HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing

The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

Characterization of drug resistance mutations in naïve and ART-treated patients infected with HIV-1 in Yaounde, Cameroon

Currently the prevalence of HIV-1 infection in Cameroon is 5.1%, CRF02_AG subtype is responsible for about 50% of infections. Since an HIV-1 drug resistance test is not yet available widely, accurate data on the prevalence of resistant viral strains are missing. The objective of this study was to determine HIV-1 genetic diversity and to characterize HIV-1 mutations conferring drug resistance among antiretroviral therapy (ART)-naïve and ART-treated patients. A cohort of 239 patients infected with HIV were followed-up between January 2007 and July 2010 in Cameroon. Two hundred and sixteen plasma samples were sequenced for phylogenetic analysis and identification of drug resistance mutations in the HIV-1 pol region. A significant genetic diversity was found: Seven pure subtypes (A1, A3, D, F1, F2, G, H), nine circulating recombinant forms (CRFs: 01_AE, 02_AG, 06cpx, 09cpx, 11cpx, 13cpx, 16cpx, 18cpx, 37cpx) and one new unique recombinant form (URF) (G/F2). The rate of transmitted drug resistance (TDR) in naïve patients was 8.2% (4/49). Around 80% of patients failing a first-line ART harbored a virus with at least one resistance mutation to two antiretroviral (ARV) classes, and 36% of those failing a second-line regimen carried a virus with at least one resistant mutation to three ARV classes. The high level of drug resistance observed in the cohort is alarming because this occurred as a result of only few years of treatment. Adherence to therapy, adequate education of physicians, and the appropriate use of genotypic resistance assay are critical points of intervention for the improvement of patient care.

Viral suppression in adults, adolescents and children receiving antiretroviral therapy in Cameroon: adolescents at high risk of virological failure in the era of "test and treat"

BACKGROUND

After the launching of the « Test & Treat » strategy and the wider accessibility to viral load (VL), evaluating virological success (VS) would help in meeting the UNAIDS targets by 2020 in Cameroon.

SETTING AND METHODS

Cross-sectional study conducted in the Chantal BIYA International Reference Centre for research on HIV/AIDS prevention and management (CIRCB), Yaoundé, Cameroon; data generated between October 2016 and August 2017 amongst adults, adolescents and children at 12, 24, 36 and ≥ 48 months on ART. VS was defined as < 1000 copies/mL of blood plasma and controlled viremia as VL < 50 copies/mL. Data were analysed by SPSS; p < 0.05 considered as significant.

RESULTS

1946 patients (70% female) were enrolled (1800 adults, 105 adolescents, 41 children); 1841 were on NNRTI-based and 105 on PI-based therapy; with 346 patients at M12, 270 at M24, 205 at M36 and 1125 at ≥ M48. The median (IQR) duration on was 48 months (24-48). Overall, VS was 79.4% (95% CI 77.6-81.2) and 67.1% (95% CI 64.9-69.1) had controlled viral replication. On NNRTI-based, VS was 79.9% vs. 71.4% on PIs-based, p = 0.003. By ART duration, VS was 84.1% (M12), 85.9% (M24), 75.1% (M36) and 77.2% (≥ M48), p = 0.001. By age, VS was 75.6% (children), 53.3% (adolescents) and 81.1% (adults), p < 0.001.

CONCLUSIONS

In this sub-population of patients receiving ART in Cameroon, about 80% might be experiencing VS, with declining performance at adolescence, with NNRTI-based regimens, and as from 36 months on ART. Thus, improving VS may require an adapted adherence support mechanism, especially for adolescents with long-term treatment in resource-limited settings.

SARS-CoV-2 antibody seroprevalence and associated risk factors in an urban district in Cameroon

The extent of SARS-CoV-2 circulation in many African countries remains unclear, underlining the need for antibody sero-surveys to assess the cumulative attack rate. Here, we present the results of a cross-sectional sero-survey of a random sample of residents of a health district in Yaounde, Cameroon, conducted from October 14 to November 26, 2020. Among the 971 participants, the test-adjusted seroprevalence of anti-SARS-CoV-2 IgG antibodies was 29·2% (95% CI 24·3-34·1). This is about 322 times greater than the 0.09% nationwide attack rate implied by COVID-19 case counts at the time. Men, obese individuals and those living in large households were significantly more likely to be seropositive, and the majority (64·2% [58·7-69·4]) of seropositive individuals reported no symptoms. Despite the high seroprevalence, most of the population had not been infected with SARS-CoV-2, highlighting the importance of continued measures to control viral spread and quick vaccine deployment to protect the vulnerable.

Nucleoside reverse transcriptase inhibitor resistance mutations associated with first-line stavudine-containing antiretroviral therapy: programmatic implications for countries phasing out stavudine

BACKGROUND

The World Health Organization Antiretroviral Treatment Guidelines recommend phasing-out stavudine because of its risk of long-term toxicity. There are two mutational pathways of stavudine resistance with different implications for zidovudine and tenofovir cross-resistance, the primary candidates for replacing stavudine. However, because resistance testing is rarely available in resource-limited settings, it is critical to identify the cross-resistance patterns associated with first-line stavudine failure.

METHODS

We analyzed HIV-1 resistance mutations following first-line stavudine failure from 35 publications comprising 1,825 individuals. We also assessed the influence of concomitant nevirapine vs. efavirenz, therapy duration, and HIV-1 subtype on the proportions of mutations associated with zidovudine vs. tenofovir cross-resistance.

