scholarly journals Review of candidate vaccines for the prevention of Lassa fever

2021 ◽  
Vol 66 (2) ◽  
pp. 91-102
Author(s):  
O. D. Popova ◽  
O. V. Zubkova ◽  
T. A. Ozharovskaia ◽  
D. I. Zrelkin ◽  
D. V. Voronina ◽  
...  

The Lassa virus one of the main etiological agent of hemorrhagic fevers in the world: according to WHO estimates, it affects 100,000 to 300,000 people annually, which results in up to 10,000 deaths [1]. Although expansion of Lassa fever caused by this pathogen is mostly limited to the West African countries: Sierra Leone, Liberia, Guinea and Nigeria, imported cases have been historically documented in Europe, the United States of America (USA), Canada, Japan, and Israel [2]. In 2017, WHO included the Lassa virus in the list of priority pathogens in need of accelerated research, development of vaccines, therapeutic agents and diagnostic tools regarding infections they cause [3]. This review describes main technological platforms used for the development of vaccines for the prevention of Lassa fever.

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Junki Maruyama ◽  
John T. Manning ◽  
Elizabeth J. Mateer ◽  
Rachel Sattler ◽  
Natalya Bukreyeva ◽  
...  

ABSTRACT Lassa virus (LASV), a member of the family Arenaviridae, is the causative agent of Lassa fever. Lassa virus is endemic in West African countries, such as Nigeria, Guinea, Liberia, and Sierra Leone, and causes outbreaks annually. Lassa fever onset begins with “flu-like” symptoms and may develop into lethal hemorrhagic disease in severe cases. Although Lassa virus is one of the most alarming pathogens from a public health perspective, there are few licensed vaccines or therapeutics against Lassa fever. The fact that animal models are limited and the fact that mostly laboratory-derived viruses are used for studies limit the successful development of countermeasures. In this study, we demonstrated that the LASV isolate LF2384-NS-DIA-1 (LF2384), which was directly isolated from a serum sample from a fatal human Lassa fever case in the 2012 Sierra Leone outbreak, causes uniformly lethal infection in outbred Hartley guinea pigs without virus-host adaptation. This is the first report of a clinically isolated strain of LASV causing lethal infection in outbred guinea pigs. This novel guinea pig model of Lassa fever may contribute to Lassa fever research and the development of vaccines and therapeutics. IMPORTANCE Lassa virus, the causative agent of Lassa fever, is a zoonotic pathogen causing annual outbreaks in West African countries. Human patients can develop lethal hemorrhagic fever in severe cases. Although Lassa virus is one of the most alarming pathogens from a public health perspective, there are few available countermeasures, such as antiviral drugs or vaccines. Moreover, the fact that animal models are not readily accessible and the fact that mostly laboratory viruses, which have been passaged many times after isolation, are used for studies further limits the successful development of countermeasures. In this study, we demonstrate that a human isolate of Lassa virus causes lethal infection uniformly in Hartley guinea pigs. This novel animal model of Lassa fever may contribute to Lassa fever research and the development of vaccines and therapeutics.


Author(s):  
Liã Bárbara Arruda ◽  
Najmul Haider ◽  
Ayodeji Olayemi ◽  
David Simons ◽  
Deborah Ehichioya ◽  
...  

AbstractLassa fever (LF), a zoonotic illness, represents a public health burden in West African countries where the Lassa virus (LASV) circulates among rodents. Human exposure hinges significantly on LASV ecology, which is in turn shaped by various parameters such as weather seasonality and even virus and rodent-host genetics. Furthermore, human behaviour, despite playing a key role in the zoonotic nature of the disease, critically affects either the spread or control of human-to-human transmission. Previous estimations on LF burden date from the 80s and it is unclear how the population expansion and the improvement on diagnostics and surveillance methods have affected such predictions. Although recent data have contributed to the awareness of epidemics, the real impact of LF in West African communities will only be possible with the intensification of interdisciplinary efforts in research and public health approaches. This review discusses the causes and consequences of LF from a One Health perspective, and how the application of this concept can improve the surveillance and control of this disease in West Africa.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ifeanyi Sunday Onah ◽  
Obiora Cornelius Collins

Lassa fever is an animal-borne acute viral illness caused by Lassa virus. It poses a serious health challenge around the world today, especially in West African countries like Ghana, Benin, Guinea, Liberia, Mali, Sierra Leone, and Nigeria. In this work, we formulate a multiple-patch Lassa fever model, where each patch denotes a socioeconomic class (SEC). Some of the important epidemiological features such as basic reproduction number of the model were determined and analysed accordingly. We further investigated how varying SECs affect the transmission dynamics of Lassa fever. We analysed the required state at which each SEC is responsible in driving the Lassa fever disease outbreak. Sensitivity analyses were carried out to determine the importance of model parameters to the disease transmission and prevalence. We carried out numerical simulation to support our analytical results. Finally, we extend some of the results of the 2-patch model to the general n -patch model.


