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Kamara ABS, Fatoma P, Moseray A. The Perspectives of Healthcare Professionals on the Strategies, Challenges, and Community Responses to Health System Response and Interventions Towards Lassa Fever Infections and Mortality in Sierra Leone. Risk Manag Healthc Policy 2024; 17:1127-1149. [PMID: 38737418 PMCID: PMC11088388 DOI: 10.2147/rmhp.s455254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 04/29/2024] [Indexed: 05/14/2024] Open
Abstract
Background Lassa fever is a critical public health issue in Sierra Leone that demands appropriate health system responses and interventions to mitigate infections and reduce mortality. Methods A qualitative study was conducted to delve into healthcare workers' experiences with Lassa fever management and interventions across diverse healthcare settings in Sierra Leone, including the Eastern Province and Freetown's Directorate of Health Security and Emergency (DHSE). Engaging ten key informants through purposive sampling, the study employed NVivo version 10 for a detailed thematic analysis using Query and Coding to systematically identify, classify, and organize key themes regarding knowledge, diagnostics, management roles, and community impact. Results The findings indicate a well-informed healthcare workforce but highlight gaps in early detection, diagnostic accuracy, and procedural standardization. Concerns were raised about the potential overestimation of disease incidence due to improved diagnostics, suggesting a historical under-detection of Lassa fever. The analysis underscores the need for a multifaceted management approach, emphasizing international collaboration and culturally sensitive community engagement to effectively tackle the disease. A significant concern identified is the high mortality rate resulting from delayed referrals and communication challenges within the health system, leading to actionable recommendations for enhancing Lassa fever response strategies. The study's thematic analysis provides a nuanced understanding of the challenges and areas for improvement, emphasizing the critical role of healthcare professionals in combating Lassa fever. Conclusion Combating Lassa fever in Sierra Leone demands an integrative strategy that extends beyond medical interventions to encompass educational and infrastructural enhancements. This research pays homage to the commitment of healthcare professionals, underscoring the importance of sustained support and recognition of their essential contributions to advancing Lassa fever management and interventions.
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Affiliation(s)
- Abu-Bakarr Steven Kamara
- Department of Public Health, School of Community Health Sciences, Njala University Bo Campus, Bo City, Sierra Leone
| | - Patrick Fatoma
- Department of Public Health, School of Community Health Sciences, Njala University Bo Campus, Bo City, Sierra Leone
| | - Andrew Moseray
- Department of Public Health, School of Community Health Sciences, Njala University Bo Campus, Bo City, Sierra Leone
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2
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Johnson DM, Khakhum N, Wang M, Warner NL, Jokinen JD, Comer JE, Lukashevich IS. Pathogenic and Apathogenic Strains of Lymphocytic Choriomeningitis Virus Have Distinct Entry and Innate Immune Activation Pathways. Viruses 2024; 16:635. [PMID: 38675975 PMCID: PMC11053560 DOI: 10.3390/v16040635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/08/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
Lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV) share many genetic and biological features including subtle differences between pathogenic and apathogenic strains. Despite remarkable genetic similarity, the viscerotropic WE strain of LCMV causes a fatal LASV fever-like hepatitis in non-human primates (NHPs) while the mouse-adapted Armstrong (ARM) strain of LCMV is deeply attenuated in NHPs and can vaccinate against LCMV-WE challenge. Here, we demonstrate that internalization of WE is more sensitive to the depletion of membrane cholesterol than ARM infection while ARM infection is more reliant on endosomal acidification. LCMV-ARM induces robust NF-κB and interferon response factor (IRF) activation while LCMV-WE seems to avoid early innate sensing and failed to induce strong NF-κB and IRF responses in dual-reporter monocyte and epithelial cells. Toll-like receptor 2 (TLR-2) signaling appears to play a critical role in NF-κB activation and the silencing of TLR-2 shuts down IL-6 production in ARM but not in WE-infected cells. Pathogenic LCMV-WE infection is poorly recognized in early endosomes and failed to induce TLR-2/Mal-dependent pro-inflammatory cytokines. Following infection, Interleukin-1 receptor-associated kinase 1 (IRAK-1) expression is diminished in LCMV-ARM- but not LCMV-WE-infected cells, which indicates it is likely involved in the LCMV-ARM NF-κB activation. By confocal microscopy, ARM and WE strains have similar intracellular trafficking although LCMV-ARM infection appears to coincide with greater co-localization of early endosome marker EEA1 with TLR-2. Both strains co-localize with Rab-7, a late endosome marker, but the interaction with LCMV-WE seems to be more prolonged. These findings suggest that LCMV-ARM's intracellular trafficking pathway may facilitate interaction with innate immune sensors, which promotes the induction of effective innate and adaptive immune responses.
