scholarly journals Dynamical System Analysis of a Lassa Fever Model with Varying Socioeconomic Classes

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ifeanyi Sunday Onah ◽  
Obiora Cornelius Collins
Keyword(s):  
Disease Transmission ◽  
System Analysis ◽  
Lassa Fever ◽  
West African ◽  
Sensitivity Analyses ◽  
Model Parameters ◽  
Lassa Virus ◽  
African Countries ◽  
Patch Model ◽  
Viral Illness

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.

scholarly journals Knowledge of Lassa Fever Disease and Its Risk Factors Among Rural People in a Nigerian Community

Proceedings ◽  
2020 ◽  
Vol 45 (1) ◽  
pp. 9
Author(s):  
Abdulrazaq Abdullahi Gobir ◽  
Clara Ladi Ejembi ◽  
Aliyu Abubakar Alhaji ◽  
Muhammad Bello Garba ◽  
Chinedu John -Camillus Igboanusi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Rural Areas ◽  
Disease Transmission ◽  
Public Awareness ◽  
Lassa Fever ◽  
Lassa Virus ◽  
African Countries ◽  
Public Health Importance ◽  
Cross Sectional ◽  
Effective Prevention

Introduction: Lassa fever disease (LFD) is an acute viral haemorrhagic fever caused by Lassa virus. It is a disease of public health importance in West Africa and a global health threat. It is endemic in some West African countries like Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria, where an estimated 300,000 to 500,000 cases occur every year with an estimated 5000 annual deaths. Persons living in rural areas and health care workers are at greatest risk. Public awareness and knowledge of the LFD and its risk factors are some of the important factors that determine disease transmission and success of preventive/control efforts. This study was therefore conducted to assess LFD-related awareness and knowledge in Gangara, a rural agrarian community in Giwa Local Government Area of Kuduna State, NorthWest Nigeria. Methods: A cross-sectional, community based descriptive study conducted in Gangara community. An interviewer- administered questionnaire was used to collect data from 556 adult respondents, selected using systematic random sampling technique. Data was analyzed using SPSS (version 20). Results: A majority of the respondents were females (52.9%) with a mean age of 37.0 ± 15.2. The level of awareness of LFD was high (66.7%) among respondents and there was a statistically significant association between awareness of LFD and not having any form of education (P < 0.00). However, most of the respondents (79.0%) have poor knowledge of LFD. Knowledge of risk factors for LFD was also poor with 59.4% not knowing that drying grains and foodstuffs on the ground is a risk factor for LFD. Conclusions: Awareness of the disease was quite high but knowledge of the disease and its risk factors was poor. For effective prevention of future outbreaks, the community needs to be properly educated on LFD and its risk factors.

scholarly journals The niche of One Health approaches in Lassa fever surveillance and control

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Liã Bárbara Arruda ◽  
Najmul Haider ◽  
Ayodeji Olayemi ◽  
David Simons ◽  
Deborah Ehichioya ◽  
...  
Keyword(s):  
Public Health ◽  
One Health ◽  
Population Expansion ◽  
Lassa Fever ◽  
West African ◽  
Lassa Virus ◽  
African Countries ◽  
Rodent Host ◽  
Public Health Burden ◽  
And Control

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.

scholarly journals Lethal Infection of Lassa Virus Isolated from a Human Clinical Sample in Outbred Guinea Pigs without Adaptation

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Junki Maruyama ◽  
John T. Manning ◽  
Elizabeth J. Mateer ◽  
Rachel Sattler ◽  
Natalya Bukreyeva ◽  
...  
Keyword(s):  
Public Health ◽  
Sierra Leone ◽  
Guinea Pigs ◽  
Lassa Fever ◽  
West African ◽  
Lassa Virus ◽  
African Countries ◽  
Successful Development ◽  
Public Health Perspective ◽  
Lethal Infection

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.

scholarly journals Sequelae of Lassa Fever: Postviral Cerebellar Ataxia

2019 ◽  
Vol 6 (12) ◽  
Author(s):  
Chiomah Ezeomah ◽  
Adeyi Adoga ◽  
Chikwe Ihekweazu ◽  
Slobodan Paessler ◽  
Irma Cisneros ◽  
...  
Keyword(s):  
Scientific Knowledge ◽  
Lassa Fever ◽  
West African ◽  
Lassa Virus ◽  
Disease Course ◽  
African Countries ◽  
Resource Limited Settings ◽  
Antiviral Compounds ◽  
Resource Limited ◽  
Bioterrorism Agent

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.

