ABSTRACT
Background: Lassa fever is an acute viral haemorrhagic disease caused by the Lassa virus (LASV). It is endemic in West Africa and infects about 300,000 people each year, leading to approximately 5000 deaths annually. The development of the LASV vaccine has been listed as a priority by the World Health Organization since 2018. Considering the accelerated development and availability of vaccines against COVID-19, we set out to assess the prospects of LASV vaccines and the progress made so far. Materials and Methods: We reviewed the progress made on twenty-six vaccine candidates listed by Salami et al. (2019) and searched for new vaccine candidates through Google Scholar, PubMed, and DOAJ from June to July 2021. We searched the articles published in English using keywords that included "vaccine" AND "Lassa fever" OR "Lassa virus" in the title/. Results: Thirty-four candidate vaccines were identified - 26 already listed in the review by Salami et al. and an additional 8, which were developed over the last seven years. 30 vaccines are still in the pre-clinical stage while 4 of them are currently undergoing clinical trials. The most promising candidates in 2019 were vesicular stomatitis virus-vectored vaccine and live-attenuated MV/LASV vaccine;both had progressed to clinical trials. Conclusions: Despite the focus on COVID-19 vaccines since 2020, LASV vaccine is under development and continues to make impressive progress, hence more emphasis should be put into exploring further clinical studies related to the most promising types of vaccines identified.
ABSTRACT
The COVID-19 pandemic has severely affected public health system and surveillance of other communicable diseases across the globe. The lockdown, travel constraints and COVID phobia turned down the number of people with illness visiting to the clinics or hospitals. Besides this, the heavy workload of SARS-CoV-2 diagnosis has led to the reduction in differential diagnosis of other diseases. Consequently, it added to the underlying burden of many diseases which remained under-diagnosed. Amidst the pandemic, the rise of emerging and re-emerging infectious diseases was observed worldwide and reported to the World Health Organization i.e., Crimean Congo Hemorrhagic Fever (2022, Iraq;2021 India), Nipah virus (2021, India), Zika virus (2021, India), and H5N1 influenza (2021, India), Monkeypox (2022, multicountry outbreak), Ebola virus disease (2022, DRC, Uganda;2021, DRC, Guinea;2020, DRC), Marburg (2022, Ghana;2021, Guinea), Yellow fever (2022, Uganda, Kenya, West and Central Africa;2021, Ghana, Venezuela, Nigeria;2020, Senegal, Guinea, Nigeria, Gabon;2020, Ethiopia, Sudan, Uganda), Dengue (2022, Nepal, Pakistan, Sao Tome, Temor-Leste;2021, Pakistan), Middle east respiratory syndrome coronavirus (2022, Oman, Qatar;2021, Saudi Arabia, UAE;2020, Saudi Arabia, UAE), Rift valley fever (2021, Kenya;2020, Mauritania), wild poliovirus type 1 (2022, Mozambique), Lassa fever (2022, Guinea, Togo, Nigeria;2020, Nigeria), Avian Influenza (H3N8) (2022, China), Avian Influenza (H5N1) (2022, USA), H10N3 influenza (2021, China), Hepatitis E virus (2022, Sudan), Measles (2022, Malawi, Afghanistan;2020, Burundi, Mexico), Mayaro virus disease (2020, French Guiana), Oropouche virus disease (2020, French Guiana). All these diseases were associated with high morbidity and burdened the public health system during the COVID-19 pandemic. During this critical public health menace, majority of the laboratory workforce was mobilized to the SARS-CoV-2 diagnosis. This has limited the surveillance efforts that likely led to under diagnosis and under-detection of many infectious pathogens. Lockdowns and travel limitations also put a hold on human and animal surveillance studies to assess the prevalence of these zoonotic viruses. In addition, lack of supplies and laboratory personnel and an overburdened workforce negatively impacted differential diagnosis of the diseases. This is especially critical given the common symptoms between COVID-19 and other pathogens causing respiratory illnesses. Additionally, the vaccination programs against various vaccine preventable diseases were also hampered which might have added to the disease burden. Despite these challenges, the world is better prepared to detect and respond to emerging/re-emerging pathogens. India now has more than 3000 COVID-19 diagnostic laboratories and an enhanced hospital infrastructure. In addition, mobile BSL-3 facilities are being validated for onsite sampling and testing in remote areas during outbreak situations and surveillance activities. This will undoubtedly be valuable as the COVID-19 pandemic evolves as well as during future outbreaks and epidemics. In conclusion, an increase in the emergence and re-emergence of viruses demonstrates that other infectious diseases have been neglected during the COVID-19 pandemic. Lessons learned from the infrastructure strengthening, collaborations with multiple stakeholders, increased laboratory and manufacturing capacity, large-scale COVID-19 surveillance, extensive network for laboratory diagnosis, and intervention strategies can be implemented to provide quick, concerted responses against the future threats associated with other zoonotic pathogens.
