ABSTRACT
Little is known about respiratory viruses infection in Guinea. Influenza surveillance has not been implemented in Guinea mainly because of the paucity of laboratory infrastructure and capacity. This paper presents the first influenza surveillance data in Guinea.Swabs were obtained from August 2018 through December 2019 at influenza sentinel sites and transported to the Institut National de Santé Publique for testing. Ribonucleic acid was extracted and tested for the presence of influenza A and B by real-time reverse transcription-polymerase chain reaction (RT-PCR). Positive samples were further characterised to determine the subtypes and lineages of influenza viruses.A total of 862 swabs were collected and tested. Twenty-three per cent of samples tested positive for influenza A and B viruses. Characterisation of positive specimens identified influenza A/H1N1pmd09 (2.5%), influenza A/H3N2 (57.3%), influenza B/Victoria lineage (36.7%) and 7 (3.5%) influenza B with undetermined lineage. Influenza B virus activity clustered in August through November while influenza A/H3N2 displayed two clusters of activities that appeared in May through August and November through December.For the first time in Guinea, the epidemiology, diversity and period of circulation of influenza viruses were studied. The results indicate the predominance and the periods of activities of influenza B Victoria lineage and influenza A/H3N2 which are important information for preventive strategies. It is warranted to extend the influenza surveillance to other parts of Guinea to better understand the epidemiology of the viruses and monitor the emergence of influenza strains with pandemic potential.
Subject(s)
Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza A Virus, H3N2 Subtype/isolation & purification , Influenza B virus/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Epidemiological Monitoring , Guinea/epidemiology , Humans , SeasonsABSTRACT
An epidemic of Ebola virus disease of unprecedented scale has been ongoing for more than a year in West Africa. As of 29 April 2015, there have been 26,277 reported total cases (of which 14,895 have been laboratory confirmed) resulting in 10,899 deaths. The source of the outbreak was traced to the prefecture of Guéckédou in the forested region of southeastern Guinea. The virus later spread to the capital, Conakry, and to the neighbouring countries of Sierra Leone, Liberia, Nigeria, Senegal and Mali. In March 2014, when the first cases were detected in Conakry, the Institut Pasteur of Dakar, Senegal, deployed a mobile laboratory in Donka hospital to provide diagnostic services to the greater Conakry urban area and other regions of Guinea. Through this process we sampled 85 Ebola viruses (EBOV) from patients infected from July to November 2014, and report their full genome sequences here. Phylogenetic analysis reveals the sustained transmission of three distinct viral lineages co-circulating in Guinea, including the urban setting of Conakry and its surroundings. One lineage is unique to Guinea and closely related to the earliest sampled viruses of the epidemic. A second lineage contains viruses probably reintroduced from neighbouring Sierra Leone on multiple occasions, while a third lineage later spread from Guinea to Mali. Each lineage is defined by multiple mutations, including non-synonymous changes in the virion protein 35 (VP35), glycoprotein (GP) and RNA-dependent RNA polymerase (L) proteins. The viral GP is characterized by a glycosylation site modification and mutations in the mucin-like domain that could modify the outer shape of the virion. These data illustrate the ongoing ability of EBOV to develop lineage-specific and potentially phenotypically important variation.
