An optimized strategy triggered at the 2nd immunization visit to prevent HIV acquisition by breastfeeding: a phase 2 trial in Burkina Faso (PREVENIR-PEV).

BACKGROUND: Mother-to-child transmission of HIV during breastfeeding remains a challenge in low- and middle-income countries (LMIC). A prevention package was initiated during the highly attended 2nd visit of the Expanded Program of Immunisation (EPI-2) to identify the undiagnosed infants living with HIV and reduce the postnatal transmission of infant exposed to HIV. METHODS: PREVENIR-PEV is a non-randomized phase II clinical trial conducted at two health centres in Bobo Dioulasso (Burkina Faso). The study recruited mothers living with HIV aged 15 years and older with their singleton breastfed infants. During EPI-2 (at 8 weeks) and upon signature of the informed consent, a point-of-care early infant diagnosis (EID) was performed. HIV exposed uninfected (HEU) infants were followed-up until 12 months of age. High risk HEU infants (i.e., whose maternal viral load ≥ 1000 cp/mL at EPI-2 or M6) received an extended postnatal prophylaxis (PNP) with lamivudine until end of follow-up or the end of breastfeeding. RESULTS: Between 4 December 2019 and 4 December 2020, 118 mothers living with HIV-1 were identified, and 102 eligible mother/infant pairs had their infants tested for HIV EID. Six infants were newly diagnosed with HIV, and 96 HEU infants were followed-up for 10 months. Among the participants followed-up, all mothers were prescribed antiretrovirals. All 18 infants eligible for PNP at either EPI-2 or 6 months (M6) were initiated on lamivudine. No HIV transmission occurred, and no serious adverse events were reported in infants receiving lamivudine. CONCLUSIONS: The PREVENIR-PEV prevention package integrated into existing care is safe and its implementation is feasible in a LMIC with a low HIV prevalence. More research is needed to target mother/infant pairs not adhering to the intervention proposed in this trial. TRIAL REGISTRATION: NCT03869944; first registered on 11/03/2019.

Seroprevalence and risk factors for SARS-CoV-2 infection in middle-sized cities of Burkina Faso: A descriptive cross-sectional study.

BACKGROUND: Since March 2020, COVID-19 has evolved from a localized outbreak to a global pandemic. We assessed the seroprevalence of COVID-19 in three towns in the Centre Sud region of Burkina Faso. METHODS: A population-based cross-sectional survey was conducted in three middle-sized cities in Burkina Faso's Centre Sud region, from June to July 2021. Subjects aged 16 or over at the time of the survey were considered for this seroprevalence study. The Biosynex COVID-19 BSS rapid test was used to detect immunoglobulin G (IgG) and immunoglobulin M (IgM) against SARS-CoV-2. A standardized questionnaire was also administered to collect additional information. RESULTS: A total of 2449 eligible participants (age ≥ 16 years) were identified. Serological tests for COVID-19 were performed in 2155 individuals, of which 2143 valid tests were retained and analyzed. Out of the entire sample, 246 positive tests were observed, corresponding to a prevalence of 11.48%. Prevalence was 9.35% (58 cases) in Kombissiri, 12.86% (80 cases) in Manga and 11.99% (108 cases) in Pô. By gender, 13.37% of women (164 cases) tested positive, and 8.95% of men (82 cases). Women accounted for 66.67% of all positive test subjects. The results from the multivariate analysis show a significantly higher seroprevalence in women (p = 0.007), people over 55 years old (p = 0.004), overweight people (p = 0.026) and those with drinking water sources at home (p = 0.013). CONCLUSIONS: The results of this study show that the COVID-19 virus also circulates in the population of middle-sized cities in Burkina Faso, far more than officially reported by the information service of the government of Burkina Faso, given the lack of systematic testing in the general population in the country. The study also highlighted the greater vulnerability of women, older and overweight individuals to the epidemic. The preventive measures put in place to fight the pandemic must take these different factors into account.

Co-circulation of two Alphaviruses in Burkina Faso: Chikungunya and O'nyong nyong viruses.