2019 ◽  
Vol 6 (12) ◽  
Author(s):  
Chiomah Ezeomah ◽  
Adeyi Adoga ◽  
Chikwe Ihekweazu ◽  
Slobodan Paessler ◽  
Irma Cisneros ◽  
...  

Abstract Lassa fever is a zoonotic disease endemic in some West African countries. It is exported to countries in America, Asia, and Europe. Antivirals against Lassa fever are important to provide a cure in patients with the disease and provide protection against it. In addition, due to the potential utilization of Lassa virus as a bioterrorism agent, vaccines against the disease can be utilized as a counterterrorism measure. Developing antiviral compounds and vaccines against the disease requires understanding of the pathogenesis of Lassa fever and its disease course, including the signs, symptoms, complications, and sequelae. An important sequela of Lassa fever is ataxia. A few cases of postviral ataxia following Lassa fever have been described in the literature. This review focuses on highlighting these cases, the gaps in scientific knowledge where further research is needed, and possible ways of diagnosing postviral ataxia after Lassa fever in resource-limited settings.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Dorathy Chinwe Obu ◽  
Obumneme Benaianh Ezeanosike ◽  
Samuel Amechi Nwukor

Lassa fever (LF) is an acute viral hemorrhagic fever caused by the Lassa virus, a zoonotic infection transmitted by the infected multimammate mouse which is endemic in West African countries. It affects all ages contributing to high maternal and neonatal mortality rates. Neonates are at risk of vertical and horizontal transmission of Lassa virus. We report a series of six newborns, three of whom were delivered to Lassa fever positive mothers and were managed as exposed babies while the remaining three were diagnosed with neonatal Lassa fever. None of the babies exposed to the virus became infected and two of these exposed babies had a positive outcome. All the babies with neonatal Lassa fever died days after birth even before confirming the diagnosis and initiating ribavirin treatment. This highlights the need for prompt diagnosis in utero with treatment of mother before delivery to improve the neonatal outcome. Also, the need to commence intravenous ribavirin treatment in highly suspicious cases of neonatal Lassa fever while awaiting confirmation of the diagnosis is emphasized.


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Umaru Bangura ◽  
Jacob Buanie ◽  
Joyce Lamin ◽  
Christopher Davis ◽  
Gédéon Ngiala Bongo ◽  
...  

Lassa fever is a viral hemorrhagic fever caused by the Lassa virus LASV, which was first isolated in the rodent Mastomys natalensis in 1974 in Kenema, Sierra Leone. As little is known about the abundance and the presence of LASV in rodents living in the Bo area, we carried out a small mammal longitudinal population survey. A standardized trapping session was performed in various habitats and seasons in six villages over two years (2014–2016) and samples collected were tested for arenavirus IgG and LASV. A Bayesian phylogenetic analysis was performed on sequences identified by PCR. A total of 1490 small mammals were collected, and 16 rodent species were identified, with M. natalensis (355, 24%) found to be the most prevalent species. Forty-one (2.8%) samples were IgG positive, and 31 of these were trapped in homes and 10 in surrounding vegetation. Twenty-nine of 41 seropositive rodents were M. natalensis. We detected four LASV by PCR in two villages, all found in M. natalensis. Phylogenetic analysis showed that the sequences were distributed within the Sierra Leonean clade within lineage IV, distinguishing a Bo sub-clade older than a Kenema sub-clade. Compared to other settings, we found a low abundance of M. natalensis and a low circulation of LASV in rodents in villages around Bo district.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
A A Gobir ◽  
C L Ejembi ◽  
A A Aliyu ◽  
M B Garba ◽  
C J C Igboanusi ◽  
...  

