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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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Adeke A, Ajayi N, Azuogu B, Chika-Igwenyi N, Onwe E. The Role of Partnership in Lassa Fever Prevention and Control in a Tertiary Health Facility in Southeastern Nigeria. NIGERIAN JOURNAL OF MEDICINE 2022. [DOI: 10.4103/njm.njm_32_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kayem ND, Benson C, Aye CYL, Barker S, Tome M, Kennedy S, Ariana P, Horby P. Lassa fever in pregnancy: a systematic review and meta-analysis. Trans R Soc Trop Med Hyg 2021; 114:385-396. [PMID: 32125412 PMCID: PMC7197258 DOI: 10.1093/trstmh/traa011] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/12/2019] [Accepted: 02/13/2020] [Indexed: 12/29/2022] Open
Abstract
Lassa fever is a zoonotic infection endemic to West Africa and is known to have adverse effects in pregnancy. We sought to synthesize and critically appraise currently available evidence on the effects of Lassa fever in pregnancy. An exhaustive bibliographic search from dates of inception to 30 September 2019 yielded 13 studies, from which individual patient data were extracted. The absolute risk of maternal death associated with Lassa fever was estimated at 33.73% (95% CI 22.05 to 46.42%, I2=72.40%, p=0.0014). The relative risk of death in pregnant women compared with non-pregnant women was estimated at 2·86 (95% CI 1.77 to 4.63, I2=27.27%, p=0.239). The formal gap analysis shows imprecise data on the risk of Lassa-related maternal and perinatal mortality and insufficient data for other pregnancy outcomes. The currently available evidence for the use of ribavirin in pregnant patients is not conclusive. With a threefold increased risk of mortality, there is a need to prioritize pregnant women as a special subgroup of interest for Lassa research. Robust prospective studies estimating the true incidence of adverse maternal and perinatal outcomes and randomized controlled trials to evaluate the efficacy of therapeutics for maternal Lassa virus infection are urgently needed.
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Affiliation(s)
- Nzelle D Kayem
- Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
| | - Charlotte Benson
- Women's Centre, John Radcliffe Hospital, Oxford University Hospitals, Oxford, OX3 9DU, UK
| | - Christina Y L Aye
- Women's Centre, John Radcliffe Hospital, Oxford University Hospitals, Oxford, OX3 9DU, UK.,Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, OX3 9DU, UK
| | - Sarah Barker
- Women's Centre, John Radcliffe Hospital, Oxford University Hospitals, Oxford, OX3 9DU, UK
| | - Mariana Tome
- Stoke Mandeville Hospital, Mandeville Road, Aylesbury, HP21 8AL, UK
| | - Stephen Kennedy
- Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, OX3 9DU, UK
| | - Proochista Ariana
- Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
| | - Peter Horby
- Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
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Abstract
Lassa fever (LF) is a lethal hemorrhagic disease primarily concentrated in the tropical savannah regions of Nigeria and the Mano River Union countries of Sierra Leone, Liberia, and Guinea. Endemic hotspots within these countries have had recurrent exposure to Lassa virus (LASV) via continual spillover from the host reservoir Mastomys natalensis. Increased trade and travel throughout the region have spread the virus to previously unexposed countries, including Ghana, Benin, Mali, and Côte d'Ivoire. In the absence of effective treatment or vaccines to LASV, preventative measures against Lassa fever rely heavily on reducing or eliminating rodent exposure, increasing the knowledge base surrounding the virus and disease in communities, and diminishing the stigmas faced by Lassa fever survivors.
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Chika-Igwenyi NM, Harrison RE, Psarra C, Gil-Cuesta J, Gulamhusein M, Onwe EO, Onoh RC, Unigwe US, Ajayi NA, Nnadozie UU, Ojide CK, Nwidi DU, Ezeanosike O, Sampson E, Adeke AS, Ugwu CN, Anebonam U, Tshiang JK, Maikere J, Reid A. Early onset of neurological features differentiates two outbreaks of Lassa fever in Ebonyi state, Nigeria during 2017-2018. PLoS Negl Trop Dis 2021; 15:e0009169. [PMID: 33684118 PMCID: PMC7984835 DOI: 10.1371/journal.pntd.0009169] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/22/2021] [Accepted: 01/22/2021] [Indexed: 01/15/2023] Open
Abstract
Lassa fever (LF) is an acute viral haemorrhagic illness with various non-specific clinical manifestations. Neurological symptoms are rare at the early stage of the disease, but may be seen in late stages, in severely ill patients.The aim of this study was to describe the epidemiological evolution, socio-demographic profiles, clinical characteristics, and outcomes of patients seen during two Lassa fever outbreaks in Ebonyi State, between December 2017 and December 2018. Routinely collected clinical data from all patients admitted to the Virology Centre of the hospital during the period were analysed retrospectively. Out of a total of 83 cases, 70(84.3%) were RT-PCR confirmed while 13 (15.7%) were probable cases. Sixty-nine (83.1%) patients were seen in outbreak 1 of whom 53.6% were urban residents, while 19%, 15%, and 10% were farmers, students and health workers respectively. There were 14 (16.8%) patients, seen in second outbreak with 92.9% rural residents. There were differences in clinical symptoms, signs and laboratory findings between the two outbreaks. The case fatality rates were 29.9% in outbreak 1 and 85.7% for outbreak 2. Neurological features and abnormal laboratory test results were associated with higher mortality rate, seen in outbreak 2. This study revealed significant differences between the two outbreaks. Of particular concern was the higher case fatality during the outbreak 2 which may be from a more virulent strain of the Lassa virus. This has important public health implications and further molecular studies are needed to better define its characteristics.
