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Madueme PGU, Chirove F. A systematic review of mathematical models of Lassa fever. Math Biosci 2024; 374:109227. [PMID: 38844262 DOI: 10.1016/j.mbs.2024.109227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/21/2024] [Accepted: 05/31/2024] [Indexed: 06/13/2024]
Abstract
This systematic review, conducted following the PRISMA guidelines, scrutinizes mathematical models employed in the study of Lassa fever. The analysis revealed the inherent heterogeneity in both models and data, posing significant challenges to parameter estimation. While health and behavioral interventions exhibit promise in mitigating the disease's spread, their efficacy is contingent upon contextual factors. Identified through this review are critical gaps, limitations, and avenues for future research, necessitating increased harmonization and standardization in modeling approaches. The considerations of seasonal and spatial variations emerge as crucial elements demanding targeted investigation. The perpetual threat of emerging diseases, coupled with the enduring public health impact of Lassa fever, underscores the imperative for sustained research endeavors and investments in mathematical modeling. The conclusion underscored that while mathematical modeling remains an invaluable tool in the combat against Lassa fever, its optimal utilization mandates multidisciplinary collaboration, refined data collection methodologies, and an enriched understanding of the intricate disease dynamics. This comprehensive approach is essential for effectively reducing the burden of Lassa fever and safeguarding the health of vulnerable populations.
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Affiliation(s)
- Praise-God Uchechukwu Madueme
- Department of Mathematics and Applied Mathematics, University of Johannesburg, Auckland Park, 2006, Johannesburg, South Africa
| | - Faraimunashe Chirove
- Department of Mathematics and Applied Mathematics, University of Johannesburg, Auckland Park, 2006, Johannesburg, South Africa.
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Elsinga J, Sunyoto T, di Stefano L, Giorgetti PF, Kyi HA, Burzio C, Campos Moreno X, Ojide CK, Ajayi N, Ewah R, Ogah EO, Dan-Nwafor C, Ahumibe A, Ochu CL, Olayinka A, Jonckheere S, Chaillet P, van Herp M. Field evaluation of validity and feasibility of Pan-Lassa rapid diagnostic test for Lassa fever in Abakaliki, Nigeria: a prospective diagnostic accuracy study. THE LANCET. INFECTIOUS DISEASES 2024:S1473-3099(24)00184-1. [PMID: 38734012 DOI: 10.1016/s1473-3099(24)00184-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 02/29/2024] [Accepted: 03/11/2024] [Indexed: 05/13/2024]
Abstract
BACKGROUND Lassa fever is a viral haemorrhagic fever with few options for diagnosis and treatment; it is also under-researched with knowledge gaps on its epidemiology. A point-of-care bedside test diagnosing Lassa fever, adhering to REASSURED criteria, is not currently available but is urgently needed in west African regions with high Lassa fever burden. We aimed to assess the validity and feasibility of a rapid diagnostic test (RDT) to confirm Lassa fever in people in Nigeria. METHODS We estimated the diagnostic performance of the ReLASV Pan-Lassa RDT (Zalgen Labs, Frederick, MD, USA) as a research-use-only test, compared to RT-PCR as a reference standard, in 217 participants at a federal tertiary hospital in Abakaliki, Nigeria. We recruited participants between Feb 17, 2022, and April 17, 2023. The RDT was performed using capillary blood at the patient bedside and using plasma at the laboratory. The performance of the test, based on REASSURED criteria, was assessed for user friendliness, rapidity and robustness, sensitivity, and specificity. FINDINGS Participants were aged between 0 and 85 years, with a median age of 33·0 years (IQR 22·0-44·3), and 24 participants were younger than 18 years. 107 (50%) participants were women and 109 (50%) were men; one participant had missing sex data. Although the specificity of the Pan-Lassa RDT was high (>90%), sensitivity at bedside using capillary blood was estimated as 4% (95% CI 1-14) at 15 min and 10% (3-22) at 25 min, far below the target of 90%. The laboratory-based RDT using plasma showed better sensitivity (46% [32-61] at 15 min and 50% [36-64] at 25 min) but did not reach the target sensitivity. Among the 52 PCR-positive participants with Lassa fever, positive RDT results were associated with lower cycle threshold values (glycoprotein precursor [GPC] gene mean 30·3 [SD 4·3], Large [L] gene mean 32·3 [3·7] vs GPC gene mean 24·5 [3·9], L gene mean 28·0 [3·6]). Personnel conducting the bedside test procedure reported being hindered by the inconvenient use of full personal protective equipment and long waiting procedures before a result could be read. INTERPRETATION The Pan-Lassa RDT is not currently recommended as a diagnostic or screening tool for suspected Lassa fever cases. Marked improvement in sensitivity and user friendliness is needed for the RDT to be adopted clinically. There remains an urgent need for better Lassa fever diagnostics to promote safety of in-hospital care and better disease outcomes in low-resource settings. FUNDING Médecins Sans Frontières.