Subject(s)
Ebolavirus/genetics , Genetic Variation/genetics , Hemorrhagic Fever, Ebola/epidemiology , Hemorrhagic Fever, Ebola/virology , Mutation/genetics , Phylogeny , Ebolavirus/isolation & purification , Evolution, Molecular , Genome, Viral/genetics , Glycoproteins/genetics , Glycoproteins/metabolism , Glycosylation , Guinea/epidemiology , Hemorrhagic Fever, Ebola/transmission , Humans , Mali/epidemiology , Molecular Sequence Data , Mucins/chemistry , Nucleocapsid Proteins , Nucleoproteins/genetics , Protein Structure, Tertiary/genetics , RNA-Dependent RNA Polymerase/genetics , Sierra Leone/epidemiology , Viral Core Proteins/geneticsABSTRACT
To clarify the role of bats in the ecology of Ebola viruses, we assessed the prevalence of Ebola virus antibodies in a large-scale sample of bats collected during 2015-2017 from countries in Africa that have had previous Ebola outbreaks (Guinea, the Democratic Republic of the Congo) or are at high risk for outbreaks (Cameroon). We analyzed 4,022 blood samples of bats from >12 frugivorous and 27 insectivorous species; 2-37 (0.05%-0.92%) bats were seropositive for Zaire and 0-30 (0%-0.75%) bats for Sudan Ebola viruses. We observed Ebola virus antibodies in 1 insectivorous bat genus and 6 frugivorous bat species. Certain bat species widespread across Africa had serologic evidence of Zaire and Sudan Ebola viruses. No viral RNA was detected in the subset of samples tested (n = 665). Ongoing surveillance of bats and other potential animal reservoirs are required to predict and prepare for future outbreaks.
Subject(s)
Animal Diseases/epidemiology , Animal Diseases/virology , Chiroptera/virology , Ebolavirus , Hemorrhagic Fever, Ebola/veterinary , Animal Diseases/history , Animal Diseases/immunology , Animals , Antibodies, Viral , Cameroon/epidemiology , Democratic Republic of the Congo/epidemiology , Disease Outbreaks , Ebolavirus/classification , Ebolavirus/genetics , Ebolavirus/immunology , Geography, Medical , Guinea/epidemiology , History, 21st Century , Public Health Surveillance , Seroepidemiologic StudiesABSTRACT
BACKGROUND: In March 2014, the World Health Organization was notified of an outbreak of Zaire ebolavirus in a remote area of Guinea. The outbreak then spread to the capital, Conakry, and to neighboring countries and has subsequently become the largest epidemic of Ebola virus disease (EVD) to date. METHODS: From March 25 to April 26, 2014, we performed a study of all patients with laboratory-confirmed EVD in Conakry. Mortality was the primary outcome. Secondary outcomes included patient characteristics, complications, treatments, and comparisons between survivors and nonsurvivors. RESULTS: Of 80 patients who presented with symptoms, 37 had laboratory-confirmed EVD. Among confirmed cases, the median age was 38 years (interquartile range, 28 to 46), 24 patients (65%) were men, and 14 (38%) were health care workers; among the health care workers, nosocomial transmission was implicated in 12 patients (32%). Patients with confirmed EVD presented to the hospital a median of 5 days (interquartile range, 3 to 7) after the onset of symptoms, most commonly with fever (in 84% of the patients; mean temperature, 38.6°C), fatigue (in 65%), diarrhea (in 62%), and tachycardia (mean heart rate, >93 beats per minute). Of these patients, 28 (76%) were treated with intravenous fluids and 37 (100%) with antibiotics. Sixteen patients (43%) died, with a median time from symptom onset to death of 8 days (interquartile range, 7 to 11). Patients who were 40 years of age or older, as compared with those under the age of 40 years, had a relative risk of death of 3.49 (95% confidence interval, 1.42 to 8.59; P=0.007). CONCLUSIONS: Patients with EVD presented with evidence of dehydration associated with vomiting and severe diarrhea. Despite attempts at volume repletion, antimicrobial therapy, and limited laboratory services, the rate of death was 43%.
Subject(s)
Dehydration/etiology , Hemorrhagic Fever, Ebola/complications , Hemorrhagic Fever, Ebola/mortality , Adult , Age Factors , Anti-Infective Agents/therapeutic use , Diarrhea/etiology , Ebolavirus , Epidemics , Female , Fever/etiology , Fluid Therapy , Guinea/epidemiology , Hemorrhagic Fever, Ebola/epidemiology , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Risk , Survival Rate , Tachycardia/etiology , Vomiting/etiologyABSTRACT
In March 2014, the World Health Organization was notified of an outbreak of a communicable disease characterized by fever, severe diarrhea, vomiting, and a high fatality rate in Guinea. Virologic investigation identified Zaire ebolavirus (EBOV) as the causative agent. Full-length genome sequencing and phylogenetic analysis showed that EBOV from Guinea forms a separate clade in relationship to the known EBOV strains from the Democratic Republic of Congo and Gabon. Epidemiologic investigation linked the laboratory-confirmed cases with the presumed first fatality of the outbreak in December 2013. This study demonstrates the emergence of a new EBOV strain in Guinea.