RESULTS

Mutations with preferential zidovudine activity, K65R or K70E, occurred in 5.3% of individuals. Mutations with preferential tenofovir activity, ≥ two thymidine analog mutations (TAMs) or Q151M, occurred in 22% of individuals. Nevirapine increased the risk of TAMs, K65R, and Q151M. Longer therapy increased the risk of TAMs and Q151M but not K65R. Subtype C and CRF01_AE increased the risk of K65R, but only CRF01_AE increased the risk of K65R without Q151M.

CONCLUSIONS

Regardless of concomitant nevirapine vs. efavirenz, therapy duration, or subtype, tenofovir was more likely than zidovudine to retain antiviral activity following first-line d4T therapy.

Monitoring HIV Drug Resistance Early Warning Indicators in Cameroon: A Study Following the Revised World Health Organization Recommendations

Background

The majority (>95%) of new HIV infection occurs in resource-limited settings, and Cameroon is still experiencing a generalized epidemic with ~122,638 patients receiving antiretroviral therapy (ART). A detrimental outcome in scaling-up ART is the emergence HIV drug resistance (HIVDR), suggesting the need for pragmatic approaches in sustaining a successful ART performance.

Methods

A survey was conducted in 15 ART sites of the Centre and Littoral regions of Cameroon in 2013 (10 urban versus 05 rural settings; 8 at tertiary/secondary versus 7 at primary healthcare levels), evaluating HIVDR-early warning indicators (EWIs) as-per the 2012 revised World Health Organization’s guidelines: EWI₁ (on-time pill pick-up), EWI₂ (retention in care), EWI₃ (no pharmacy stock-outs), EWI₄ (dispensing practices), EWI₅ (virological suppression). Poor performance was interpreted as potential HIVDR.

Results

Only 33.3% (4/12) of sites reached the desirable performance for “on-time pill pick-up” (57.1% urban versus 0% rural; p<0.0001) besides 25% (3/12) with fair performance. 69.2% (9/13) reached the desirable performance for “retention in care” (77.8% urban versus 50% rural; p=0.01) beside 7.7% (1/13) with fair performance. Only 14.4% (2/13) reached the desirable performance of “no pharmacy stock-outs” (11.1% urban versus 25% rural; p=0.02). All 15 sites reached the desirable performance of 0% “dispensing mono- or dual-therapy”. Data were unavailable to evaluate “virological suppression” due to limited access to viral load testing (min-max: <1%-15%). Potential HIVDR was higher in rural (57.9%) compared to urban (27.8%) settings, p=0.02; and at primary (57.9%) compared to secondary/tertiary (33.3%) healthcare levels, p=0.09.

Conclusions

Delayed pill pick-up and pharmacy stock-outs are major factors favoring HIVDR emergence, with higher risks in rural settings and at primary healthcare. Retention in care appears acceptable in general while ART dispensing practices are standard. There is need to support patient-adherence to pharmacy appointments while reinforcing the national drug supply system.

Immuno-virological response and associated factors amongst HIV-1 vertically infected adolescents in Yaoundé-Cameroon

Introduction

Limited studies have reported the outcomes of lifelong antiretroviral therapy (ART) amongst adolescents living with HIV (ALWHIV) in resource-limited settings (RLS), thus classifying this population as underserved. We therefore aimed to ascertain the immunological and virological responses, and associated factors amongst Cameroonian ALWHIV.

Method

A cross-sectional and observational study was conducted from January through May 2016 at the National Social Insurance Fund Health Centre in Yaoundé-Cameroon. Immunological and virological responses were evaluated using CD4 cell count and viral load respectively, with viral suppression (VS) defined as <50 copies/ml. Adherence was evaluated using self-reported missing doses during the past 14 days. Data were analyzed using R v.3.3.0, with p<0.05 considered statistically significant.

Results

Of the 145 ALWHIV on ART enrolled in the study, 52% were female, median age [interquartile (IQR)] was 13 [11–16] years, median [IQR] time-on-ART was 7 [5–10] years, 48% were orphans, 92% were on first-line ART and 36% were adherent to ART. Following ART response, 79% (114/145) had CD4 ≥500/mm³, 71.0% (103/145) were on VS of whom 52.4% (76/145) had a sustained VS. Duration of ART was associated with immune restoration (Odd Ratio 3.73 [1.26–12.21]) but not with virological response. Risks of poor adherence were greater in orphans of both parents (p = 0.078).

Conclusion

In this urban setting of Cameroon, ALWHIV receiving ART show favorable immunological and virological response in a medium run. For long-term ART success, implementing a close monitoring of adherence and risks of viral rebound would be highly relevant, especially for orphans of both parents.

Diagnostic performance of a colorimetric RT -LAMP for the identification of SARS-CoV-2: A multicenter prospective clinical evaluation in sub-Saharan Africa

BACKGROUND

Management and control of the COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus SARS-CoV-2 is critically dependent on quick and reliable identification of the virus in clinical specimens. Detection of viral RNA by a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a simple, reliable and cost-effective assay, deployable in resource-limited settings (RLS). Our objective was to evaluate the intrinsic and extrinsic performances of RT-LAMP in RLS.

