International review of blood donation nucleic acid amplification testing

BACKGROUND AND OBJECTIVES

Nucleic acid amplification testing (NAT), in blood services context, is used for the detection of viral and parasite nucleic acids to reduce transfusion-transmitted infections. This project reviewed NAT for screening blood donations globally.

MATERIALS AND METHODS

A survey on NAT usage, developed by the International Society of Blood Transfusion Working Party on Transfusion-transmitted Infectious Diseases (ISBT WP-TTID), was distributed through ISBT WP-TTID members. Data were analysed using descriptive statistics.

RESULTS

Forty-three responses were received from 32 countries. Increased adoption of blood donation viral screening by NAT was observed over the past decade. NAT-positive donations were detected for all viruses tested in 2019 (proportion of donations positive by NAT were 0.0099% for human immunodeficiency virus [HIV], 0.0063% for hepatitis C virus [HCV], 0.0247% for hepatitis B virus [HBV], 0.0323% for hepatitis E virus [HEV], 0.0014% for West Nile virus [WNV] and 0.00005% for Zika virus [ZIKV]). Globally, over 3100 NAT-positive donations were identified as NAT yield or solely by NAT in 2019 and over 22,000 since the introduction of NAT, with HBV accounting for over half. NAT-positivity rate was higher in first-time donors for all viruses tested except WNV. During 2019, a small number of participants performed NAT for parasites (Trypanosoma cruzi, Babesia spp., Plasmodium spp.).

CONCLUSION

This survey captures current use of blood donation NAT globally. There has been increased NAT usage over the last decade. It is clear that NAT contributes to improving blood transfusion safety globally; however, there is a need to overcome economic barriers for regions/countries not performing NAT.

Laboratory Based Surveillance of HIV-1 Acquired Drug Resistance in Cameroon: Implications for Use of Tenofovir-Lamivudine-Dolutegravir (TLD) as Second- or Third-Line Regimens

Increased HIV drug resistance (HIVDR) with antiretroviral therapy (ART) rollout may jeopardize therapeutic options, especially in this era of transition to fixed-dose tenofovir-lamivudine-dolutegravir (TLD). We studied acquired HIVDR (ADR) patterns and describe potentially active drugs after first- and second-line failure in resource-limited settings (RLS) like Cameroon. A laboratory-based study with 759 patients (≥15 years) experiencing virological failure was carried out at the Chantal Biya International Reference Centre (CIRCB), Yaoundé, Cameroon. Socio-demographic, therapeutic and immunovirological data from patient records were analysed according to HIV-1 genotypic profiles. Median (IQR) ART-duration was 63 (50-308) months. Median CD4 and viremia were 153 (IQR:50-308) cells/mm3 and 138,666 (IQR:28,979-533,066) copies/mL, respectively. Overall ADR was high (93.4% first-line; 92.9%-second-line). TDF, potentially active in 35.7% of participants after first-line and 45.1% after second-line, suggested sub-optimal TLD-efficacy in second-line (64.3%) and third-line (54.9%). All PI/r preserved high efficacy after first-line failure while only DRV/r preserved high-level efficacy (87.9%) after second-line failure. In this resource-limited setting (RLS), ADR is high in ART-failing patients. PI/r strategies remain potent backbones for second-line ART, while only DRV/r remains very potent despite second-line failure. Though TLD use would be preferable, blind use for second- and third-line regimens may be sub-optimal (functional monotherapy with dolutegravir) with high risk of further failure, thus suggesting strategies for selective ART switch to TLD in failing patients in RLS.

Pre-Treatment HIV Drug Resistance and Genetic Diversity in Cameroon: Implications for First-Line Regimens

The efficacy of first-line antiretroviral therapy (ART) may be hampered by the presence of HIV drug resistance (HIVDR). We described HIV-1 pre-treatment drug resistance (PDR) patterns, effect of viral clades on PDR, and programmatic implications on first-line regimens in Cameroon. A sentinel surveillance of PDR was conducted from 2014 to 2019. Sequencing of HIV-1 protease and reverse transcriptase was performed, and HIVDR was interpreted using Stanford HIVdb.v.9.4. In total, 379 sequences were obtained from participants (62% female, mean age 36 ± 10 years). The overall PDR rate was 15.0% [95% CI: 11.8-19.0] nationwide, with significant disparity between regions (p = 0.03). NNRTI PDR was highest (12.4%), of which 7.9% had DRMs to EFV/NVP. Two regions had EFV/NVP PDR above the 10% critical threshold, namely the Far North (15%) and East (10.9%). Eighteen viral strains were identified, predominated by CRF02_AG (65.4%), with no influence of genetic diversity PDR occurrence. TDF-3TC-DTG predictive efficacy was superior (98.4%) to TDF-3TC-EFV (92%), p < 0.0001. The overall high rate of PDR in Cameroon, not substantially affected by the wide HIV-1 genetic diversity, underscores the poor efficacy of EFV/NVP-based first-line ART nationwide, with major implications in two regions of the country. This supports the need for a rapid transition to NNRTI-sparing regimens, with TDF-3TC-DTG having optimal efficacy at the programmatic level.

Metagenomic Detection of Divergent Insect- and Bat-Associated Viruses in Plasma from Two African Individuals Enrolled in Blood-Borne Surveillance

Metagenomic next-generation sequencing (mNGS) has enabled the high-throughput multiplexed identification of sequences from microbes of potential medical relevance. This approach has become indispensable for viral pathogen discovery and broad-based surveillance of emerging or re-emerging pathogens. From 2015 to 2019, plasma was collected from 9586 individuals in Cameroon and the Democratic Republic of the Congo enrolled in a combined hepatitis virus and retrovirus surveillance program. A subset (n = 726) of the patient specimens was analyzed by mNGS to identify viral co-infections. While co-infections from known blood-borne viruses were detected, divergent sequences from nine poorly characterized or previously uncharacterized viruses were also identified in two individuals. These were assigned to the following groups by genomic and phylogenetic analyses: densovirus, nodavirus, jingmenvirus, bastrovirus, dicistrovirus, picornavirus, and cyclovirus. Although of unclear pathogenicity, these viruses were found circulating at high enough concentrations in plasma for genomes to be assembled and were most closely related to those previously associated with bird or bat excrement. Phylogenetic analyses and in silico host predictions suggested that these are invertebrate viruses likely transmitted through feces containing consumed insects or through contaminated shellfish. This study highlights the power of metagenomics and in silico host prediction in characterizing novel viral infections in susceptible individuals, including those who are immunocompromised from hepatitis viruses and retroviruses, or potentially exposed to zoonotic viruses from animal reservoir species.

Measuring hepatitis B pgRNA stability using an updated automated HBV pgRNA assay with increased sensitivity

BACKGROUND

HBV pregenomic RNA (pgRNA) is a circulating biomarker for covalently closed circular DNA activity in HBV-infected individuals and has been studied for treatment efficacy, disease staging, and off-therapy outcomes; however, data on the stability are scarce. Increasing HBV pgRNA assay sensitivity may improve its predictive value and provide additional insights at low viral levels.

METHODS

Modifications to a fully automated first (v1) generation HBV pgRNA assay improved sensitivity up to 15-fold over the previous assay. Flexible sample input volumes yielded lower limits of quantitation of 10 and 22 copies/mL for 0.6 and 0.2 mL assays, respectively. Results are standardized to secondary standards that are traceable to the WHO HBV DNA standard, and internal and external controls are included.

RESULTS

Comparison between v1 and modified v2 assays showed increased sensitivity from 152 copies/mL with v1 to 10 (0.6 mL) and 22 (0.2 mL) copies/mL with v2, respectively. Quantitated v2 results were indistinguishable from v1, indicating that comparisons can be made to previous studies. Single timepoint treatment-naive blood donors or longitudinal draws from patients with chronic hepatitis B on AB-729, an investigational siRNA therapy, showed improved detection and quantifiable pgRNA with v2 compared with v1. Stability testing demonstrated excellent HBV pgRNA plasma stability after 3 freeze-thaw cycles, for at least 7 days at 25-37 °C and at least 30 days at 4°C, with ≤0.25 Log U/mL decrease.

CONCLUSION

HBV pgRNA v2 assays with increased sensitivity and flexible input volumes demonstrated increased detection and quantitation of low viral titer samples. Highly sensitive HBV pgRNA assays may be useful in refining predictive treatment outcomes based on this marker. HBV pgRNA was stable under multiple conditions, which increases the reliability of this marker.

Characterization of HBV surface antigen isoforms in the natural history and treatment of HBV infection

BACKGROUND

The loss of HBV HBsAg or functional cure is a desirable goal of hepatitis B management. The relative abundances of HBsAg isoforms may offer additional diagnostic and predicting values. To evaluate the clinical utility of HBsAg isoforms, we developed novel prototype assays on the ARCHITECT automated serology platform that specifically detects total-HBsAg (T-HBsAg), large (L-HBsAg), and middle (M-HBsAg) products of the S gene to determine the isoform composition of human specimens from acute and chronic HBV infection and during long-term nucleos(t)ide analog therapy.