Subject(s)
Disease Outbreaks , Ebolavirus/genetics , Hemorrhagic Fever, Ebola/epidemiology , Adolescent , Adult , Base Sequence , Child , Ebolavirus/classification , Ebolavirus/isolation & purification , Female , Guinea/epidemiology , Hemorrhagic Fever, Ebola/virology , Humans , Male , Phylogeny , RNA, Viral/analysis , Young AdultABSTRACT
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 feasibility and added value of using the Xpert Ebola Assay in an Ebola control program in Guinea. A total of 218 samples were collected during diagnosis, treatment, and convalescence of patients. Median time for obtaining results was reduced from 334 min to 165 min. Twenty-six samples were positive for Ebola virus. Xpert cycle thresholds were consistently lower, and 8 (31%) samples were negative by routine PCR. Several logistic and safety issues were identified. We suggest that implementation of the Xpert Ebola Assay under programmatic conditions is feasible and represents a major advance in diagnosis of Ebola virus disease without apparent loss of assay sensitivity.
Subject(s)
Ebolavirus/genetics , Hemorrhagic Fever, Ebola/diagnosis , Hemorrhagic Fever, Ebola/virology , Molecular Typing/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Genes, Viral , Guinea , Hemorrhagic Fever, Ebola/epidemiology , Hemorrhagic Fever, Ebola/prevention & control , Humans , Male , Middle Aged , Molecular Typing/standards , RNA, Viral , Reproducibility of Results , Sensitivity and Specificity , Young AdultABSTRACT
The prevalence and consequences of malaria among infants are not well characterized and may be underestimated. A better understanding of the risk for malaria in early infancy is critical for drug development and informed decision making. In a cross-sectional survey in Guinea, The Gambia, and Benin, countries with different malaria transmission intensities, the overall prevalence of malaria among infants <6 months of age was 11.8% (Guinea, 21.7%; The Gambia, 3.7%; and Benin, 10.2%). Seroprevalence ranged from 5.7% in The Gambia to 41.6% in Guinea. Mean parasite densities in infants were significantly lower than those in children 1-9 years of age in The Gambia (p<0.0001) and Benin (p = 0.0021). Malaria in infants was significantly associated with fever or recent history of fever (p = 0.007) and anemia (p = 0.001). Targeted preventive interventions, adequate drug formulations, and treatment guidelines are needed to address the sizeable prevalence of malaria among young infants in malaria-endemic countries.