METHODS

This is a multicenter prospective observational study of diagnostic accuracy, conducted from October 2020 to February 2021 in four African Countries: Cameroon, Ethiopia, Kenya and Nigeria; and in Italy. We enroled 1657 individuals who were either COVID-19 suspect cases, or asymptomatic and presented for screening. RNA extracted from pharyngeal swabs was tested in parallel by a colorimetric RT-LAMP and by a standard real time polymerase chain reaction (RT-PCR).

FINDINGS

The sensitivity and specificity of index RT LAMP compared to standard RT-PCR on 1657 prospective specimens from infected individuals was determined. For a subset of 1292 specimens, which underwent exactly the same procedures in different countries, we obtained very high specificity (98%) and positive predictive value (PPV = 99%), while the sensitivity was 87%, with a negative predictive value NPV = 70%, Stratification of RT-PCR data showed superior sensitivity achieved with an RT-PCR cycle threshold (Ct) below 35 (97%), which decreased to 60% above 35.

INTERPRETATION

In this field trial, RT-LAMP appears to be a reliable assay, comparable to RT-PCR, particularly with medium-high viral loads (Ct < 35). Hence, RT-LAMP can be deployed in RLS for timely management and prevention of COVID-19, without compromising the quality of output.

Population-based monitoring of emerging HIV-1 drug resistance on antiretroviral therapy and associated factors in a sentinel site in Cameroon: low levels of resistance but poor programmatic performance

BACKGROUND

Scale-up of antiretroviral therapy (ART) in resource-limited settings has drastically reduced HIV-related morbidity and mortality. However, challenges in long-term ART, adherence and HIV drug resistance (HIVDR) itself, require monitoring to limit HIVDR emergence among ART-experienced populations, in order to ensure regimen efficacy.

METHODS

A longitudinal study was conducted from 2009-2011 in a cohort of 141 HIV-infected adult patients (aged >21) at the national social insurance centre hospital in Yaounde, Cameroon. As per-WHO HIVDR protocol, HIV-1 protease-reverse transcriptase genotyping was performed at baseline and at endpoint (12 months) on first-line ART using ViroSeq™ Genotyping kit.

RESULTS

At baseline, a prevalence of 3.6% (5/139) HIVDR was observed [protease inhibitors M46I (1/5), G73A (1/5), L90LM (1/5); nucleoside reverse transcriptase inhibitors: M184V (1/5), T215F (1/5); non-nucleoside reverse transcriptase inhibitors: K103N (1/5), Y181Y/C (2/5), M230ML (1/5)]. At endpoint, 54.0% (76) patients were followed-up, 9.2% (13) died, and 3.5% (5) transferred, 38.5% (47) lost to follow-up (LTFU). 69.7% (53/76) of those followed-up had viremia <40 copies/ml and 90.8% (69/76) <1000 copies/ml. 4/7 patients with viremia ≥1000 copies/ml harbored HIVDR (prevalence: 5.3%; 4/76), with M184V/I (4/4) and K103K/N (3/4) being the most prevalent mutations. LTFU was favored by costs for consultation/laboratory tests, drug shortages, workload (physician/patient ratio: 1/180) and community disengagement.

CONCLUSIONS

Low levels of HIVDR at baseline and at endpoint suggest a probable effectiveness of ART regimens used in Cameroon. However the possible high rate of HIVDR among LTFUs limited the strengths of our findings. Evaluating HIVDR among LTFU, improving adherence, task shifting, subsidizing/harmonizing costs for routine follow-up, are urgent measures to ensure an improved success of the country ART performance.

High Burden of HBV-Infection and Atypical HBV Strains among HIV-infected Cameroonians

AIM

To investigate the prevalence and genotypic profile of overt and occult hepatitis-B infection (OBI) among HIV-infected individuals in Cameroon.

METHODS

212 HIV-infected Cameroonians, aged 37.6 [IQR: 32.6-46.6] followed-up at the University Health Centre in Yaoundé, were tested for HBsAg, anti-HBs, anti-HBc IgG/IgM, HBV-DNA and anti-HCV IgG. HBV positive cases were tested for Hepatitis Delta virus (HDV) using anti-HDV IgG and HDV-RNA. Liver function was assessed by alanine and aspartate aminotransaminases. OBI was defined as negative-HBsAg and detectable HBV-DNA. In occult or overt HBVinfected participants, HBV reverse transcriptase (RT)/surface (S) sequences were analyzed for drug resistance, immuneescape mutants, and phylogeny.

RESULTS

Overall, 78.3% (166/212) participants had past/ongoing HBV-exposure, with 39.1% (83/212) carrying "HBcAbpositive alone". Prevalence of overt HBV (positive-HBsAg) was 11.8% (25/212), prevalence of HBV and HDV was respectively 6.9% (12/175) and 12% (3/25). Phylogeny of HBV-RT/S revealed the co-circulation of genotypes A and E. All HBV-coinfected participants harbored HBV strains with at least one immune-escape mutation. Of note, one HBV variant carried the vaccine-escape mutation G145R that hinders HBsAg neutralization by antibodies. For the first time, a novel 9 aa-deletion (s115-s123), located in the HBsAg "a" determinant, was found concomitantly with OBI. A stop codon in the S region (associated with increased risk of hepatocellular carcinoma) was found in six cases.

CONCLUSION

High prevalence of overt/occult HBV-infection and circulating atypical strains highlight the importance of HBV-surveillance among HIV-infected Cameroonians and strategies to detect OBI in highly endemic countries.