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Affiliation(s)
- Dylan M. Johnson
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA; (N.K.); (J.E.C.)
- Sandia National Laboratories, Department of Biotechnology & Bioengineering, Livermore, CA 94550, USA
| | - Nittaya Khakhum
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA; (N.K.); (J.E.C.)
| | - Min Wang
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA;
| | - Nikole L. Warner
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA
| | - Jenny D. Jokinen
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA;
| | - Jason E. Comer
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA; (N.K.); (J.E.C.)
| | - Igor S. Lukashevich
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA;
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3
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Olayemi A, Schmid DW, Fleischer R, Wilhelm K, Heni AC, Mueller-Klein N, Haikukutu L, Fichet-Calvet E, Günther S, Sommer S. MHC-I alleles mediate clearance and antibody response to the zoonotic Lassa virus in Mastomys rodent reservoirs. PLoS Negl Trop Dis 2024; 18:e0011984. [PMID: 38421939 PMCID: PMC10903922 DOI: 10.1371/journal.pntd.0011984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 02/09/2024] [Indexed: 03/02/2024] Open
Abstract
West African Mastomys rodents are the primary reservoir of the zoonotic Lassa virus (LASV). The virus causes haemorrhagic Lassa fever and considerable mortality in humans. To date, the role of Mastomys immunogenetics in resistance to, and persistence of, LASV infections is largely unknown. Here, we investigated the role of Major Histocompatibility Complex class I (MHC-I) on LASV infection status (i.e., active vs. cleared infection, determined via PCR and an immunofluorescence assay on IgG antibodies, respectively) in Mastomys natalensis and M. erythroleucus sampled within southwestern Nigeria. We identified more than 190 and 90 MHC-I alleles by Illumina high throughput-sequencing in M. natalensis and M. erythroleucus, respectively, with different MHC allele compositions and frequencies between LASV endemic and non-endemic sites. In M. natalensis, the MHC allele ManaMHC-I*006 was negatively associated with active infections (PCR-positive) and positively associated with cleared infections (IgG-positive) simultaneously, suggesting efficient immune responses that facilitate LASV clearance in animals carrying this allele. Contrarily, alleles ManaMHC-I*008 and ManaMHC-I*021 in M. natalensis, and MaerMHC-I*008 in M. erythroleucus, were positively associated with active infection, implying susceptibility. Alleles associated with susceptibility shared a glutamic acid at the positively selected codon 57, while ManaMHC-I*006 featured an arginine. There was no link between number of MHC alleles per Mastomys individual and LASV prevalence. Thus, specific alleles, but not MHC diversity per se, seem to mediate antibody responses to viremia. We conclude that co-evolution with LASV likely shaped the MHC-I diversity of the main LASV reservoirs in southwestern Nigeria, and that information on reservoir immunogenetics may hold insights into transmission dynamics and zoonotic spillover risks.