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Affiliation(s)
- Jelte Elsinga
- Luxembourg Operational Research Unit, Médecins Sans Frontières, Luxembourg City, Luxembourg; Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Temmy Sunyoto
- Luxembourg Operational Research Unit, Médecins Sans Frontières, Luxembourg City, Luxembourg.
| | | | | | | | - Chiara Burzio
- Operational Centre Belgium, Médecins Sans Frontières, Brussels, Belgium
| | | | - Chiedozie K Ojide
- Alex Ekwueme Federal University Teaching Hospital, Federal Ministry of Health, Abakaliki, Nigeria
| | - Nnennaya Ajayi
- Alex Ekwueme Federal University Teaching Hospital, Federal Ministry of Health, Abakaliki, Nigeria
| | - Richard Ewah
- Alex Ekwueme Federal University Teaching Hospital, Federal Ministry of Health, Abakaliki, Nigeria
| | - Emeka O Ogah
- Alex Ekwueme Federal University Teaching Hospital, Federal Ministry of Health, Abakaliki, Nigeria
| | | | - Anthony Ahumibe
- Nigerian Center for Disease Control and Prevention, Abuja, Nigeria
| | | | - Adebola Olayinka
- Nigerian Center for Disease Control and Prevention, Abuja, Nigeria
| | - Sylvie Jonckheere
- Operational Centre Belgium, Médecins Sans Frontières, Brussels, Belgium
| | - Pascale Chaillet
- Operational Centre Belgium, Médecins Sans Frontières, Brussels, Belgium
| | - Michel van Herp
- Operational Centre Belgium, Médecins Sans Frontières, Brussels, Belgium
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SAMSON T, AROMOLARAN O, AKINGBADE T. Lassa fever cases and mortality in Nigeria: Quantile Regression vs. Machine Learning Models. J Public Health Afr 2023; 14:2712. [PMID: 38259425 PMCID: PMC10801397 DOI: 10.4081/jphia.2024.2712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024] Open
Abstract
Lassa fever (LF) is caused by the Lassa fever virus (LFV). It is endemic in West Africa, of which % of the infections are ascribed to Nigeria. This disease affects mostly the productive age and hence a proper understanding of the dynamics of this disease will help in formulating policies that would help in curbing the spread of LF. The objective of this study is to compare the performance of quantile regression models with that of Machine Learning models in. Data between between 7th January 2018 2018 and 17th December, 2022 on suspected cases, confirmed cases and deaths resulting from LF were retrieved from the Nigeria Centre for Disease Control (NCDC). The data obtained were fitted to quantile regression models (QRM) at 25, 50 and 75% as well as to Machine learning models. The response variable being confirmed cases and mortality due to Lassa fever in Nigeria while the independent variables were total confirmed cases, the week, month and year. Result showed that the highest monthly mean confirmed cases (56) and mortality (9) from LF were reported in February. The first quarter of the year reported the highest cases of both confirmed cases and deaths in Nigeria. Result also revealed that for the confirmed cases, quantile regression at 50% outperformed the best of the MLM, Gaussian-matern5/2 GPR (RMSE=10.3393 vs. 11.615), while for mortality, the medium Gaussian SVM (RMSE=1.6441 vs. 1.8352) outperformed QRM. Quantile regression model at 50% better captured the dynamics of the confirmed cases of LF in Nigeria while the medium Gaussian SVM better captured the mortality of LF in Nigeria. Among the features selected, confirmed cases was found to be the most important feature that drive its mortality with the implication that as the confirmed cases of Lassa fever increases, is a significant increase in its mortality. This therefore necessitates a need for a better intervention measures that will help curb Lassa fever mortality as a result of the increase in the confirmed cases. There is also a need for promotion of good community hygiene which could include; discouraging rodents from entering homes and putting food in rodent proof containers to avoid contamination to help hart the spread of Lassa fever in Nigeria.