Abstract Background Lassa fever disease (LFD) is a viral haemorrhagic fever that is endemic in some West african countries where an estimated 300,000 to 500,000 cases and 5000 deaths occur yearly. The World Health Organization described it as a global health threat. At community level, its prevention relies on promoting good “community hygiene”. This study was conducted to assess practice of community hygiene measures against LFD and its associated factors. Methods A cross-sectional, community based descriptive study conducted during a LFD epidemic in a a rural community of Nigeria. An interviewer-administered questionnaire was used to collect data from 556 adult respondents, selected using systematic random sampling technique. Data was analyzed using SPSS. Results A majority of the respondents were females (52.9%). Educational attainment was significantly associated with safe food storage at the multivariate level (aOR= 1.31, 95% CI: 1.10-1.54,P= 0.002) while having a good knowledge of LFD was a significant predictor of maintaining good housing standards (aOR= 3.73, 95% CI: 1.09-12.80,P=0.036). Conclusions Predictors of practice of community hygiene against LFD include education and having an excellent knowledge of LFD. To improve community hygiene practices in the community, there is need for a comprehensive LFD behavior change communication intervention. Key messages Cubing the global threat of LFD depends on its effective prevention in endemic West African communities. This study shows that such preventive measures are poor and there is need for more response to address the problem.


2017 ◽  
Vol 41 (1) ◽  
pp. 279-310 ◽  
Author(s):  
Vaughn W. M. Watson ◽  
Michelle G. Knight-Manuel

Given polarizing popular-media narratives of immigrant youth from West African countries, we construct an interdisciplinary framework engaging a Sankofan approach to analyze education research literature on social processes of navigating identities and engaging civically across immigrant youth’s heritage practices and Indigenous knowledges. In examining social processes, we disrupt three areas of inequalities affecting educational experiences of immigrant youth: (a) homogenizing notions of a monolithic West Africa and immigrant youth’s West African countries, (b) deficit understandings of identities and the heterogeneity of Black immigrant youth from West African countries living in the United States, and (c) singular views of youth’s civic engagement. We provide implications for researchers, policymakers, and educators to better meet youth’s teaching and learning needs.


2021 ◽  
Vol 17 (10) ◽  
pp. e1009966
Author(s):  
Derek R. Stein ◽  
Bryce M. Warner ◽  
Jonathan Audet ◽  
Geoff Soule ◽  
Vinayakumar Siragam ◽  
...  

Nigeria continues to experience ever increasing annual outbreaks of Lassa fever (LF). The World Health Organization has recently declared Lassa virus (LASV) as a priority pathogen for accelerated research leading to a renewed international effort to develop relevant animal models of disease and effective countermeasures to reduce LF morbidity and mortality in endemic West African countries. A limiting factor in evaluating medical countermeasures against LF is a lack of well characterized animal models outside of those based on infection with LASV strain Josiah originating form Sierra Leone, circa 1976. Here we genetically characterize five recent LASV isolates collected from the 2018 outbreak in Nigeria. Three isolates were further evaluated in vivo and despite being closely related and from the same spatial / geographic region of Nigeria, only one of the three isolates proved lethal in strain 13 guinea pigs and non-human primates (NHP). Additionally, this isolate exhibited atypical pathogenesis characteristics in the NHP model, most notably respiratory failure, not commonly described in hemorrhagic cases of LF. These results suggest that there is considerable phenotypic heterogeneity in LASV infections in Nigeria, which leads to a multitude of pathogenesis characteristics that could account for differences between subclinical and lethal LF infections. Most importantly, the development of disease models using currently circulating LASV strains in West Africa are critical for the evaluation of potential vaccines and medical countermeasures.


Author(s):  
Ulrike Gut

This chapter describes the history, role, and structural properties of English in the West African countries the Gambia, Sierra Leone, Liberia, Ghana, Nigeria, the anglophone part of Cameroon, and the island of Saint Helena. It provides an overview of the historical phases of trading contact, British colonization and missionary activities and describes the current role of English in these multilingual countries. Further, it outlines the commonalities and differences in the vocabulary, phonology, morphology, and syntax of the varieties of English spoken in anglophone West Africa. It shows that Liberian Settler English and Saint Helenian English have distinct phonological and morphosyntactic features compared to the other West African Englishes. While some phonological areal features shared by several West African Englishes can be identified, an areal profile does not seem to exist on the level of morphosyntax.


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