RESULTS

In the early phase of acute HBV infection, L-HBsAg and M-HBsAg emerged within days and were in parallel to T-HBsAg during the entire course of infection. M-HBsAg levels were consistently higher than L-HBsAg levels. Patients with HBeAg(+) chronic hepatitis B had higher T-HBsAg, M-HBsAg, and L-HBsAg levels compared with HBeAg(-) patients. Correlations of M-HBsAg and L-HBsAg to T-HBsAg were similar in both. In contrast, there was no strong correlation between L-HBsAg or M-HBsAg with HBV DNA levels. During long-term nucleos(t)ide analog treatment, changes in HBsAg isoform abundance were proportional to T-HBsAg regardless of treatment responses for both HBeAg(+) and HBeAg(-) chronic hepatitis B. A larger sample size may be necessary to detect a significant difference.

CONCLUSION

HBsAg isoform compositions parallel T-HBsAg levels in both acute and chronic hepatitis B infection. L-HBsAg and M-HBsAg individual biomarkers do not appear to provide an additional diagnostic benefit for staging chronic disease or monitoring response to treatment with current therapies.

Implementation of an Africa-specific donor health questionnaire for human immunodeficiency virus risk screening

BACKGROUND AND OBJECTIVES

We had previously developed an Africa-specific donor health questionnaire (ASDHQ) based on local risk factors and designed a scoring scheme. This study assessed the performance of a new donor health questionnaire by comparing the human immunodeficiency virus (HIV) status in accepted versus deferred donors by ASDHQ and comparing the rate of risk deferrals with historical data.

MATERIALS AND METHODS

Data were collected during a cross-sectional study conducted over 15 months at three referral-hospital-based blood services in Cameroon. ASDHQ was administered to blood donors aged 18-65 years in the same screening conditions as the routine questionnaire. The main outcomes of the study were ASDHQ sensitivity and specificity with regard to HIV laboratory testing as well as donor deferral rates for each of the routine screening algorithms and for ASDHQ.

RESULTS

Overall, 71/11,120 (0.6%) were confirmed as HIV positive. The mean ASDHQ score was 95.80 ± 4.4 in HIV-negative donors and 94.80 ± 4.4 in HIV-positive donors (p = 0.05). The optimal cut-off provided by the receiver operating characteristic (ROC) curve for the best performance of ASDHQ was 95.04. Using this optimal cut-off, the ASDHQ sensitivity and specificity were 57% and 53%, respectively (area under curve = 0.58 [0.51, 0.64], p = 0.028). Using ASDHQ, the HIV prevalence was 0.7% in deferred donors and 0.6% in accepted donors.

CONCLUSION

ASDHQ might be efficient only in specific conditions that maximize truthful donor responses, requiring each blood service to create an environment of trust and transparency to increase donor compliance and improve the accuracy of the questionnaire.

Whole blood versus red cell concentrates for children with severe anaemia: a secondary analysis of the Transfusion and Treatment of African Children (TRACT) trial

BACKGROUND

The TRACT trial established the timing of transfusion in children with uncomplicated anaemia (haemoglobin 4-6 g/dL) and the optimal volume (20 vs 30 mL/kg whole blood or 10 vs 15 mL/kg red cell concentrates) for transfusion in children admitted to hospital with severe anaemia (haemoglobin <6 g/dL) on day 28 mortality (primary endpoint). Because data on the safety of blood components are scarce, we conducted a secondary analysis to examine the safety and efficacy of different pack types (whole blood vs red cell concentrates) on clinical outcomes.

METHODS

This study is a secondary analysis of the TRACT trial data restricted to those who received an immediate transfusion (using whole blood or red cell concentrates). TRACT was an open-label, multicentre, factorial, randomised trial conducted in three hospitals in Uganda (Soroti, Mbale, and Mulago) and one hospital in Malawi (Blantyre). The trial enrolled children aged between 2 months and 12 years admitted to hospital with severe anaemia (haemoglobin <6 g/dL). The pack type used (supplied by blood banks) was based only on availability at the time. The outcomes were haemoglobin recovery at 8 h and 180 days, requirement for retransfusion, length of hospital stay, changes in heart and respiratory rates until day 180, and the main clinical endpoints (mortality until day 28 and day 180, and readmission until day 180), measured using multivariate regression models.

FINDINGS

Between Sept 17, 2014, and May 15, 2017, 3199 children with severe anaemia were enrolled into the TRACT trial. 3188 children were considered in our secondary analysis. The median age was 37 months (IQR 18-64). Whole blood was the first pack provided for 1632 (41%) of 3992 transfusions. Haemoglobin recovery at 8 h was significantly lower in those who received packed cells or settled cells than those who received whole blood, with a mean of 1·4 g/dL (95% CI -1·6 to -1·1) in children who received 30 mL/kg and -1·3 g/dL (-1·5 to -1·0) in those who received 20 mL/kg packed cells versus whole blood, and -1·5 g/dL (-1·7 to -1·3) in those who received 30 mL/kg and -1·0 g/dL (-1·2 to -0·9) in those who received 20 mL/kg settled cells versus whole blood (overall p<0·0001). Compared to whole blood, children who received blood as packed or settled cells in their first transfusion had higher odds of receiving a second transfusion (odds ratio 2·32 [95% CI 1·30 to 4·12] for packed cells and 2·97 [2·18 to 4·05] for settled cells; p<0·001) and longer hospital stays (hazard ratio 0·94 [95% CI 0·81 to 1·10] for packed cells and 0·86 [0·79 to 0·94] for settled cells; p=0·0024). There was no association between the type of blood supplied for the first transfusion and mortality at 28 days or 180 days, or readmission to hospital for any cause. 823 (26%) of 3188 children presented with severe tachycardia and 2077 (65%) with tachypnoea, but these complications resolved over time. No child developed features of confirmed cardiopulmonary overload.

INTERPRETATION

Our study suggests that the use of packed or settled cells rather than whole blood leads to additional transfusions, increasing the use of a scarce resource in most of sub-Saharan Africa. These findings have substantial cost implications for blood transfusion and health services. Nevertheless, a clinical trial comparing whole blood transfusion with red cell concentrates might be needed to inform policy makers.

FUNDING

UK Medical Research Council (MRC) and the Department for International Development.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Knowledge, attitude and seropositivity of hepatitis B virus among blood donors in the Bamenda Regional Hospital Blood Bank, Cameroon

Introduction

despite the existence of a preventive vaccine against hepatitis B viral (HBV) infection, approximately 250 million people are infected with the virus worldwide. This study aimed at evaluating the level of knowledge, attitude and seropositivity of the disease among apparently healthy, potential blood donors at the blood service of the Bamenda Regional Hospital Blood Bank.

Methods

a cross-sectional study was carried out from March to May 2019 among 250 blood donors. Following screening for hepatitis B surface antigen (HBsAg) using the one-step HBsAg test strip, information on the level of knowledge and attitude towards the infection was obtained using a self-administered questionnaire. The correlation analysis was done to assess relationships between selected factors and knowledge of hepatitis B, p-value of 0.05 was considered as statistical significance.

Results

the seropositivity of HBV was 6.4% (n = 16). Overall, 46.8% (n = 19) of the study participants had adequate knowledge while 76.3% (n = 31) had a positive attitude toward the disease. The highest seropositivity was observed in singles (7.1%; n = 13), primary school leavers (14.3%; n = 5), unskilled laborers (14.5%; n = 8) and replacement donors (9.33%; n = 7). The probability of being hepatitis B seropositive was higher in males, students (aOR: 8.8, 95% CI 0.7-96.1; p = 0.046) and those who had attained higher education (aOR: 3.2, 95% CI 0.8-12.7; p = 0.016). Independent factors responsible for higher odds of inadequate knowledge were being a male and attaining secondary education. On the contrary, students (aOR: 0.3, 95% CI 0.1-0.8; p = 0.012) and those with a history of blood donation (aOR: 0.5, 95% CI 0.2-0.9; p = 0.042) recorded lower odds of inadequate knowledge.

Conclusion

the prevalence of hepatitis B among blood donors in this blood service is in the high intermediate category. Overall, the level of knowledge on this infection among these blood donors is average. These findings suggest that health education on HBV infection should be provided to the public as a major strategy to curb the infection.

Trends in serological markers of transfusion transmissible infections in blood donations at the Bamenda Hospital-based Blood Service, Cameroon

OBJECTIVES

The rate and trend of transfusion transmissible infections (TTIs) in blood donations from 2012 to 2017 at the Bamenda Regional Hospital Blood Service (BRHBS), Cameroon was assessed.

MATERIALS AND METHODS

A six-year retrospective study was conducted by reviewing the records of donors. Blood was screened for HIV, hepatitis B, hepatitis C and syphilis. Data was analyzed using IBM SPSS Statistics version 21. Differences in seropositivity rates for the four TTIs were analyzed using Chi² test or Fisher's exact test where appropriate. Associations between sociodemographic characteristics and the TTIs markers were assessed using multiple logistic regression analysis.

RESULTS

A total of 12,115 blood donations was included in the study and of these, the overall seropositivity rate of the four conventional TTIs markers was 10.5% (n=1,273). Of the seropositive cases, 23.8% (n=303) showed reactivity with at least two of the markers combined. When the markers were assessed individually, HBsAg recorded the highest seropositivity rate (4.7%), followed by anti-HIV and anti-syphilis (2.2%), and then by anti-HCV (1.7%). A significant decrease in the trend of the combined serological markers, HBsAg and anti-syphilis was observed over the years (P≤0.05).