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Affiliation(s)
- Nneka M. Chika-Igwenyi
- Department of Medicine, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | | | - Christina Psarra
- Médecins sans Frontières Operational Research Unit (LuxOR), Operational Centre Brussels, Belgium
| | - Julita Gil-Cuesta
- Médecins sans Frontières Operational Research Unit (LuxOR), Operational Centre Brussels, Belgium
| | - Maria Gulamhusein
- Médecins sans Frontières Operational Research Unit (LuxOR), Operational Centre Brussels, Belgium
| | - Emeka O. Onwe
- Department of Paediatrics, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Robinson C. Onoh
- Department of Obstetrics and Gynaecology, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Uche S. Unigwe
- Department of Medicine, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
- University of Nigeria Teaching Hospital, Ituku Ozalla Enugu, Nigeria
| | - Nnennaya A. Ajayi
- Department of Medicine, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Ugochukwu U. Nnadozie
- Division of Plastic Surgery, Department of Surgery, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Chiedozie K. Ojide
- Department of Medical Microbiology, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
- Virology Laboratory, Virology Centre,AlexEkwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Damian U. Nwidi
- Department of Medicine, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Obumneme Ezeanosike
- Department of Paediatrics, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | - Emeka Sampson
- Ebonyi State Ministry of Health, Abakaliki, Ebonyi, Nigeria
| | - Azuka S. Adeke
- Department of Community Medicine, Alex Ekwueme Federal University Teaching Hospital Abakiliki, Abakaliki, Ebonyi, Nigeria
| | - Collins N. Ugwu
- Department of Medicine, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Abakaliki, Ebonyi, Nigeria
| | | | | | | | - Anthony Reid
- Médecins sans Frontières Operational Research Unit (LuxOR), Operational Centre Brussels, Belgium
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Emperador DM, Mazzola LT, Kelly-Cirino C. An open-source molecular diagnostic platform approach for outbreak and epidemic preparedness. Afr J Lab Med 2020; 9:1017. [PMID: 33102172 PMCID: PMC7564747 DOI: 10.4102/ajlm.v9i2.1017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Background Diagnostic development for outbreak pathogens has typically followed a disease-specific reactive rather than proactive response. Given the diversity of outbreak pathogens, particularly those prioritised by the World Health Organization Research and Development Blueprint, a more flexible and proactive approach to epidemic preparedness is needed to expand access to critical molecular diagnostic tests in peripheral and resource-constrained deployment settings. Objective New and more sustainable directives are needed to spur the development of high-quality products, particularly for epidemics more often found in low- and middle-income countries. To leverage and de-risk the development process, we present the benefits and challenges of an open-source business model for co-development of molecular diagnostic tests for decentralised settings. Methods We identify key outbreak pathogens that are available only for testing in high infrastructure laboratories and compare in-country installed base platforms that could be leveraged for menu expansion. Key strengths and challenges for development are highlighted for both platform and assay developers, with discussion of how to leverage and de-risk the process through an open-source development model. Results Depending on the specific partner strengths, options for partnership roles are presented. The proposed open-source business model addresses the particular challenges in the detection of outbreak- and epidemic-prone pathogens in low- and middle-income countries, reduces development and deployment risks to support outbreak response, strengthens diagnostic capacity and creates a viable market for product developers. Conclusion We hope this model for a collaborative and open-source approach for molecular diagnostics serves to encourage stakeholders to consider co-development partnerships to improve outbreak preparedness and epidemic/pandemic response.
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Affiliation(s)
- Devy M Emperador
- Foundation for Innovative and New Diagnostics, Geneva, Switzerland
| | - Laura T Mazzola
- Foundation for Innovative and New Diagnostics, San Francisco, California, United States
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Usifoh SF, Odigie AE, Ighedosa SU, Uwagie-Ero EA, Aighewi IT. Lassa Fever-associated Stigmatization among Staff and Students of the University of Benin, Nigeria. J Epidemiol Glob Health 2020; 9:107-115. [PMID: 31241868 PMCID: PMC7310750 DOI: 10.2991/jegh.k.190514.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/21/2019] [Indexed: 11/10/2022] Open
Abstract
Lassa Fever (LF) remains a health burden in several endemic areas of Nigeria, and its toll remains unabated over several decades. Although most studies have focused on virological and clinical considerations, few studies have attempted to address the perceived psychosocial component of LF disease in Nigeria. Evaluation of stigmatization and discrimination faced by LF survivors is an important step in improving individual health and protecting public health. This study aimed to assess LF-associated stigmatization associated among staff and students of the University of Benin. Descriptive analyses of 600 consenting respondents (300 staff and 300 students) sampled using pretested questionnaires was conducted, and the Chi-square test was used to test for significant association between perceived LF stigmatization and predefined variables. LF was a potential cause of stigmatization in a higher proportion of student (n = 162, 57.9%) than staff (n = 112, 39.9%). LF-associated stigmatization among students was significantly associated with sex (p = 0.012) and poor knowledge (p = 0.013) of LF transmission and prevention. A greater tendency for stigmatization was observed among females than males. A comprehensive emergency response plan incorporating accurate knowledge dissemination about the disease may be a first step toward tackling perceived LF stigmatization.
