Lassa Fever

Background and Aim: There is insufficient information about the successfully managed Lassa fever (LF) patients in Nigeria. This study aimed to utilize the One Health approach to identify the risk factors for LF infection among LF patients who were managed and on follow-up at the Federal Medical Center, Owo, Ondo State, Nigeria. Materials and Methods: A cross-sectional study was done on 101 LF survivors who were managed and on follow-up at the Federal Medical Center. The data were collected using a semi-structured interviewer-administered questionnaire. The respondents were assessed for symptoms and factors that might have predisposed them to LF, and the data were analyzed with SPSS version 23 (IBM Corp., NY, USA). Those who had more than 3 identifiable risks were categorized as high risk. Descriptive statistics were done, and the association between sociodemographic characteristics and high risk was explored using Chi-square test. Results: The median age of the respondents was 33 ye...

Emergence of severe viral infections in recent years and limited availability of antiviral chemotherapeutic agents for prevention and treatment of these infections are among the most common causes of human illness and death. Therefore, there is an urgent need to develop antiviral drugs that have a potentially critical role in the prevention and treatment of various fatal and debilitating viral infections. Triazole derivatives occupy a pivotal position in modern medicinal chemistry and several have found applications as medicines. A large volume of research has been carried out on triazole and their derivatives for antiviral activity and pharmacological importance of this scaffold has been well established. This review is primarily addressed to description of the recent advances in the synthesis and evaluation of triazole derivatives as antiviral agents which may facilitate the development of more potent and effective antiviral agents.

News of infectious diseases, particularly zoonosis, has been ubiquitous in most developing countries since the last few decades. In Nigeria, Lassa fever has become a perennial blight in specific parts of the country with a high crude fatality rate. While most studies have attended to this problem through the medical lens, this study seeks to use a sociological perspective to identify the household determinants of preventive health practices adopted in the rural areas of Ose local government (Ondo State) to avert Lassa fever.
The study specifically documents the household awareness, perception, and knowledge regarding Lassa fever. Also, an assessment of preventive health practices, exposures, and attitudes related to Lassa fever, as well as social relations and treatment pathway of Lassa fever-related symptoms were attempted. The WHO (2016) Lassa fever preventive practice manual was adopted to score the household preventive-health practice. Literatures were reviewed along the stated objectives. And a combination of Health belief Model and Structural-functionalism of Emile Durkheim was employed as the theoretical framework.
The research adopted a descriptive and exploratory-cross-sectional-non-experimental survey design. Data collection was triangulated (combining quantitative and qualitative methods) to make up for the inefficiency of either method. With the aid of Taro Yamane (1973) sample size determination formula, a total of 623 questionnaires was administered and complemented with 12 in-depth interviews, and 1 key informant interview in 7 rural communities of Ose local government. In the absence of a comprehensive sampling frame containing the list of all households in Ondo state, this study espoused a multistage cluster sampling approach because of the large number of potential households in the study area. The quantitative data were analysed through SPSS (Version 20), at univariate (charts and graph), bivariate (Pearson Chi-square, ANOVA, and Pearson Product Monument Correlation) and multivariate (charts, and step-wise linear regression) levels of analysis. The qualitative data were analysed thematically and discussed along with the quantitative results.
The findings revealed that despite the good awareness about Lassa fever in 94% of the households, 90.2% and 85% of them still scored low in general knowledge of Lassa fever and preventive health practices respectively. Also, the level of knowledge (beta=0.17), age (beta=0.05) and level of exposures (beta=0.36) were found to be good predictors of preventive health practices in the study area. In addition, the study discovered that Mastomys natalensis is prevalent in Ose local government, despite the denials of the people. And the factors that could predict the choice of the treatment pathway for Lassa fever-related symptoms were identified. Finally, the study recommends that the NYSC members should be used to co-ordinate a monthly Lassa fever awareness with emphasis on the risk factors, transmission route, preventive practices and symptoms of Lassa fever. A mini infectious diseases test centre with permanent emergency lines which can be reachable anytime and at no cost should also be put in place in endemic places to hasten response to outbreaks and contain the spread on time.