BACKGROUND: Chikungunya virus (CHIKV) and O'nyong nyong virus (ONNV) are phylogenetically related alphaviruses in the Semliki Forest Virus (SFV) antigenic complex of the Togaviridae family. There are limited data on the circulation of these two viruses in Burkina Faso. The aim of our study was to assess their circulation in the country by determining seroprevalence to each of the viruses in blood donor samples and by retrospective molecular and serological testing of samples collected as part of national measles and rubella surveillance. METHODOLOGY/PRINCIPAL FINDINGS: All blood donor samples were analyzed on the Luminex platform using CHIKV and ONNV E2 antigens. Patient samples collected during national measles-rubella surveillance were screened by an initial ELISA for CHIKV IgM (CHIKjj Detect IgM ELISA) at the national laboratory. The positive samples were then analyzed by a second ELISA test for CHIKV IgM (CDC MAC-ELISA) at the reference laboratory. Finally, samples that had IgM positive results for both ELISA tests and had sufficient residual volume were tested by plaque reduction neutralization testing (PRNT) for CHIKV and ONNV. These same patient samples were also analyzed by rRT-PCR for CHIKV. Among the blood donor specimens, 55.49% of the samples were positive for alphaviruses including both CHIKV and ONNV positive samples. Among patient samples collected as part of national measles and rubella surveillance, 3.09% were IgM positive for CHIKV, including 2.5% confirmed by PRNT. PRNT failed to demonstrate any ONNV infections in these samples. No samples tested by RT-qPCR. had detectable CHIKV RNA. CONCLUSIONS/SIGNIFICANCE: Our results suggest that CHIKV and ONNV have been circulating in the population of Burkina Faso and may have been confused with malaria, dengue fever or other febrile diseases such as measles or rubella. Our study underscores the necessity to enhance arbovirus surveillance systems in Burkina Faso.

Development and field evaluation in African and Asian countries of an hepatitis B virus PCR on open polyvalent platforms to determine treatment eligibility: results from the "Agence Nationale de Recherche sur le Sida et les hépatites" 12327 study.

OBJECTIVES: Widespread testing and treatment are essential to eliminate hepatitis B virus (HBV) infection as a public health concern. However, in resource-limited countries, access to HBV PCR is limited. In this study, we developed a quantitative HBV PCR assay on open molecular platforms and evaluate its performance in diagnosing clinically significant HBV DNA thresholds as defined by the WHO (2000 IU/mL, 20 000 IU/mL, and 200 000 IU/mL). METHODS: We implemented our HBV PCR test in seven African and Asian countries and France, using either an in-house laboratory method or a European conformity for in vitro diagnostic (CE-IVD) marked version of the PCR (Generic HBV Charge Virale, Biocentric). Results were compared with reference tests (Roche Cobas AmpliPrep/Cobas TaqMan and Abbott RealTime on Abbott m2000). RESULTS: There was a good agreement between the HBV DNA results of 1015 samples tested by the PCR on open polyvalent platforms and the results from reference tests (mean difference (bias ± standard deviation [SD]): -0.3 ± 0.7 log10 IU/mL and -0.2 ± 0.9 log10 IU/mL when compared with Roche and Abbott tests, respectively). Kappa-Cohen agreements between the HBV PCR on open polyvalent platforms and the Roche/Abbott assays appeared almost perfect for HBV DNA levels ranged from >20 000 to 200 000 IU/mL and >200 000 IU/mL, substantial and moderate for HBV DNA levels ranged from 2000 to 20 000 IU/mL when compared with Abbott and Roche, respectively. The assay's performance was consistent across genotypes A, B, C, D, and E. DISCUSSION: This field evaluation showed that our HBV PCR test is a valuable alternative to proprietary PCR systems. PCR assays on open platforms contribute to expanding clinical laboratory solutions for diagnosing individuals who meet the viral load criteria for antiviral therapy (>20 000 IU/mL) and mother-to-child prophylaxis (>200 000 IU/mL).

Costs of integrating hepatitis B screening and antiviral prophylaxis into routine antenatal care in Burkina Faso: Treat all versus targeted strategies.

OBJECTIVE: Economic feasibility of eliminating mother-to-child transmission (MTCT) of hepatitis B virus (HBV) in highly endemic African countries remains uncertain. Prevention of MTCT (PMTCT) involves screening pregnant women for hepatitis B surface antigen (HBsAg), identifying those with high viral loads or hepatitis B e antigen (HBeAg), and administering tenofovir prophylaxis to high-risk women. We estimated the costs of integrating PMTCT services into antenatal care in Burkina Faso, based on four different strategies to select women for tenofovir prophylaxis: (1) HBV DNA (≥200 000 IU/mL), (2) HBeAg, (3) hepatitis B core-related antigen rapid diagnostic test (HBcrAg-RDT) and (4) all HBsAg-positive women. METHODS: Using a micro-costing approach, we estimated the incremental economic cost of integrating each strategy into routine antenatal care in 2024, compared to neonatal vaccination alone. Sensitivity analyses explored variations in prevalence, service coverage, test and tenofovir prices. RESULTS: HBcrAg-RDT strategy was the least expensive, with a total economic cost of US$3959689, compared to HBV DNA (US$6128875), HBeAg (US$4135233), and treat-all (US$4141206). The cost per pregnant woman receiving tenofovir prophylaxis varied from US$61.88 (Treat-all) to US$1071.05 (HBV DNA). The Treat-All strategy had the lowest marginal cost due to a higher number of women on tenofovir (66928) compared to HBV DNA (5722), HBeAg (10020), and HBcrAg-RDT (7234). In sensitivity analyses, the treat-all strategy became less expensive when the tenofovir price decreased. CONCLUSION: HBcrAg-RDT minimizes resource use and costs, representing 0.61% of Burkina Faso's 2022 health budget. This study highlights the potential economic feasibility of these strategies and provides valuable resources for conducting cost-effectiveness analyses.