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Affiliation(s)
- Stella Folajole Usifoh
- Department of Clinical Pharmacy and Pharmacy Practice, Faculty of Pharmacy, University of Benin, Benin City, Nigeria
| | - Amienwanlen Eugene Odigie
- Department of Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Benin, Benin City, Nigeria
| | | | | | - Isoken Tito Aighewi
- Department of Environmental Management and Toxicology, Faculty of Life Sciences, University of Benin, Benin City, Nigeria
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Babalola SO, Babatunde JA, Remilekun OM, Amaobichukwu AR, Abiodun AM, Jide I, Adeshina ASI, Chikwe I, Aremu OS. Lassa virus RNA detection from suspected cases in Nigeria, 2011-2017. Pan Afr Med J 2019; 34:76. [PMID: 31819792 PMCID: PMC6884721 DOI: 10.11604/pamj.2019.34.76.16425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/02/2019] [Indexed: 11/11/2022] Open
Abstract
Introduction The diagnosis of Lassa fever is crucial to confirm cases, as well as to control/prevent nosocomial and community-based transmission and initiation of treatment, which is still limited in the country. Thus, we aimed at providing some information on the laboratory detection of Lassa from suspected cases in Nigeria. Methods This was a retrospective study of seasonal Lassa fever outbreaks data from 1,263 samples analyzed using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) at the Virology Research Laboratory, College of Medicine, University of Lagos/Lagos University Teaching Hospital between year 2011 and 2017. Data were analyzed using the 21st edition of SPSS statistical software (2015). Results The RT-PCR test confirmed the presence of Lassa in 112 (8.9%) comprising 61 (54.4%) males, 48 (42.9%) females and 3 (2.7%) individuals without gender information. Those aged between 18 and 49 years were mostly affected. There was a decline in the detection of Lassa from 4.7% in 2011/2012 to less than 1% by the 2014/2015. However, during the 2015/2016 and 2016/2017 seasons the detection rates increased to 10.4% and 15.1% respectively. The Northern region of Nigeria reported high confirmed cases of Lassa. The South Western region also witnessed an increased Lassa fever positivity rate of 13.4% of which Lagos and Ogun states being the focal state of Lassa activity in the region. Conclusion These established the need for heightening the continued surveillance for Lassa as well as the establishment of other testing facilities within these endemic regions for prompt diagnosis of Lassa fever.
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Affiliation(s)
- Salu Olumuyiwa Babalola
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos (CMUL), PM.B. 12003, Lagos, Nigeria.,Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria
| | - James Ayorinde Babatunde
- Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria.,Department of Biochemistry, College of Medicine, University of Lagos, PM.B. 12003, Lagos, Nigeria
| | - Orenolu Mercy Remilekun
- Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria
| | - Anyanwu Roosevelt Amaobichukwu
- Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria
| | - Abdullah Mariam Abiodun
- Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria
| | - Idris Jide
- Honourable Commissioner for Health, Lagos State Ministry of Health, Alausa, Ikeja, Lagos, Nigeria
| | - Abdus-Salam Ismail Adeshina
- Epidemiology Unit, Directorate of Disease Control, Lagos State Ministry of Health, Alausa, Ikeja, Lagos, Nigeria
| | - Ihekweazu Chikwe
- Nigerian Centre for Disease Control (NCDC), Plot 801, Ebitu Ukiwe Street, Jabi, Abuja, Nigeria
| | - Omilabu Sunday Aremu
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos (CMUL), PM.B. 12003, Lagos, Nigeria.,Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria
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Affiliation(s)
| | - Daniel O. Oluwayelu
- Department of Veterinary Microbiology, University of Ibadan, Ibadan, Nigeria
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10
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Mazzola LT, Kelly-Cirino C. Diagnostics for Lassa fever virus: a genetically diverse pathogen found in low-resource settings. BMJ Glob Health 2019; 4:e001116. [PMID: 30899575 PMCID: PMC6407561 DOI: 10.1136/bmjgh-2018-001116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/31/2018] [Accepted: 11/06/2018] [Indexed: 11/18/2022] Open
Abstract
Lassa fever virus (LASV) causes acute viral haemorrhagic fever with symptoms similar to those seen with Ebola virus infections. LASV is endemic to West Africa and is transmitted through contact with excretions of infected Mastomys natalensis rodents and other rodent species. Due to a high fatality rate, lack of treatment options and difficulties with prevention and control, LASV is one of the high-priority pathogens included in the WHO R&D Blueprint. The WHO LASV vaccine strategy relies on availability of effective diagnostic tests. Current diagnostics for LASV include in-house and commercial (primarily research-only) laboratory-based serological and nucleic acid amplification tests. There are two commercially available (for research use only) rapid diagnostic tests (RDTs), and a number of multiplex panels for differential detection of LASV infection from other endemic diseases with similar symptoms have been evaluated. However, a number of diagnostic gaps remain. Lineage detection is a challenge due to the genomic diversity of LASV, as pan-lineage sensitivity for both molecular and immunological detection is necessary for surveillance and outbreak response. While pan-lineage ELISA and RDTs are commercially available (for research use only), validation and external quality assessment (EQA) is needed to confirm detection sensitivity for all known or relevant strains. Variable sensitivity of LASV PCR tests also highlights the need for improved validation and EQA. Given that LASV outbreaks typically occur in low-resource settings, more options for point-of-care testing would be valuable. These requirements should be taken into account in target product profiles for improved LASV diagnostics.
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Genetic characterization of Lassa virus strains isolated from 2012 to 2016 in southeastern Nigeria. PLoS Negl Trop Dis 2018; 12:e0006971. [PMID: 30500827 PMCID: PMC6267959 DOI: 10.1371/journal.pntd.0006971] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/03/2018] [Indexed: 01/20/2023] Open
Abstract
Lassa virus (LASV) is endemic in parts of West Africa where it causes Lassa fever (LF), a viral hemorrhagic fever with frequent fatal outcomes. The diverse LASV strains are grouped into six major lineages based on the geographical location of the isolated strains. In this study, we have focused on the lineage II strains from southern Nigeria. We determined the viral sequences from positive cases of LF reported at tertiary hospitals in Ebonyi and Enugu between 2012 and 2016. Reverse transcription-polymerase chain reaction (RT-PCR) showed that 29 out of 123 suspected cases were positive for the virus among which 11 viral gene sequences were determined. Phylogenetic analysis of the complete coding sequences of the four viral proteins revealed that lineage II strains are broadly divided into two genetic clades that diverged from a common ancestor 195 years ago. One clade, consisting of strains from Ebonyi and Enugu, was more conserved than the other from Irrua, although the four viral proteins were evolving at similar rates in both clades. These results suggested that the viruses of these clades have been distinctively evolving in geographically separate parts of southern Nigeria. Furthermore, the epidemiological data of the 2014 outbreak highlighted the role of human-to-human transmission in this outbreak, which was supported by phylogenetic analysis showing that 13 of the 16 sequences clustered together. These results provide new insights into the evolution of LASV in southern Nigeria and have important implications for vaccine development, diagnostic assay design, and LF outbreak management. Lassa fever (LF) is a viral hemorrhagic fever caused by Lassa virus (LASV). The different LASV strains are grouped into lineages based on the geographical location of the isolated strains. The aim of our study was to characterize the lineage II strains in southern Nigeria. We sequenced LASV RNA genome from positive cases of LF between 2012 and 2016 which were reported at tertiary hospitals in Ebonyi and Enugu in southeastern Nigeria. Phylogenetic analysis of the viral proteins showed the division of lineage II strains into two genetic clades with one clade being more conserved than the other despite evolving at similar rates. Also, our phylogenetic analysis supported the role of human to human transmission in the 2014 outbreak, in keeping with the epidemiological data. These results provide additional information on the evolution of LASV in southern Nigeria and LF outbreak management.