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Affiliation(s)
- Ayodeji Olayemi
- Natural History Museum, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Dominik Werner Schmid
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Ramona Fleischer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Kerstin Wilhelm
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | | | - Nadine Mueller-Klein
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Lavinia Haikukutu
- Department of Wildlife Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Elisabeth Fichet-Calvet
- Department of Zoonoses Control, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stephan Günther
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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Adesina AS, Oyeyiola A, Obadare A, Igbokwe J, Abejegah C, Akhilomen P, Bangura U, Asogun D, Tobin E, Ayodeji O, Osoniyi O, Davis C, Thomson EC, Pahlmann M, Günther S, Fichet-Calvet E, Olayemi A. Circulation of Lassa virus across the endemic Edo-Ondo axis, Nigeria, with cross-species transmission between multimammate mice. Emerg Microbes Infect 2023; 12:2219350. [PMID: 37288752 PMCID: PMC10251791 DOI: 10.1080/22221751.2023.2219350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/24/2023] [Indexed: 06/09/2023]
Abstract
We phylogenetically compared sequences of the zoonotic Lassa virus (LASV) obtained from Mastomys rodents in seven localities across the highly endemic Edo and Ondo States within Nigeria. Sequencing 1641 nt from the S segment of the virus genome, we resolved clades within lineage II that were either limited to Ebudin and Okhuesan in Edo state (2g-beta) or along Owo-Okeluse-Ifon in Ondo state (2g-gamma). We also found clades within Ekpoma, a relatively large cosmopolitan town in Edo state, that extended into other localities within Edo (2g-alpha) and Ondo (2g-delta). LASV variants from M. natalensis within Ebudin and Ekpoma in Edo State (dated approximately 1961) were more ancient compared to those from Ondo state (approximately 1977), suggesting a broadly east-west virus migration across south-western Nigeria; a pattern not always consistent with LASV sequences derived from humans in the same localities. Additionally, in Ebudin and Ekpoma, LASV sequences between M. natalensis and M. erythroleucus were interspersed on the phylogenetic tree, but those from M. erythroleucus were estimated to emerge more recently (approximately 2005). Overall, our results show that LASV amplification in certain localities (reaching a prevalence as high as 76% in Okeluse), anthropogenically-aided spread of rodent-borne variants amidst the larger towns (involving communal accommodation such as student hostels), and virus-exchange between syntopic M. natalensis and M. erythroleucus rodents (as the latter, a savanna species, encroaches southward into the degraded forest) pose perpetual zoonotic hazard across the Edo-Ondo Lassa fever belt, threatening to accelerate the dissemination of the virus into non endemic areas.
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Affiliation(s)
- Adetunji Samuel Adesina
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Akinlabi Oyeyiola
- Natural History Museum, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Adeoba Obadare
- Natural History Museum, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Joseph Igbokwe
- Department of Zoology, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | | | | | - Umaru Bangura
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Danny Asogun
- Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria
| | - Ekaete Tobin
- Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria
| | | | - Omolaja Osoniyi
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Chris Davis
- Centre for Virus Research, University of Glasgow, Glasgow, UK
| | - Emma C Thomson
- Centre for Virus Research, University of Glasgow, Glasgow, UK
| | - Meike Pahlmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stephan Günther
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Ayodeji Olayemi
- Natural History Museum, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
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5
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Fan Y, Hou Y, Li Q, Dian Z, Wang B, Xia X. RNA virus diversity in rodents. Arch Microbiol 2023; 206:9. [PMID: 38038743 DOI: 10.1007/s00203-023-03732-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023]
Abstract
Many zoonotic disease emergencies are associated with RNA viruses in rodents that substantially impact public health. With the widespread application of meta-genomics and meta-transcriptomics for virus discovery over the last decade, viral sequences deposited in public databases have expanded rapidly, and the number of novel viruses discovered in rodents has increased. As important reservoirs of zoonotic viruses, rodents have attracted increasing attention for the risk of potential spillover of rodent-borne viruses. However, knowledge of rodent viral diversity and the major factors contributing to the risk of zoonotic epidemic outbreaks remains limited. Therefore, this study analyzes the diversity and composition of rodent RNA viruses using virus records from the Database of Rodent-associated Viruses (DRodVir/ZOVER), which covers the published literatures and records in GenBank database, reviews the main rodent RNA virus-induced human infectious diseases, and discusses potential challenges in this field.