Optimised prevention of postnatal HIV transmission in Zambia and Burkina Faso (PROMISE-EPI): a phase 3, open-label, randomised controlled trial.

BACKGROUND: Transmission through breastfeeding accounts for more than half of the unacceptably high number of new paediatric HIV infections worldwide. We hypothesised that, in addition to maternal antiretroviral therapy (ART), extended postnatal prophylaxis with lamivudine, guided by point-of-care assays for maternal viral load, could reduce postnatal transmission. METHODS: We did a phase 3, open-label, randomised controlled trial at four health-care facilities in Zambia and four health-care facilities in Burkina Faso. Mothers with HIV and their breastfed infants without HIV attending the second visit of the Expanded Programme of Immunisation (EPI-2; infant age 6-8 weeks) were randomly assigned 1:1 to intervention or control groups. In the intervention group, maternal viral load was measured using Xpert HIV viral load assay at EPI-2 and at 6 months, with results provided immediately. Infants whose mothers had a viral load of 1000 copies per mL or higher were started on lamivudine syrup twice per day for 12 months or 1 month after breastfeeding discontinuation. The control group followed national guidelines for prevention of postnatal transmission of HIV. The primary outcome assessed by modified intention to treat was infant HIV infection at age 12 months, with HIV DNA point-of-care testing at 6 months and at 12 months. This trial is registered with ClinicalTrials.gov (NCT03870438). FINDINGS: Between Dec 12, 2019 and Sept 30, 2021, 34 054 mothers were screened for HIV. Among them, 1506 mothers with HIV and their infants without HIV, including 1342 mother and infant pairs from Zambia and 164 from Burkina Faso, were eligible and randomly assigned 1:1 to the intervention (n=753) or control group (n=753). At baseline, the median age of the mothers was 30·6 years (IQR 26·0-34·7), 1480 (98·4%) of 1504 were receiving ART, and 169 (11·5%) of 1466 had a viral load ≥1000 copies/mL. There was one case of HIV transmission in the intervention group and six in the control group, resulting in a transmission incidence of 0·19 per 100 person-years (95% CI 0·005-1·04) in the intervention group and 1·16 per 100 person-years (0·43-2·53) in the control group, which did not reach statistical significance (p=0·066). HIV-free survival and serious adverse events were similar in both groups. INTERPRETATION: Our intervention, initiated at EPI-2 and based on extended single-drug postnatal prophylaxis guided by point-of-care maternal viral load could be an important strategy for paediatric HIV elimination. FUNDING: The EDCTP2 programme with the support of the UK Department of Health & Social Care.

Evaluation of the prevention of mother-to-child transmission of HIV programs at the second immunization visit in Burkina Faso and Zambia.

OBJECTIVE: Our study aimed to assess the PMTCT indicators in Burkina Faso and Zambia using a patient-orientated innovative strategy based on the second visit in the Expanded Program on Immunization (EPI-2) visit at 6-8 weeks. DESIGN: This was a cross sectional study. METHODS: We assessed women attending EPI-2 at primary healthcare facilities in Burkina Faso and Zambia with their children about their exposure to PMTCT interventions. For women living with HIV (WLHIV), viral load was measured and their children were tested for HIV DNA using point of care devices. RESULTS: Overall, 25 093 were enrolled from Burkina Faso and 8961 women from Zambia. Almost, all women attended at least one antenatal care visit. Among those aware of their HIV-positive status, 95.8 and 99.2% were on antiretroviral therapy (ART) in Burkina Faso and Zambia, respectively. Among WLHIV on ART, 75 and 79.2% achieved a viral load suppression (viral load <1000 copies/ml) in Burkina Faso and Zambia, respectively. Infant postnatal prophylaxis was administered from birth until EPI-2 to 60.9 and 89.7% of HIV-exposed children in Burkina Faso and Zambia, respectively. In Burkina Faso, only 60 of 192 (31.3%) of HIV-exposed children were sampled at day 42 for early infant diagnosis (EID) and 3 (1.6%) received a result by EPI-2. In Zambia, these figures were 879 of 1465 (64.0%) and 9.9% (145/1465), respectively for HIV-exposed children sampled at birth. CONCLUSION: This evaluation strategy at EPI-2 visit could strengthen program monitoring and help identifying gaps to be addressed on the last mile towards elimination of MTCT of HIV.