CONCLUSION

There is a decrease in seropositivity rates of TTIs markers in this blood service. Ongoing efforts toward the prevention of these infections is encouraged and should be intensified to improve blood safety.

Transfusion management of severe anaemia in African children: a consensus algorithm

The phase III Transfusion and Treatment of severe anaemia in African Children Trial (TRACT) found that conservative management of uncomplicated severe anaemia [haemoglobin (Hb) 40-60 g/l] was safe, and that transfusion volume (20 vs. 30 ml/kg whole blood equivalent) for children with severe anaemia (Hb <60 g/l) had strong but opposing effects on mortality, depending on fever status (>37·5°C). In 2020 a stakeholder meeting of paediatric and blood transfusion groups from Africa reviewed the results and additional analyses. Among all 3196 children receiving an initial transfusion there was no evidence that nutritional status, presence of shock, malaria parasite burden or sickle cell disease status influenced outcomes or modified the interaction with fever status on volume required. Fever status at the time of ordering blood was a reliable determinant of volume required for optimal outcome. Elevated heart and respiratory rates normalised irrespective of transfusion volume and without diuretics. By consensus, a transfusion management algorithm was developed, incorporating three additional measurements of Hb post-admission, alongside clinical monitoring. The proposed algorithm should help clinicians safely implement findings from TRACT. Further research should assess its implementation in routine clinical practice.

Prevalence and factors associated with overweight and obesity in selected health areas in a rural health district in Cameroon: a cross-sectional analysis

Background

Overweight and obesity are major public health problems worldwide, with projections suggesting a proportional increase in the number of affected individuals in developing countries by the year 2030. Evidence-based preventive strategies are needed to reduce the burden of overweight and obesity in developing countries. We assessed the prevalence of, and factors associated with overweight and obesity in selected health areas in West Cameroon.

Methods

Data were collected from a community-based cross-sectional study, involving the consecutive recruitment of participants aged 18 years or older. Overweight and obesity were defined according to the WHO classification. The statistical software R (version 3.5.1, The R Foundation for statistical computing, Vienna, Austria) was used for statistical analysis. Multivariable logistic regression analysis was used to assess independent factors associated with overweight and obesity, and obesity.

Results

Records of 485 participants were included for analysis. The age and sex-standardized prevalence of overweight, obesity, and overweight and obesity were 31.1% (95% CI, 27.0–35.2), 18.9% (95% CI, 14.9–22.9), and 50.1% (95% CI, 45.7–54.6), respectively. In multivariable analysis, being female (adjusted OR [aOR] = 2.79, 95% CI = 1.69–4.63), married (aOR = 3.90, 95% CI = 2.23–6.95), and having secondary or tertiary education (aOR = 3.27, 95% CI = 1.77–6.17) were associated with higher odds of overweight and obesity, while current smokers had lower odds of overweight and obesity (aOR = 0.37, 95% CI = 0.16–0.82) when compared to their respective counterpart. Compared to their respective reference categories, being female being (aOR = 3.74, 95% CI = 2.01–7.30), married (aOR = 2.58, 95% CI = 1.37–5.05) and having secondary or tertiary education (aOR = 2.03, 95% CI = 1.00–4.23) were associated with higher odds of obesity after adjustments for confounding.

Conclusion

We observed a high prevalence of overweight and obesity in this study. The odds of overweight and obesity was higher in females, married participants, and those with higher levels of education. Community-based interventions to control overweight and obesity should consider targeting these groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10403-w.

Distribution of haemoglobin genotypes, knowledge, attitude and practices towards sickle cell disease among unmarried youths in the Buea Health District, Cameroon

Introduction

sickle cell disease (SCD) is one of the commonest genetic causes of morbidity and mortality in the world. In resource-limited settings, SCD prevention through public education and screening could be a significant strategy to curb its prevalence. The study aimed at determining the distribution of haemoglobin genotypes among unmarried youths in Buea, Cameroon as well as their knowledge, attitude and practices towards SCD.

Methods

a community-based, analytic, cross-sectional study was conducted within the city of Buea. Data was collected from 410 youths using self-administered questionnaires. Of the 410 youths, 100 were selected by purposive random sampling and their haemoglobin genotyping was done using haemoglobin electrophoresis. The data was analysed using the statistical software Epi Info Version 7.

Results

the majority (51.5%) of the 410 respondents were females. The modal age range was 18- 21 years (46.8%) and 60.4% had tertiary education. Less than one quarter (20.5%) had good knowledge of SCD. Only 13.2% knew their genotype and 59.3% were willing to avoid carrier marriages. Out of the 100 participants for genotyping, 84.0% had normal haemoglobin (HbAA) and 16.0% had the sickle cell trait (HbAS).

Conclusion

most of the respondents had moderate knowledge of SCD. Only a few knew their haemoglobin genotype and more than half were willing to avoid carrier marriages. The prevalence of sickle cell trait is high in Buea. The promotion of preventive methods like public education and genetic screening is recommended to reduce the burden of SCD in Cameroon.

Trends in blood donations, blood donors' knowledge, practices and expectations during the COVID-19 pandemic in Cameroon

INTRODUCTION

The COVID-19 pandemic, caused by a novel coronavirus, has already affected over 99 062 people in 53 African countries and killed 3082. The pandemic threatens blood supply but we do not yet know its impact on blood donations or on the perceptions and expectations of donors.

METHODS

We conducted a cross-sectional study in four hospital-based blood services in Cameroon, using a survey design and focusing on the subjective and cultural aspects of donors. Using a semi-structured questionnaire, we collected the participants' responses as to their understanding of COVID-19 and of current protection measures, and their expectations. Data on trends of blood donations were collected retrospectively for the period from 1st January to 30th April 2019 and the same period in 2020.

RESULTS

Of 494 donors included, 432 (87·4%) were enrolled from fixed blood collection sites and 62 (12·6%) were contacted by phone. A total of 464 (93·9%) participants believed that the COVID-19 is a lung disease, but some declared it to be imaginary (7·7%), a foreign disease (8·3%) or a blood-borne disease (3·2%). The participants reported that the distribution of face masks and hydroalcoholic solutions (92·5%), social distancing and hygiene (6·3%) are the most important measures that need to be in place for safe donation. The number of blood donations dropped by 21·5% between 2019 and 2020.

CONCLUSION

Most of the donors know COVID-19, its transmission routes and manifestations. In the absence of barrier measures, they perceive blood donation as a threat to their health. Distribution of masks and hydroalcoholic solution might motivate more donors and improve the blood supply.

Hypertension prevalence, associated factors, treatment and control in rural Cameroon: a cross-sectional study

INTRODUCTION

Sub-Saharan Africa is experiencing a surge in the burden of hypertension, and rural communities are increasingly affected by the epidemic.

OBJECTIVES

We aimed to determine the prevalence of and factors associated with hypertension in rural communities of the Baham Health District (BHD), Cameroon. In addition, we sought to assess awareness, treatment and control rates of hypertension among community members.

DESIGN

A community-based cross-sectional study.

SETTING

Participants from five health areas in the BHD were recruited from August to October 2018.

PARTICIPANTS

Consenting participants aged 18 years and above were included.

RESULTS

We included 526 participants in this study. The median age of the participants was 53.0 (IQR=35-65) years and 67.1% were female. The crude prevalence of hypertension was 40.9% (95% CI=36.7-45.1) with no gender disparity. The age-standardised prevalence of hypertension was 23.9% (95% CI=20.3-27.5). Five-year increase in age (adjusted OR (AOR)=1.34; 95% CI=1.23-1.44), family history of hypertension (AOR=2.22; 95% CI=1.37-3.60) and obesity (AOR=2.57; 95% CI=1.40-4.69) were associated with higher odds of hypertension after controlling for confounding. The rates of awareness, treatment and control of hypertension were 37.2% (95% CI=31.0-43.9), 20.9% (95% CI=16.0-26.9) and 22.2% (95% CI=12.2- 37.0), respectively.

CONCLUSION

The high prevalence of hypertension in these rural communities is associated with contrastingly low awareness, treatment and control rates. Age, family history of hypertension and obesity are the major drivers of hypertension in this community. Veracious policies are needed to improve awareness, prevention, diagnosis, treatment and control of hypertension in these rural communities.

Effects of HIV infection, antiretroviral therapy, and immune status on the speed of information processing and complex motor functions in adult Cameroonians

HIV-associated neurocognitive deficits include impaired speed-of-information processing (SIP) and motor functions. There is lack of Cameroonian adult norms for assessing SIP or motor functions. This study of 683 Cameroonians (320 HIV+, 363 HIV-) establishes demographically-adjusted norms for six SIP [Wechsler-Adult-Intelligence-Scale (WAIS)-III Digit Symbol (WAIS-IIIDS) and Symbol Search (WAIS-IIISS), Stroop Color-Naming, Stroop Word-Reading, Trail-Making Test-A (TMT-A), Color Trails-1 (CTT1)], and two motor function [Grooved Pegboard-dominant (GP-DH) and non-dominant (GP-NDH) hands] tests. We assessed viral effects on SIP and motor functions. HIV-infected persons had significantly lower (worse) T scores on GP-DH, WAIS-IIIDS, Stroop Word-Reading, TMT-A; lower motor and SIP summary T scores. Significantly higher proportion of cases (20.7%) than controls (10.3%) had impaired SIP. Male cases had better T scores than female cases on GP-NDH, WAIS-IIIDS, WAIS-IIISS, TMT-A, CTT1; better SIP summary T scores. Antiretroviral therapy (ART) was associated with significantly better T scores on GP-NDH, WAIS-IIIDS, Stroop Color-Naming; better motor and SIP summary T scores. Cases with higher CD4 had better T scores on WAIS-IIIDS, TMT-A, CTT1; better SIP summary T scores. Overall, we demonstrate that HIV infection in Cameroon is associated with deficits in SIP and motor functions; ART and higher CD4 are associated with better cognitive performance. We provide SIP and psychomotor functions normative standards, which will be useful for neurobehavioral studies in Cameroon of diseases affecting the brain.

