Erwan Piriou

Erwan Piriou
Doctors Without Borders · Public Health

PhD (immunology)

About

46
Publications
14,616
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994
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Publications

Publications (46)
Article
Full-text available
Background: Progress toward the global target for 95% virological suppression among those on antiretroviral treatment (ART) is still suboptimal. We describe the viral load (VL) cascade, the incidence of virological failure and associated risk factors among people living with HIV receiving first-line ART in an HIV cohort in Myanmar treated by the M...
Article
Full-text available
Background: Severe febrile illness without a known source (SFWS) is a challenge for clinicians when deciding how to manage a patient, particularly given the wide spectrum of potential aetiologies that contribute to fever. These infections are difficult to distinguish clinically, and accurate diagnosis requires a plethora of diagnostics including b...
Preprint
Full-text available
Background: Severe febrile illness without a known source (SFWS) is a challenge for clinicians when deciding how to manage a patient, particularly given the wide spectrum of potential aetiologies that contribute to fever. These infections are difficult to distinguish clinically, and accurate diagnosis requires a plethora of diagnostics including bl...
Preprint
Full-text available
Background: Severe febrile illness without a known source (SFWS) is a challenge for clinicians when deciding how to manage a patient, particularly given the wide spectrum of potential aetiologies that contribute to fever. These infections are difficult to distinguish clinically, and accurate diagnosis requires a plethora of diagnostics including bl...
Article
Full-text available
Background: Rapid diagnostic tests (RDT) for malaria are common, but their performance varies. Tests using histidine-rich protein 2 (HRP2) antigen are most common, and many have high sensitivity. HRP2 tests can remain positive for weeks after treatment, limiting their specificity and usefulness in high-transmission settings. Tests using Plasmodium...
Article
Full-text available
Background: Sulfadoxine-pyrimethamine (SP) is a cornerstone of malaria chemoprophylaxis and is considered for programmes in the Democratic Republic of Congo (DRC). However, SP efficacy is threatened by drug resistance, that is conferred by mutations in the dhfr and dhps genes. The World Health Organization has specified that intermittent preventiv...
Preprint
Background: Severe febrile illness without a known source (SFWS) is a challenge for clinicians when deciding how to manage a patient, particularly given the wide spectrum of potential aetiologies that contribute to fever. These infections are difficult to distinguish clinically, and accurate diagnosis requires a plethora of diagnostics including bl...
Article
Background: The EBV viral glycoprotein gp350 has been proposed as a candidate antigen for an EBV vaccine. However, the proposed formulations of these vaccines have not taken into account the presence of two unique EBV strains (EBV-1 and EBV-2) present in areas of high incidence of the EBV associated cancer, Burkitt's lymphoma. Methods: In this s...
Article
Full-text available
Background Between 2009 and 2012, malaria cases diagnosed in a Médecins sans Frontières programme have increased fivefold in Baraka, South Kivu, Democratic Republic of the Congo (DRC). The cause of this increase is not known. An in vivo drug efficacy trial was conducted to determine whether increased treatment failure rates may have contributed to...
Article
The combination of Epstein-Barr virus (EBV) infection and high malaria exposure are risk factors for endemic Burkitt lymphoma, and evidence suggests that infants in regions of high malaria exposure have earlier EBV infection and increased EBV reactivation. Here we analysed the longitudinal antibody response to EBV in Kenyan infants with different l...
Article
Full-text available
Rapid diagnostic methods are essential in control of Ebola outbreaks and lead to timely isolation of cases and improved epidemiologic surveillance. Diagnosis during Ebola outbreaks in West Africa has relied on PCR performed in laboratories outside this region. Because time between sampling and PCR results can be considerable, we assessed the feasib...
Data
Technical Appendix. Ebola virus cycle threshold (Ct) for Xpert Ebola Assay (nucleocapsid protein [NP] and glycoprotein [GP] genes) and for routine PCR (NP gene) for samples identified as positive for Ebola virus from 8 patients by Xpert Ebola Assay at Médecins Sans Frontières Donka Ebola Treatment Center, Conakry, Guinea, May–June 2015.
Article
Full-text available
Endemic Burkitt lymphoma is associated with Epstein-Barr virus (EBV) and Plasmodium falciparum coinfection, although how P. falciparum exposure affects the dynamics of EBV infection is unclear. We have used a modeling approach to study EBV infection kinetics in a longitudinal cohort of children living in regions of high and low malaria transmission...