Leptospirosis Cases among Outpatients with Non-Malaria Fever Attending Primary Care Clinics during the Rainy Season in Bobo Dioulasso, Burkina Faso.

Leptospirosis is presumably an important cause of non-malarial fever in West Africa. In this study, outpatients consulting in primary care clinics during the rainy season were tested for leptospirosis, and clinical characteristics associated with leptospirosis cases were explored. Patients with fever ≥ 39°C were recruited in nine primary health care centers in Bobo Dioulasso (Burkina Faso). Diagnosis of malaria was ruled out using a rapid diagnostic test (RDT; SD Bioline Malaria®). Leptospirosis cases were defined as patients who tested positive for Leptospira IgM (Leptocheck-WB RDT and Leptospira IgM ELISA assay, Panbio) or DNA in plasma (LipL32 polymerase chain reaction [PCR]). Among 350 patients, 202 tested positive for malaria and were excluded, and 148 met the eligibility criteria and were included. Among these, 26 subjects were considered to be leptospirosis cases: 23 tested positive for Leptospira IgM (15.5%) and three tested positive by PCR (2.2%). Headaches, abdominal symptoms, and myalgia were frequently reported without any difference between leptospirosis cases and negative cases. Cough was more frequently observed among subjects testing positive for leptospirosis (P = 0.02). Water exposure, presence of a skin injury, and walking barefoot were associated with a Leptospira-positive test. All leptospirosis cases recovered without sequelae. A significant portion of outpatients with non-malarial febrile illness during the rainy season in Burkina Faso had epidemiological factors associated with leptospirosis and tested positive for Leptospira. The favorable outcome of leptospirosis cases was reassuring; this could be due in particular to the young age of the patients.

A Qualitative Study of the Experience of COVID-19 Patients in Burkina Faso.

In Burkina Faso, the health system is characterized by systemic insufficient and antiquated health-care infrastructures. Consequently, few health-care establishments have the required resources to diagnose and manage patients with COVID-19, and fewer still have intensive care facilities for severely ill patients with COVID. Furthermore, there is a widespread scarcity of qualified health-care staff. The aim of this study was to explore the experiences of patients with COVID-19 who recovered after being cared for in Bobo Dioulasso and Ouagadougou. Using individual semistructured interviews, we performed a cross-sectional qualitative, descriptive study from June 12 to 30, 2020 with the aid of 13 well-educated patients who had survived COVID-19. The results reveal that prior to hospital admission, the main reason that prompted patients to seek care was onset of symptoms of COVID-19, regardless of whether they had been in contact with suspected or confirmed cases. Transmission was mainly believed to have occurred in the community, in the hospital, and during travel. Patient management was punctuated by frequent self-medication with medicinal plants or pharmaceutical drugs. The participants reported a negative perception of hospitalization or home-based management, with several forms of stigmatization, but a positive perception influenced by the satisfactory quality of management in health-care centers. This report of patient experiences could be helpful in improving the management of COVID-19 in Burkina Faso, both in the health-care setting and in home-based care.

An emerging clade of Chikungunya West African genotype discovered in real-time during 2023 outbreak in Senegal.

Chikungunya (CHIKV) is a re-emerging endemic arbovirus in West Africa. Since July 2023, Senegal and Burkina Faso have been experiencing an ongoing outbreak, with over 300 confirmed cases detected so far in the regions of Kédougou and Tambacounda in Senegal, the largest recorded outbreak yet. CHIKV is typically maintained in a sylvatic cycle in Senegal but its evolution and factors contributing to re-emergence are so far unknown in West Africa, leaving a gap in understanding and responding to recurrent epidemics. We produced, in real-time, the first locally-generated and publicly available CHIKV whole genomes in West Africa, to characterize the genetic diversity of circulating strains, along with phylodynamic analysis to estimate time of emergence and population growth dynamics. A novel strain of the West African genotype, phylogenetically distinct from strains circulating in previous outbreaks, was identified. This suggests a likely new spillover from sylvatic cycles in rural Senegal and potential of seeding larger epidemics in urban settings in Senegal and elsewhere.