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12
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Widespread arenavirus occurrence and seroprevalence in small mammals, Nigeria. Parasit Vectors 2018; 11:416. [PMID: 30005641 PMCID: PMC6045851 DOI: 10.1186/s13071-018-2991-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 07/03/2018] [Indexed: 11/10/2022] Open
Abstract
Background Lassa fever, killing thousands of people annually, is the most reported viral zoonotic disease in Nigeria. Recently, different rodent species carrying diverse lineages of the Lassa virus (LASV) in addition to a novel Mobala-like genetic sequence were detected within the country. Here, screening 906 small mammal specimens from 11 localities for IgG antibodies and incorporating previous PCR detection data involving the same populations, we further describe arenavirus prevalence across Nigeria in relation to host species and geographical location. Methods Small mammals were trapped during the period 2011–2015 according to geographical location (endemic and non-endemic zones for Lassa fever), season (rainy and dry seasons between 2011 and 2012 for certain localities) and habitat (indoors, peridomestic settings and sylvatic vegetation). Identification of animal specimens from genera such as Mastomys and Mus (Nannomys) was assisted by DNA sequencing. Small mammals were tested for LASV IgG antibody using an indirect immunofluorescence assay (IFA). Results Small mammals were infected in both the endemic and non-endemic zones for Lassa fever, with a wider range of species IgG-positive (n = 8) than those which had been previously detected to be PCR-positive (n = 3). IgG-positive species, according to number of infected individuals, were Mastomys natalensis (n = 40), Mastomys erythroleucus (n = 15), Praomys daltoni (n = 6), Mus baoulei (n = 5), Rattus rattus (n = 2), Crocidura spp. (n = 2), Mus minutoides (n = 1) and Praomys misonnei (n = 1). Multimammate mice (Mastomys natalensis and M. erythroleucus) were the most ubiquitously infected, with animals testing positive by either PCR or IgG in 7 out of the 11 localities sampled. IgG prevalence in M. natalensis ranged from 1% in Abagboro, 17–36 % in Eguare Egoro, Ekpoma and Ngel Nyaki, up to 52 % in Mayo Ranewo. Prevalence according to locality, season and age was not, however, statistically significant for M. natalensis in Eguare Egoro and Ekpoma, localities that were sampled longitudinally. Conclusions Overall, our study demonstrates that arenavirus occurrence is probably more widely distributed geographically and in extent of host taxa than is currently realized. This expanded scope should be taken into consideration in Lassa fever control efforts. Further sampling should also be carried out to isolate and characterize potential arenaviruses present in small mammal populations we found to be seropositive.
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Isere EE, Fatiregun AA, Ilesanmi O, Ijarotimi I, Egube B, Adejugbagbe A, Famokun GA. Lessons Learnt from Epidemiological Investigation of Lassa Fever Outbreak in a Southwest State of Nigeria December 2015 to April 2016. PLOS CURRENTS 2018; 10. [PMID: 30094105 PMCID: PMC6063375 DOI: 10.1371/currents.outbreaks.bc4396a6650d0ed1985d731583bf5ded] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Introduction: An outbreak of Lassa Fever (LF) reported and confirmed in Ondo state, Southwest Nigeria in January 2016 was investigated. This paper provides the epidemiology of the LF and lessons learnt from the investigation of the outbreak. Methods: The incidence management system (IMS) model was used for the outbreak coordination. Cases and deaths were identified through the routine surveillance system using standard definitions for suspected and confirmed cases and deaths respectively. Blood specimens collected from suspect cases were sent for confirmation at a WHO accredited laboratory. Active case search was intensified, and identified contacts of confirmed cases were followed up for the maximum incubation period of the disease. Other public health responses included infection prevention and control, communication and advocacy as well as case management. Data collected were analysed using SPSS 20, by time, place and persons and important lessons drawn were discussed. Results: We identified 90 suspected LF cases of which 19 were confirmed by the laboratory. More than half (52.6%) of the confirmed cases were females with majority (73.7%) in the age group ≥ 15 years. The Case Fatality Rate (CFR) of 63.2% among the laboratory-confirmed positive cases where 9 of 19 cases died, was significantly higher compared to the laboratory confirmed negative cases where 6 of the 65 cases died ( CFR; 8.5%) p ≤ 0.05. Two hundred and eighty-seven contacts of the confirmed cases were identified, out of which 267(93.0%) completed the follow-up without developing any symptoms and 2 (0.7%) developed symptoms consistent with LF and were confirmed by the laboratory. More than half of the contacts were females (64.5%) with most of them (89.2%) in the age group ≥ 25 years. Discussion: One key lesson learnt from the investigation was that the confirmed cases were mainly primary cases; hence the needs to focus on measures of breaking the chain of transmission in the animal-man interphase during Lassa fever epidemic preparedness and response. In addition, the high case fatality rate despite early reporting and investigation suggested the need for a review of the case management policy and structure in the State. Key Words: Lassa fever, Outbreak Response, Incident Management System, Nigeria
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Olayemi A, Obadare A, Oyeyiola A, Fasogbon S, Igbokwe J, Igbahenah F, Ortsega D, Günther S, Verheyen E, Fichet-Calvet E. Small mammal diversity and dynamics within Nigeria, with emphasis on reservoirs of the lassa virus. SYST BIODIVERS 2017. [DOI: 10.1080/14772000.2017.1358220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ayodeji Olayemi
- Natural History Museum, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - Adeoba Obadare
- Natural History Museum, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - Akinlabi Oyeyiola
- Natural History Museum, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | | | - Joseph Igbokwe
- Natural History Museum, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - Felix Igbahenah
- Geography Department, Benue State University, Makurdi, Benue State, Nigeria
| | - Daniel Ortsega
- Geography Department, Benue State University, Makurdi, Benue State, Nigeria