Subject(s)
Malaria, Falciparum/epidemiology , Adolescent , Antibodies, Protozoan/blood , Benin/epidemiology , Child , Child, Preschool , Cross-Sectional Studies , Endemic Diseases , Gambia/epidemiology , Guinea/epidemiology , Humans , Infant , Infant, Newborn , Malaria, Falciparum/immunology , Malaria, Falciparum/transmission , Prevalence , Seroepidemiologic StudiesABSTRACT
BACKGROUND: The case fatality ratio (CFR) of Ebola virus disease (EVD) can vary over time and space for reasons that are not fully understood. This makes it difficult to define the baseline CFRs needed to evaluate treatments in the absence of randomized controls. Here, we investigate whether viremia in EVD patients may be used to evaluate baseline EVD CFRs. METHODS AND FINDINGS: We analyzed the laboratory and epidemiological records of patients with EVD confirmed by reverse transcription PCR hospitalized in the Conakry area, Guinea, between 1 March 2014 and 28 February 2015. We used viremia and other variables to model the CFR. Data for 699 EVD patients were analyzed. In the week following symptom onset, mean viremia remained stable, and the CFR increased with viremia, V, from 21% (95% CI 16%-27%) for low viremia (V < 104.4 copies/ml) to 53% (95% CI 44%-61%) for intermediate viremia (104.4 ≤ V < 105.2 copies/ml) and 81% (95% CI 75%-87%) for high viremia (V ≥ 105.2 copies/ml). Compared to adults (15-44 y old [y.o.]), the CFR was larger in young children (0-4 y.o.) (odds ratio [OR]: 2.44; 95% CI 1.02-5.86) and older adults (≥ 45 y.o.) (OR: 2.84; 95% CI 1.81-4.46) but lower in children (5-14 y.o.) (OR: 0.46; 95% CI 0.24-0.86). An order of magnitude increase in mean viremia in cases after July 2014 compared to those before coincided with a 14% increase in the CFR. Our findings come from a large hospital-based study in Conakry and may not be generalizable to settings with different case profiles, such as with individuals who never sought care. CONCLUSIONS: Viremia in EVD patients was a strong predictor of death that partly explained variations in CFR in the study population. This study provides baseline CFRs by viremia group, which allow appropriate adjustment when estimating efficacy in treatment studies. In randomized controlled trials, stratifying analysis on viremia groups could reduce sample size requirements by 25%. We hypothesize that monitoring the viremia of hospitalized patients may inform the ability of surveillance systems to detect EVD patients from the different severity strata.
Subject(s)
Ebolavirus/physiology , Hemorrhagic Fever, Ebola/mortality , Viremia/mortality , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cohort Studies , Female , Guinea/epidemiology , Hemorrhagic Fever, Ebola/epidemiology , Hemorrhagic Fever, Ebola/virology , Humans , Infant , Infant, Newborn , Male , Middle Aged , Retrospective Studies , Time Factors , Viremia/epidemiology , Viremia/virology , Young AdultABSTRACT
In the absence of a vaccine or specific treatments for Ebola virus disease (EVD), early identification of cases is crucial for the control of EVD epidemics. We evaluated a new extraction kit (SpeedXtract (SE), Qiagen) on sera and swabs in combination with an improved diagnostic reverse transcription recombinase polymerase amplification assay for the detection of Ebola virus (EBOV-RT-RPA). The performance of combined extraction and detection was best for swabs. Sensitivity and specificity of the combined SE and EBOV-RT-RPA were tested in a mobile laboratory consisting of a mobile glovebox and a Diagnostics-in-a-Suitcase powered by a battery and solar panel, deployed to Matoto Conakry, Guinea as part of the reinforced surveillance strategy in April 2015 to reach the goal of zero cases. The EBOV-RT-RPA was evaluated in comparison to two real-time PCR assays. Of 928 post-mortem swabs, 120 tested positive, and the combined SE and EBOV-RT-RPA yielded a sensitivity and specificity of 100% in reference to one real-time RT-PCR assay. Another widely used real-time RT-PCR was much less sensitive than expected. Results were provided very fast within 30 to 60 min, and the field deployment of the mobile laboratory helped improve burial management and community engagement.
Subject(s)
Ebolavirus/isolation & purification , Hemorrhagic Fever, Ebola/diagnosis , Recombinases/metabolism , Reverse Transcriptase Polymerase Chain Reaction/methods , Disease Outbreaks , Early Diagnosis , Ebolavirus/genetics , Guinea , Hemorrhagic Fever, Ebola/virology , Humans , RNA, Viral/analysis , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Reproducibility of Results , Sensitivity and Specificity , Time FactorsABSTRACT
We have discovered the first indigenous African hantavirus, Sangassou virus (SANGV). The virus was isolated from an African wood mouse (Hylomyscus simus), trapped in a forest habitat in Guinea, West Africa. Here, we report on the characterization of the genetic and functional properties of the virus. The complete genome of SANGV was determined and showed typical hantavirus organization. The small (S), medium (M), and large (L) genome segments containing genes encoding nucleocapsid protein, two envelope glycoproteins, and viral polymerase were found to be 1,746, 3,650, and 6,531 nucleotides long, respectively. The exact 5' and 3' termini for all three segments of the SANGV genome were determined and were predicted to form the panhandle structures typical of bunyaviruses. Phylogenetic analyses of all three segment sequences confirmed SANGV as a Murinae-associated hantavirus most closely related to the European Dobrava-Belgrade virus. We showed, however, that SANGV uses ß(1) integrin rather than ß(3) integrin and decay-accelerating factor (DAF)/CD55 as an entry receptor. In addition, we demonstrated a strong induction of type III lambda interferon (IFN-λ) expression in type I IFN-deficient Vero E6 cells by SANGV. These properties are unique within Murinae-associated hantaviruses and make the virus useful in comparative studies focusing on hantavirus pathogenesis.