The burden of the coronavirus disease 2019 virus infection in Burkina Faso: Results from a World Health Organization UNITY population-based, age-stratified sero-epidemiological investigation.

BACKGROUND: This study aimed to estimate the anti-SARS-CoV-2 antibody seroprevalence in the general population of Bobo-Dioulasso and Ouagadougou (Burkina Faso). METHODS: We collected from March to April 2021 blood samples from randomly selected residents in both main cities based on the World Health Organization (WHO) sero-epidemiological investigations protocols and tested them with WANTAI SARS-CoV-2 total antibodies enzyme-linked immunosorbent assay (ELISA) kits intended for qualitative assessment. We also recorded participants' socio-demographic and clinical characteristics and information on exposure to SARS-CoV-2. Data were analysed with descriptive and comparative statistics. RESULTS: We tested 5240 blood samples collected between 03 March and 16 April 2021. The overall test-adjusted seroprevalence for SARS-CoV-2 antibodies was (67.8% [95% CI 65.9-70.2]) (N = 3553/3982). Seroprevalence was highest among participants aged 15-18 years old (74.2% [95% CI 70.5-77.5]) (N = 465/627), compared with those aged 10-14 years old (62.6% [95% CI 58.7-66.4]) (N = 395/631), or those over 18 (67.6% [95% CI 66.2-69.1]) (N = 2693/3982). Approximately 71.0% (601/860) of participants aged 10-18 years old who tested positive for SARS-CoV-2 antibodies experienced no clinical COVID-19 symptoms in the weeks before the survey, compared with 39.3% (1059/2693) among those aged over 18 years old. CONCLUSION: This study reports the results of the first known large serological survey in the general population of Burkina Faso. It shows high circulation of SARS-CoV-2 in the two cities and a high proportion of asymptomatic adolescents. Further studies are needed to identify the SARS-CoV-2 variants and to elucidate the factors protecting some infected individuals from developing clinical COVID-19.

Incidence rate and predictors of COVID-19 in the two largest cities of Burkina Faso - prospective cohort study in 2021 (ANRS-COV13).

BACKGROUND: Early data on COVID-19 (based primarily on PCR testing) indicated a low burden in Sub-Saharan Africa. To better understand this, this study aimed to estimate the incidence rate and identify predictors of SARS-CoV-2 seroconversion in the two largest cities of Burkina Faso. This study is part of the EmulCOVID-19 project (ANRS-COV13). METHODS: Our study utilized the WHO Unity protocol for cohort sero-epidemiological studies of COVID-19 in general population. We conducted random sampling stratified by age group and sex. Individuals aged 10 years and older in the cities of Ouagadougou and Bobo-Dioulasso, Burkina Faso were included and surveyed at 4 time points, each 21 days apart, from March 3 to May 15, 2021. WANTAI SARS-CoV-2 Ab ELISA serological tests were used to detect total antibodies (IgM, IgG) in serum. Predictors were investigated using Cox proportional hazards regression. RESULTS: We analyzed the data from 1399 participants (1051 in Ouagadougou, 348 in Bobo-Dioulasso) who were SARS-CoV-2 seronegative at baseline and had at least one follow-up visit. The incidence rate of SARS-CoV-2 seroconversion was 14.3 cases [95%CI 13.3-15.4] per 100 person-weeks. The incidence rate was almost three times higher in Ouagadougou than in Bobo-Dioulasso (Incidence rate ratio: IRR = 2.7 [2.2-3.2], p < 0.001). The highest incidence rate was reported among women aged 19-59 years in Ouagadougou (22.8 cases [19.6-26.4] per 100 person-weeks) and the lowest among participants aged 60 years and over in Bobo-Dioulasso, 6.3 cases [4.6-8.6] per 100 person-weeks. Multivariable analysis showed that participants aged 19 years and older were almost twice as likely to seroconvert during the study period compared with those aged 10 to 18 years (Hazard ratio: HR = 1.7 [1.3-2.3], p < 0.001). Those aged 10-18 years exhibited more asymptomatic forms than those aged 19 years and older, among those who achieved seroconversion (72.9% vs. 40.4%, p < 0.001). CONCLUSION: The spread of COVID-19 is more rapid in adults and in large cities. Strategies to control this pandemic in Burkina Faso, must take this into account. Adults living in large cities should be the priority targets for vaccination efforts against COVID-19.