Article
Full-text available
Co-infection with HIV and visceral leishmaniasis is an important consideration in treatment of either disease in endemic areas. Diagnosis of HIV in resource-limited settings relies on rapid diagnostic tests used together in an algorithm. A limitation of the HIV diagnostic algorithm is that it is vulnerable to falsely positive reactions due to cross...
Article
Full-text available
Objective To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results. Methods We collated 25 616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the s...
Article
Full-text available
Objective To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results. Methods We collated 25 616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the s...
Article
Full-text available
Current WHO testing guidelines for resource limited settings diagnose HIV on the basis of screening tests without a confirmation test due to cost constraints. This leads to a potential risk of false positive HIV diagnosis. In this paper, we evaluate the dilution test, a novel method for confirmation testing, which is simple, rapid, and low cost. Th...
Article
Full-text available
Background In Ethiopia a tiebreaker algorithm using 3 rapid diagnostic tests (RDTs) in series is used to diagnose HIV. Discordant results between the first 2 RDTs are resolved by a third `tiebreaker¿ RDT. Médecins Sans Frontières uses an alternate serial algorithm of 2 RDTs followed by a confirmation test for all double positive RDT results. The pr...
Article
The development of endemic Burkitt’s lymphoma (eBL) is closely associated with EBV infection and holoendemic malaria infections. The role of EBV in the development of malignancy has been studied in depth, but there is still little known about the mechanisms by which malaria affects Burkitt’s lymphomagenesis. Activation induced cytidine deaminase (A...
Conference Paper
Full-text available
Background: CD4 testing is required to identify people eligible for antiretroviral therapy. Point-of-care (POC) CD4 testing enables persons who test HIV-positive to be assessed for antiretroviral therapy (ART) eligibility the same day, thus minimizing pre-ART loss to follow-up. Médecins Sans Frontières (MSF) has introduced POC CD4 testing using Pim...
Article
Full-text available
Recent trends to earlier access to anti-retroviral treatment underline the importance of accurate HIV diagnosis. The WHO HIV testing strategy recommends the use of two or three rapid diagnostic tests (RDTs) combined in an algorithm and assume a population is serologically stable over time. Yet RDTs are prone to cross reactivity which can lead to fa...
Article
Full-text available
Background Malaria rapid diagnostic tests (RDTs) are commonly used in Médecins Sans Frontières (MSF) programmes to detect acute malaria infection. Programmes in regions with both Plasmodium falciparum and non-falciparum malaria (i.e. Plasmodium ovale, Plasmodium malariae and Plasmodium vivax) use a three-band P. falciparum/Pan test such as the SD B...
Article
Full-text available
Infection with Epstein-Barr virus (EBV) early in life and repeated malaria exposure have been proposed as risk factors for endemic Burkitt lymphoma (eBL). Infants were enrolled from 2 rural sites in Kenya: the Kisumu District, where malaria transmission is holoendemic and risk for eBL is high, and the Nandi District, where malaria transmission is l...
Data
Absolute lymphocyte counts for the different B cell subpopulations in infants from areas with divergent malaria exposure according to age.
Article
Full-text available
Plasmodium falciparum infection leads to alterations in B cell subset distribution. During infancy, development of peripheral B cell subsets is also occurring. However, it is unknown if infants living a malaria endemic region have alterations in B cell subsets that is independent of an age effect. To evaluate the impact of exposure to P. falciparum...
Article
Full-text available
Endemic Burkitt's lymphoma (BL) is an extranodal tumor appearing predominantly in the jaw in younger children while abdominal tumors predominate with increasing age. Previous studies have identified elevated levels of antibodies to Plasmodium falciparum schizont extracts and Epstein-Barr virus (EBV) viral capsid antigens (VCA) in endemic BL relativ...
Article
To study the long term the effects of chronic exposure to P. falciparum malaria on Epstein–Barr virus (EBV) reactivation in children, EBV-specific antibody levels were measured in a cross-sectional survey of two groups of Kenyan children with divergent malaria exposure, varying in age from 1 to 14 years. A total of 169 children were analyzed within...
Article
We studied simultaneously Epstein-Barr virus (EBV)-specific CD4(+) and CD8(+) T cell responses during and after infectious mononucleosis (IM), using a previously described 12-day stimulation protocol with EBNA1 or BZLF1 peptide pools. Effector function of EBV-specific T cells was determined after restimulation by measuring intracellular interferon-...