ABSTRACT
Globalization and high-speed means of transportation contribute to the spread of infections dangerous to humans. Airborne pathogens have pandemic potential as currently shown in case of the novel coronavirus SARS-CoV-2. Natural focal Lassa fever (LF) common in West African countries, in 35 cases was registered in non-endemic geographical areas because any person infected with Lassa virus (LASV) is a long-term source of infection (up to two months). Cases of person-to-person infection in endemic territories are described. In Germany, the facts of secondary virus transmission from patients to doctors have been recorded during the examination and blood collection from an apparently healthy person as well as during the autopsy of a deceased subjects due to severe LF course. Nonspecific malaise symptoms in LF are also characteristic of numerous other diseases common on the African continent, e.g., malaria and typhoid fever or viral infections such as yellow fever, Chikungunya, dengue and Zika, monkey pox and Ebola virus disease. In this regard, there may be similar dermatological manifestations. Timely detection of cases and differential diagnosis are crucial to ensure safe patient care and use of affordable antiviral therapy for LL provided by the drug Ribavirin. Research methods for studying LASV use polymerase chain reaction (PCR) for detecting viral RNA, electron microscopy, isolation of infectious virus cultured sensitive cells, indirect immunofluorescence reaction, enzyme immunoassay (ELISA) and immuno-chromatographic assays for the detection of antibodies and/or antigen as well as immunoblotting. Currently, test kits based on molecular and genetic methods are mainly used for LF laboratory diagnostics. Since the 1980s, ribavirin has been used to treat patients with LF. The serum accumulation of the drug in large quantities causes hemolysis, development of anemia and impaired renal function. In this regard, treatment options are being considered with decline in its concentration due to combined use with other antiviral drugs. A search for new therapeutic agents capable of inhibiting viral replication at disease early stage has been in progress due to lack of any approved vaccines.
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In January 2023, a total of 64 infectious diseases were reported globally, affecting 235 countries and regions. Except for influenza, the top five infectious diseases affecting greatest number of countries and regions were COVID-19 (235), monkeypox (110), dengue fever (31), measles (27) and cholera (15). The top five infectious diseases with highest case fatality rates were Nipah virus disease (62.5%), Ebola virus disease (47.0%), Crimean-Congo haemorrhagic fever (37.5%), Lassa fever (15.1%) and West Nile fever (7.6%). The top five infectious diseases with greatest number of deaths were COVID-19, malaria, cholera, measles and dengue fever. The prevalent infectious diseases in Asia were COVID-19, cholera and dengue fever, the prevalent infectious diseases in Africa were COVID-19, cholera, yellow fever, Lassa fever, malaria and monkeypox, the prevalent infectious diseases in America were COVID-19, cholera, monkeypox, dengue fever and chikungunya fever, the prevalent infectious disease in Europe were COVID-19, monkeypox and invasive group A streptococcus infection.