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Affiliation(s)
- Yayu Fan
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, 650500, People's Republic of China
| | - Yutong Hou
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, 650500, People's Republic of China
| | - Qian Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, 650500, People's Republic of China
| | - Ziqin Dian
- Department of Clinical Laboratory, The First People's Hospital of Yunnan Province, Kunming, Yunnan, 650032, People's Republic of China
| | - Binghui Wang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, 650500, People's Republic of China.
| | - Xueshan Xia
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, 650500, People's Republic of China.
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6
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Kayem ND, Okogbenin S, Okoeguale J, Momoh M, Njoku A, Eifediyi R, Enodiana X, Ngwu H, Irhiogbe W, Ighodalo Y, Olokor T, Odigie G, Castle L, Duraffour S, Oestereich L, Dahal P, Ariana P, Gunther S, Horby P. Seroepidemiology of Lassa virus in pregnant women in Southern Nigeria: A prospective hospital-based cohort study. PLoS Negl Trop Dis 2023; 17:e0011354. [PMID: 37216412 DOI: 10.1371/journal.pntd.0011354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 05/06/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND There is limited epidemiological evidence on Lassa fever in pregnant women with acute gaps on prevalence, infection incidence, and risk factors. Such evidence would facilitate the design of therapeutic and vaccine trials and the design of control programs. Our study sought to address some of these gaps by estimating the seroprevalence and seroconversion risk of Lassa fever in pregnant women. METHODOLOGY/PRINCIPAL FINDINGS We conducted a prospective hospital-based cohort between February and December 2019 in Edo State, Southern Nigeria, enrolling pregnant women at antenatal clinic and following them up at delivery. Samples were evaluated for IgG antibodies against Lassa virus. The study demonstrates a seroprevalence of Lassa IgG antibodies of 49.6% and a seroconversion risk of 20.8%. Seropositivity was strongly correlated with rodent exposure around homes with an attributable risk proportion of 35%. Seroreversion was also seen with a seroreversion risk of 13.4%. CONCLUSIONS/SIGNIFICANCE Our study suggests that 50% of pregnant women were at risk of Lassa infection and that 35.0% of infections might be preventable by avoiding rodent exposure and conditions which facilitate infestation and the risk of human-rodent contact. While the evidence on rodent exposure is subjective and further studies are needed to provide a better understanding of the avenues of human-rodent interaction; public health measures to decrease the risk of rodent infestation and the risk of spill over events may be beneficial. With an estimated seroconversion risk of 20.8%, our study suggests an appreciable risk of contracting Lassa fever during pregnancy and while most of these seroconversions may not be new infections, given the high risk of adverse outcomes in pregnancy, it supports the need for preventative and therapeutic options against Lassa fever in pregnancy. The occurrence of seroreversion in our study suggests that the prevalence obtained in this, and other cohorts may be an underestimate of the actual proportion of women of childbearing age who present at pregnancy with prior LASV exposure. Additionally, the occurrence of both seroconversion and seroreversion in this cohort suggests that these parameters would need to be considered for the development of Lassa vaccine efficacy, effectiveness, and utility models.