| | - Stephan Günther
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Erik Verheyen
- Royal Belgian Institute of Natural Sciences, Brussels, Belgium and University of Antwerp, Antwerp, Belgium
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Olowookere SA, Adegbenro CA, Idowu A, Omisore AG, Shabi OM, Ikem UR, Ekwere GA, Oderinde IF. Knowledge Attitude and Practices Toward Lassa Fever Control and Prevention Among Residents of Ile-Ife, Southwest Nigeria. INTERNATIONAL QUARTERLY OF COMMUNITY HEALTH EDUCATION 2017; 37:107-112. [PMID: 28511600 DOI: 10.1177/0272684x17701261] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lassa fever had been reported as a cause of death especially in endemic parts of Nigeria. This study assessed the knowledge, attitude, and practices toward Lassa fever control and prevention among residents of Ile-Ife, southwest Nigeria. Descriptive cross-sectional study was conducted among consenting randomly selected adults using an interviewer administered questionnaire. Data were analyzed using descriptive and inferential statistics. A total of 400 questionnaires with completed data were analyzed (response rate 96%). Majority, 207 (51.8%), were males while 193 (48.2%) were females. Most, 234 (58.5%), had tertiary education while 148 (37%) had secondary education. Fifty-nine percent had heard of Lassa fever with radio as their major source of information. About 76% had inadequate knowledge, 54% had negative attitude while 51% had poor practice toward Lassa fever. Determinants of knowledge of Lassa fever include having higher education (Adjusted Odd Ratio (AOR) = 11.49, 95% CI [3.10, 42.69], p = .0001), being in civil service (AOR = 0.22, 95% CI [0.09, 0.51], p = .01), and earning higher income (AOR = 4.23, 95% CI [2.61, 6.84], p = .0001). In conclusion, the knowledge, attitude, as well as preventive practices to Lassa fever were poor. It is necessary to increase public education and improve hygienic practices.
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Affiliation(s)
- S A Olowookere
- 1 Department of Community Health, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - C A Adegbenro
- 1 Department of Community Health, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - A Idowu
- 2 Department of Community Medicine, Bowen University Teaching Hospital, Ogbomosho, Nigeria
| | - A G Omisore
- 3 Department of Community Medicine, Osun State University, Osogbo, Nigeria
| | - O M Shabi
- 4 Department of Family Medicine, Federal Teaching Hospital, Ido-Ekiti, Ekiti State
| | - U R Ikem
- 1 Department of Community Health, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - G A Ekwere
- 1 Department of Community Health, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - I F Oderinde
- 1 Department of Community Health, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria
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Fatiregun AA, Isere EE. Epidemic preparedness and management: A guide on Lassa fever outbreak preparedness plan. Niger Med J 2017; 58:1-6. [PMID: 29238121 PMCID: PMC5715560 DOI: 10.4103/0300-1652.218414] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Epidemic prone diseases threaten public health security. These include diseases such as cholera, meningitis, and hemorrhagic fevers, especially Lassa fever for which Nigeria reports considerable morbidity and mortality annually. Interestingly, where emergency epidemic preparedness plans are in place, timely detection of outbreaks is followed by a prompt and appropriate response. Furthermore, due to the nature of spread of Lassa fever in an outbreak setting, there is the need for health-care workers to be familiar with the emerging epidemic management framework that has worked in other settings for effective preparedness and response. This paper, therefore, discussed the principles of epidemic management using an emergency operating center model, review the epidemiology of Lassa fever in Nigeria, and provide guidance on what is expected to be done in preparing for epidemic of the disease at the health facilities, local and state government levels in line with the Integrated Disease Surveillance and Response strategy.
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Affiliation(s)
| | - Elvis Efe Isere
- Cluster Coordinator, World Health Organization, Akure, Ondo State, Nigeria
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Iroezindu MO, Unigwe US, Okwara CC, Ozoh GA, Ndu AC, Ohanu ME, Nwoko UO, Okoroafor UW, Ejimudo E, Tobin EA, Asogun DA. Lessons learnt from the management of a case of Lassa fever and follow-up of nosocomial primary contacts in Nigeria during Ebola virus disease outbreak in West Africa. Trop Med Int Health 2015; 20:1424-1430. [PMID: 26171669 DOI: 10.1111/tmi.12565] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To describe our experiences in the management of a case of Lassa fever (LF) and follow-up of nosocomial primary contacts during the 2014 Ebola outbreak in West Africa. METHODS Clinical management of the index case and infection control/surveillance activities for primary contacts are described. Laboratory confirmation was by Lassa virus-specific reverse-transcriptase PCR. RESULTS A 28-year-old man with a 10-day history of febrile illness was referred to a major tertiary hospital in south-east Nigeria from a city that previously experienced a LF outbreak and was recently affected by Ebola. On observation of haemorrhagic features, clinicians were at a crossroads. Diagnosis of LF was confirmed at a National Reference Centre. The patient died despite initiation of ribavirin therapy. Response activities identified 121 primary contacts comprising 78 (64.5%) hospital staff/interns, 19 (15.7%) medical students, 18 (14.9%) inpatients and 6 (5.0%) relatives. Their mean age was 32.8 ± 6.6 years, and 65.3% were women. Twenty (16.5%) had high-risk exposure and were offered ribavirin as post-exposure prophylaxis. No secondary case of LF occurred. Fatigue (43.8%) and dizziness (31.3%) were the commonest side effects of ribavirin. CONCLUSIONS Response activities contained nosocomial spread of LF, but challenges were experienced including lack of a purpose-built isolation facility, absence of local Lassa virus laboratory capacity, failure to use appropriate protective equipment and stigmatisation of contacts. A key lesson is that the weak health systems of Africa should be comprehensively strengthened; otherwise, we might win the Ebola battle but lose the one against less virulent infections for which effective treatment exists.