ABSTRACT
In December 2022, a total of 68 infectious diseases were reported globally, affecting 235 countries and regions. Except for influenza, the top five infectious diseases affecting greatest number of countries and regions were COVID-19 (235), monkeypox (110), dengue fever (28), measles (27) and cholera (14). The top five infectious diseases with highest case fatality rates were Ebola virus disease (47.0%), Rift Valley fever (44.2%), Crimean-Congo haemorrhagic fever (40.0%), Lassa fever (17.6%) and West Nile fever (7.6%). The top five infectious diseases with greatest number of deaths were COVID-19, malaria, cholera, dengue fever and measles. The prevalent infectious diseases in Asia were COVID-19, cholera and dengue fever, the prevalent infectious diseases in Africa were COVID-19, cholera, yellow fever, Lassa fever, monkeypox, malaria and measles, the prevalent infectious diseases in America were COVID-19, cholera, monkeypox, dengue fever and chikungunya fever, the prevalent infectious disease in Europe were COVID-19, monkeypox and invasive group A streptococcus infection.
ABSTRACT
Vaccination is effective in preventing the increase of disease, especially emerging infectious diseases (EIDs), and it is particularly important for people in close contact with infected sources and susceptible populations who are at increased risk of getting infectious diseases due to behavior, occupation or health. Despite targeted vaccination guidelines, inadequate vaccination of the key populations fails to receive widespread attention, resulting in a high-risk transition of disease from key populations to general populations. Strengthening the vaccination of the susceptible groups can effectively block the spread of pathogens to general populations, and reduce the consumption of medical resources in universal vaccination, which has significant economic value. In this review, we describe the prevalence of EIDs, analyze the experience and lessons of infectious disease vaccination in key populations through several cases, and further explore the causes for the decline in vaccination rates of key populations. According to the trends of EIDs, a plan to strengthen the vaccination of key populations is proposed to effectively prevent the transition of EIDs from key populations to general populations.
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Background: Experience from the Zaire Ebolavirus epidemic in the eastern Democratic Republic of the Congo (2018-2020) demonstrates that early initiation of essential critical care and administration of Zaire Ebolavirus specific monoclonal antibodies may be associated with improved outcomes among patients with Ebola virus disease (EVD). Objectives: This series describes 13 EVD patients and 276 patients with suspected EVD treated during a Zaire Ebolavirus outbreak in Guinea in 2021. Method: Patients with confirmed or suspected EVD were treated in two Ebola treatment centres (ETC) in the region of N'zérékoré. Data were reviewed from all patients with suspected or confirmed EVD hospitalised in these two ETCs during the outbreak (14 February 2021 - 19 June 2021). Ebola-specific monoclonal antibodies, were available 2 weeks after onset of the outbreak. Results: Nine of the 13 EVD patients (age range: 22-70 years) survived. The four EVD patients who died, including one pregnant woman, presented with multi-organ dysfunction and died within 48 h of admission. All eight patients who received Ebola-specific monoclonal antibodies survived. Four of the 13 EVD patients were health workers. Improvement of ETC design facilitated implementation of WHO-recommended 'optimized supportive care for EVD'. In this context, pragmatic clinical training was integrated in routine ETC activities. Initial clinical manifestations of 13 confirmed EVD patients were similar to those of 276 patients with suspected, but subsequently non confirmed EVD. These patients suffered from other acute infections (e.g. malaria in 183 of 276 patients; 66%). Five of the 276 patients with suspected EVD died. One of these five patients had Lassa virus disease and a coronavirus disease 2019 (COVID-19) co-infection. Conclusion: Multidisciplinary outbreak response teams can rapidly optimise ETC design. Trained clinical teams can provide WHO-recommended optimised supportive care, including safe administration of Ebola-specific monoclonal antibodies. Pragmatic training in essential critical care can be integrated in routine ETC activities. Contribution: This article describes clinical realities associated with implementation of WHO-recommended standards of 'optimized supportive care' and administration of Ebola virus specific treatments. In this context, the importance of essential design principles of ETCs is underlined, which allow continuous visual contact and verbal interaction of health workers and families with their patients. Elements that may contribute to further quality of care improvements for patients with confirmed or suspected EVD are discussed.
