IgM and IgG). Viral loads were measured by quantitative real-time PCR (qRT-PCR) in samples obtained in the first 5 days of infection. Statistical analyses were performed to evaluate factors that might correlate with differences in the viral load of primary or secondary infection.

RESULTS

A total of 229 DENV cases were confirmed; among them, 22.7% were secondary infections. No significant differences were found between the viral load of primary and secondary infections.

CONCLUSION

We detected a high percentage of secondary DENV infections in a non-endemic area; this finding might correspond to socio-demographic characteristics of the group under study or indicate a previous cryptic DENV circulation causing inapparent infections.

Is zidovudine first-line therapy virologically comparable to tenofovir in resource-limited settings?

OBJECTIVE

To compare virologic success between adult patients on tenofovir (TDF) and zidovudine (AZT)-containing first-line antiretroviral (ART) regimens in 10 rural clinics in Lesotho, Southern Africa.

METHODS

Multicentre cross-sectional study, patients ≥16 years, on first-line ART ≥6 months, receiving AZT/lamivudine (3TC) or TDF/3TC combined with efavirenz (EFV) or nevirapine (NVP). Patient characteristics and clinical/therapeutic history were collected on the day of blood draw for viral load (VL). Analysis was stratified for non-nucleoside reverse transcriptase inhibitor (EFV or NVP). A logistic regression model weighted for patients' baseline characteristics was used to assess the likelihood of virologic success (<80 copies/ml) in patients with TDF- as compared to AZT-backbones.

RESULTS

In total 1539 patients were included in the analysis. Most were clinically and immunologically stable (clinical failure: 2.7% (AZT) and 2.8% (TDF); immunological failure: 4.6% (AZT) and 4.8% (TDF)). In EFV-based regimens (n = 1162), TDF was significantly associated with higher rates of virologic suppression than AZT (93.8% vs. 88.1%; weighted odds ratio: 2.15 (95% CI: 1.29-3.58; P = 0.003)). In NVP-based regimens, a similar trend was observed, but not significant (89.4% vs. 86.7%; 1.99 (0.83-4.75, P = 0.121)).

CONCLUSION

These findings support the WHO recommendation to use TDF/3TC/EFV as first-line regimen. They do, however, not support the recommendation that patients who are clinically stable on AZT should continue on this first-line regimen.

The interaction between malaria and human immunodeficiency virus infection in severely anaemic Malawian children: a prospective longitudinal study

OBJECTIVE

Malaria and human immunodeficiency virus (HIV) infection are co-prevalent in sub-Saharan Africa and cause severe anaemia in children. Interactions between these infections occur in adults, although these are less clear in children. The aim of study was to determine their interaction in a cohort of severely anaemic children.

METHODS

Severely anaemic Malawian children were enrolled, tested for HIV and malaria, transfused and followed for 18 months for malaria incidence. Antiretrovirals were not widely available in Malawi during the study period.

RESULTS

Of 381 children (haemoglobin <5 g/dl), 357 consented for HIV testing, 12.6% were HIV-infected, and 59.5% had malaria parasitaemia. At enrolment, HIV-infected children had similar malaria parasitaemia prevalence (59.1% vs. 58.7%; P = 0.96) and parasite density (geometric mean [parasites/μl] 6903 vs. 12417; P = 0.18) as HIV-negative children. There were no differences in mean CD4%, or prevalence of severe immunosuppression, between those with and without malaria parasitaemia. Plasma viral load correlated negatively with log parasitaemia (r = -0.78; P = 0.01). During follow-up, HIV-infected children did not experience more frequent parasitaemias or symptomatic malaria episodes. Adjusted risk estimates (95% CI) for malaria parasitaemia in HIV-infected children at 6 and 18 months follow-up were 0.39 (0.13-1.14) and 0.40 (0.11-1.51), respectively.

CONCLUSIONS

Severely anaemic HIV-infected children showed no increased susceptibility to asymptomatic or symptomatic malaria during or following their anaemic episode, although all experienced lower parasite prevalence during follow-up. This contrasts with data in adults and may relate to the malaria immunity of young children which is insufficiently developed to be impaired by HIV. The negative correlation between viral load and malaria parasitaemia remains unexplained.

Understanding HIV viral load: implications for counselling

This paper provides an overview of HIV viral loads in blood and genital fluids and how these relate to HIV transmission during sexual activity. Current knowledge around HIV viral loads and transmission are then discussed in relation to HIV disclosure laws in Canada. HIV counsellors and health care workers should ensure that their clients/patients are aware that blood viral load is not necessarily equivalent to genital tract viral load and that the development of drug resistance within the two compartments may be unrelated. This is an important factor in preventing the spread of HIV as well as for HIV-positive individuals in not unintentionally exposing themselves to potential legal repercussions.