Subject(s)
Genetic Variation , Hantavirus Infections/veterinary , Murinae/virology , Orthohantavirus/genetics , Orthohantavirus/isolation & purification , Rodent Diseases/virology , Africa , Animals , Base Sequence , Cell Line , Genome, Viral , Orthohantavirus/classification , Hantavirus Infections/virology , Humans , Mice , Molecular Sequence Data , PhylogenyABSTRACT
OBJECTIVES: To assess the public health relevance of Lassa arenavirus and hantavirus infections in a subpopulation of recently febrile patients. METHODS: In a human seroprevalence study, we enrolled 253 participants on the basis of reported high fever during the last 3 months. They represented roughly 20% of the population of Bantou and Tanganya villages. Comprehensive serological screening and confirmatory assays (enzyme-linked immunosorbent assay, immunofluorescence assay, Western blot analysis) with several Lassa virus and hantavirus antigens were used to ensure high specificity and broad detection capacity. RESULTS: We found a Lassa IgG prevalence of 40.3% (102/253) and a hantavirus IgG prevalence of 1.2% (3/253). The Lassa IgM prevalence reached 2.8% (7/253). CONCLUSIONS: High Lassa virus seroprevalence in recently febrile patients indicates that Lassa fever is a significant public health problem in the region. Human hantavirus infections also occur in the region but their public health relevance remains to be determined.
Subject(s)
Coinfection/epidemiology , Hantavirus Infections/epidemiology , Lassa Fever/epidemiology , Adolescent , Adult , Aged , Coinfection/prevention & control , Female , Guinea/epidemiology , Hantavirus Infections/prevention & control , Humans , Lassa Fever/prevention & control , Logistic Models , Male , Mass Screening/methods , Middle Aged , Multivariate Analysis , Seroepidemiologic StudiesABSTRACT
To understand 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) circulation in West Africa, we collected influenza surveillance data from ministries of health and influenza laboratories in 10 countries, including Cameroon, from 4 May 2009 through 3 April 2010. A total of 10,203 respiratory specimens were tested, of which 25% were positive for influenza virus. Until the end of December 2009, only 14% of all detected strains were A(H1N1)pdm09, but the frequency increased to 89% from January through 3 April 2010. Five West African countries did not report their first A(H1N1)pdm09 case until 6 months after the emergence of the pandemic in North America, in April 2009. The time from first detection of A(H1N1)pdm09 in a country to the time of A(H1N1)pdm09 predominance varied from 0 to 37 weeks. Seven countries did not report A(H1N1)pdm09 predominance until 2010. Introduction and transmission of A(H1N1)pdm09 were delayed in this region.
Subject(s)
Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Pandemics , Adult , Africa, Western/epidemiology , Child , Child, Preschool , Humans , Infant , Orthomyxoviridae , Time FactorsABSTRACT
Despite the protection provided by several factors, including maternal antibodies, the burden of malaria in young infants may be higher than previously thought. Infants with congenital or neonatal malaria may have a different clinical presentation than older children, and diagnosis may be confused with other neonatal diseases due to an overlap of clinical manifestations. In addition, there is little information on the use of artemisinin-based combination therapy in young infants. There is the need for a more accurate estimate of the parasite prevalence and the incidence of clinical malaria in infants under 6 months old, as well as a better characterization of risk factors, pharmacokinetic profiles, safety and efficacy of currently available anti-malarial treatments, in order to develop evidence-based treatment guidelines for this population.