ABSTRACT
Background: Pseudotyped virus systems that incorporate viral proteins have been widely employed for the rapid determination of the effectiveness and neutralizing activity of drug and vaccine candidates in biosafety level 2 facilities. We report an efficient method for producing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus with dual luciferase and fluorescent protein reporters. Moreover, using the established method, we also aimed to investigate whether Korean red ginseng (KRG), a valuable Korean herbal medicine, can attenuate infectivity of the pseudotyped virus. Methods: A pseudovirus of SARS-CoV-2 (SARS-2pv) was constructed and efficiently produced using lentivirus vector systems available in the public domain by the introduction of critical mutations in the cytoplasmic tail of the spike protein. KRG extract was dose-dependently treated to Calu-3 cells during SARS2-pv treatment to evaluate the protective activity against SARS-CoV-2. Results: The use of Calu-3 cells or the expression of angiotensin-converting enzyme 2 (ACE2) in HEK293T cells enabled SARS-2pv infection of host cells. Coexpression of transmembrane protease serine subtype 2 (TMPRSS2), which is the activator of spike protein, with ACE2 dramatically elevated luciferase activity, confirming the importance of the TMPRSS2-mediated pathway during SARS-CoV-2 entry. Our pseudovirus assay also revealed that KRG elicited resistance to SARS-CoV-2 infection in lung cells, suggesting its beneficial health effect. Conclusion: The method demonstrated the production of SARS-2pv for the analysis of vaccine or drug candidates. When KRG was assessed by the method, it protected host cells from coronavirus infection. Further studies will be followed for demonstrating this potential benefit.
ABSTRACT
This review focuses on the management of Novel Corona Virus with antiviral drugs and antibiotics and therefore the worldwide dissemination of COVID-19 has been accompanied by increased use of antibiotics, according to this review, which focuses on the therapy of Novel Corona Virus with antiviral medicines and antiviral. This is linked to COVID-19 patients' priority of viral infections. In low-and middle-income countries, identifying viruses is difficult because to a lack of medical or cheap infrastructure that is easily accessible and inexpensive among diseases and pathogens. The possibility of COVID-19 spreading has increased public awareness of the need of antibiotic management systems, as well as infection control and control measures that can minimize microbial load. In underdeveloped nations, these measures are commonly employed. During the COVID-19 pandemic, studies were conducted as a test for worldwide antibiotic resistance. Respiratory problems are being blamed on the Novel Corona Virus that Include pneumonia, colds, sneezing and coughing, and other respiratory diseases. Humans are infected with the Coronavirus by airborne droplets. The World Health Organization has warned against visiting public areas and avoiding close contact with an infected individual. First, on December 31, 2019, the Coronavirus (2019-nCoV) was separated from the Wuhan market in China, resulting in the COVID-19 pandemic of extremely complicated viral illnesses. Patients with risk factors are more prone to develop secondary infections, which necessitate the use of antibiotics. Attempts to duplicate the medication, on the other hand, raised knowledge of the antibiotics' significance beyond infection management. Antiviral, immunomodulatory action, and unique pharmacokinetic profile of antibiotics play a significant part in the therapy of pneumonia;other benefits include cardiac safety, improved lung tissue access, and possible antiviral, and immunomodulation, but some adverse effects by usage. SARS-CoV-2 has generated an epidemic of the highly infectious new coronavirus 2019 (COVID-19), which poses a severe public health concern. Given the potential for a COVID-19 outbreak, a better knowledge of the virus is critical in the event of therapeutic alternatives. We offer a thorough analysis of antimicrobials and antiviral COVID-19 in this review. We also go about COVID-19's current treatments. Copyright © 2022, Anka Publishers. All rights reserved.