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Affiliation(s)
| | - Sylvanus Okogbenin
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Joseph Okoeguale
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Mojeed Momoh
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Antonia Njoku
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Reuben Eifediyi
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Xavier Enodiana
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Hilary Ngwu
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Wilfred Irhiogbe
- Department of Obstetrics and Gynaecology, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Yemisi Ighodalo
- Institute of Lassa fever Research and Control, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Thomas Olokor
- Institute of Lassa fever Research and Control, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - George Odigie
- Institute of Lassa fever Research and Control, Irrua Specialist Teaching Hospital, Irrua, Nigeria
| | - Lyndsey Castle
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sophie Duraffour
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Lisa Oestereich
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Prabin Dahal
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Proochista Ariana
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Stephan Gunther
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Peter Horby
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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7
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Grant DS, Engel EJ, Roberts Yerkes N, Kanneh L, Koninga J, Gbakie MA, Alhasan F, Kanneh FB, Kanneh IM, Kamara FK, Momoh M, Yillah MS, Foday M, Okoli A, Zeoli A, Weldon C, Bishop CM, Zheng C, Hartnett J, Chao K, Shore K, Melnik LI, Mucci M, Bond NG, Doyle P, Yenni R, Podgorski R, Ficenec SC, Moses L, Shaffer JG, Garry RF, Schieffelin JS. Seroprevalence of anti-Lassa Virus IgG antibodies in three districts of Sierra Leone: A cross-sectional, population-based study. PLoS Negl Trop Dis 2023; 17:e0010938. [PMID: 36758101 PMCID: PMC9946222 DOI: 10.1371/journal.pntd.0010938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 02/22/2023] [Accepted: 11/09/2022] [Indexed: 02/11/2023] Open
Abstract
BACKGROUND Lassa virus (LASV), the cause of the acute viral hemorrhagic illness Lassa fever (LF), is endemic in West Africa. Infections in humans occur mainly after exposure to infected excrement or urine of the rodent-host, Mastomys natalensis. The prevalence of exposure to LASV in Sierra Leone is crudely estimated and largely unknown. This cross-sectional study aimed to establish a baseline point seroprevalence of IgG antibodies to LASV in three administrative districts of Sierra Leone and identify potential risk factors for seropositivity and LASV exposure. METHODOLOGY AND PRINCIPAL FINDINGS Between 2015 and 2018, over 10,642 participants from Kenema, Tonkolili, and Port Loko Districts were enrolled in this cross-sectional study. Previous LASV and LF epidemiological studies support classification of these districts as "endemic," "emerging," and "non-endemic", respectively. Dried blood spot samples were tested for LASV antibodies by ELISA to determine the seropositivity of participants, indicating previous exposure to LASV. Surveys were administered to each participant to assess demographic and environmental factors associated with a higher risk of exposure to LASV. Overall seroprevalence for antibodies to LASV was 16.0%. In Kenema, Port Loko, and Tonkolili Districts, seroprevalences were 20.1%, 14.1%, and 10.6%, respectively. In a multivariate analysis, individuals were more likely to be LASV seropositive if they were living in Kenema District, regardless of sex, age, or occupation. Environmental factors contributed to an increased risk of LASV exposure, including poor housing construction and proximity to bushland, forested areas, and refuse. CONCLUSIONS AND SIGNIFICANCE In this study we determine a baseline LASV seroprevalence in three districts which will inform future epidemiological, ecological, and clinical studies on LF and the LASV in Sierra Leone. The heterogeneity of the distribution of LASV and LF over both space, and time, can make the design of efficacy trials and intervention programs difficult. Having more studies on the prevalence of LASV and identifying potential hyper-endemic areas will greatly increase the awareness of LF and improve targeted control programs related to LASV.
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Affiliation(s)
- Donald S. Grant
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Emily J. Engel
- Department of Pediatrics, Sections of Pediatric Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Nicole Roberts Yerkes
- Department of Pediatrics, Sections of Pediatric Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Lansana Kanneh
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - James Koninga
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Michael A. Gbakie
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Foday Alhasan
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Franklyn B. Kanneh
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Ibrahim Mustapha Kanneh
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Fatima K. Kamara
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Mambu Momoh
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
- Eastern Technical University of Sierra Leone, Kenema, Sierra Leone
| | - Mohamed S. Yillah
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Momoh Foday
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health and Sanitation, Kenema, Sierra Leone
| | - Adaora Okoli
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Ashley Zeoli
- Department of Pediatrics, Sections of Pediatric Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Caroline Weldon
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Christopher M. Bishop
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Crystal Zheng
- Department of Internal Medicine, Section of Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Jessica Hartnett
- Department of Pediatrics, Sections of Pediatric Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Karissa Chao
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Kayla Shore
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Lilia I. Melnik
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Mallory Mucci
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Nell G. Bond
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Philip Doyle
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Rachael Yenni
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Rachel Podgorski
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Samuel C. Ficenec
- Department of Internal Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Lina Moses
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Jeffrey G. Shaffer
- Department of Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Robert F. Garry
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - John S. Schieffelin
- Department of Pediatrics, Sections of Pediatric Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
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8
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Understanding Host–Virus Interactions: Assessment of Innate Immune Responses in Mastomys natalensis Cells after Arenavirus Infection. Viruses 2022; 14:v14091986. [PMID: 36146793 PMCID: PMC9506377 DOI: 10.3390/v14091986] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/30/2022] [Accepted: 08/31/2022] [Indexed: 11/23/2022] Open
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.