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 ◽  
...  
Keyword(s):  
Sierra Leone ◽  
The United States ◽  
Lassa Fever ◽  
West African ◽  
Diagnostic Tools ◽  
Lassa Virus ◽  
African Countries ◽  
Hemorrhagic Fevers ◽  
Imported Cases ◽  
Technological Platforms

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.

scholarly journals Dynamical System Analysis and Optimal Control Measures of Lassa Fever Disease Model

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Ifeanyi Sunday Onah ◽  
Obiora Cornelius Collins ◽  
Praise-God Uchechukwu Madueme ◽  
Godwin Christopher Ezike Mbah
Keyword(s):  
Optimal Control ◽  
Disease Transmission ◽  
System Analysis ◽  
Disease Model ◽  
Minimum Cost ◽  
Lassa Fever ◽  
Control Measures ◽  
Extended Model ◽  
Lassa Virus ◽  
Intervention Measures

Lassa fever is an animal-borne acute viral illness caused by the Lassa virus. This disease is endemic in parts of West Africa including Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria. We formulate a mathematical model for Lassa fever disease transmission under the assumption of a homogeneously mixed population. We highlighted the basic factors influencing the transmission of Lassa fever and also determined and analyzed the important mathematical features of the model. We extended the model by introducing various control intervention measures, like external protection, isolation, treatment, and rodent control. The extended model was analyzed and compared with the basic model by appropriate qualitative analysis and numerical simulation approach. We invoked the optimal control theory so as to determine how to reduce the spread of the disease with minimum cost.

scholarly journals Case series of outcome of newborn babies exposed to Lassa fever virus infection

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Dorathy Chinwe Obu ◽  
Obumneme Benaianh Ezeanosike ◽  
Samuel Amechi Nwukor
Keyword(s):  
Horizontal Transmission ◽  
Case Series ◽  
Hemorrhagic Fever ◽  
Positive Outcome ◽  
Lassa Fever ◽  
West African ◽  
Lassa Virus ◽  
African Countries ◽  
Lassa Fever Virus ◽  
Prompt Diagnosis

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.

scholarly journals Community hygiene against lassa fever disease and its predictors in a Nigerian rural settlement

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
A A Gobir ◽  
C L Ejembi ◽  
A A Aliyu ◽  
M B Garba ◽  
C J C Igboanusi ◽  
...  
Keyword(s):  
Sampling Technique ◽  
Lassa Fever ◽  
West African ◽  
World Health ◽  
Food Storage ◽  
African Countries ◽  
Cross Sectional ◽  
Effective Prevention ◽  
Viral Haemorrhagic Fever ◽  
Hygiene Measures

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.

scholarly journals Differential pathogenesis of closely related 2018 Nigerian outbreak clade III Lassa virus isolates

2021 ◽  
Vol 17 (10) ◽  
pp. e1009966
Author(s):  
Derek R. Stein ◽  
Bryce M. Warner ◽  
Jonathan Audet ◽  
Geoff Soule ◽  
Vinayakumar Siragam ◽  
...  
Keyword(s):  
Animal Models ◽  
Lassa Fever ◽  
Geographic Region ◽  
World Health ◽  
Limiting Factor ◽  
Lassa Virus ◽  
African Countries ◽  
Animal Models Of Disease ◽  
Medical Countermeasures

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.

scholarly journals Lassa Fever: Viral Replication, Disease Pathogenesis, and Host Immune Modulations

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 437
Author(s):  
Hinh Ly
Keyword(s):  
Lassa Fever ◽  
West African ◽  
Host Factors ◽  
Current Status ◽  
Special Issue ◽  
African Countries ◽  
Disease Pathogenesis ◽  
Virus Life Cycle ◽  
Key Issues ◽  
Made In

Despite major discoveries made in the last few decades about Lassa fever, there are still many unresolved key issues that hamper the development of effective vaccines and therapies against this deadly disease that is endemic in several West African countries. Some of these issues include the lack of a detailed understanding of the viral and participating host factors in completing the virus life cycle, in mediating disease pathogenesis or protection from disease, and in activating or suppressing host innate and cellular immunity against virus infection, as well as of the animal models required for testing vaccines and therapeutics. This Special Issue is devoted to understanding some of these important issues and to exploring the current status of the research and development in combating Lassa fever.

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