Declining trends in early warning indicators for HIV drug resistance in Cameroon from 2008-2010: lessons and challenges for low-resource settings

BACKGROUND

Rapid scale-up of antiretroviral therapy (ART) and limited access to genotyping assays in low-resource settings (LRS) are inevitably accompanied by an increasing risk of HIV drug resistance (HIVDR). The current study aims to evaluate early warning indicators (EWI) as an efficient strategy to limit the development and spread of preventable HIVDR in these settings, in order to sustain the performance of national antiretroviral therapy (ART) rollout programmes.

METHODS

Surveys were conducted in 2008, 2009 and 2010 within 10 Cameroonian ART clinics, based on five HIVDR EWIs: (1) Good prescribing practices; (2) Patient lost to follow-up; (3) Patient retention on first line ART; (4) On-time drug pick-up; (5) Continuous drug supply. Analysis was performed as per the World Health Organisation (WHO) protocol.

RESULTS

An overall decreasing performance of the national ART programme was observed from 2008 to 2010: EWI(1) (100% to 70%); EWI(2) (40% to 20%); EWI(3) (70% to 0%); EWI(4) (0% throughout); EWI(5) (90% to 40%). Thus, prescribing practices (EWI(1)) were in conformity with national guidelines, while patient adherence (EWI(2), EWI(3), and EWI(4)) and drug supply (EWI(5)) were lower overtime; with a heavy workload (median ratio ≈1/64 staff/patients) and community disengagement observed all over the study sites.

CONCLUSIONS

In order to limit risks of HIVDR emergence in poor settings like Cameroon, continuous drug supply, community empowerment to support adherence, and probably a reduction in workload by task shifting, are the potential urgent measures to be undertaken. Such evidence-based interventions, rapidly generated and less costly, would be relevant in limiting the spread of preventable HIVDR and in sustaining the performance of ART programmes in LRS.

Plant microRNAs from Moringa oleifera Regulate Immune Response and HIV Infection

Traditional medicine is often chosen due to its affordability, its familiarity with patient’s cultural practices, and its wider access to the local community. Plants play an important role in providing indispensable nutrients, while specific small RNAs can regulate human gene expression in a cross-kingdom manner. The aim of the study was to evaluate the effects of plant-enriched purified extract microRNAs from Moringa oleifera seeds (MO) on the immune response and on HIV infection. Bioinformatic analysis shows that plant microRNAs (p-miRs) from MO belonging to 18 conserved families, including p-miR160h, p-miR166, p-miR482b, p-miR159c, p-miR395d, p-miR2118a, p-miR393a, p-miR167f-3p, and p-miR858b are predicted to target with high affinity BCL2, IL2RA, TNF, and VAV1, all these being involved in the cell cycle, apoptosis, immune response and also in the regulation of HIV pathogenesis. The effects of MO p-miRs transfected into HIV+ PBMCs were analyzed and revealed a decrease in viability associated with an increase of apoptosis; an increase of T helper cells expressing Fas and a decrease of intracellular Bcl2 protein expression. Meanwhile no effects were detected in PBMCs from healthy donors. In CD4⁺ T cells, transfection significantly reduced cell activation and modified the T cell differentiation, thereby decreasing both central and effector memory cells while increasing terminal effector memory cells. Interestingly, the p-miRs transfection induces a reduction of intracellular HIV p24 protein and a reduction of viral DNA integration. Finally, we evaluated the effect of synthetic (mimic) p-miR858b whose sequence is present in the MO p-miR pool and predicted to target VAV1, a protein involved in HIV-Nef binding. This protein plays a pivotal role in T cell antigen receptor (TCR) signaling, so triggering the activation of various pathways. The transfection of HIV+ PBMCs with the synthetic p-miR858b showed a reduced expression of VAV1 and HIV p24 proteins. Overall, our evidence defines putative mechanisms underlying a supplementary benefit of traditional medicine, alongside current antiretroviral therapy, in managing HIV infection in resource-limited settings where MO remains widely available.

The pros and cons of the QuantiFERON test for the diagnosis of tuberculosis, prediction of disease progression, and treatment monitoring

OBJECTIVE/BACKGROUND

Tuberculosis (TB) is a re-emerging disease with the advent of human immunodeficiency virus/AIDS infections. Discovered in 1959, diagnosed by various approaches and treated with antibiotics, the treatment of TB infection still poses public health concerns. Many cases of resistance and cross-resistance are observed. Diagnosis by culture, which is considered as the standard method, takes too long (20-30days) and is not suitable for extrapulmonary TB. QuantiFERON test, which is an indirect immunoassay based on blood, was developed. Much hope was placed in this new approach because it is based on blood, and many research teams have used it. We discuss the results of these different research groups who have used QuantiFERON for diagnosis, prediction of disease progression, or monitoring patients during the treatment of TB.

METHODS

Articles published in PubMed and documents published on Google were searched with the keywords: diagnosis and TB and QuantiFERON; TB and QuantiFERON and therapeutic monitoring; interferon-γ release assay; disease progression. These articles were read and analyzed.

RESULTS

The results were controversial with regards to using the QuantiFERON test for the diagnosis of TB according to the study population (ethnic group, bacillus Calmette-Guérin vaccine use) and according to the state of the immune system of the people studied (human immunodeficiency virus immunosuppression in cancer medication, hypertension). Also, research findings were controversial with regards to using QuantiFERON for monitoring TB patients on anti-TB medications. Also, the predictive positive value for the progression to TB among immigrant close contacts of both interferon-γ release assays was not better than that of the tuberculin skin test.