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Affiliation(s)
- Michael O Iroezindu
- Department of Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Uche S Unigwe
- Department of Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Celestine C Okwara
- Department of Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Gladys A Ozoh
- Department of Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Anne C Ndu
- Department of Community Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Martin E Ohanu
- Department of Medical Microbiology, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Ugochukwu O Nwoko
- Department of Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Uwadiegwu W Okoroafor
- Department of Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
| | - Esinulo Ejimudo
- Nigeria Centre for Disease Control and Prevention, Abuja, Nigeria
| | - Ekaete A Tobin
- Institute of Lassa Fever Research and Control, Irrua Specialist Hospital, Irrua, Edo State, Nigeria
| | - Danny A Asogun
- Institute of Lassa Fever Research and Control, Irrua Specialist Hospital, Irrua, Edo State, Nigeria
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Mylne AQN, Pigott DM, Longbottom J, Shearer F, Duda KA, Messina JP, Weiss DJ, Moyes CL, Golding N, Hay SI. Mapping the zoonotic niche of Lassa fever in Africa. Trans R Soc Trop Med Hyg 2015; 109:483-92. [PMID: 26085474 PMCID: PMC4501400 DOI: 10.1093/trstmh/trv047] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/29/2015] [Indexed: 02/05/2023] Open
Abstract
Background Lassa fever is a viral haemorrhagic illness responsible for disease outbreaks across West Africa. It is a zoonosis, with the primary reservoir species identified as the Natal multimammate mouse, Mastomys natalensis. The host is distributed across sub-Saharan Africa while the virus' range appears to be restricted to West Africa. The majority of infections result from interactions between the animal reservoir and human populations, although secondary transmission between humans can occur, particularly in hospital settings. Methods Using a species distribution model, the locations of confirmed human and animal infections with Lassa virus (LASV) were used to generate a probabilistic surface of zoonotic transmission potential across sub-Saharan Africa. Results Our results predict that 37.7 million people in 14 countries, across much of West Africa, live in areas where conditions are suitable for zoonotic transmission of LASV. Four of these countries, where at-risk populations are predicted, have yet to report any cases of Lassa fever. Conclusions These maps act as a spatial guide for future surveillance activities to better characterise the geographical distribution of the disease and understand the anthropological, virological and zoological interactions necessary for viral transmission. Combining this zoonotic niche map with detailed patient travel histories can aid differential diagnoses of febrile illnesses, enabling a more rapid response in providing care and reducing the risk of onward transmission.
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Affiliation(s)
- Adrian Q N Mylne
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Joshua Longbottom
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Freya Shearer
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | | | | | - Catherine L Moyes
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Nick Golding
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Simon I Hay
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA Fogarty International Center, National Institutes of Health, Bethesda, Maryland, USA
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Kyei NNA, Abilba MM, Kwawu FK, Agbenohevi PG, Bonney JHK, Agbemaple TK, Nimo-Paintsil SC, Ampofo W, Ohene SA, Nyarko EO. Imported Lassa fever: a report of 2 cases in Ghana. BMC Infect Dis 2015; 15:217. [PMID: 26022703 PMCID: PMC4448534 DOI: 10.1186/s12879-015-0956-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 05/20/2015] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Lassa fever is a potentially fatal acute viral illness caused by Lassa virus which is carried by rodents and is endemic in some West African countries. Importation of emerging infections such as Lassa fever, Ebola Virus Disease and other viral hemorrhagic fevers into non endemic regions is a growing threat particularly as international travel and commitments in resolving conflicts in endemic countries in the West Africa sub-region continue. CASE PRESENTATION We report the first two recorded imported cases of Lassa fever among Ghanaian Peace keepers in rural Liberia, who became ill while on Peace keeping mission. They were subsequently evacuated to the UN level IV hospital in Accra, where their illnesses were laboratory confirmed. One of the patients recovered with ribavirin treatment and supportive therapy. No secondary clinical cases occurred in Ghana. CONCLUSIONS Healthcare providers at all levels of care should thus have a high index of suspicion for these infectious diseases and adopt standard infection control measures when treating patients in endemic regions or returning travelers from an endemic region with a febrile illness even of a known etiology.
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Affiliation(s)
| | - Mark M Abilba
- 37 Military Hospital, Neghelli Barracks, Accra, Ghana.
| | | | | | - Joseph H K Bonney
- Noguchi Memorial Research Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Ghana.
| | | | - Shirley C Nimo-Paintsil
- Noguchi Memorial Research Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Ghana.
| | - William Ampofo
- Noguchi Memorial Research Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Ghana.
| | - Sally-Ann Ohene
- World Health Organization Ghana Country Office, P. O Box MB 142, Accra, Ghana.
