Molecular confirmation of Lassa fever imported into Ghana

Background: Recent reports have shown an expansion of Lassa virus from the area where it was first isolated in Nigeria to other areas of West Africa. Two Ghanaian soldiers on a United Nations peacekeeping mission in Liberia were taken ill with viral haemorrhagic fever syndrome following the death of a sick colleague and were referred to a military hospital in Accra, Ghana, in May 2013. Blood samples from the soldiers and five asymptomatic close contacts were subjected to laboratory investigations.Objective: We report the results of these investigations to highlight the importance of molecular diagnostic applications and the need for heightened awareness about Lassa fever in West Africa.Methods: We used molecular assays on sera from the two patients to identify the causativeorganism. Upon detection of positive signals for Lassa virus ribonucleic material by two differentpolymerase chain reaction assays, sequencing and phylogenetic analyses were performed.Results: The presence of Lassa virus in the soldiers’ blood samples was shown by L-gene segment homology to be the Macenta and las803792 strains previously isolated in Liberia, with close relationships then confirmed by phylogenetic tree construction. The five asymptomatic close contacts were negative for Lassa virus.Conclusions: The Lassa virus strains identified in the two Ghanaian soldiers had molecular epidemiological links to strains from Liberia. Lassa virus was probably responsible for the outbreak of viral haemorrhagic fever in the military camp. These data confirm Lassa fever endemicity in West Africa.

Download Full-text

Blood-Borne Viruses

Tutorial Topics in Infection for the Combined Infection Training Programme ◽

10.1093/oso/9780198801740.003.0034 ◽

2019 ◽

Author(s):

C. Y. William Tong ◽

Mark Hopkins

Keyword(s):

Body Fluid ◽

Healthcare Setting ◽

Needle Stick Injury ◽

Post Exposure Prophylaxis ◽

Lassa Virus ◽

Haemorrhagic Fever ◽

Needle Stick ◽

Viral Haemorrhagic Fever ◽

Human T Cell ◽

Human Immunodeficiency Viruses

Blood- borne viruses (BBVs) are viral infections transmitted by blood or body fluid. In practice, any viral infection that achieves a high viral load in blood or body fluid can be transmitted through exposure to infected biological materials. In western countries, the most significant BBVs are human immunodeficiency viruses (HIV1 and HIV2), hepatitis B virus (HBV) and hepatitis C virus (HCV). Other viruses that can be transmitted by blood and body fluid include human T cell lymphotropic viruses (HTLV1 and HTLV2), cytomegalovirus, West Nile virus and viruses responsible for viral haemorrhagic fever such as Ebola virus, Lassa virus, and Crimean-Congo haemorrhagic fever virus. BBVs are transmitted via exposure to blood and body fluid. Some examples of routes of transmission include: ● Sharing needles in people who inject drugs (PWID); ● Medical re-use of contaminated instruments (common in resource poor settings); ● Sharps injuries in healthcare setting, including in laboratories (less commonly through mucosal exposure); ● Transfusion of blood contaminated with BBVs (failure to screen blood donors); ● Transplantation of organs from BBV-infected donors; ● Sexual exposure to BBV-infected body fluid; and ● Exposure to maternal BBV infection: intrauterine, perinatally, or postnatally. If exposure to a BBV is via a needle stick injury in a healthcare setting, immediate first aid needs to be carried out by gently encouraging bleeding and washing the exposed area with soap and water. Prompt reporting of the incident is required so that an assessment can be done as soon as possible to determine if post-exposure prophylaxis (PEP) is required. The decision may be aided by urgent assessment of source patient infection status. The British Medical Association has issued guidance for testing adults who lack the capacity to consent. In the case of a sexual exposure to a BBV, immediate consultation to a genito-urinary medicine (GUM) clinic is warranted. The risk of transmission of BBVs associated with exposure depends on the nature of the exposure and the body fluid involved. The following factors are important in needle stick injuries: ● Deep percutaneous injury. ● Freshly used sharps. ● Visible blood on sharps.

Download Full-text

Identification of Common CD8+ T Cell Epitopes from Lassa Fever Survivors in Nigeria and Sierra Leone

Journal of Virology ◽

10.1128/jvi.00153-20 ◽

2020 ◽

Vol 94 (12) ◽

Author(s):

Saori Sakabe ◽

Jessica N. Hartnett ◽

Nhi Ngo ◽

Augustine Goba ◽

Mambu Momoh ◽

...