CONCLUSION

The QuantiFERON has advantages and limitations depending on the type of population studied. Recommendations are made to improve the sensitivity and specificity and to differentiate between latent and active TB by adding other specific proteins in the Mycobacterium tuberculosis antigen cocktail.

Feasibility and utility of active case finding of HIV-infected children and adolescents by provider-initiated testing and counselling: evidence from the Laquintinie hospital in Douala, Cameroon

BACKGROUND

Universal HIV testing and treatment of infected children remain challenging in resource-limited settings (RLS), leading to undiagnosed children/adolescents and limited access to pediatric antiretroviral therapy (ART). Our objective was to evaluate the feasibility of active cases finding of HIV-infected children/adolescents by provider-initiated testing and counseling in a health facility.

METHODS

A cross-sectional prospective study was conducted from January through April 2016 at 6 entry-points (inpatient, outpatient, neonatology, immunization/family planning, tuberculosis, day-care units) at the Laquintinie Hospital of Douala (LHD), Cameroon. At each entry-point, following counseling with consenting parents, children/adolescents (0-19 years old) with unknown HIV status were tested using the Rapid Diagnostic Test (RDT) (Determine®) and confirmed with a second RDT (Oraquick®) according to national guidelines. For children less than 18 months, PCR was performed to confirm every positive RDT. Community health workers linked infected participants by accompanying them from the entry-point to the treatment centre for an immediate ART initiation following the « test and treat » strategy. Statistical analysis was performed, with p < 0.05 considered significant.

RESULTS

Out of 3439 children seen at entry-points, 2107 had an unknown HIV status (61.3%) and HIV testing acceptance rate was 99.9% (2104). Their mean age was 2.1 (Sd = 2.96) years, with a sex ratio boy/girl of 6/5. HIV prevalence was 2.1% (44), without a significant difference between boys and girls (p = 0.081). High rates of HIV-infection were found among siblings/descendants (22.2%), TB treatment unit attendees (11.4%) and hospitalized children/adolescents (5.6%); p < 0.001. Up to 95.4% (42/44) of those infected children/adolescents were initiated on ART. Overall, 487 (23.2%) deaths were registered (122 per month) and among them, 7 (15.9%) were HIV-positive; mainly due to tuberculosis and malnutrition.

CONCLUSION

The consistent rate of unknown HIV status among children/adolescents attending health facilities, the high acceptability rates of HIV testing and linkage to ART, underscore the feasibility and utility of an active case finding model, using multiple entry-points at the health facility, in achieving the 90-90-90 targets for paediatric HIV/AIDS in RLS.

Early warning indicators for HIV drug resistance in Cameroon during the year 2010

Background

Rapid scale-up of antiretroviral therapy (ART) in resource-limited settings is accompanied with an increasing risk of HIV drug resistance (HIVDR), which in turn could compromise the performance of national ART rollout programme. In order to sustain the effectiveness of ART in a resource-limited country like Cameroon, HIVDR early warning indicators (EWI) may provide relevant corrective measures to support the control and therapeutic management of AIDS.

Methods

A retrospective study was conducted in 2010 among 40 ART sites (12 Approved Treatment Centers and 28 Management Units) distributed over the 10 regions of Cameroon. Five standardized EWIs were selected for the evaluation using data from January through December, among which: (1) Good ARV prescribing practices: target = 100%; (2) Patient lost to follow-up: target ≤20%; (3) Patient retention on first line ART: target ≥70%; (4) On-time drug pick-up: target ≥90%; (5) ARV drug supply continuity: target = 100%. Analysis was performed using a Data Quality Assessment tool, following WHO protocol.

Results

The number of sites attaining the required performance are: 90% (36/40) for EWI₁, 20% (8/40) for EWI₂; 20% (8/40) for EWI₃; 0% (0/37) for EWI₄; and 45% (17/38) for EWI 5. ARV prescribing practices were in conformity with the national guidelines in almost all the sites, whereas patient adherence to ART (EWI₂, EWI₃, and EWI₄) was very low. A high rate of patients was lost-to-follow-up and others failing first line ART before 12 months of initiation. Discontinuity in drug supply observed in about half of the sites may negatively impact ARV prescription and patient adherence. These poor ART performances may also be due to low number of trained staff and community disengagement.

Conclusions

The poor performance of the national ART programme, due to patient non-adherence and drug stock outs, requires corrective measures to limit risks of HIVDR emergence in Cameroon.

Factors associated with risk of HIV-infection among pregnant women in Cameroon: Evidence from the 2016 national sentinel surveillance survey of HIV and syphilis

BACKGROUND

Human Immunodeficiency Virus infection (HIV) remains a public health concern in Cameroon that requires regular surveillance for informed policy-making to guide programmatic interventions. Using data from the 2016 HIV national sentinel survey in Cameroon, we ascertained HIV prevalence and factors associated with risk of infection among pregnant women.

METHODS

A cross-sectional study was conducted throughout 2016 in the 10 regions of Cameroon, targeting 7000 first antenatal care (ANC-1) attendees (4000 from urban and 3000 from rural areas) in 60 sentinel health facilities. HIV serological test was performed using the national serial algorithm at the National Reference Laboratory (NRL). Prevalence was determined, and multivariate logistic regression was used to assess determinants of HIV infection, with p-value<0.05 considered statistically significant.