New Genomes from the Congo Basin Expand History of CRF01_AE Origin and Dissemination

Although the first HIV circulating recombinant form (CRF01_AE) is the predominant strain in many Asian countries, it is uncommonly found in the Congo Basin from where it first originated. To fill the gap in the evolutionary history of this important strain, we sequenced near complete genomes from HIV samples with subgenomic CRF01_AE regions collected in Cameroon and the Democratic Republic of the Congo from 2001 to 2006. HIV genomes were generated from N = 13 plasma specimens by next-generation sequencing of metagenomic libraries prepared with spiked primers targeting HIV, followed by Sanger gap-filling. Genome sequences were aligned to reference strains, including Asian and African CRF01_AE sequences, and evaluated by phylogenetic and recombinant analysis to identify four CRF01_AE strains from Cameroon. We also identified two CRF02, one CRF27, and six unique recombinant form genomes (01|A1|G, 01|02|F|U, F|G|01, A1|D|01, F|G|01, and A1|G|01). Phylogenetic analysis, including the four new African CRF01_AE genomes, placed these samples as a bridge between basal Central African Republic CRF01_AE strains and all Asian, European, and American CRF01_AE strains. Molecular dating confirmed previous estimates indicating that the most recent common CRF01_AE ancestor emerged in the early 1970s (1968–1970) and spread beyond Africa around 1980 to Asia. The new sequences and analysis presented in this study expand the molecular history of the CRF01_AE clade, and are illustrated in an interactive Next Strain phylogenetic tree, map, and timeline at (https://nextstrain.org/community/EduanWilkinson/hiv-1_crf01).

Factors influencing the return of inactive blood donors in a Cameroonian blood bank

Identify factors that influence the return of donors to increase their loyalty while improving blood safety is crucial in our context. Between October 2017 and April 2018, we conducted a descriptive cross-sectional study at the Blood Bank of the Yaoundé University Teaching Hospital. The study included all former donors who had not donated blood voluntarily for over a year. Quantitative variables were described using means and standard deviations. Fisher's exact test and Chi² test were used for association measures between qualitative variables. Statistical test results were considered significant for a P<0.05 value. We interviewed a total of 101 inactive donors. The study population was 74.3% male, donors average 30±7 years. Female gender and good staff hospitality were the factors most associated with the intention to return. The barriers to donor return were mainly lack of information on blood needs (35.60%) and time constraint for blood donation (26.73%). Pro-social motivations such as altruism (30.70%) were the main possible sources of motivation cited. To reduce blood deficiency and mortality due to lack of blood products, non-financial material compensation, good outreach and communication strategy can increase inactive donors' loyalty and consequently in improving blood safety in our context.

The use of the GeeniusTM HIV-1/2 Rapid confirmatory test for the enrolment of patients and blood donors in the WHO Universal Test and Treat Strategy in Cameroon, Africa

BACKGROUND AND OBJECTIVE

In the WHO Universal test and treat strategy, false-positive HIV blood donors and patients may be unnecessarily put under antiretroviral treatment and false-negative subjects may be lost to follow-up. This study assessed the false positivity rate of the Cameroonian national HIV screening testing algorithm and the benefit of a confirmation test in the enrolment of patients and donors in the HIV care programme.

METHODS

We included initial HIV reactive blood donors and patients in a cross-sectional study conducted in two Cameroonian hospitals. Samples were retested according to the Cameroon national algorithm for HIV diagnosis. A positive or discordant sample was retested with the Geenius Bio-Rad HIV 1&2 (Bio-Rad, Marnes-la-Coquette, France) for confirmation. The Geenius HIV-1-positive results with 'poor' profiles were retested for RNA as well as the Geenius indeterminate results.

RESULTS

Of the 356 participants, 190/225 (84·4%) patients and 76/131 (58%) blood donors were declared positive with the national algorithm; 257 participants (96·6%) were confirmed HIV-1-positive. The study revealed that about 34/1000 blood donors and patients are false-positive and unnecessarily put on treatment; 89/1000 blood donors and patients declared discordant could have been included immediately in the HIV care programme if confirmatory testing was performed. The second test of the algorithm had a false-negative rate of 3%. Eleven samples (3·1%) were Geenius poor positive and NAT negative.

CONCLUSION

The universal test and treat strategy may identify and refer more individuals to HIV care if a third rapid confirmatory test is performed for discordant cases.

Programme quality indicators of HIV drug resistance among adolescents in urban versus rural settings of the centre region of Cameroon

BACKGROUND

The high rate of mortality among HIV-vertically infected adolescents might be favoured by HIV drug resistance (HIVDR) emergence, which calls for timeous actions in this underserved population. We thus sought to evaluate program quality indicators (PQIs) of HIVDR among HIV-vertically infected adolescents on antiretroviral therapy (ART).

METHODS

A study was conducted in the Centre region of Cameroon among adolescents (10-19 years) receiving ART in two urban (The Mother-Child Centre of the Chantal BIYA Foundation, the National Social Welfare Hospital) and three rural (Mfou District Hospital, Mbalmayo District Hospital and Nkomo Medical Center) health facilities. Following an exhaustive sampling from ART registers, patient medical files and pharmacy records, data was abstracted for seven PQIs: on-time drug pick-up; retention in care; pharmacy stock outs; dispensing practices; viral load coverage; viral suppression and adequate switch to second-line. Performance in PQIs was interpreted following the WHO-recommended thresholds (desirable, fair and/or poor); with p < 0.05 considered significant.

RESULTS

Among 967 adolescents (888 urban versus 79 rural) registered in the study sites, validated data was available for 633 (554 in urban and 79 in rural). Performance in the urban vs. rural settings was respectively: on-time drug pick-up was significantly poorer in rural (79% vs. 46%, p = 0.00000006); retention in care was fair in urban (80% vs. 72%, p = 0.17); pharmacy stock outs was significantly higher in urban settings (92% vs. 50%, p = 0.004); dispensing practices was desirable (100% vs. 100%, p = 1.000); viral load coverage was desirable only in urban sites (84% vs. 37%, p < 0.0001); viral suppression was poor (33% vs. 53%, p = 0.08); adequate switch to second-line varied (38.1% vs. 100%, p = 0.384).

CONCLUSION

Among adolescents on ART in Cameroon, dispensing practices are appropriate, while adherence to ART program and viral load coverage are better in urban settings. However, in both urban and rural settings, pharmacy stock outs, poor viral suppression and inadequate switch to second-line among adolescents require corrective public-health actions to limit HIVDR and to improve transition towards adult care in countries sharing similar programmatic features.

Prevalence and determinants of anaemia in children aged months in Africa: a protocol for systematic review and meta-analysis

INTRODUCTION

Anaemia, especially in children aged <5 years, is a global health problem disproportionately affecting populations in low-income and middle-income countries. It is associated with high disability and death rates and has a negative effect on development. This study seeks to evaluate the prevalence and determinants of anaemia in children aged 6-59 months residing in Africa.

METHODS AND ANALYSIS

This protocol was prepared using the 2015 Preferred Reporting Items for Systematic Reviews and Meta-analyses for Protocols guidelines. Relevant citations will be identified by searching EMBASE, Web of Science, PubMed, Global Medicus Index and African Journals Online from inception to 30 September 2019 with no language restrictions. Two authors will independently screen and select eligible studies for the review. Random-effect meta-analytic methods will be used to pool study-specific estimates and heterogeneity will be assessed and quantified using the χ2 test on Cochrane's Q and I2 statistics, respectively. Publication bias will be evaluated using funnel plots and Egger's test. Subgroup analysis and multiple meta-regression using backward elimination will be performed to investigate sources of substantial heterogeneity.

ETHICS AND DISSEMINATION

No ethical approval is required for this study as it is based on already published data. The findings of the review will be published in a peer-reviewed journal and presented at conferences.