Keyword(s):

T Cell ◽

West Africa ◽

Sierra Leone ◽

T Cell Responses ◽

Lassa Fever ◽

Health Concern ◽

Lassa Virus ◽

T Cell Epitopes ◽

Virus Surface ◽

Cell Responses

ABSTRACT Early and robust T cell responses have been associated with survival from Lassa fever (LF), but the Lassa virus-specific memory responses have not been well characterized. Regions within the virus surface glycoprotein (GPC) and nucleoprotein (NP) are the main targets of the Lassa virus-specific T cell responses, but, to date, only a few T cell epitopes within these proteins have been identified. We identified GPC and NP regions containing T cell epitopes and HLA haplotypes from LF survivors and used predictive HLA-binding algorithms to identify putative epitopes, which were then experimentally tested using autologous survivor samples. We identified 12 CD8-positive (CD8+) T cell epitopes, including epitopes common to both Nigerian and Sierra Leonean survivors. These data should be useful for the identification of dominant Lassa virus-specific T cell responses in Lassa fever survivors and vaccinated individuals as well as for designing vaccines that elicit cell-mediated immunity. IMPORTANCE The high morbidity and mortality associated with clinical cases of Lassa fever, together with the lack of licensed vaccines and limited and partially effective interventions, make Lassa virus (LASV) an important health concern in its regions of endemicity in West Africa. Previous infection with LASV protects from disease after subsequent exposure, providing a framework for designing vaccines to elicit similar protective immunity. Multiple major lineages of LASV circulate in West Africa, and therefore, ideal vaccine candidates should elicit immunity to all lineages. We therefore sought to identify common T cell epitopes between Lassa fever survivors from Sierra Leone and Nigeria, where distinct lineages circulate. We identified three such epitopes derived from highly conserved regions within LASV proteins. In this process, we also identified nine other T cell epitopes. These data should help in the design of an effective pan-LASV vaccine.

Download Full-text

Phylogeography of Lassa Virus in Nigeria

Journal of Virology ◽

10.1128/jvi.00929-19 ◽

2019 ◽

Vol 93 (21) ◽

Cited By ~ 10

Author(s):

Deborah U. Ehichioya ◽

Simon Dellicour ◽

Meike Pahlmann ◽

Toni Rieger ◽

Lisa Oestereich ◽

...

Keyword(s):

West Africa ◽

Case Fatality ◽

Hemorrhagic Fever ◽

Lassa Fever ◽

Future Research ◽

Lassa Virus ◽

Southeastern Part ◽

Data Set ◽

Content Type ◽

Virus Strains

ABSTRACT Lassa virus is genetically diverse with several lineages circulating in West Africa. This study aimed at describing the sequence variability of Lassa virus across Nigeria and inferring its spatiotemporal evolution. We sequenced and isolated 77 Lassa virus strains from 16 Nigerian states. The final data set, including previous works, comprised metadata and sequences of 219 unique strains sampled between 1969 and 2018 in 22 states. Most of this data originated from Lassa fever patients diagnosed at Irrua Specialist Teaching Hospital, Edo State, Nigeria. The majority of sequences clustered with the main Nigerian lineages II and III, while a few sequences formed a new cluster related to Lassa virus strains from Hylomyscus pamfi. Within lineages II and III, seven and five sublineages, respectively, were distinguishable. Phylogeographic analysis suggests an origin of lineage II in the southeastern part of the country around Ebonyi State and a main vector of dispersal toward the west across the Niger River, through Anambra, Kogi, Delta, and Edo into Ondo State. The frontline of virus dispersal appears to be in Ondo. Minor vectors are directed northeast toward Taraba and Adamawa and south toward Imo and Rivers. Lineage III might have spread from northern Plateau State into Kaduna, Nasarawa, Federal Capital Territory, and Bauchi. One sublineage moved south and crossed the Benue River into Benue State. This study provides a geographic mapping of lineages and phylogenetic clusters in Nigeria at a higher resolution. In addition, we estimated the direction and time frame of virus dispersal in the country. IMPORTANCE Lassa virus is the causative agent of Lassa fever, a viral hemorrhagic fever with a case fatality rate of approximately 30% in Africa. Previous studies disclosed a geographical pattern in the distribution of Lassa virus strains and a westward movement of the virus across West Africa during evolution. Our study provides a deeper understanding of the geography of genetic lineages and sublineages of the virus in Nigeria. In addition, we modeled how the virus spread in the country. This knowledge allows us to predict into which geographical areas the virus might spread in the future and prioritize areas for Lassa fever surveillance. Our study not only aimed to generate Lassa virus sequences from across Nigeria but also to isolate and conserve the respective viruses for future research. Both isolates and sequences are important for the development and evaluation of medical countermeasures to treat and prevent Lassa fever, such as diagnostics, therapeutics, and vaccines.

Download Full-text

Predicting the evolution of Lassa Virus endemic area and population at risk over the next decades

10.1101/2021.09.22.461380 ◽

2021 ◽

Author(s):

Raphaëlle Klitting ◽

Liana E. Kafetzopoulou ◽

Wim Thiery ◽

Gytis Dudas ◽

Sophie Gryseels ◽

...