Subject(s)
Antimalarials/administration & dosage , Malaria/epidemiology , Malaria/pathology , Antimalarials/pharmacokinetics , Humans , Incidence , Infant , Infant, Newborn , PrevalenceABSTRACT
Information on the replication of viral haemorrhagic fever viruses is not readily available and has never been analysed in a comparative approach. Here, we compared the cell culture growth characteristics of haemorrhagic fever viruses (HFV), of the Arenaviridae, Filoviridae, Bunyaviridae, and Flavivridae virus families by performing quantitative analysis of cell culture supernatants by (i) electron microscopy for the quantification of virus particles, (ii) quantitative real time PCR for the quantification of genomes, and (iii) determination of focus forming units by coating fluorescent antibodies to infected cell monolayers for the quantification of virus infectivity.The comparative analysis revealed that filovirus and RVFV replication results in a surplus of genomes but varying degrees of packaging efficiency and infectious particles. More efficient replication and packaging was observed for Lassa virus, and Dengue virus resulting in a better yield of infectious particles while, YFV turned out to be most efficient with only 4 particles inducing one FFU. For Crimean-Congo haemorrhagic fever virus (CCHFV) a surplus of empty shells was observed with only one in 24 particles equipped with a genome. The complete particles turned out to be extraordinarily infectious.
Subject(s)
Genome, Viral , Hemorrhagic Fevers, Viral/virology , RNA Viruses/growth & development , RNA Viruses/genetics , Virion/growth & development , Virion/genetics , Cell Culture Techniques , Cell Line , Humans , RNA Viruses/ultrastructure , Virion/ultrastructure , Virus CultivationABSTRACT
We recently discovered a novel hantavirus, Sangassou virus, in Guinea, West Africa. Using enzyme-linked immunosorbent assays followed by confirmatory and serotyping assays, we retrospectively detected hantavirus antibodies in 3 (4.4%) of 68 patients with fever of unknown origin in Sangassou village, Forest Guinea. A population-based survey in Forest Guinea (n = 649) found the prevalence of hantavirus antibodies to be 1.2%. Specific neutralizing antibodies against Sangassou virus were demonstrated in serum samples from 2 patients and in 2 serum samples of the serosurvey. Our data allow us to conclude that hantavirus infections may be a significant unrecognized medical problem in at least this part of Africa.
Subject(s)
Antibodies, Viral/blood , Hantavirus Infections/blood , Orthohantavirus/isolation & purification , Antibodies, Neutralizing/blood , Child , Enzyme-Linked Immunosorbent Assay , Female , Guinea/epidemiology , Orthohantavirus/immunology , Hantavirus Infections/epidemiology , Hantavirus Infections/immunology , Hantavirus Infections/transmission , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Retrospective Studies , Seroepidemiologic StudiesABSTRACT
BACKGROUND: Ebola virus emerged in West Africa in December 2013. The ease of mobility, porous borders, and lack of public health infrastructure led to the largest Ebola virus disease (EVD) outbreak to date. INTERVENTION: The 2013 EVD outbreak signalled the need for laboratory diagnostic capabilities in areas without strong public health systems. As part of the United States' Department of Defense response, MRIGlobal was contracted to design, fabricate, equip, deploy, and operate two mobile diagnostic laboratories (MDLs). The first laboratory analysed blood samples from patients in an adjacent Ebola Treatment Centre (ETC) and buccal swabs from the deceased in the community in Moyamba, Sierra Leone. The second laboratory was deployed to support an ETC in Conakry, Guinea. The Department of Defense provided real-time quantitative reverse transcription polymerase chain reaction assays that were deployed and validated on-site. LESSONS LEARNT: Prompt and accurate molecular diagnostics reduced sample turn-around times from over 24 h to under 4 h. Experienced laboratory staff tested up to 110 samples per day and on-site engineering proved necessary for MDL setup and operation. As the Ebola response slowed, the sustainment of the MDLs' operations was prioritised, including staff training and the transition of the MDLs to local governments. Training programmes for local staff were prepared in Sierra Leone and Guinea. RECOMMENDATIONS: The MRIGlobal MDL team significantly contributed to establishing increased laboratory capacity during the EVD outbreak in West Africa. Using the MDLs for molecular diagnosis is highly recommended until more sustainable solutions can be provided.