Variability in HIV-1 Integrase Gene and 3'-Polypurine Tract Sequences in Cameroon Clinical Isolates, and Implications for Integrase Inhibitors Efficacy

Integrase strand-transfer inhibitors (INSTIs) are now included in preferred first-line antiretroviral therapy (ART) for HIV-infected adults. Studies of Western clade-B HIV-1 show increased resistance to INSTIs following mutations in integrase and nef 3′polypurine tract (3′-PPT). With anticipated shifts in Africa (where 25.6-million HIV-infected people resides) to INSTIs-based ART, it is critical to monitor patients in African countries for resistance-associated mutations (RAMs) affecting INSTIs efficacy. We analyzed HIV-1 integrase and 3′-PPT sequences in 345 clinical samples from INSTIs-naïve HIV-infected Cameroonians for polymorphisms and RAMs that affect INSTIs. Phylogeny showed high genetic diversity, with the predominance of HIV-1 CRF02_AG. Major INSTIs RAMs T66A and N155K were found in two (0.6%) samples. Integrase polymorphic and accessory RAMs found included T97A, E157Q, A128T, M50I, S119R, L74M, L74I, S230N, and E138D (0.3′23.5% of samples). Ten (3.2%) samples had both I72V+L74M, L74M+T97A, or I72V+T97A mutations; thirty-one (9.8%) had 3′-PPT mutations. The low frequency of major INSTIs RAMs shows that INSTIs-based ART can be successfully used in Cameroon. Several samples had ≥1 INSTIs accessory RAMs known to reduce INSTIs efficacy; thus, INSTIs-based ART would require genetic surveillance. The 3′-PPT mutations could also affect INSTIs. For patients failing INSTIs-based ART with no INSTIs RAMs, monitoring 3′-PPT sequences could reveal treatment failure etiology.

Author Correction: Metagenomic sequencing with spiked primer enrichment for viral diagnostics and genomic surveillance

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Malaria in patients with sickle cell anaemia: burden, risk factors and outcome at the Laquintinie hospital, Cameroon

BACKGROUND

It is believed that the current prevalence of malaria in endemic areas reflects selection for the carrier form of sickle cell trait through a survival advantage. Malaria has been incriminated as a great cause of mortality in people with sickle cell disease (SCD). However, people with SCD, a high-risk group, do not benefit from free or subsisized malaria prevention and treatment in Cameroon unlike other vulnerable groups which may be due to insufficient evidence to guide policy makers. This study aimed at describing clinical and socio-demographic characteristics of patients with malaria, determining the prevalence of malaria in hospitalized children and in those with SCD and without, compare frequency of presentation of malaria related complications (using clinical and laboratory elements that define severe malaria) between children admitted for malaria with SCD and those without and finally, determing the risk factors for death in children admitted for malaria.

METHODS

This was a retrospective analysis of admission records of children age 1 to 18 years with a confirmed malaria diagnosis admitted at the Laquintinie Hospital during January 2015 through December 2018. Clinical features, laboratory characteristics and outcome of malarial infections, stratified by SCD status were studied. Patients with HIV infection, malnutrition, renal failure and discharged against medical advice were excluded from the study. Data were analysed using Epi-info 7 software and analysis done. Chi square test, Odds ratios, CI and student's t test were used to determine association between variables. Statistical significance was set at p-value ≤0.05.

RESULTS

The prevalence of malaria was lower among children with SCD than it was among children without SCD (23.5% vs 44.9%). Similarly, among those with a positive microscopy, the mean parasite density was significantly lower among children with SCD than it was among children without SCD (22,875.6 vs 57,053.6 parasites/ μl with t-value - 3.2, p-value 0.002). The mean hemoglobin concentration was lower in SCD as compared to non SCD (5.7 g/l vs 7.4 g/l, t-value - 12.5, p-value < 0.001). Overall mortality in SCD was 3.4% and malaria was reponsible for 20.4% of these deaths as compared to the 35.4% in non SCD patients. Convulsion and impaired consciousness were significantly lower in SCD group (OR:0.1, CI: 0.1-0.3, p value < 0.01 and OR:0.1, CI:0.1-0.2, p-value < 0.001 respectively). Death was significantly higher in SCD patients with malaria as compared to SCD patients admitted for other pathologies (3.2% vs 1.5%., OR:2.2, CI:1-5, p-value 0.050).

CONCLUSION

The SCD population has a lower mortality related to malaria compared to the non-SCD population. Meanwhile, within the SCD population, those admitted with malaria are twice more likely to die than those admitted for other pathologies. Jaundice, hepatomegaly and splenomegaly were common in SCD with malaria, however no risk factors for malaria severity or malaria related death was identified.

Metagenomic sequencing with spiked primer enrichment for viral diagnostics and genomic surveillance

Metagenomic next-generation sequencing (mNGS), the shotgun sequencing of RNA and DNA from clinical samples, has proved useful for broad-spectrum pathogen detection and the genomic surveillance of viral outbreaks. An additional target enrichment step is generally needed for high-sensitivity pathogen identification in low-titre infections, yet available methods using PCR or capture probes can be limited by high cost, narrow scope of detection, lengthy protocols and/or cross-contamination. Here, we developed metagenomic sequencing with spiked primer enrichment (MSSPE), a method for enriching targeted RNA viral sequences while simultaneously retaining metagenomic sensitivity for other pathogens. We evaluated MSSPE for 14 different viruses, yielding a median tenfold enrichment and mean 47% (±16%) increase in the breadth of genome coverage over mNGS alone. Virus detection using MSSPE arboviral or haemorrhagic fever viral panels was comparable in sensitivity to specific PCR, demonstrating 95% accuracy for the detection of Zika, Ebola, dengue, chikungunya and yellow fever viruses in plasma samples from infected patients. Notably, sequences from re-emerging and/or co-infecting viruses that have not been specifically targeted a priori, including Powassan and Usutu, were successfully enriched using MSSPE. MSSPE is simple, low cost, fast and deployable on either benchtop or portable nanopore sequencers, making this method directly applicable for diagnostic laboratory and field use.

This study describes a new method that improves the sensitivity of viral detection compared with next-generation sequencing and enables the detection of emerging flaviviruses not specifically targeted a priori. Metagenomic sequencing with spiked primer enrichment is simple, low cost, fast and deployable on either benchtop or portable nanopore sequencers, making it applicable for diagnostic laboratory and field use.

The spectrum of heart disease among adults at the Bamenda Regional Hospital, North west Cameroon: a semi urban setting

OBJECTIVE

We sought to determine the spectrum of heart diseases among adult patients at the Bamenda Regional Hospital in the North West Region of Cameroon. This is a chart review of echocardiographic records.

RESULTS

In total, 673 records were included in our study, of which 506 had a definite heart disease. Of the 506, 93 had mixed cardiopathies. Their ages ranged from 18 to 105 years with a median age of 64.0 (Interquartile range = 47-75) years. Females accounted for a greater proportion (55.3%) of the study population. The most common echocardiographic diagnoses were hypertensive heart disease (41.1%), valvular heart disease (22.3%) and cardiomyopathies (11.4%). The prevalence of heart failure was 17.5%, with hypertensive heart disease being the leading cause.

Occult hepatitis B infection among blood donors from Yaoundé, Cameroon

BACKGROUND

In Cameroon, the prevention of hepatitis B virus (HBV) transmission by blood transfusion is still only based on hepatitis B surface antigen (HBsAg) screening. However, occult HBV infection (OBI) characterised by the absence of detectable HBsAg and low level of viral DNA remains a potential threat for blood safety. The prevalence of OBI was investigated in blood donors from Yaoundé to provide evidence-based recommendations to improve HBV blood safety.

MATERIAL AND METHODS

Blood donations from August 1st, 2016 to March 31st, 2017 were routinely screened for HBV, human immunodeficiency virus (HIV), and hepatitis C virus (HCV) infections (Murex HBsAg Version 3, Murex HIV Ag/Ab Combination, and Murex HCV Ag/Ab Combination [DiaSorin]). Additional HBV investigations were performed, including hepatitis B core antibody ([HBc] Monolisa Anti-HBc PLUS; BIO-RAD) and HBV DNA tested in minipools of two samples using the quantitative Cobas Taqman HBV assay (Roche; LoQ: 6 IU/mL) and HBV DNA genotyping by sequencing.

RESULTS

Of 1,162 donations analysed, 91 (7.8%) were reactive for HBsAg. All of them were also anti-HBc positive. Among the 1,071 HBsAg negative samples, 522 (48.7%) were reactive for anti-HBc. Six (0.56% of all donations) samples fulfilled the consensus definition of OBI and showed low HBV DNA loads (all <6 IU/mL). Following nested polymerase chain reaction amplifications, HBV DNA sequences were obtained for 4 of these samples (1 nearly whole genome [3123 nt], 2 Pre-S/S regions [1,356 nt], and 1 S region [445 nt]). Phylogenetic analysis identified genotype E in all samples.

DISCUSSION

Around 1 in 100 Cameroonian blood donors screened who resulted HBsAg negative and anti-HBc positive carried occult HBV infection. HBsAg alone for screening prospective donors is not sufficient to eliminate the risk of HBV transfusion transmission in Cameroon, and because anti-HBc screening does not seem to be feasible without compromising blood supply, implementation of HBV nucleic acid testing could be considered when possible.

Near-Full-Length Genetic Characterization of a Novel HIV-1 Unique Recombinant with Similarities to A1, CRF01_AE, and CRFO2_AG Viruses in Yaoundé, Cameroon

Variations in the HIV genome influence HIV/AIDS epidemiology. We report here a novel HIV-1 unique recombinant form (URF) isolated from an HIV-infected female (NACMR092) in Cameroon, based on the analyses of near-full-length viral genome (partial gag, full-length pol, env, tat, rev, vif, vpr, vpu, and nef genes, and partial 3'-long terminal repeat). Phylogeny, recombination breakpoints, and recombination map analyses showed that NACMR092 was infected with a mosaic URF that had eight breakpoints (two in gag, one in pol, one in vpr, two in env, and two in the nef regions), nine subgenomic regions, and included fragments that had important similarities with HIV-1 subtypes A1, CRF02_AG, and CRF01_AE. This novel mosaic URF underscores complex recombination events occurring between HIV-1 subtypes circulating in Cameroon. Continued monitoring and detection of such recombinants and accurate classification of HIV genotype is important for tracking viral molecular epidemiology and antigenic diversity.