Keyword(s):

At Risk ◽

West Africa ◽

Endemic Area ◽

Hemorrhagic Fever ◽

Lassa Fever ◽

Environmental Data ◽

World Health ◽

Lassa Virus ◽

Viral Genomes ◽

Health Organization

AbstractLassa fever is listed among the diseases that pose the greatest risks to public health by the World Health Organization. This severe viral hemorrhagic fever is caused by Lassa virus, a zoonotic pathogen that repeatedly spills over to humans from its rodent reservoirs. It is currently not known how climate change, transformations in land use, and human population growth could affect the endemic area of this virus, currently limited to parts of West Africa. By exploring the environmental data associated with virus occurrence, we show how temperature, precipitation and the presence of pastures determine ecological suitability for virus circulation. We project that regions in Central and East Africa will likely become suitable for Lassa virus over the next decades and estimate that the total population living in areas suitable for Lassa virus may grow from about 100 million to 700 million by 2070. By analysing geotagged viral genomes, we find that in the event of Lassa virus being introduced into a new suitable region, its spread might remain spatially limited over the first decades. Our results highlight how the endemic area of Lassa virus may expand well beyond West Africa in the next decades due to human impact on the environment, putting hundreds of million more people at risk of infection.

Download Full-text

Management of viral haemorrhagic fever in the Netherlands

Eurosurveillance ◽

10.2807/esm.07.03.00338-en ◽

2002 ◽

Vol 7 (3) ◽

pp. 48-50 ◽

Cited By ~ 9

Author(s):

C Swaan ◽

P- J. van den Broek ◽

S Wijnands ◽

J. E. van Steenbergen

Keyword(s):

The Netherlands ◽

Burkina Faso ◽

Laboratory Tests ◽

Lassa Fever ◽

Haemorrhagic Fever ◽

Notifiable Diseases ◽

Viral Haemorrhagic Fever ◽

Contact Investigation ◽

Discharge From Hospital ◽

Seriously Ill

Two cases of Lassa fever have been reported in the Netherlands since viral haemorrhagic fevers became notifiable diseases in 1978. In 1980, an expatriate from Burkina Faso who was not seriously ill was confirmed by laboratory tests after his discharge from hospital. The second case occured in 2000: the patient died on the 11th day of admission to hospital. The problems we faced in the management of this case and the contact investigation - more than one hundred contacts - highlighted the need for national recommendations in the Netherlands.

Download Full-text

Domestic risk factors for increased rodent abundance in a Lassa fever endemic region of rural Upper Guinea

Scientific Reports ◽

10.1038/s41598-021-00113-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Julia Clark ◽

Laith Yakob ◽

Moussa Douno ◽

Joseph Lamine ◽

N.’Faly Magassouba ◽

...

Keyword(s):

Risk Factors ◽

Regression Analysis ◽

Lassa Fever ◽

Mastomys Natalensis ◽

Haemorrhagic Fever ◽

Endemic Region ◽

Simple Process ◽

Viral Haemorrhagic Fever ◽

Rodent Abundance ◽

Multimammate Rat

AbstractLassa fever (LF) is a viral haemorrhagic fever endemic in West Africa and spread primarily by the multimammate rat, Mastomys natalensis. As there is no vaccine, reduction of rodent-human transmission is essential for disease control. As the household is thought to be a key site of transmission, understanding domestic risk factors for M. natalensis abundance is crucial. Rodent captures in conjunction with domestic surveys were carried out in 6 villages in an area of rural Upper Guinea with high LF endemicity. 120 rodent traps were set in rooms along a transect in each village for three nights, and the survey was administered in each household on the transects. This study was able to detect several domestic risk factors for increased rodent abundance in rural Upper Guinea. Regression analysis demonstrated that having > 8 holes (RR = 1.8 [1.0004–3.2, p = 0.048), the presence of rodent burrows (RR = 2.3 [1.6–3.23, p = 0.000003), and being in a multi-room square building (RR = 2.0 [1.3–2.9], p = 0.001) were associated with increased rodent abundance. The most addressable of these may be rodent burrows, as burrow patching is a relatively simple process that may reduce rodent entry. Further study is warranted to explicitly link domestic rodent abundance to LF risk, to better characterize domestic risk factors, and to evaluate how household rodent-proofing interventions could contribute to LF control.

Download Full-text

Immunoinformatics-Guided Designing of Peptide Vaccine against Lassa Virus with Dynamic and Immune Simulation Studies

10.20944/preprints201909.0076.v2 ◽

2019 ◽

Cited By ~ 1

Author(s):

Sifat Bin Sayed ◽

Zulkar Nain ◽

Faruq Abdullah ◽

Md. Shakil Ahmed khan ◽

Zahurul Haque ◽

...