HIV Replication Increases the Mitochondrial DNA Content of Plasma Extracellular Vesicles.

Extracellular vesicles (EVs) and their cargo have been studied intensively as potential sources of biomarkers in HIV infection; however, their DNA content, particularly the mitochondrial portion (mtDNA), remains largely unexplored. It is well known that human immunodeficiency virus (HIV) infection and prolonged antiretroviral therapy (ART) lead to mitochondrial dysfunction and reduced mtDNA copy in cells and tissues. Moreover, mtDNA is a well-known damage-associated molecular pattern molecule that could potentially contribute to increased immune activation, oxidative stress, and inflammatory response. We investigated the mtDNA content of large and small plasma EVs in persons living with HIV (PLWH) and its implications for viral replication, ART use, and immune status. Venous blood was collected from 196 PLWH, ART-treated or ART-naïve (66 with ongoing viral replication, ≥20 copies/mL), and from 53 HIV-negative persons, all recruited at five HIV testing or treatment centers in Burkina Faso. Large and small plasma EVs were purified and counted, and mtDNA level was measured by RT-qPCR. Regardless of HIV status, mtDNA was more abundant in large than small EVs. It was more abundant in EVs of viremic than aviremic and control participants and tended to be more abundant in participants treated with Tenofovir compared with Zidovudine. When ART treatment was longer than six months and viremia was undetectable, no variation in EV mtDNA content versus CD4 and CD8 count or CD4/CD8 ratio was observed. However, mtDNA in large and small EVs decreased with years of HIV infection and ART. Our results highlight the impact of viral replication and ART on large and small EVs' mtDNA content. The mechanisms underlying the differential incorporation of mtDNA into EVs and their effects on the surrounding cells warrant further investigation.

Prevention of mother-to-child transmission of HIV at the second immunization visit: a cross-sectional study, Burkina Faso.

Objective: To evaluate the performance of the cascade of activities for prevention of mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV) at the second immunization visit in Burkina Faso. Methods: In a cross-sectional study, we recruited mothers attending the second immunization visit for their infant in 20 health centres of Bobo-Dioulasso city, Burkina Faso over 12 months (2019-2020). We administered a short questionnaire to 14 176 mothers and performed HIV serological tests on mothers who had not been tested in the last 3 months. All mothers were asked about their attendance for antenatal care and HIV rapid testing. HIV-infected mothers were also asked about the timing of their HIV diagnosis, antiretroviral therapy, pre-exposure prophylaxis initiation at birth and infant diagnosis of HIV. Findings: Of 14 136 respondents, 13 738 (97.2%) had at least one HIV serological test in their lifetime. Of 13 078 mothers who were never tested or were HIV-negative, 12 454 (95.2%) were tested during or after their last pregnancy. Among HIV-infected mothers already aware of their status, 110/111 (99.1%) women were on antiretroviral therapy. Among HIV-exposed infants, 84/101 (83.2%) babies received 6 weeks of antiretroviral prophylaxis at birth and 58/110 (52.7%) had a blood sample collected for early infant diagnosis. Only two mothers received their child's test results at the time of the second immunization visit. Four mothers were newly diagnosed as HIV-positive during the study. Conclusion: Collecting data at the second immunization visit, a visit rarely missed by mothers, could be useful for identifying gaps in the PMTCT cascade in settings where mothers are difficult to reach, such as in low-income countries with intermediate or low HIV prevalence.

Screening of Circulation of Usutu and West Nile Viruses: A One Health Approach in Humans, Domestic Animals and Mosquitoes in Burkina Faso, West Africa.

Usutu virus (USUV) and West Nile virus (WNV) are phylogenetically closely related arboviruses. These viruses mainly follow an enzootic cycle involving mosquitoes and birds, but they occasionally infect humans and other mammals, inducing neurotropic disorders. Since the discovery of USUV, only two human cases have been reported in Africa, including one in Burkina Faso in 2004. Since then, no studies have been conducted to measure the extent of the circulation of this virus in Burkina Faso, and no study regarding the circulation of WNV has been conducted. Our study aimed to determine the seroprevalence of USUV and WNV in blood donations and in animals (horses, dogs, chickens and pigeons) and to perform molecular screening in patients with febrile fever and in Culex quinquefasciatus and Aedes aegypti mosquitoes. The prevalence of USUV and WNV was studied by serological (ELISA and microneutralization tests) and molecular analyses (RT-qPCR) of mosquito, dog, domestic bird, horse, and human samples in Burkina Faso between 2019 and 2021. We detected a very active transmission of both viruses in Burkina Faso. WNV and USUV seroprevalence is particularly high in humans (19.16% and 14.17%, respectively) and horses (17.28% and 6.17%). Molecular screening did not detect WNV or USUV in the mosquito or human samples tested. Our study shows an active spread of USUV and WNV in Burkina Faso, especially for WNV. This study highlights the value of developing surveillance programs to better prevent, detect, and alert people to USUV and WNV circulation in both primary and incidental hosts.