Near full genome characterization of HIV-1 unique recombinant forms in Cameroon reveals dominant CRF02_AG and F2 recombination patterns

INTRODUCTION

In Cameroon, a manifold diversity of HIV strains exists with CRF02_AG and unique recombinant forms (URFs) being the predominant strains. In recent years, a steady increase in URFs and clade F2 viruses has been monitored through partial genome sequencing. There is an information gap in the characterization of emerging URFs along the full genome, which is needed to address the challenges URFs pose towards diagnosis, treatment and HIV-1 vaccine design.

METHOD

Eighteen Cameroonian URFs from samples collected between the years 2000 and 2015 were studied using a newly developed near full genome sequencing (NFGS) protocol based on variable nested RT-PCRs with a versatile primer set. Near full genomes were characterized for recombination patterns and sequence signatures with possible impact on antiretroviral treatment or Env-directed immune responses. Third-generation sequencing (3GS) of near full or half genomes (HGs) gave insight into intra-patient URF diversity.

RESULTS

The characterized URFs were composed of a broad variety of subtypes and recombinants including A, F, G, CRF01_AE, CRF02_AG and CRF22_01A1. Phylogenetic analysis unveiled dominant CRF02_AG and F2 recombination patterns. 3GS indicated a high intra-patient URF diversity with up to four distinct viral sub-populations present in plasma at the same time. URF pol genomic analysis revealed a number of accessory drug resistance mutations (DRMs) in the ART-naïve participants. Genotypic env analysis suggests CCR5 usage in 14/18 samples and identified deviations at residues, critical for gp120/gp41 interphase and CD4 binding site broadly neutralizing antibodies in more than half of the studied URFs. V1V2 sites of immune pressure in the human RV144 vaccine study varied in more than a third of URFs.

CONCLUSIONS

This study identified novel mosaic patterns in URFs in Cameroon. In line with the regional predominance of CRF_02AG and the increased prevalence of clade F2, prominent CRF_02AG and F2 background patterns were observed underlying the URFs. In the context of the novel mosaic genomes, the impact of the identified accessory DRMs and Env epitope variations on treatment and immune control remains elusive. The evolving diversity of HIV-1 URFs in Cameroon requires continuous monitoring to respond to the increasing challenges for diagnosis, antiretroviral treatment and prevention.

Development of a Versatile, Near Full Genome Amplification and Sequencing Approach for a Broad Variety of HIV-1 Group M Variants

Near full genome sequencing (NFGS) of HIV-1 is required to assess the genetic composition of HIV-1 strains comprehensively. Population-wide, it enables a determination of the heterogeneity of HIV-1 and the emergence of novel/recombinant strains, while for each individual it constitutes a diagnostic instrument to assist targeted therapeutic measures against viral components. There is still a lack of robust and adaptable techniques for efficient NFGS from miscellaneous HIV-1 subtypes. Using rational primer design, a broad primer set was developed for the amplification and sequencing of diverse HIV-1 group M variants from plasma. Using pure subtypes as well as diverse, unique recombinant forms (URF), variable amplicon approaches were developed for NFGS comprising all functional genes. Twenty-three different genomes composed of subtypes A (A1), B, F (F2), G, CRF01_AE, CRF02_AG, and CRF22_01A1 were successfully determined. The NFGS approach was robust irrespective of viral loads (≥306 copies/mL) and amplification method. Third-generation sequencing (TGS), single genome amplification (SGA), cloning, and bulk sequencing yielded similar outcomes concerning subtype composition and recombinant breakpoint patterns. The introduction of a simple and versatile near full genome amplification, sequencing, and cloning method enables broad application in phylogenetic studies of diverse HIV-1 subtypes and can contribute to personalized HIV therapy and diagnosis.

Hepatitis C virus surveillance and identification of human pegivirus 2 in a large Cameroonian cohort

The prevalence of chronic hepatitis C virus (HCV) and the presence of human pegivirus 2 (HPgV-2) have not been examined in Cameroon, although HCV has been associated with HPgV-2 infections previously. Herein we aimed to characterize the burden and genetic diversity of HCV and the presence of HPgV-2 in Cameroon. Retrospective plasma specimens collected from N = 12 369 consenting subjects in South Cameroon from 2013 to 2016 were included in the study. The majority (97.1%) of participants were patients seeking health care. All specimens were screened for HCV using the Abbott RealTime HCV viral load assay and positive specimens with remaining volume were also screened for HPgV-2 antibodies on the Abbott ARCHITECT instrument, followed by molecular characterization. Overall, HCV RNA was detected in 305 (2.47%; 95% CI: 2.21%-2.75%) specimens. Notably, the prevalence of HCV RNA was 9.09% amongst participants over age 40 and 3.81% amongst males. Phylogenetic classification of N = 103 HCV sequences identified genotypes 1 (19.4%), 2 (15.5%) and 4 (65.1%) within the study cohort. Amongst HCV RNA-positive specimens, N = 28 (10.6%; 95% CI: 7.44%-14.90%) specimens also had detectable HPgV-2 antibodies. Of these, N = 2 viremic HPgV-2 infections were confirmed by sequencing and shared 93-94 median % identity with strains found on other continents. This is the first study to determine the prevalence of chronic HCV in Cameroon, and the discovery of HPgV-2 in this study cohort expands the geography of HPgV-2 to the African continent, indicating a widespread distribution exists.

Effects of HIV on executive function and verbal fluency in Cameroon

HIV-associated neurocognitive disorders (HAND) are frequently associated with impaired executive function and verbal fluency. Given limited knowledge concerning HAND in Sub-Saharan-Africa and lack of Cameroonian adult neuropsychological (NP) test norms, we administered four executive function [Halstead Category Test (HCT), Wisconsin Card Sorting Test (WCST), Color Trails-II (CTT2), and Stroop Color-Word-Interference (SCWT)] and three verbal fluency (Category, Action, and Letter Fluency) tests to 742 adult Cameroonians (395 HIV-, 347 HIV+). We developed demographically-corrected NP test norms and examined the effects of HIV and related variables on subjects' executive function and verbal fluency. HIV+ subjects had significantly lower T-scores on CTT2 (P = 0.005), HCT (P = 0.032), WCST (P < 0.001); lower executive function composite (P = 0.002) and Action Fluency (P = 0.03) T-scores. ART, viremia, and CD4 counts did not affect T-scores. Compared to cases harboring other viral subtypes, subjects harboring HIV-1 CRF02_AG had marginally higher CTT2 T-scores, significantly higher SCWT (P = 0.015) and executive function (P = 0.018) T-scores. Thus, HIV-1 infection in Cameroon is associated with impaired executive function and some aspects of verbal fluency, and viral genotype influenced executive function. We report the first normative data for assessing executive function and verbal fluency in adult Cameroonians and provide regression-based formulas for computing demographically-adjusted T-scores. These norms will be useful for investigating HIV/AIDS and other diseases affecting cognitive functioning in Cameroon.

Universal Target Capture of HIV Sequences From NGS Libraries

Background: Global surveillance of viral sequence diversity is needed to keep pace with the constant evolution of HIV. Recent next generation sequencing (NGS) methods have realized the goal of sequencing circulating virus directly from patient specimens. Yet, a simple, universal approach that maximizes sensitivity and sequencing capacity remains elusive. Here we present a novel HIV enrichment strategy to yield near complete genomes from low viral load specimens. Methodology: A non-redundant biotin-labeled probe set (HIV-xGen; n = 652) was synthesized to tile all HIV-1 (groups M, N, O, and P) and HIV-2 (A and B) strains. Illumina Nextera barcoded libraries of either gene-specific or randomly primed cDNA derived from infected plasma were hybridized to probes in a single pool and unbound sequences were washed away. Captured viral cDNA was amplified by Illumina adaptor primers, sequenced on a MiSeq, and NGS reads were demultiplexed for alignment with CLC Bio software. Results: HIV-xGen probes selectively captured and amplified reads spanning the entirety of the HIV phylogenetic tree. HIV sequences clearly present in unenriched libraries of specimens but previously not observed due to high host background levels, insufficient sequencing depth or the extent of multiplexing, were now enriched by >1,000-fold. Thus, xGen selection not only substantially increased the depth of existing sequence, but also extended overall genome coverage by an average of 40%. We characterized 50 new, diverse HIV strains from clinical specimens and demonstrated a viral load cutoff of approximately log 3.5 copies/ml for full length coverage. Genome coverage was <20% for 5/10 samples with viral loads <log 3.5 copies/ml and >90% for 35/40 samples with higher viral loads. Conclusions: Characterization of >20 complete genomes at a time is now possible from a single probe hybridization and MiSeq run. With the versatility to capture all HIV strains and the sensitivity to detect low titer specimens, HIV-xGen will serve as an important tool for monitoring HIV sequence diversity.

Prevalence of anti-hepatitis C antibodies and its co-infection with HIV in rural Cameroon

Objective

To evaluate the prevalence of the co-infection between the human immunodeficiency virus (HIV) and hepatitis C virus (HCV), and the prevalence of factors associated with HCV transmission in a rural Cameroonian community.