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Nnaji ND, Onyeaka H, Reuben RC, Uwishema O, Olovo CV, Anyogu A. The deuce-ace of Lassa Fever, Ebola virus disease and COVID-19 simultaneous infections and epidemics in West Africa: clinical and public health implications. Trop Med Health 2021; 49:102. [PMID: 34965891 PMCID: PMC8716304 DOI: 10.1186/s41182-021-00390-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/09/2021] [Indexed: 01/08/2023] Open
Abstract
Globally, the prevailing COVID-19 pandemic has caused unprecedented clinical and public health concerns with increasing morbidity and mortality. Unfortunately, the burden of COVID-19 in Africa has been further exacerbated by the simultaneous epidemics of Ebola virus disease (EVD) and Lassa Fever (LF) which has created a huge burden on African healthcare systems. As Africa struggles to contain the spread of the second (and third) waves of the COVID-19 pandemic, the number of reported cases of LF is also increasing, and recently, new outbreaks of EVD. Before the pandemic, many of Africa's frail healthcare systems were already overburdened due to resource limitations in staffing and infrastructure, and also, multiple endemic tropical diseases. However, the shared epidemiological and pathophysiological features of COVID-19, EVD and LF as well their simultaneous occurrence in Africa may result in misdiagnosis at the onset of infection, an increased possibility of co-infection, and rapid and silent community spread of the virus(es). Other challenges include high population mobility across porous borders, risk of human-to-animal transmission and reverse zoonotic spread, and other public health concerns. This review highlights some major clinical and public health challenges toward responses to the COVID-19 pandemic amidst the deuce-ace of recurrent LF and EVD epidemics in Africa. Applying the One Health approach in infectious disease surveillance and preparedness is essential in mitigating emerging and re-emerging (co-)epidemics in Africa and beyond.
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Affiliation(s)
| | - Helen Onyeaka
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Rine Christopher Reuben
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, Germany
| | - Olivier Uwishema
- Oli Health Magazine Organization, Research and Education, Kigali, Rwanda
- Clinton Global Initiative University, New York, USA
- Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey
| | - Chinasa Valerie Olovo
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
- Department of Biochemistry and Molecular Biology, School of Medicine, Jiangsu University Zhenjiang, Zhenjiang, 212013 Jiangsu People’s Republic of China
| | - Amarachukwu Anyogu
- School of Biomedical Sciences, University of West London, London, W5 5RF UK
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Common Themes in Zoonotic Spillover and Disease Emergence: Lessons Learned from Bat- and Rodent-Borne RNA Viruses. Viruses 2021; 13:v13081509. [PMID: 34452374 PMCID: PMC8402684 DOI: 10.3390/v13081509] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 12/18/2022] Open
Abstract
Rodents (order Rodentia), followed by bats (order Chiroptera), comprise the largest percentage of living mammals on earth. Thus, it is not surprising that these two orders account for many of the reservoirs of the zoonotic RNA viruses discovered to date. The spillover of these viruses from wildlife to human do not typically result in pandemics but rather geographically confined outbreaks of human infection and disease. While limited geographically, these viruses cause thousands of cases of human disease each year. In this review, we focus on three questions regarding zoonotic viruses that originate in bats and rodents. First, what biological strategies have evolved that allow RNA viruses to reside in bats and rodents? Second, what are the environmental and ecological causes that drive viral spillover? Third, how does virus spillover occur from bats and rodents to humans?
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