RESULTS

Of the 7000 targeted participants, a total of 6859 first ANC-1 attendees were enrolled (98.0% sampling coverage). Median age was 26 [IQR: 21-30] years and 47,40% had a secondary school level of education. The national prevalence of HIV was 5.70% (95% CI: 4.93-6.40) and range from 9.7% in East region to 2.6% in North region. The prevalence was 5.58% (95% CI: 95%: 4.88-6.35) in urban and 5.87% (95% CI: 5.04-6.78) in rural settings. Factors that were associated with HIV infection included marital status, women who were married or living with their partner are less likely to be infected than singles women (aOR = 0.60; 95% CI: 0.46-0.78), multiparity [aOR = 1.5(95%CI:1.0-2.2)] and been living in the Centre, East, North-west and South-west regions. HIV infection was also significantly associated with age, with the risk of being infected increasing with age.

CONCLUSION

Pregnant women in Cameroon are still disproportionately infected with HIV compared with the general population (prevalence 4.3%). Preventive actions to curb the epidemic amongst pregnant women should prioritize interventions targeting single pregnant women, who are older, and residing particularly in the Centre, East, North West and South West regions of the country.

HIV-Infected or -Exposed Children Exhibit Lower Immunogenicity to Hepatitis B Vaccine in Yaoundé, Cameroon: An Appeal for Revised Policies in Tropical Settings?

Background

Since 2005, anti-hepatitis B virus (anti-HBV) vaccine is part of the Expanded Program on Immunization (EPI) for infants born in Cameroon, with 99% anti-HBV coverage. In a context of generalized HIV epidemiology, we assessed paediatric anti-HBV vaccine response according to HIV status, feeding option and age in a tropical context.

Methodology

Prospective, observational and cross-sectional study conducted among 82 children (27 [IQR: 9–47] months, min-max: 6–59), after complete anti-HBV vaccination (Zilbrix Hepta: 10μg AgHBs) at the Essos Health Centre in Yaounde, Cameroon, classified as group-A: HIV unexposed (28), group-B: HIV-exposed/uninfected (29), group-C: HIV-infected (25). Quantitative anti-HBs ELISA was interpreted as “no”, “low-” or “protective-response” with <1, 1–10, or ≥10 IU/L respectively; with p-value<0.05 considered significant.

Results

Children were all HBV-unexposed (AcHBc-negative) and uninfected (HBsAg-negative). Response to anti-HBV vaccine was 80.49% (66/82), with only 45.12% (37/82) developed a protective-response (≥10IU/L). According to HIV status, 60.71% (17/28) developed a protective-response in group-A, vs. 51.72% (15/29) and 20% (5/25) in group-B and group-C respectively, Odds Ratio (OR): 2.627 [CI_95% 0.933–7.500], p = 0.041. According to feeding option during first six months of life, 47.67% (21/45) developed a protective-response on exclusive breastfeeding vs. 43.24% (16/37) on mixed or formula feeding, OR: 1.148 [CI_95% 0.437–3.026], p = 0.757. According to age, protective-response decreased significantly as children grow older: 58.33% (28/48) <24 months vs. 26.47% (9/34) ≥24 months, OR: 3.889 [CI_95% 1.362–11.356], p = 0.004; and specifically 67.65% (23/34) ≤6 months vs. 0%, (0/5) 33–41 months, p = 0.008.

Conclusions

Anti-HBV vaccine provides low rate of protection (<50%) among children in general, and particularly if HIV-exposed, infected and/or older children. Implementing policies for early vaccination, specific immunization algorithm for HIV-exposed/infected children, and monitoring vaccine response would ensure effective protection in tropical settings, pending extensive/confirmatory investigations.

Next-generation sequencing provides an added value in determining drug resistance and viral tropism in Cameroonian HIV-1 vertically infected children

With limited and low-genetic barrier drugs used for the prevention of mother-to-child transmission (PMTCT) of HIV in sub-Saharan Africa, vertically transmitted HIV-1 drug-resistance (HIVDR) is concerning and might prompt optimal pediatric strategies.The aim of this study was to ascertain HIVDR and viral-tropism in majority and minority populations among Cameroonian vertically infected children.A comparative analysis among 18 HIV-infected children (7 from PMTCT-exposed mothers and 11 from mothers without PMTCT-exposure) was performed. HIVDR and HIV-1 co-receptor usage was evaluated by analyzing sequences obtained by both Sanger sequencing and ultra-deep 454-pyrosequencing (UDPS), set at 1% threshold.Overall, median (interquartile range) age, viremia, and CD4 count were 6 (4-10) years, 5.5 (4.9-6.0) log10 copies/mL, and 526 (282-645) cells/mm, respectively. All children had wild-type viruses through both Sanger sequencing and UDPS, except for 1 PMTCT-exposed infant harboring minority K103N (8.31%), born to a mother exposed to AZT+3TC+NVP. X4-tropic viruses were found in 5 of 15 (33.3%) children (including 2 cases detected only by UDPS). Rate of X4-tropic viruses was 0% (0/6) below 5 years (also as minority species), and became relatively high above 5 years (55.6% [5/9], P = .040. X4-tropic viruses were higher with CD4 ≤15% (4/9 [44.4%]) versus CD4 >15% (1/6 [16.7%], P = .580); similarly for CD4 ≤200 (3/4 [75%]) versus CD4 >200 (2/11 [18.2%] cells/mm, P = .077.NGS has the ability of excluding NRTI- and NNRTI-mutations as minority species in all but 1 children, thus supporting the safe use of these drug-classes in those without such mutations, henceforth sparing ritonavir-boosted protease inhibitors or integrase inhibitors for the few remaining cases. In children under five years, X4-tropic variants would be rare, suggesting vertical-transmission with CCR5-tropic viruses and possible maraviroc usage at younger ages.