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Affiliation(s)
- T.K SAMSON
- Statistics Programme, College of Agriculture, Engineering and Science
| | - O. AROMOLARAN
- Microbiology Programme, College of Agriculture, Engineering and Science, Bowen University, Iwo, Nigeria
| | - T. AKINGBADE
- Statistics Programme, College of Agriculture, Engineering and Science
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Cadmus S, Taiwo OJ, Akinseye V, Cadmus E, Famokun G, Fagbemi S, Ansumana R, Omoluabi A, Ayinmode A, Oluwayelu D, Odemuyiwa S, Tomori O. Ecological correlates and predictors of Lassa fever incidence in Ondo State, Nigeria 2017-2021: an emerging urban trend. Sci Rep 2023; 13:20855. [PMID: 38012226 PMCID: PMC10682180 DOI: 10.1038/s41598-023-47820-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023] Open
Abstract
Lassa fever (LF) is prevalent in many West African countries, including Nigeria. Efforts to combat LF have primarily focused on rural areas where interactions between rodents and humans are common. However, recent studies indicate a shift in its occurrence from rural to urban areas. We analysed secondary data of reported LF outbreaks from 2017 to 2021 in Ondo State, Nigeria to identify the distribution pattern, ecological variations, and other determinants of disease spread from the ward level using nearest neighbour statistics and regression analysis. Data utilised include LF incidence, ecological variables involving population, nighttime light intensity, vegetation, temperature, market presence, road length, and building area coverage. ArcGIS Pro 3.0 software was employed for spatial analysis. Results revealed spatio-temporal clustering of LF incidents between 2017 and 2021, with an increasing trend followed by a decline in 2021. All wards in Owo Local Government Area were identified as LF hotspots. The ecological variables exhibited significant correlations with the number of LF cases in the wards, except for maximum temperature. Notably, these variables varied significantly between wards with confirmed LF and those without. Therefore, it is important to prioritise strategies for mitigating LF outbreaks in urban areas of Nigeria and other LF-endemic countries.
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Affiliation(s)
- Simeon Cadmus
- Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
- Damien Foundation Genomics and Mycobacteria Research and Training Centre, University of Ibadan, Ibadan, Oyo State, Nigeria.
- Centre for Control and Prevention of Zoonoses, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria.
| | | | - Victor Akinseye
- Damien Foundation Genomics and Mycobacteria Research and Training Centre, University of Ibadan, Ibadan, Oyo State, Nigeria
- Department of Chemical Sciences, Augustine University, Ilara-Epe, Lagos State, Nigeria
| | - Eniola Cadmus
- Department of Community Medicine, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Gboyega Famokun
- Department of Epidemiology and Disease Control, Ondo State Ministry of Health, Ondo State, Nigeria
| | - Stephen Fagbemi
- Department of Epidemiology and Disease Control, Ondo State Ministry of Health, Ondo State, Nigeria
| | - Rashid Ansumana
- School of Community Health Sciences, Njala University, Bo, Sierra Leone
| | | | - Adekunle Ayinmode
- Centre for Control and Prevention of Zoonoses, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
- Department of Veterinary Parasitology and Entomology, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Daniel Oluwayelu
- Centre for Control and Prevention of Zoonoses, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
- Department of Veterinary Microbiology, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Solomon Odemuyiwa
- Centre for Control and Prevention of Zoonoses, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA
| | - Oyewale Tomori
- African Centre of Excellence for Genomics of Infectious Diseases, Redeemer's University, Ede, Osun State, Nigeria
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Grant DS, Samuels RJ, Garry RF, Schieffelin JS. Lassa Fever Natural History and Clinical Management. Curr Top Microbiol Immunol 2023. [PMID: 37106159 DOI: 10.1007/82_2023_263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Lassa fever is caused by Lassa virus (LASV), an Old World Mammarenavirus that is carried by Mastomys natalensis and other rodents. It is endemic in Sierra Leone, Nigeria, and other countries in West Africa. The clinical presentation of LASV infection is heterogenous varying from an inapparent or mild illness to a fatal hemorrhagic fever. Exposure to LASV is usually through contact with rodent excreta. After an incubation period of 1-3 weeks, initial symptoms such as fever, headache, and fatigue develop that may progress to sore throat, retrosternal chest pain, conjunctival injection, vomiting, diarrhea, and abdominal pain. Severe illness, including hypotension, shock, and multiorgan failure, develops in a minority of patients. Patient demographics and case fatality rates are distinctly different in Sierra Leone and Nigeria. Laboratory diagnosis relies on the detection of LASV antigens or genomic RNA. LASV-specific immunoglobulin G and M assays can also contribute to clinical management. The mainstay of treatment for Lassa fever is supportive care. The nucleoside analog ribavirin is commonly used to treat acute Lassa fever but is considered useful only if treatment is begun early in the disease course. Drugs in development, including a monoclonal antibody cocktail, have the potential to impact the management of Lassa fever.
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Affiliation(s)
- Donald S Grant
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health, Kenema, Sierra Leone
- College of Medicine and Allied Health Sciences (COMAHS), University of Sierra Leone, Freetown, Sierra Leone
| | - Robert J Samuels
- Lassa Fever Program, Kenema Government Hospital, Ministry of Health, Kenema, Sierra Leone
| | - Robert F Garry
- School of Medicine, Department of Microbiology and Immunology, Tulane University, New Orleans, LA, 70112, USA
- Zalgen Labs, Frederick, MD, 21703, USA
- Global Virus Network (GVN), Baltimore, MD, 21201, USA
| | - John S Schieffelin
- School of Medicine, Department of Pediatrics, Tulane University, New Orleans, LA, 70112, USA.
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