ABSTRACT
BACKGROUND: The 2013-16 Ebola virus disease epidemic in west Africa caused international alarm due to its rapid and extensive spread resulting in a significant death toll and social unrest within the affected region. The large number of cases provided an opportunity to study the long-term kinetics of Zaire ebolavirus-specific immune response of survivors in addition to known contacts of those infected with the virus. METHODS: In this observational cohort study, we worked with leaders of Ebola virus disease survivor associations in two regions of Guinea, Guéckédou and Coyah, to recruit survivors of Ebola virus disease, contacts from households of individuals known to have had Ebola virus disease, and individuals who were not knowingly associated with infected individuals or had not had Ebola virus disease symptoms to serve as negative controls. We did Zaire ebolavirus glycoprotein-specific T cell analysis on peripheral blood mononuclear cells (PBMCs) on location in Guinea and transported plasma and PBMCs back to Europe for antibody quantification by ELISA, functional neutralising antibody analysis using live Zaire ebolavirus, and T cell phenotype studies. We report on the longitudinal cellular and humoral response among Ebola virus disease survivors and highlight potentially paucisymptomatic infection. FINDINGS: We recruited 117 survivors of Ebola virus disease, 66 contacts, and 23 negative controls. The mean neutralising antibody titre among the Ebola virus disease survivors 3-14 months after infection was 1/174 (95% CI 1/136-1/223). Individual results varied greatly from 1/10 to more than 1/1000 but were on average ten times greater than that induced after 1 month by single dose Ebola virus vaccines. Following reactivation with glycoprotein peptide, the mean T cell responses among 116 Ebola virus disease survivors as measured by ELISpot was 305 spot-forming units (95% CI 257-353). The dominant CD8+ polyfunctional T cell phenotype, as measured among 53 Ebola virus disease survivors, was interferon γ+, tumour necrosis factor+, interleukin-2-, and the mean response was 0·046% of total CD8+ T cells (95% CI 0·021-0·071). Additionally, both neutralising antibody and T cell responses were detected in six (9%) of 66 Ebola virus disease contacts. We also noted that four (3%) of 117 individuals with Ebola virus disease infections did not have circulating Ebola virus-specific antibodies 3 months after infection. INTERPRETATION: The continuous high titre of neutralising antibodies and increased T cell response might support the concept of long-term protective immunity in survivors. The existence of antibody and T cell responses in contacts of individuals with Ebola virus disease adds further evidence to the existence of sub-clinical Ebola virus infection. FUNDING: US Food & Drug Administration, Horizon 2020 EU EVIDENT, Wellcome, UK Department for International Development. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.
Subject(s)
Antibodies, Viral/blood , Ebolavirus/immunology , Hemorrhagic Fever, Ebola/immunology , Survivors/statistics & numerical data , T-Lymphocytes/immunology , Adolescent , Adult , Antibodies, Viral/immunology , Antibodies, Viral/isolation & purification , Child , Child, Preschool , Ebolavirus/pathogenicity , Epidemics , Female , Guinea/epidemiology , Hemorrhagic Fever, Ebola/blood , Hemorrhagic Fever, Ebola/transmission , Hemorrhagic Fever, Ebola/virology , Humans , Immunity, Cellular , Immunity, Humoral , Infant , Infant, Newborn , Longitudinal Studies , Male , Middle Aged , Time Factors , Young AdultABSTRACT
Long-term follow up studies from Ebola virus disease (EVD) survivors (EBOV_S) are lacking. Here, we evaluate immune and gene expression profiles in 35 Guinean EBOV_S from the last West African outbreak, a median of 23 months (IQR [18-25]) after discharge from treatment center. Compared with healthy donors, EBOV_S exhibit increases of blood markers of inflammation, intestinal tissue damage, T cell and B cell activation and a depletion of circulating dendritic cells. All survivors have EBOV-specific IgG antibodies and robust and polyfunctional EBOV-specific memory T-cell responses. Deep sequencing of the genes expressed in blood reveals an enrichment in 'inflammation' and 'antiviral' pathways. Integrated analyses identify specific immune markers associated with the persistence of clinical symptoms. This study identifies a set of biological and genetic markers that could be used to define a signature of "chronic Ebola virus disease (CEVD)".