Plasma vesicular miR-155 as a biomarker of immune activation in antiretroviral treated people living with HIV.

People living with HIV (PLWH), despite suppression of viral replication with antiretroviral therapy (ART), have high morbidity and mortality due to immune activation and chronic inflammation. Discovering new biomarkers of immune activation status under ART will be pertinent to improve PLWH quality of life when the majority will be treated. We stipulate that plasma large and small extracellular vesicle (EVs) and their microRNA content could be easily measured biomarkers to monitor immune activation in PLWH. Venous blood samples from n = 128 ART-treated PLWH with suppressed viral load (≤ 20 copies/mL) and n = 60 HIV-uninfected participants were collected at five testing or treatment centers of PLWH in Burkina Faso. Large and small plasma EVs were purified, counted, and the mature miRNAs miR-29a, miR-146a, and miR-155 were quantified by RT-qPCR. Diagnostic performances of large and small EVs miRNAs level were evaluated by receiver operating characteristic (ROC) curve analysis and principal component analysis (PCA). Among the EVs microRNA measured, only large EVs miR-155 copies distinguished PLWH with immune activation, with AUC of 0.75 for CD4/CD8 < 1 (95% CI: 0.58-0.91, P = 0.0212), and 0.77 for CD8 T cells ≥ 500/µL (95% CI: 0.63-0.92, P = 0.0096). In addition, PCA results suggest that large EVs miR-155 copies may be a biomarker of immune activation. Since miR-155 may influence immune cell function, its enrichment in large EV subpopulations could be a functional biomarker of immune activation in PLWH on ART. This measure could help to monitor and diagnose the immune activation with more accuracy.

Serological Evidence of Zika Virus Circulation in Burkina Faso.

Zika virus (ZIKV) and dengue virus (DENV) are two closely related members of the Flaviviridae family, both transmitted by mosquitoes of the genus Aedes, and are among the arboviruses most at risk to human health. Burkina Faso has been facing an upsurge in DENV outbreaks since 2013. Unlike DENV, there is no serological evidence of ZIKV circulation in humans in Burkina Faso. The main objective of our study was to determine the seroprevalence of ZIKV and DENV in blood donors in Burkina Faso. A total of 501 donor samples collected in the two major cities of the country in 2020 were first tested by a competitive enzyme-linked immunosorbent assay to detect flavivirus antibodies. Positive sera were then tested using Luminex to detect ZIKV and DENV antibodies and virus-specific microneutralization tests against ZIKV were performed. The ZIKV seroprevalence was 22.75% in the donor samples and we found seropositivity for all DENV-serotypes ranging from 19.56% for DENV-1 to 48.86% for DENV-2. Molecular analyses performed on samples from febrile patients and Aedes aegypti mosquitoes between 2019 and 2021 were negative. Our study showed the important circulation of ZIKV and DENV detected by serology although molecular evidence of the circulation of ZIKV could not be demonstrated. It is essential to strengthen existing arbovirus surveillance in Burkina Faso and more broadly in West Africa by focusing on fevers of unknown origin and integrating vector surveillance to assess the extent of ZIKV circulation and identify the circulating strain. Further studies are needed to better understand the epidemiology of this virus in order to define appropriate prevention and response methods.

Screening for Hepatitis B in partners and children of women positive for surface antigen, Burkina Faso.

Objective: To evaluate the implementation of a screening strategy for the partners and children of pregnant women with hepatitis B virus (HBV) attending antenatal care. Methods: We identified pregnant women positive for HBV surface antigen (HBsAg) at antenatal consultation in Ouagadougou, Burkina Faso. At post-test counselling, women were advised to disclose their HBV status to partners and to encourage their partner and children to be screened for HBsAg. We used multivariable logistic regression to explore factors associated with uptake of screening and HBsAg positivity among family members. Findings: Of 1000 HBsAg-positive women, 436/1000 partners and 215/1281 children were screened. HBsAg was detected in 55 (12.6%) partners and 24 (11.2%) children. After adjusting for confounders, uptake of screening was higher in partners who were married, who attended the woman's first post-test consultation and to whom the woman had disclosed her HBV status. In children, HBsAg positivity was associated with being born before the introduction of infant hepatitis B vaccination in Burkina Faso (not significant in the multivariable analysis), having a mother positive for HBV e-antigen (adjusted OR: 8.57; 95% CI: 2.49-29.48) or having a mother with HBV DNA level ≥ 200 000 IU/mL (OR: 6.83; 95% CI: 1.61-29.00). Conclusion: In low-income countries, the antenatal consultation provides a cost-effective opportunity to identify HBV-infected household contacts and link them to care. Children born before the introduction of infant hepatitis B vaccination and whose mother has higher viral load or infectivity should be a priority for testing and linkage to care.