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The rubber plantation environment and Lassa fever epidemics in Liberia, 2008–2012: A spatial regression. Spat Spatiotemporal Epidemiol 2014; 11:163-74. [DOI: 10.1016/j.sste.2014.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 03/12/2014] [Accepted: 04/30/2014] [Indexed: 11/19/2022]
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Peterson AT, Moses LM, Bausch DG. Mapping transmission risk of Lassa fever in West Africa: the importance of quality control, sampling bias, and error weighting. PLoS One 2014; 9:e100711. [PMID: 25105746 PMCID: PMC4126660 DOI: 10.1371/journal.pone.0100711] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 05/13/2014] [Indexed: 12/15/2022] Open
Abstract
Lassa fever is a disease that has been reported from sites across West Africa; it is caused by an arenavirus that is hosted by the rodent M. natalensis. Although it is confined to West Africa, and has been documented in detail in some well-studied areas, the details of the distribution of risk of Lassa virus infection remain poorly known at the level of the broader region. In this paper, we explored the effects of certainty of diagnosis, oversampling in well-studied region, and error balance on results of mapping exercises. Each of the three factors assessed in this study had clear and consistent influences on model results, overestimating risk in southern, humid zones in West Africa, and underestimating risk in drier and more northern areas. The final, adjusted risk map indicates broad risk areas across much of West Africa. Although risk maps are increasingly easy to develop from disease occurrence data and raster data sets summarizing aspects of environments and landscapes, this process is highly sensitive to issues of data quality, sampling design, and design of analysis, with macrogeographic implications of each of these issues and the potential for misrepresenting real patterns of risk.
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Affiliation(s)
- A. Townsend Peterson
- Biodiversity Institute, University of Kansas, Lawrence, Kansas, United States of America
- * E-mail:
| | - Lina M. Moses
- Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Daniel G. Bausch
- Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
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Olowookere SA, Fatiregun AA, Gbolahan OO, Adepoju EG. Diagnostic proficiency and reporting of Lassa fever by physicians in Osun State of Nigeria. BMC Infect Dis 2014; 14:344. [PMID: 24950705 PMCID: PMC4230318 DOI: 10.1186/1471-2334-14-344] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 06/17/2014] [Indexed: 11/10/2022] Open
Abstract
Background Lassa fever is highly contagious and commonly results in death. It is therefore necessary to diagnose and report any suspected case of Lassa fever to facilitate preventive strategies. This study assessed the preparedness of physicians in the diagnosis and reporting of Lassa fever. Methods The study design was descriptive cross-sectional. The consenting medical doctors completed a self-administered questionnaire on the diagnosis and reporting of Lassa fever. Descriptive and inferential statistics were used in data analyses. Results One hundred seventy-five physicians participated in the study. The mean age was 41.5 ± 10.9 years (range, 24–75 years). Most of the physicians were male (78.9%) and had practiced medicine ≥ 20 years (51.5%). Most of the physicians had a good knowledge regarding the diagnosis and reporting of Lassa fever; however, none of the physicians had ever diagnosed or reported a suspected case. Predictors of good knowledge include male sex, not practicing at a secondary health care level and post graduation year more than 20 years. Conclusion There is disparity in knowledge and practices of physicians regarding the diagnosis and reporting of Lassa fever. Thus, it is necessary to improve the knowledge and practices of physicians regarding the diagnosis and reporting of Lassa fever.
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Affiliation(s)
- Samuel Anu Olowookere
- Department of Community Health, Faculty of Clinical Sciences, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun state, Nigeria.
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Grant DS, Khan H, Schieffelin J, Bausch DG. Lassa Fever. Emerg Infect Dis 2014. [DOI: 10.1016/b978-0-12-416975-3.00004-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Ajayi NA, Nwigwe CG, Azuogu BN, Onyire BN, Nwonwu EU, Ogbonnaya LU, Onwe FI, Ekaete T, Günther S, Ukwaja KN. Containing a Lassa fever epidemic in a resource-limited setting: outbreak description and lessons learned from Abakaliki, Nigeria (January–March 2012). Int J Infect Dis 2013; 17:e1011-6. [DOI: 10.1016/j.ijid.2013.05.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 05/28/2013] [Accepted: 05/30/2013] [Indexed: 01/25/2023] Open
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Kelly JD, Barrie MB, Ross RA, Temple BA, Moses LM, Bausch DG. Housing equity for health equity: a rights-based approach to the control of Lassa fever in post-war Sierra Leone. BMC INTERNATIONAL HEALTH AND HUMAN RIGHTS 2013; 13:2. [PMID: 23282054 PMCID: PMC3562201 DOI: 10.1186/1472-698x-13-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 12/27/2012] [Indexed: 02/03/2023]
Abstract
Poor quality housing is an infringement on the rights of all humans to a standard of living adequate for health. Among the many vulnerabilities of those without adequate shelter is the risk of disease spread by rodents and other pests. One such disease is Lassa fever, an acute and sometimes severe viral hemorrhagic illness endemic in West Africa. Lassa virus is maintained in the rodent Mastomys natalensis, commonly known as the "multimammate rat," which frequently invades the domestic environment, putting humans at risk of Lassa fever. The highest reported incidence of Lassa fever in the world is consistently in the Kenema District of Sierra Leone, a region that was at the center of Sierra Leone's civil war in which tens of thousands of lives were lost and hundreds of thousands of dwellings destroyed. Despite the end of the war in 2002, most of Kenema's population still lives in inadequate housing that puts them at risk of rodent invasion and Lassa fever. Furthermore, despite years of health education and village hygiene campaigns, the incidence of Lassa fever in Kenema District appears to be increasing. We focus on Lassa fever as a matter of human rights, proposing a strategy to improve housing quality, and discuss how housing equity has the potential to improve health equity and ultimately economic productivity in Sierra Leone. The manuscript is designed to spur discussion and action towards provision of housing and prevention of disease in one of the world's most vulnerable populations.