Lassa and Ebola viruses cause acute, often fatal, hemorrhagic fever diseases, for which no effective vaccines are currently available. Although lethal human disease outbreaks have been confined so far to sub-Saharan Africa, they also pose significant epidemiological concern worldwide as demonstrated by several instances of accidental importation of the viruses into North America and Europe. In the present study, we developed experimental individual vaccines for Lassa virus and bivalent vaccines for Lassa and Ebola viruses that are based on an RNA replicon vector derived from an attenuated strain of Venezuelan equine encephalitis virus. The Lassa and Ebola virus genes were expressed from recombinant replicon RNAs that also encoded the replicase function and were capable of efficient intracellular self-amplification. For vaccinations, the recombinant replicons were incorporated into virus-like replicon particles. Guinea pigs vaccinated with particles expressing Lassa virus nucleoprotein or glycoprotein genes were protected from lethal challenge with Lassa virus. Vaccination with particles expressing Ebola virus glycoprotein gene also protected the animals from lethal challenge with Ebola virus. In order to evaluate a single vaccine protecting against both Lassa and Ebola viruses, we developed dual-expression particles that expressed glycoprotein genes of both Ebola and Lassa viruses. Vaccination of guinea pigs with either dual-expression particles or with a mixture of particles expressing Ebola and Lassa virus glycoprotein genes protected the animals against challenges with Ebola and Lassa viruses. The results showed that immune responses can be induced against multiple vaccine antigens coexpressed from an alphavirus replicon and suggested the possibility of engineering multivalent vaccines based upon alphavirus vectors for arenaviruses, filoviruses, and possibly other emerging pathogens.

The purpose was to establish simple statistics of the effects of lassa fever in northern part of
Edo State, Nigeria. Lassa fever activity in the northern part of Edo state, Nigeria, was confirmed
in 2004 by laboratory analysis of samples sent to Bernhard–Nocht Institute (BNI) for Tropical
Medicine Hamburg, Germany. The published report of that study is re-analysed to determine
in statistical terms, what the values presented in percentages translate to in number of persons
in the hospital and the area. In the year 2004, 12,000 persons presented with febrile illness at
Irrua Specialist Teaching Hospital (ISTH), Irrua; 832 (6.5%) had lassa fever confirmed by reversetranscriptase-
polymerase chain reaction (RT-PCR). 4,096 (32.26%) of those with febrile illness
had acute infection as they tested positive for IgM antibody. 333 (33.33%) of about 1000 staff
of the hospital had sub-clinical infection as they tested positive for IgG and negative for IgM
antibody. At least 208 of the 832 patients (25%) of the hospital with confirmed lassa fever must
have died in the year 2004. 967 (5.9%) of relatives or members of the public who had contact with
infected persons had confirmed lassa fever. 555 (66.67%) of those with confirmed lassa fever
are close relatives. The epidemics occur in clusters of households, houses, streets or villages. It
is concluded that high lassa fever activity in the area has wider effects than what is observed
in hospital admitted patients. Further seroepidemiological survey involving large population
sample in the area should be carried out to establish more accurate seroepidemiological data
on lassa fever. This study is expected to impact positively on the generation of political priority
for the control of lassa fever in Nigeria.
[Afr J Health Sci. 2010; 16:52-56]

Introduction: Lassa fever (LF) is a communicable viral haemorrhagic disease. Person-to-person spread occurs by inhalation or direct contact with the bodily fluids of an infected patient. Infection Prevention and Control (IPC) is essential in healthcare facilities for the wellbeing and safety of patients, staff and visitors. Federal Teaching Hospital, Abakaliki is the designated treatment center for LF in Ebonyi State. We assessed IPC practices in this facility during the 2018 outbreak of LF involving healthcare workers.

Background: Lassa fever is a viral haemorrhagic disease, endemic in West Africa, and with great potential for nosocomial spread. Objectives: The study set out to assess the knowledge and serostatus of Lassa fever among health workers in an Esan West LGA of Edo State, South-South Nigeria. Methods: A descriptive cross-sectional study was carried out among 150 consenting Primary health care and secondary health workers using pre-tested structured intervieweradministered questionnaires and phlebotomy for data collection. ELISA was used to assess for Lassa virus-specific IgM and IgG antibodies. Results: One hundred and forty-two (94.7%) respondents were aware of Lassa fever, with 50 (33.3%) of the respondents having poor knowledge, 44 (29.3%) fair knowledge, and 56 (37.3%) good knowledge. Knowledge was significantly associated with respondents’ designation (p < 0.001), sex (p = 0.02), and age (p = 0.01). The prevalence of IgG was found to be 50.7%, with no IgM detected. IgG seropositi...