Subject(s)
Ebolavirus/immunology , Hemorrhagic Fever, Ebola/complications , Hemorrhagic Fever, Ebola/immunology , Immune System Diseases/complications , Immune System Diseases/immunology , Adult , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antiviral Agents/pharmacology , B-Lymphocytes/immunology , Cytokines/blood , Ebolavirus/drug effects , Ebolavirus/genetics , Female , Genetic Markers , Hemorrhagic Fever, Ebola/drug therapy , Hemorrhagic Fever, Ebola/virology , Humans , Immune System Diseases/genetics , Immunoglobulin G/blood , Immunoglobulin G/immunology , Inflammation/genetics , Lymphocyte Activation , Male , Survivors , T-Lymphocytes/immunology , Transcriptome , Young AdultABSTRACT
To guide One Health capacity building efforts in the Republic of Guinea in the wake of the 2014-2016 Ebola virus disease (EVD) outbreak, we sought to identify and assess the existing systems and structures for zoonotic disease detection and control. We partnered with the government ministries responsible for human, animal, and environmental health to identify a list of zoonotic diseases - rabies, anthrax, brucellosis, viral hemorrhagic fevers, trypanosomiasis and highly pathogenic avian influenza - as the country's top priorities. We used each priority disease as a case study to identify existing processes for prevention, surveillance, diagnosis, laboratory confirmation, reporting and response across the three ministries. Results were used to produce disease-specific systems "maps" emphasizing linkages across the systems, as well as opportunities for improvement. We identified brucellosis as a particularly neglected condition. Past efforts to build avian influenza capabilities, which had degraded substantially in less than a decade, highlighted the challenge of sustainability. We observed a keen interest across sectors to reinvigorate national rabies control, and given the regional and global support for One Health approaches to rabies elimination, rabies could serve as an ideal disease to test incipient One Health coordination mechanisms and procedures. Overall, we identified five major categories of gaps and challenges: (1) Coordination; (2) Training; (3) Infrastructure; (4) Public Awareness; and (5) Research. We developed and prioritized recommendations to address the gaps, estimated the level of resource investment needed, and estimated a timeline for implementation. These prioritized recommendations can be used by the Government of Guinea to plan strategically for future One Health efforts, ideally under the auspices of the national One Health Platform. This work demonstrates an effective methodology for mapping systems and structures for zoonotic diseases, and the benefit of conducting a baseline review of systemic capabilities prior to embarking on capacity building efforts.
ABSTRACT
In the wake of the 2014-2016, West Africa Ebola virus disease (EVD) outbreak, the Government of Guinea recognized an opportunity to strengthen its national laboratory system, incorporating capacity and investments developed during the response. The Ministry of Health (MOH) identified creation of a holistic, safe, secure, and timely national specimen referral system as a priority for improved detection and confirmation of priority diseases, in line with national Integrated Disease Surveillance and Response guidelines. The project consisted of two parts, each led by different implementing partners working collaboratively together and with the Ministry of Health: the development and approval of a national specimen referral policy, and pilot implementation of a specimen referral system, modeled on the policy, in three prefectures. This paper describes the successful execution of the project, highlighting the opportunities and challenges of building sustainable health systems capacity during and after public health emergencies, and provides lessons learned for strengthening national capabilities for surveillance and disease diagnosis.