Predictors of poor retention on antiretroviral therapy as a major HIV drug resistance early warning indicator in Cameroon: results from a nationwide systematic random sampling

Background

Retention on lifelong antiretroviral therapy (ART) is essential in sustaining treatment success while preventing HIV drug resistance (HIVDR), especially in resource-limited settings (RLS). In an era of rising numbers of patients on ART, mastering patients in care is becoming more strategic for programmatic interventions. Due to lapses and uncertainty with the current WHO sampling approach in Cameroon, we thus aimed to ascertain the national performance of, and determinants in, retention on ART at 12 months.

Methods

Using a systematic random sampling, a survey was conducted in the ten regions (56 sites) of Cameroon, within the “reporting period” of October 2013–November 2014, enrolling 5005 eligible adults and children. Performance in retention on ART at 12 months was interpreted following the definition of HIVDR early warning indicator: excellent (>85%), fair (85–75%), poor (<75); and factors with p-value < 0.01 were considered statistically significant.

Results

Majority (74.4%) of patients were in urban settings, and 50.9% were managed in reference treatment centres. Nationwide, retention on ART at 12 months was 60.4% (2023/3349); only six sites and one region achieved acceptable performances. Retention performance varied in reference treatment centres (54.2%) vs. management units (66.8%), p < 0.0001; male (57.1%) vs. women (62.0%), p = 0.007; and with WHO clinical stage I (63.3%) vs. other stages (55.6%), p = 0.007; but neither for age (adults [60.3%] vs. children [58.8%], p = 0.730) nor for immune status (CD4_351–500 [65.9%] vs. other CD4-staging [59.86%], p = 0.077).

Conclusions

Poor retention in care, within 12 months of ART initiation, urges active search for lost-to-follow-up targeting preferentially male and symptomatic patients, especially within reference ART clinics. Such sampling strategy could be further strengthened for informed ART monitoring and HIVDR prevention perspectives.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1991-3) contains supplementary material, which is available to authorized users.

Baseline integrase drug resistance mutations and conserved regions across HIV-1 clades in Cameroon: implications for transition to dolutegravir in resource-limited settings

BACKGROUND

Transition to dolutegravir-based regimens in resource-limited settings (RLS) requires prior understanding of HIV-1 integrase variants and conserved regions. Therefore, we evaluated integrase drug resistance mutations (DRMs) and conserved regions amongst integrase strand transfer inhibitor (INSTI)-naive patients harbouring diverse HIV-1 clades in Cameroon.

METHODS

A cross-sectional study was conducted amongst 918 INSTI-naive patients from Cameroon (89 ART-naive and 829 ART-experienced patients). HIV-1 sequences were interpreted regarding INSTI-DRMs using the Stanford HIVdb v8.9-1 and the 2019 IAS-USA list. Amino acid positions with <1% variability were considered as highly conserved. Subtyping was performed by phylogeny.

RESULTS

Overall prevalence (95% CI) of INSTI-DRMs was 0.8% (0.4-1.7), with 0.0% (0.0-4.0) amongst ART-naive versus 0.9% (0.5-1.9) amongst ART-experienced patients; P = 0.44. Accessory mutations (95% CI) were found in 33.8% (30.9-37.0), with 38.2% (28.1-49.1) amongst ART-naive versus 33.4% (30.4-36.7) amongst ART-experienced patients; P = 0.21. Of 288 HIV-1 integrase amino acid positions, 58.3% were highly conserved across subtypes in the following major regions: V75-G82, E85-P90, H114-G118, K127-W132, E138-G149, Q168-L172, T174-V180, W235-A239 and L241-D253. Wide genetic diversity was found (37 clades), including groups M (92.3%), N (1.4%), O (6.2%) and P (0.1%). Amongst group M, CRF02_AG was predominant (47.4%), with a significantly higher frequency (95% CI) of accessory mutations compared with non-AG [41.4% (36.8-46.0) versus 27.1% (23.3-31.2) respectively; P < 0.001].

CONCLUSIONS

The low baseline of INSTI-DRMs (<1%) in Cameroon suggests effectiveness of dolutegravir-based regimens. In spite of high conservation across clades, the variability of accessory mutations between major circulating strains underscores the need for monitoring the selection of INSTI-DRMs while scaling up dolutegravir-based regimens in RLS.

Feasibility Study of HIV Sentinel Surveillance using PMTCT data in Cameroon: from Scientific Success to Programmatic Failure

Background

In low-income countries (LICs), HIV sentinel surveillance surveys (HIV-SSS) are recommended in between two demographic and health surveys, due to low-cost than the latter. Using the classical unlinked anonymous testing (UAT), HIV-SSS among pregnant women raised certain ethical and financial challenges. We therefore aimed at evaluating how to use prevention of mother-to-child transmission of HIV (PMTCT) routine data as an alternative approach for HIV-SSS in LICs.

Methods

A survey conducted through 2012 among first antenatal-care attendees (ANC1) in the ten regions of Cameroon. HIV testing was performed at PMTCT clinics as-per the national serial algorithm (rapid test), and PMTCT site laboratory (PMTCT-SL) performances were evaluated by comparison with results of the national reference laboratory (NRL), determined as the reference standard.