Article
After infection with the Epstein - Barr virus, a common gammaherpes virus which infects and persists in the B cells, an equilibrium is established in which newly infected and differentiating B cells are controlled by cytotoxic T cell (CTL) responses. Disturbance of this equilibrium, which can occur in immunocompromised situations, can lead to uncon...
Article
Full-text available
Healthy individuals carry a constant number of Epstein-Barr virus-infected B cells in the peripheral blood over time. Here, we show that interindividual differences in Epstein-Barr virus DNA levels are maintained after HIV infection, providing evidence for the existence of an individual Epstein-Barr virus setpoint. Immune activation may contribute...
Article
Knowledge of the most dominant T-cell epitopes in the context of the local human leukocyte antigen (HLA) background is a prerequisite for the development of an effective HIV vaccine. In 100 Ethiopian subjects, 16 different HLA-A, 23 HLA-B, and 12 HLA-C specificities were observed. Ninety-four percent of the population carried at least 1 of the 5 mo...
Article
Epstein-Barr virus (EBV) is a widespread, persistent herpesvirus that can transform B cells and that is associated with malignant lymphomas. EBV dynamics and specific immunity in human immunodeficiency virus (HIV)–1–infected children are unknown. We found that, in 74% of EBV-seropositive, HIV-1–infected children, EBV DNA loads at the start of highl...
Article
The etiology of infectious mononucleosis is poorly understood and usually detected many weeks after infection. Here, we present a unique case of primary symptomatic EBV infection after kidney transplantation, in whom we analyzed both EBV-specific CD4+ and CD8+ T cells in detail from the moment of infection up to latency. We show that EBV-specific T...
Article
Full-text available
In this study we investigated the long-term effect of highly active antiretroviral therapy (HAART) on HIV-specific CD4+ T-cell responses in comparison with virus-specific CD4+ T-cell responses against the persistent herpes viruses cytomegalovirus (CMV) and Epstein-Barr virus (EBV). To this end, HIV- and herpes virus-specific cellular immune respons...
Article
Full-text available
We previously observed a loss of Epstein-Barr virus (EBV)-specific CD8+ T cells in subjects progressing to EBV-related non-Hodgkin lymphoma (NHL), correlating with loss of CD4+ T cells. The aim of the present study was to determine the role of EBV-specific CD4+ T cells in the development of NHL during chronic HIV infection. To this end, CD4+ and CD...
Article
Full-text available
The incidence of (EBV-related) malignancies in HIV-infected subjects has declined since the introduction of highly active antiretroviral therapy (HAART). To investigate the effect of HAART on EBV infection, we performed a longitudinal analysis of the T cell response to both a latent and a lytic Ag and EBV viral load in 10 subjects from early in HIV...
Article
A lower function of EBV-specific CD8(+) T cells in HIV-infected subjects could be related to a lack of specific CD4(+) T cell help. Therefore, we studied EBV-specific CD4(+) T cells in both healthy donors and untreated or highly active antiretroviral therapy (HAART)-treated HIV-seropositive homosexual men. To this end, PBMC were stimulated with ove...
Article
HLA-B57 has been shown to be associated with long-term asymptomatic HIV-1 infection. To investigate the biological mechanism by which the HLA-B57 allele could protect from HIV-1 disease, we studied both the number of CD8(+) T cells as well as CD8(+) T cell responsiveness directed to different HIV-1 Gag peptides presented by HLA-A2, -B8 or -B57. T c...
Article
Studies in humans have provided evidence that CD8(+) T cells exhibit distinct phenotypical and functional properties dependent on virus specificity. It is not known how these T-cell phenotypes develop over the course of infection. Dynamics and properties of T cells specific for human immunodeficiency virus (HIV), cytomegalovirus (CMV), and Epstein-...
Article
Objective: EBV-specific CD8+ T cells have been extensively studied in various settings, and appear to play a major role in the control of EBV-related malignancies. In contrast, it is still unclear whether EBV-specific CD4+ T cells play a role in vivo. To study this question, an assay was developed to measure the CD4+ T-cell response towards two EBV...
Article
Full-text available
In contrast to the situation in the post-transplant setting, in HIV-infected individuals an elevated EBV load is not predictive of EBV-related malignancies. To study whether a high EBV load is already a normal situation early in HIV infection and is not related to a decrease in immune function over time, we investigated EBV load and EBV-specific CD...

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