Vesicular MicroRNA as Potential Biomarkers of Viral Rebound.

Changes in the cellular microRNA (miRNA) expression profile in response to HIV infection, replication or latency have been reported. Nevertheless, little is known concerning the abundance of miRNA in extracellular vesicles (EVs). In the search for a reliable predictor of viral rebound, we quantified the amount of miR-29a, miR-146a, and miR-155 in two types of plasma extracellular vesicles. Venous blood was collected from 235 ART-treated and ART-naive persons living with HIV (85 with ongoing viral replication, ≥20 copies/mL) and 60 HIV-negative participants at five HIV testing or treatment centers in Burkina Faso. Large and small plasma EVs were purified and counted, and mature miRNA miR-29a, miR-146a, and miR-155 were measured by RT-qPCR. Diagnostic performance of miRNA levels in large and small EVs was evaluated by a receiver operating characteristic curve analysis. The median duration of HIV infection was 36 months (IQR 14-117). The median duration of ART was 34 months (IQR 13-85). The virus was undetectable in 63.8% of these persons. In the others, viral load ranged from 108 to 33,978 copies/mL (median = 30,032). Large EVs were more abundant in viremic participants than aviremic. All three miRNAs were significantly more abundant in small EVs in persons with detectable HIV RNA, and their expression levels in copies per vesicle were a more reliable indicator of viral replication in ART-treated patients with low viremia (20-1000 copies/mL). HIV replication increased the production of large EVs more than small EVs. Combined with viral load measurement, quantifying EV-associated miRNA abundance relative to the number of vesicles provides a more reliable marker of the viral status. The expression level as copies per small vesicle could predict the viral rebound in ART-treated patients with undetectable viral loads.

Immunovirological discordance among female sex workers who start antiretroviral therapy in Burkina Faso.

BACKGROUND: In people living with HIV/AIDS (PLWHA), initiation of antiretroviral therapy (ART) leads to sustained effective suppression of viral replication and increasing CD4 + T cell count. However, a fraction of ART-treated patients still fail to reach adequate CD4 + T cell number despite a suppressed viral load (VL), and this phenomenon is defined as immunovirological discordance (IVD). In Africa, several studies have reported immunovirological outcomes of antiretroviral therapy, but little is known about IVD occurrence in Female sex workers (FSW). This study aimed to assess the prevalence of IVD and associated factors among a cohort of HIV infected FSW in Burkina Faso. METHODS: We conducted a cohort study from December 2003 to October 2016. Immunovirological discordance was defined as CD4 + T cell gain < 100 cells/µL despite a suppressed VL (VL < 1000 copies/mL) 12 months after ART initiation. The CD4 + T cells were counted using BD FACSCount™ System and point of care Pima™ CD4 + Analyzer. HIV-1 RNA was quantified by real-time polymerase-chain-reaction assay with the use of the ABI 7000 system. We conducted a logistic regression to identify factors associated with discordant responses. RESULTS: Among the 123 HIV-1 infected FSW having at least 12 months follow-up on ART, 105 (85.4%) achieved HIV-1 RNA suppression. Among the latter 25 gained less than 100 CD4 + T cells within 12 months follow-up. The IVD rate was 23.8% (95%CI 16.04%-33.11%). After adjustment for age, WHO clinical stage and ART regimen including nucleoside/nucleotide reverse transcriptase inhibitors, only baseline CD4 + T cell count between 200 to 350 cells/µL (adjusted OR: 4.15; 95%CI 1.13-15.22) and 350 to 500 cells/µL (adjusted OR: 17.50; 95%CI 2.68-114.31) remain significantly associated with IVD occurrence. CONCLUSIONS: Immunovirological discordance response was common in FSW with proportions close to those observed in the general population. A diagnosis and personalized follow-up of patients who do not achieve full immune reconstitution would make it possible to avoid complications in terms of morbidity and mortality.