Results

The mean age of the 174 participants included in the study was 30.3 (standard deviation = 13.26) years (age range 12–77 years). the prevalence of HCV/HIV co-infection was 1.7% [95% confidence interval (CI) 1.1–5.9]. The prevalence of HCV and HIV were 6.3% (95% CI 2.9–10.3) and 6.9 (95% CI 5.2–11.3), respectively. Histories of scarification (62.1%), multiple sex partners (31.0%) and sexually transmitted diseases (66.1%) were the most common risk factors of HCV transmission in this study.

ARCHITECT HIV Combo Ag/Ab and RealTime HIV-1 Assays Detect Diverse HIV Strains in Clinical Specimens

Periodic evaluation of the impact of viral diversity on diagnostic tests is critical to ensure current technologies are keeping pace with viral evolution. To determine whether HIV diversity impacts the ARCHITECT HIV Combo Ag/Ab (HIV Combo) or RealTime HIV-1 (RT) assays, a set of N = 199 HIV clinical specimens from Cameroon, Senegal, Saudi Arabia, and Thailand were sequenced and tested in both assays. The panel included historical groups N and P specimens and a newly identified group N specimen. These and specimens classified as H, U (unclassified)/URF (unique recombinant form), CRF (circulating recombinant form) 01, 02, 06, 09, 11, 13, 18, 22, 37, and 43 were detected by both the RT assay (1.75–6.84 log copies/ml) and the HIV Combo assay (3.26–1121.96 sample to cutoff ratios). Sequence alignment identified 3 or fewer mismatches to the RT assay oligos in 82.4% of samples. Altogether, these data demonstrate the HIV Combo and RT assays detect diverse strains of HIV in clinical specimens.

Diagnosis, Prevalence, Awareness, Treatment, Prevention, and Control of Hypertension in Cameroon: Protocol for a Systematic Review and Meta-Analysis of Clinic-Based and Community-Based Studies

Background

Hypertension holds a unique place in population health and health care because it is the leading cause of cardiovascular disease and the most common noncommunicable condition seen in primary care worldwide. Without effective prevention and control, raised blood pressure significantly increases the risk of stroke, myocardial infarction, chronic kidney disease, heart failure, dementia, renal failure, and blindness. There is an urgent need for stakeholders—including individuals and families—across the health system, researchers, and decision makers to work collaboratively for improving prevention, screening and detection, diagnosis and evaluation, awareness, treatment and medication adherence, management, and control for people with or at high risk for hypertension. Meeting this need will help reduce the burden of hypertension-related disease, prevent complications, and reduce the need for hospitalization, costly interventions, and premature deaths.

Objective

This review aims to synthesize evidence on the epidemiological landscape and control of hypertension in Cameroon, and to identify elements that could potentially inform interventions to combat hypertension in this setting and elsewhere in sub-Saharan Africa.

Methods

The full search process will involve several steps, including selecting relevant databases, keywords, and Medical Subject Headings (MeSH); searching for relevant studies from the selected databases; searching OpenGrey and the Grey Literature Report for gray literature; hand searching in Google Scholar; and soliciting missed publications (if any) from relevant authors. We will select qualitative, quantitative, or mixed-methods studies with data on the epidemiology and control of hypertension in Cameroon. We will include published literature in French or English from electronic databases up to December 31, 2016, and involving adults aged 18 years or older. Both facility and population-based studies on hypertension will be included. Two reviewers of the team will independently search, screen, extract data, and assess the quality of selected studies using suitable tools. Selected studies will be analyzed by narrative synthesis, meta-analysis, or both, depending on the nature of the data retrieved in line with the review objectives.

Results

This review is part of an ongoing research program on disease prevention and control in the context of the dual burden of communicable and noncommunicable diseases in Africa. The first results are expected in 2017.

Conclusions

This review will provide a comprehensive assessment of the burden of hypertension and control measures that have been designed and implemented in Cameroon. Findings will form the knowledge base relevant to stakeholders across the health system and researchers who are involved in hypertension prevention and control in the community and clinic settings in Cameroon, as a yardstick for similar African countries.

Trial Registration

PROSPERO registration number: CRD42017054950; http://www.crd.york.ac.uk/PROSPERO/ display_record.asp?ID=CRD42017054950 (Archived by WebCite at http://www.webcitation.org/6qYSjt9Jc)

Risk factors for human immunodeficiency virus among blood donors in Cameroon: evidence for the design of an Africa-specific donor history questionnaire

BACKGROUND

In sub-Saharan Africa improving the deferral of at-risk blood donors would be a cost-effective approach to reducing transfusion-transmitted human immunodeficiency virus (HIV) infections. We performed a pilot case-control study to identify the risk factors for HIV infection and to develop an adapted donor history questionnaire (DHQ) for sub-Saharan Africa.

STUDY DESIGN AND METHODS

We recruited 137 HIV-positive donors (cases) and 256 HIV-negative donors (controls) and gathered risk factor data using audio computer-assisted self-interview. Variables with univariate associations were entered into a logistic regression model to assess independent associations. A scoring scheme to distinguish between HIV-positive and HIV-negative donors was developed using receiver operating characteristics curves.

RESULTS

We identified 16 risk factors including sex with sex worker, past history or treatment for sexually transmitted infections, and having a partner who used injected or noninjected illegal drugs. Two novel risks were related to local behavior: polygamy (odds ratio [OR], 22.7; 95% confidence interval [CI], 5.9-86.7) and medical or grooming treatment on the street (OR, 1.8; 95% CI, 1.0-3.0). Using the 16 selected items the mean scores (>100) were 82.6 ± 6.7 (range, 53.2-95.1) and 85.1 ± 5.2 for HIV-negative donors versus 77.9 ± 6.8 for HIV-positive ones (p = 0.000). Donors who scored between 80 and 90 were more likely to be HIV negative than those who scored less (OR, 31.4; 95% CI, 3.1-313.9).

CONCLUSION

We identified both typical and novel HIV risk factors among Cameroonian blood donors. An adapted DHQ and score that discriminate HIV-negative donors may be an inexpensive means of reducing transfusion-transmitted HIV through predonation screening.

Depressive symptoms in HIV-infected and seronegative control subjects in Cameroon: Effect of age, education and gender

Depression is a leading cause of HIV/AIDS disease burden; it worsens health outcomes and quality of life. Addressing this problem requires accurate quantification of the extra burden of depression to HIV/AIDS in a given population, and knowledge of the baseline depression prevalence in the general population. There has been no previous study of depression in the general Cameroonian population. The current study attempts to address that important need. We used the Beck Depression Inventory-II to assess the prevalence and severity of depressive symptoms in 270 HIV-infected and seronegative Cameroonians. Univariate analyses showed a trend toward higher depressive symptoms among cases, compared to controls (p = 0.055), and among older subjects (>40 years), compared to younger subjects (≤40 years) (p = 0.059). Analysis of depression severity showed that 33.73% of cases had moderate-to-severe depressive symptoms, compared to 19.8% of controls (p<0.01). However, multivariable negative binomial regression analyses showed no effect of age, HIV status, CD4 levels, viral loads, ART, or opportunistic infections on the risk of depressive symptoms. Both univariate and multivariable regression analyses showed significantly higher risk of depressive symptoms among females compared to males; this was significant for both female controls and female cases. Female cases had significantly higher CD4 cell counts and lower viral loads, compared to males. Both univariate and multivariable regression analyses showed that lower education (≤10 years) was associated with increased risk of depressive symptoms. This study shows a high prevalence of depressive symptoms among seronegative controls and HIV-infected Cameroonians. Integrating care for mental disorders such as depression into primary health care and existing HIV/AIDS treatment programs in Cameroon may improve the wellbeing of the general population and could lower the HIV/AIDS burden.

Identification of rare HIV-1 Group N, HBV AE, and HTLV-3 strains in rural South Cameroon

Surveillance of emerging viral variants is critical to ensuring that blood screening and diagnostic tests detect all infections regardless of strain or geographic location. In this study, we conducted serological and molecular surveillance to monitor the prevalence and diversity of HIV, HBV, and HTLV in South Cameroon. The prevalence of HIV was 8.53%, HBV was 10.45%, and HTLV was 1.04% amongst study participants. Molecular characterization of 555 HIV-1 specimens identified incredible diversity, including 7 subtypes, 12 CRFs, 6 unclassified, 24 Group O and 2 Group N infections. Amongst 401 HBV sequences were found a rare HBV AE recombinant and two emerging sub-genotype A strains. In addition to HTLV-1 and HTLV-2 strains, sequencing confirmed the fifth known HTLV-3 infection to date. Continued HIV/HBV/HTLV surveillance and vigilance for newly emerging strains in South Cameroon will be essential to ensure diagnostic tests and research stay a step ahead of these rapidly evolving viruses.