ABSTRACT
Background: Lassa fever is an acute viral haemorrhagic disease caused by the Lassa virus (LASV). It is endemic in West Africa and infects about 300,000 people each year, leading to approximately 5000 deaths annually. The development of the LASV vaccine has been listed as a priority by the World Health Organization since 2018. Considering the accelerated development and availability of vaccines against COVID-19, we set out to assess the prospects of LASV vaccines and the progress made so far. Material(s) and Method(s): We reviewed the progress made on twenty-six vaccine candidates listed by Salami et al. (2019) and searched for new vaccine candidates through Google Scholar, PubMed, and DOAJ from June to July 2021. We searched the articles published in English using keywords that included "vaccine" AND "Lassa fever" OR "Lassa virus" in the title/. Result(s): Thirty-four candidate vaccines were identified - 26 already listed in the review by Salami et al. and an additional 8, which were developed over the last seven years. 30 vaccines are still in the pre-clinical stage while 4 of them are currently undergoing clinical trials. The most promising candidates in 2019 were vesicular stomatitis virus-vectored vaccine and live-attenuated MV/LASV vaccine;both had progressed to clinical trials. Conclusion(s): Despite the focus on COVID-19 vaccines since 2020, LASV vaccine is under development and continues to make impressive progress, hence more emphasis should be put into exploring further clinical studies related to the most promising types of vaccines identified. Copyright © 2022, African Traditional, Herbal Medicine Supporters Initiative. All rights reserved.
ABSTRACT
Lassa fever (LF) and yellow fever (YF) belong to a group of viral hemorrhagic fevers (VHFs). These viruses have common features and damages the organs and blood vessels; they also impair the body's homeostasis. Some VHFs cause mild disease, while some cause severe disease and death such as in the case of Ebola or Marburg. LF virus and YF virus are two of the most recent emerging viruses in Africa, resulting in severe hemorrhagic fever in humans. Lassa fever virus is continuously on the rise both in Nigeria and neighboring countries in West Africa, with an estimate of over 500,000 cases of LF, and 5000 deaths, annually. YF virus is endemic in temperate climate regions of Africa, Central America (Guatemala, Honduras, Nicaragua, El Salvador), and South America (such as Brazil, Argentina, Peru, and Chile) with an annual estimated cases of 200,000 and 30,000 deaths globally. This review examines the impact of the COVID-19 pandemic on the trend in epidemiology of these two VHFs to delineate responses that are associated with protective or pathogenic outcomes.
ABSTRACT
Mammarenaviruses include many significant worldwide-widespread human pathogens, among them Lassa virus (LASV), having a dramatic morbidity and mortality rate. They are a potential high-risk menace to the worldwide public health since there are no treatments and there is a high possibility of animal-to-human and human-to-human viral transmission. These viruses enter into the cells by endocytosis fusing its membrane envelope with the late endosomal membrane thanks to the glycoprotein GP2, a membrane fusion protein of class I. This protein contains different domains, among them the N-terminal fusion peptide (NFP), the internal fusion loop (IFL), the membrane proximal external region (MPER) and the transmembrane domain (TMD). All these domains are implicated in the membrane fusion process. In this work, we have used an all-atom molecular dynamics study to know the binding of these protein domains with a complex membrane mimicking the late endosome one. We show that the NFP/IFL domain is capable of spontaneously inserting into the membrane without a significant change of secondary structure, the MPER domain locates at the bilayer interface with an orientation parallel to the membrane surface and tends to interact with other MPER domains, and the TMD domain tilts inside the bilayer. Moreover, they predominantly interact with negatively charged phospholipids. Overall, these membrane-interacting domains would characterise a target that would make possible to find effective antiviral molecules against LASV in particular and Mammarenaviruses in general.