Keyword(s):

Peptide Vaccine ◽

Lassa Fever ◽

Cell Mediated Immunity ◽

Lassa Virus ◽

Adequate Treatment ◽

Viral Haemorrhagic Fever ◽

Worldwide Population ◽

The Stability

Lassa virus (LASV) is responsible for a type of acute viral haemorrhagic fever referred to as Lassa fever. Lack of adequate treatment and preventive measures against LASV resulted in a high mortality rate in its endemic regions. In this study, a multi-epitope vaccine was designed using immunoinformatics as a prophylactic agent against the virus. Following a rigorous assessment, the vaccine was built using T-cell (NCTL=8 and NHTL=6) and B-cell (NLBL=4) epitopes from each LASV-derived protein with suitable linkers and adjuvant. The physicochemistry, immunogenic potency and safeness of the designed vaccine (~68 kDa) were assessed. In addition, chosen CTL and HTL epitopes of our vaccine showed 97.37% worldwide population coverage. Besides, disulphide engineering also improved the stability of the chimeric vaccine. Molecular docking of our vaccine protein with toll-like receptor (TLR2) showed binding efficiency followed by dynamic simulation for stable interaction. Furthermore, higher levels of cell-mediated immunity and rapid antigen clearance were suggested by immune simulation and repeated-exposure simulation, respectively. Finally, the optimized codons were used in in silico cloning to ensure higher expression within E. coli K12 bacterium. With further assessment both in vitro and in vivo, we believe that our proposed peptide-vaccine would be potential immunogen against Lassa fever.

Download Full-text

Lassa fever infection from West Africa, dynamic and epidemiology of the virus on the population 1969–2019: a systematic review and meta-analysis

10.21203/rs.2.10777/v1 ◽

2019 ◽

Author(s):

Roland Eric YESSINOU ◽

Alain Richi Kamga Waladjo ◽

Dramou Ignace ◽

Justin Adinsi ◽

Elsie Sangnidjo ◽

...

Keyword(s):

West Africa ◽

Meta Analysis ◽

Hospital Staff ◽

Lassa Fever ◽

Lassa Virus ◽

Health Authorities ◽

Review Period ◽

Pooled Prevalence ◽

Public Health Authorities ◽

High Level

Abstract Background Lassa virus (LASV) is a highly prevalent arenavirus that affects two to three million people in West Africa. This rodent borne virus which has serious consequences on the population and hospital staff in endemic areas. In this article, we review prevalence of LASV with a focus on the dynamic and epidemiology of the disease of 1969-2019. What informs on the evolution and the extent of the disease in this at-risk zone in order to prepare response measures in the event of an epidemic. Methods We was conducted a retrospective review through literatures search using the AGORA, PubMed, Science Direct, Scopus, researchgate and Google scholar Database on Lassa fever (LF) from West Africa. A total 34 articles were studied from 11 countries. Studies were categorized by host and country, and meta-analysis conducted to determine pooled prevalence estimates for each category Analysis was done using the metaprop command in STATA version 15 and MetaXL software. Results A total of 18.111 individual samples from 11 countries, described in 34 articles were studied. Meta-analysis of twenty six studies have indicated that the pooled prevalence was 19.0% [95% CI (15.0-23.0%), I2 = 97.93%]. There was a high level of heterogeneity between studies; however, the high prevalence of LASV was noted in several countries as Nigeria (12-42%), followed by Sierra Leone (8-43%), and then Guinea (9-40%). Pooled prevalence of LASV for human in studies conducted over the entire review period was 22.0% [95% CI (17.0-28.0%), I2 = 98.0%]; eighteen studies), while she was 9.0% [95% CI (4.0-15.0%), I2 = 97.0%]; eight studies) for Mastomys spp. Conclusion The knowledge of the geographical distribution and epidemiology may have help for disease control efforts and limit the risk of transmission, both locally and internationally. This study is also important in order to guide interventions, public health authorities and inform on the evolution of the disease and its magnitude in the population.

Download Full-text

Genome Sequence of Lassa Virus Isolated from the First Domestically Acquired Case in Germany

Genome Announcements ◽

10.1128/genomea.00938-16 ◽

2016 ◽

Vol 4 (5) ◽

Cited By ~ 11

Author(s):

Svenja Wolff ◽

Tilman Schultze ◽

Sarah Katharina Fehling ◽

Jan Philipp Mengel ◽

Gerrit Kann ◽

...

Keyword(s):

West Africa ◽

Genome Sequence ◽

Treatment Options ◽

Specific Treatment ◽

Hemorrhagic Fever ◽

Lassa Fever ◽

Lassa Virus ◽

First Case

Lassa virus (LASV) is a zoonotic, hemorrhagic fever-causing virus endemic in West Africa, for which no approved vaccines or specific treatment options exist. Here, we report the genome sequence of LASV isolated from the first case of acquired Lassa fever disease outside of Africa.

Download Full-text