This paper argues that addressing the underlying structural drivers of disease vulnerability is essential for a 'One Health' approach to tackling zoonotic diseases in Africa. Through three case studies-trypanosomiasis in Zimbabwe, Ebola and Lassa fever in Sierra Leone and Rift Valley fever in Kenya-we show how political interests, commercial investments and conflict and securitization all generate patterns of vulnerability, reshaping the political ecology of disease landscapes, influencing traditional coping mechanisms and affecting health service provision and outbreak responses. A historical, political economy approach reveals patterns of 'structural violence' that reinforce inequalities and marginalization of certain groups, increasing disease risks. Addressing the politics of One Health requires analysing trade-offs and conflicts between interests and visions of the future. For all zoonotic diseases economic and political dimensions are ultimately critical and On...

The family Arenaviridae, genus Arenavirus, consists of two phylogenetically independent groups: Old World (OW) and New World (NW) complexes. The Lassa and Lujo viruses in the OW complex and the Guanarito, Junin, Machupo, Sabia, and Chapare viruses in the NW complex cause viral hemorrhagic fever (VHF) in humans, leading to serious public health concerns. These viruses are also considered potential bioterrorism agents. Therefore, it is of great importance to detect these pathogens rapidly and specifically in order to minimize the risk and scale of arenavirus outbreaks. However, these arenaviruses are classified as BSL-4 pathogens, thus making it difficult to develop diagnostic techniques for these virus infections in institutes without BSL-4 facilities. To overcome these difficulties, antibody detection systems in the form of an enzyme-linked immunosorbent assay (ELISA) and an indirect immunofluorescence assay were developed using recombinant nucleoproteins (rNPs) derived from these v...

The Lassa virus (an arenavirus) is found in West Africa, where it sometimes causes a severe hemorrhagic illness called Lassa fever. Laboratory diagnosis has traditionally been by the indirect fluorescent-antibody (IFA) test. However, enzyme-linked immunosorbent assays (ELISAs) for Lassa virus antigen and immunoglobulin M (IgM) and G (IgG) antibodies have been developed that are thought to be more sensitive and specific. We compared ELISA and IFA testing on sera from 305 suspected cases of Lassa fever by using virus isolation with a positive reverse transcription-PCR (RT-PCR) test as the "gold standard." Virus isolation and RT-PCR were positive on 50 (16%) of the 305 suspected cases. Taken together, Lassa virus antigen and IgM ELISAs were 88% (95% confidence interval [CI], 77 to 95%) sensitive and 90% (95% CI, 88 to 91%) specific for acute infection. Due to the stringent gold standard used, these likely represent underestimates. Diagnosis could often be made on a single ser...

The objective was to develop a case-pattern model for Lassa fever (LF) among humans and derive predictors of time-trend point distribution of LF cases in Liberia in view of the prevailing under-reporting and public health challenge posed by the disease in the country. A retrospective 5 years data of LF distribution countrywide among humans were used to train a time-trend model of the disease in Liberia. A time-trend quadratic model was selected due to its goodness-of-fit (R2 = 0.89, and P < 0.05) and best performance compared to linear and exponential models. Parameter predictors were run on least square method to predict LF cases for a prospective 5 years period, covering 2013-2017. The two-stage predictive model of LF case-pattern between 2013 and 2017 was characterized by a prospective decline within the South-coast County of Grand Bassa over the forecast period and an upward case-trend within the Northern County of Nimba. Case specific exponential increase was predicted for t...

Lassa fever is a zoonotic disease endemic in West Africa but with no previous case reported in Ghana. We describe the first two laboratory confirmed cases of Lassa fever from the Ashanti Region of Ghana detected in October and December, 2011.

Many emerging infections are RNA virus spillovers from animal reservoirs. Reservoir identification is necessary for predicting the geographic extent of infection risk, but rarely are taxonomic levels below the animal species considered as reservoir, and only key circumstances in nature and methodology allow intrinsic virus-host associations to be distinguished from simple geographic (co-)isolation. We sampled and genetically characterized in detail a contact zone of two subtaxa of the rodent Mastomys natalensis in Tanzania. We find two distinct arenaviruses, Gairo and Morogoro virus, each spatially confined to a single M. natalensis subtaxon, only co-occurring at the contact zone's centre. Inter-subtaxon hybridization at this centre and a continuum of quality habitat for M. natalensis show that both viruses have the ecological opportunity to spread into the other substaxon's range, but do not, strongly suggesting host-intrinsic barriers. Such barriers could explain why human...