Subject(s)
Lassa virus , Virus Internalization , Animals , Endosomes , Humans , Membrane Fusion , PeptidesABSTRACT
The earliest cases of COVID-19 disease in Africa were, in most cases, the result of imports from abroad. The Democratic republic of the Congo (DRC) identified the first case at the beginning of 2020. Two days after his return from France, the first patient was tested positively in the capital, Kinshasa. The travel restrictions and status of the state of emergency were announced on 24 March 2020. A lockdown followed. In June of the same year, 11 provinces were already affected by COVID-19 disease. The negative socio-economic impact has occurred and is similar to that in any other country. The DRC does not differ from other African countries or on the issue of infectious diseases such as HIV, malaria, cholera, measles or Ebola virus disease. Recurring Ebola epidemics are addressed by vaccination with Ervebo vaccine. Unlike Ebola, part of the population does not believe in the existence of SARS-CoV-2 and does not respect basic anti-epidemic measures. Medical capacities were very limited at the beginning of the SARS-CoV-2 epidemic, both in terms of diagnosis and testing and availability of treatment (60 ventilators to 83 million inhabitants). The situation is complicated as a result of 20 years continuing wars. Another African country, Guinea, is currently facing not only COVID-19, but also the zoonotic disease of Lassa fever, which has been detected in several patients. Copyright © 2021, Medakta s.r.o.. All rights reserved.
ABSTRACT
In May 2022, a total of 66 infectious diseases were reported globally, affecting 233 countries and regions. Except for influenza, the top five infectious diseases affecting greatest number of countries and regions were COVID-19 (233), monkeypox (36), dengue fever (31), measles (24) and cholera (11). The top five infectious diseases with highest case fatality rates were Ebola virus disease (100.0%), Middle East Respiratory Syndrome (34.4%), Crimean-Congo hemorrhagic fever (22.2%), Lassa fever (19.8%) and monkeypox (4.0%). The top five infectious diseases with greatest number of deaths were COVID-19, malaria, cholera, dengue fever and measles. The prevalent infectious diseases in Asia were COVID-19, dengue fever and cholera, the prevalent infectious diseases in Africa were COVID-19, Ebola virus disease, cholera, yellow fever, Lassa fever, malaria and monkeypox, the prevalent infectious diseases in America were COVID-19, dengue fever, chikungunya fever and Zika virus disease, the prevalent infectious disease in Europe were COVID-19, monkeypox and acute hepatitis of unknown aetiology.
ABSTRACT
Mastomys natalensis is the natural host of various arenaviruses, including the human-pathogenic Lassa virus. Homologous arenaviruses, defined here as those having M. natalensis as a natural host, can establish long-lasting infection in M. natalensis, while these animals rapidly clear arenaviruses having another rodent species as a natural host (heterologous viruses). Little is known about the mechanisms behind the underlying arenavirus-host barriers. The innate immune system, particularly the type I interferon (IFN) response, might play a role. In this study, we developed and validated RT-PCR assays to analyse the expression of M. natalensis interferon-stimulated genes (ISGs). We then used these assays to study if homologous and heterologous viruses induce different IFN responses in M. natalensis cells. Infection experiments were performed with the homologous Lassa and Morogoro viruses and the related but heterologous Mobala virus. Compared to the direct induction with IFN or Poly(I:C), arenaviruses generally induced a weak IFN response. However, the ISG-expression profiles of homologous and heterologous viruses were similar. Our data indicate that, at least in M. natalensis cells, the IFN system is not a major factor in the virus-host barrier for arenaviruses. Our system provides a valuable tool for future in vivo investigation of arenavirus host restrictions at the level of the innate immune response.
Subject(s)
Arenaviridae Infections , Arenavirus , Interferon Type I , Animals , Arenavirus/physiology , Humans , Immunity, Innate , Murinae , TanzaniaABSTRACT
The COVID-19 pandemic caught the world largely unprepared, including scientific and policy communities. On April 10-13, 2022, researchers across academia, industry, government, and nonprofit organizations met at the Keystone symposium "Lessons from the Pandemic: Responding to Emerging Zoonotic Viral Diseases" to discuss the successes and challenges of the COVID-19 pandemic and what lessons can be applied moving forward. Speakers focused on experiences not only from the COVID-19 pandemic but also from outbreaks of other pathogens, including the Ebola virus, Lassa virus, and Nipah virus. A general consensus was that investments made during the COVID-19 pandemic in infrastructure, collaborations, laboratory and manufacturing capacity, diagnostics, clinical trial networks, and regulatory enhancements-notably, in low-to-middle income countries-must be maintained and strengthened to enable quick, concerted responses to future threats, especially to zoonotic pathogens.