Results

Acceptance rate for HIV testing was 99%, for a total of 6521 ANC1 (49 · 3% aged 15–24) enrolled nationwide. Among 6103 eligible ANC1, sensitivity (using NRL testing as the reference standard) was 81 · 2%, ranging from 58 · 8% (South region) to 100% (West region); thus implying that 18 · 8% HIV-infected ANC1 declared HIV-negative at the PMTCT-SL were positive from NRL-results. Specificity was 99 · 3%, without significant disparity across sites. At population-level, this implies that every year in Cameroon, ~2,500 HIV-infected women are wrongly declared seronegative, while ~1,000 are wrongly declared seropositive. Only 44 · 4% (16/36) of evaluated laboratories reached the quality target of 80%.

Conclusions

The study identified weaknesses in routine PMTCT HIV testing. As Cameroon transitions to using routine PMTCT data for HIV-SSS among pregnant women, there is need in optimizing quality system to ensure robust routine HIV testing for programmatic and surveillance purposes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2119-5) contains supplementary material, which is available to authorized users.

First case of Dolutegravir and Darunavir/r multi drug-resistant HIV-1 in Cameroon following exposure to Raltegravir: lessons and implications in the era of transition to Dolutegravir-based regimens

Background

Sub-Saharan African countries are transitioning to dolutegravir-based regimens, even for patients with extensive previous drug exposure, including first-generation integrase strand-transfer inhibitors (INSTI) such as raltegravir. Such exposure might have implications on cross-resistance to dolutegravir-based antiretroviral therapies (ART).

Case presentation

We report a 65 years old Cameroonian, previously exposed to raltegravir, and failing on third-line treatment with multi-drug resistance to darunavir/r and dolutegravir. Genotypic resistance testing (GRT) and viral tropism were performed during monitoring time points. The patient initiated ART in August 2007. At the time point of the first (29.04.2010), second (01.12.2017) and third (08.08.2019) GRT, prior ART exposure included 3TC, d4T, NVP and EFV; additionally TDF, DRV/r and RAL; and additionally ABC and DTG respectively. First GRT revealed mutations associated with resistance only to first-generation Non-nucleoside reverse transcriptase inhibitors (NNRTI). Second GRT revealed mutations associated with high-level resistance to all NRTIs, first generation NNRTIs, all ritonavir boosted protease inhibitors (PI/r), and all INSTI, while viral tropism (using geno2pheno) revealed a CCR5-tropic virus with a false positive rate (FPR) of 60.9% suggesting effectiveness of maraviroc (MRV). The third GRT showed high-level resistance to NRTI, NNRTI, all PI and all INSTI, with additional mutations (H221HY for NNRTI and S147G for INSTI), and a CCR5-tropic virus with a slightly reduced FPR (57.0%). Without any locally available active therapeutic option, the patient has been on a maintenance therapy with “DRV/r (600mg x 2/day)+TDF+3TC” and patient/family-centered adherence has been reinforced. Since the first viral load (VL) measurement in 2010, the patient has had 12 VL tests with the VL ranging from 4.97 Log to 6.44 Log copies/mL and the CD4 count never exceeded 200 cells/μL.

Conclusions

As African countries transition to dolutegravir-based regimens, prior raltegravir-exposure may prompt selection (and potential transmission) of dolutegravir-resistance, supporting case surveillance.

Alarming rates of virological failure and HIV-1 drug resistance amongst adolescents living with perinatal HIV in both urban and rural settings: evidence from the EDCTP READY-study in Cameroon

OBJECTIVES

Adolescents living with perinatal HIV infection (ALPHI) experience persistently high mortality rates, particularly in resource-limited settings. It is therefore clinically important for us to understand the therapeutic response, acquired HIV drug resistance (HIVDR) and associated factors among ALPHI, according to geographical location.

METHODS

A study was conducted among consenting ALPHI in two urban and two rural health facilities in the Centre Region of Cameroon. World Health Organization (WHO) clinical staging, self-reported adherence, HIVDR early warning indicators (EWIs), immunological status (CD4 count) and plasma viral load (VL) were assessed. For those experiencing virological failure (VF, VL ≥ 1000 copies/mL), HIVDR testing was performed and interpreted using the Stanford HIV Drug Resistance Database v.8.9-1.

RESULTS

Of the 270 participants, most were on nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens (61.7% urban vs. 82.2% rural), and about one-third were poorly adherent (30.1% vs. 35.1%). Clinical failure rates (WHO-stage III/IV) in both settings were < 15%. In urban settings, the immunological failure (IF) rate (CD₄  < 250 cells/μL) was 15.8%, statistically associated with late adolescence, female gender and poor adherence. The VF rate was 34.2%, statistically associated with poor adherence and NNRTI-based antiretroviral therapy. In the rural context, the IF rate was 26.9% and the VF rate was 52.7%, both statistically associated with advanced clinical stages. HIVDR rate was over 90% in both settings. EWIs were delayed drug pick-up, drug stock-outs and suboptimal viral suppression.

CONCLUSIONS

Poor adherence, late adolescent age, female gender and advanced clinical staging worsen IF. The VF rate is high and consistent with the presence of HIVDR in both settings, driven by poor adherence, NNRTI-based regimen and advanced clinical staging.