Adherence to Antiretroviral Therapy (ART) in Yaoundé-Cameroon: Association with Opportunistic Infections, Depression, ART Regimen and Side Effects

Following global efforts to increase antiretroviral therapy (ART) access in Sub-Saharan Africa, ART coverage among HIV-infected Cameroonians increased from 0% in 2003 to 22% in 2014. However, the success of current HIV treatment programs depends not only on access to ART, but also on retention in care and good treatment adherence. This is necessary to achieve viral suppression, prevent virologic failure, and reduce viral transmission and HIV/AIDS-related deaths. Previous studies in Cameroon showed poor adherence, treatment interruption, and loss to follow-up among HIV+ subjects on ART, but the factors that influence ART adherence are not well known. In the current cross-sectional study, patient/self-reported questionnaires and pharmacy medication refill data were used to quantify ART adherence and determine the factors associated with increased risk of non-adherence among HIV-infected Cameroonians. We demonstrated that drug side-effects, low CD4 cell counts and higher viral loads are associated with increased risk of non-adherence, and compared to females, males were more likely to forego ART because of side effects (p<0.05). Univariate logistic regression analysis demonstrated that subjects with opportunistic infections (on antibiotics) had 2.42-times higher odds of having been non-adherent (p<0.001). Multivariable analysis controlling for ART regimen, age, gender, and education showed that subjects with opportunistic infections had 3.1-times higher odds of having been non-adherent (p<0.0003), with significantly longer periods of non-adherence, compared to subjects without opportunistic infections (p = 0.02). We further showed that compared to younger subjects (≤40 years), older subjects (>40 years) were less likely to be non-adherent (p<0.01) and had shorter non-adherent periods (p<0.0001). The presence of depression symptoms correlated with non-adherence to ART during antibiotic treatment (r = 0.53, p = 0.04), and was associated with lower CD4 cell counts (p = 0.04) and longer non-adherent periods (p = 0.04). Change in ART regimen was significantly associated with increased likelihood of non-adherence and increased duration of the non-adherence period. Addressing these underlying risk factors could improve ART adherence, retention in care and treatment outcomes for HIV/AIDS patients in Cameroon.

Surveillance of nosocomial infections in the Yaounde University Teaching Hospital, Cameroon

Background

Nosocomial infections (NI) represent a real public health problem in developing countries. Their surveillance is recommended to provide needed information for better control. The aim of this study was to describe the frequency and distribution of NI in the Yaoundé University Teaching Hospital (YUTH).

Methods

It was a longitudinal and descriptive study targeting hospitalized patients in the intensive care, gynaecological, surgical and neonatal units. Each consenting patient was administered a questionnaire at the beginning of the study and followed up daily for the duration of their hospitalization using a standardized grid to detect all nosocomial infections. Cumulative incidence was used to estimate NI frequency.

Results

There were 307 patients included. The cumulative incidence and specific mortality rate of NI were 19.21% (16.9–21.5) and 28% (16.2–42.5) respectively. Septicaemia (20.34%), infection of the skin and soft tissues (20.34%) and urinary tract infections (15.25%) were the most frequent type of NI. Klebsiella spp. was the most frequently isolated bacterium (27%).

Conclusion

Nosocomial infections contribute to high hospital morbidity in the Yaounde University Teaching Hospital. Strategies need to be identified for a sustainable and continuous monitoring of NI in all health facilities of Cameroon. In addition, Further studies should identify NI determinants and interventions for efficient and better control.

Reducing risks of Transfusion-transmitted infections in a resource-limited hospital-based blood bank: the case of the Yaoundé University Teaching Hospital, Cameroon

BACKGROUND AND OBJECTIVES

Although interest in assessing risk of TTIs, very few trends in blood safety epidemiological data from resource-limited blood services are reported in the literature. This analysis aims at reporting trends in seroprevalences of TTIs in blood donations in the Yaoundé University Teaching Hospital (UTH) from 2011 to 2015 and to describe reasons for these changes.

MATERIALS AND METHODS

All donations of 2015 were tested for HIV 1&2 antibodies and the P24 antigen, HBsAg, HCV antibody and the Treponema pallidum antibody. Screening for HIV uses a national algorithm based on the systematic use of two assays of different principles: a rapid determination testing assay and an EIA HIV 1 & 2 Ab-Ag. The tests used for HBsAg and HCVAb screening were all based on EIA techniques. Treponema pallidum antibody screening was based on Treponema Pallidum hemagglutination assay (TPHA) and rapid immunochromatographic test (RIT). Screening techniques and results from 2015 were compared to retrospective data from 2011, 2012, 2013 and 2014.

RESULTS

In 2015, 13·4% (n = 214) of 1,596 blood donations were seropositive for at least one screened TTIs. The most frequent serological marker was HBsAg with 123 (7·7%) blood units contaminated. Nineteen (1·2%) and 18 (1·1%) blood units was positive for HIV and syphilis, respectively. There was a significant decrease in the total number of blood donations (P < 10^-4) and HIV, HBsAg and syphilis seroprevalences and an increase in the proportion of voluntary non-remunerated blood donor (P < 0·05). HCVAb seroprevalence was 3·8% in 2015 and has not decreased significantly over the years (P = 0·09).

CONCLUSION

Significant progress is noted in reduction in seroprevalences of HIV, HBV, HCV and syphilis since the beginning of a regular registration of data in 1990.

Utility of Metagenomic Next-Generation Sequencing for Characterization of HIV and Human Pegivirus Diversity

Given the dynamic changes in HIV-1 complexity and diversity, next-generation sequencing (NGS) has the potential to revolutionize strategies for effective HIV global surveillance. In this study, we explore the utility of metagenomic NGS to characterize divergent strains of HIV-1 and to simultaneously screen for other co-infecting viruses. Thirty-five HIV-1-infected Cameroonian blood donor specimens with viral loads of >4.4 log₁₀ copies/ml were selected to include a diverse representation of group M strains. Random-primed NGS libraries, prepared from plasma specimens, resulted in greater than 90% genome coverage for 88% of specimens. Correct subtype designations based on NGS were concordant with sub-region PCR data in 31 of 35 (89%) cases. Complete genomes were assembled for 25 strains, including circulating recombinant forms with relatively limited data available (7 CRF11_cpx, 2 CRF13_cpx, 1 CRF18_cpx, and 1 CRF37_cpx), as well as 9 unique recombinant forms. HPgV (formerly designated GBV-C) co-infection was detected in 9 of 35 (25%) specimens, of which eight specimens yielded complete genomes. The recovered HPgV genomes formed a diverse cluster with genotype 1 sequences previously reported from Ghana, Uganda, and Japan. The extensive genome coverage obtained by NGS improved accuracy and confidence in phylogenetic classification of the HIV-1 strains present in the study population relative to conventional sub-region PCR. In addition, these data demonstrate the potential for metagenomic analysis to be used for routine characterization of HIV-1 and identification of other viral co-infections.

Anemia in patients on chronic hemodialysis in Cameroon: prevalence, characteristics and management in low resources setting

BACKGROUND

Anemia is a common complication of chronic kidney disease. We investigated the prevalence, characteristics and management of anemia in patients on chronic hemodialysis and assessed the response to blood-transfusion based management in Cameroon.

METHODS

This was a cohort study of five months' duration (August-December 2008) conducted at the Yaoundé General Hospital's hemodialysis center, involving 95 patients (67 men, 70.5%) on chronic hemodialysis by a native arteriovenous fistula. A monthly evaluation included full blood counts, number of pints of red cell concentrates transfused, and vital status.

RESULTS

At baseline, 75 (79%) patients had anemia which was microcytic and hypochromic in 32 (43%). Anemia was corrected in 67 (70.5%) patients using blood transfusion only, while 28 (29.5%) patients were receiving erythropoietin (11 regularly, 39%). Only 77.2% of 342 pints (median 3.0, range 0-17 per patients) of red cell concentrates prescribed were effectively received during the follow-up at an unacceptably high cost to patients and families. Mean hemoglobin and mean corpuscular hemoglobin levels remained stable during follow-up, while mean corpuscular volume increased. Erythropoietin treatment was the main determinant of favorable trajectories of hematological markers.

CONCLUSIONS

Patients on chronic hemodialysis have predominantly microcytic hypochromic anemia, with limited capacity for correction using blood transfusion.

MUSCULOSKELETAL PRESENTATION OF MULTIPLE MYELOMA AT GENERAL HOSPITAL DOUALA, CAMEROON

Background: very little is known about musculoskeletal features of multiple myeloma (MM) in Africa.

OBJECTIVES

To describe the musculoskeletal features of multiple myeloma at presentation in a tertiary health care centre in sub-Saharan Africa.

DESIGN

A Cross sectional observational study.

SETTING

The Douala General Hospital, Cameroon from 2007 to 2013.

SUBJECTS

A patient was said to have MM according the current international consensus criteria for diagnosis and staging of MM. Patients with monoclonal gammopathy of undetermined significance, solitary plamocytoma and other haematologic malignancies were excluded.

RESULTS

A total of 62 patients were diagnosed with multiple myeloma, 63% were female. Mean age was 57 ± 12,1 (19-81) years. Musculoskeletal presentation included spine bone pains (75.6%); vertebral fracture with spinal cord compression in 46.8 %. Other clinical features at presentation included anaemia (70.93%), and nephropathy (17.74%). The average percentage of bone marrow plasmacytosis at diagnosis was 33% and Immunoglobulin G was found in 86% of patients. Sixty three per cent of patients were diagnosed at stage III of the disease.

CONCLUSION

Presence of bone pain and anaemia should alert the clinician to investigate along the lines of multiple myeloma. Majority of the patients have osteolytic lesions and pathologic fractures at the time of diagnosis.