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Affiliation(s)
- J Daniel Kelly
- Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, 1430 Tulane Avenue SL-17, New Orleans, LA, 70112, USA
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Abstract
Arenaviruses are a family of enveloped negative-stranded RNA viruses that can cause severe human disease ranging from encephalitis symptoms to fulminant hemorrhagic fever. The bi‑segmented RNA genome encodes four polypeptides: the nucleoprotein NP, the surface glycoprotein GP, the polymerase L, and the RING finger protein Z. Although it is the smallest arenavirus protein with a length of 90 to 99 amino acids and a molecular weight of approx. 11 kDa, the Z protein has multiple functions in the viral life cycle including (i) regulation of viral RNA synthesis, (ii) orchestration of viral assembly and budding, (iii) interaction with host cell proteins, and (iv) interferon antagonism. In this review, we summarize our current understanding of the structural and functional role of the Z protein in the arenavirus replication cycle.
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Affiliation(s)
- Sarah Katharina Fehling
- Institut für Virologie der Philipps-Universität Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany.
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Molecular diagnostics for lassa fever at Irrua specialist teaching hospital, Nigeria: lessons learnt from two years of laboratory operation. PLoS Negl Trop Dis 2012; 6:e1839. [PMID: 23029594 PMCID: PMC3459880 DOI: 10.1371/journal.pntd.0001839] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 08/14/2012] [Indexed: 01/18/2023] Open
Abstract
Background Lassa fever is a viral hemorrhagic fever endemic in West Africa. However, none of the hospitals in the endemic areas of Nigeria has the capacity to perform Lassa virus diagnostics. Case identification and management solely relies on non-specific clinical criteria. The Irrua Specialist Teaching Hospital (ISTH) in the central senatorial district of Edo State struggled with this challenge for many years. Methodology/Principal Findings A laboratory for molecular diagnosis of Lassa fever, complying with basic standards of diagnostic PCR facilities, was established at ISTH in 2008. During 2009 through 2010, samples of 1,650 suspected cases were processed, of which 198 (12%) tested positive by Lassa virus RT-PCR. No remarkable demographic differences were observed between PCR-positive and negative patients. The case fatality rate for Lassa fever was 31%. Nearly two thirds of confirmed cases attended the emergency departments of ISTH. The time window for therapeutic intervention was extremely short, as 50% of the fatal cases died within 2 days of hospitalization—often before ribavirin treatment could be commenced. Fatal Lassa fever cases were older (p = 0.005), had lower body temperature (p<0.0001), and had higher creatinine (p<0.0001) and blood urea levels (p<0.0001) than survivors. Lassa fever incidence in the hospital followed a seasonal pattern with a peak between November and March. Lassa virus sequences obtained from the patients originating from Edo State formed—within lineage II—a separate clade that could be further subdivided into three clusters. Conclusions/Significance Lassa fever case management was improved at a tertiary health institution in Nigeria through establishment of a laboratory for routine diagnostics of Lassa virus. Data collected in two years of operation demonstrate that Lassa fever is a serious public health problem in Edo State and reveal new insights into the disease in hospitalized patients. In the past, diagnostic testing for Lassa fever patients in Nigeria has been performed nearly exclusively outside of the country. Patients thus were managed on-site based on clinical suspicion alone, posing risks to patients and health care workers and exhausting resources. To tackle this problem, we established a diagnostic PCR laboratory directly at a referral hospital serving a Lassa fever endemic area in Nigeria. Long-term collaboration between partners in the North and the South was crucial to implement this project. Training of laboratory staff in the partner institutions and on-site, mobilization of local human and financial resources, good management of the laboratory, a basic quality management and control system, and a stable supply chain for consumables and reagents were among the key factors for success. The laboratory reliably delivered results in a short turnaround time, despite some problems due to PCR contamination. The service has improved patient and contact management including treatment with ribavirin and led to better protection of health care workers against hospital-acquired infections. The data provide new insights into disease progression and a basis for further optimization of case management including supportive treatment.
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Dzotsi EK, Ohene SA, Asiedu-Bekoe F, Amankwa J, Sarkodie B, Adjabeng M, Thouphique AM, Ofei A, Oduro J, Atitogo D, Bonney JHK, Paintsil SCN, Ampofo W. The first cases of Lassa fever in Ghana. Ghana Med J 2012; 46:166-170. [PMID: 23661832 PMCID: PMC3645162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
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.
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Affiliation(s)
- E K Dzotsi
- Disease Surveillance Department, Ghana Health Service, Accra, Ghana
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Ehichioya DU, Asogun DA, Ehimuan J, Okokhere PO, Pahlmann M, Olschläger S, Becker-Ziaja B, Günther S, Omilabu SA. Hospital-based surveillance for Lassa fever in Edo State, Nigeria, 2005-2008. Trop Med Int Health 2012; 17:1001-4. [PMID: 22594713 DOI: 10.1111/j.1365-3156.2012.03010.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To estimate the burden of Lassa fever in northern and central Edo, a state in south Nigeria where Lassa fever has been reported. METHODS Blood samples were obtained from 60 patients hospitalised at the Irrua Specialist Teaching Hospital (ISTH), Irrua, with a clinical suspicion of Lassa fever and from 451 febrile outpatients seen at the ISTH and hospitals in Ekpoma, Iruekpen, Uromi, Auchi and Igarra. All samples were tested retrospectively by Lassa virus-specific RT-PCR. Outpatients were additionally screened for Lassa virus-specific antibodies by indirect immunofluorescent antibody assay. RESULTS Lassa virus was detected in 25 of 60 (42%) patients with a clinical suspicion of Lassa fever. The disease affected persons of all age groups and with various occupations, including healthcare workers. The clinical picture was dominated by gastrointestinal symptoms. The case fatality rate was 29%. Lassa virus was detected in 2 of 451 (0.44%) febrile outpatients, and 8 (1.8%) were positive for Lassa virus-specific IgG. CONCLUSIONS Lassa fever contributes to hospital mortality in Edo State. The low prevalence of the disease among outpatients and the low seroprevalence may indicate that the population-level incidence is not high. Surveillance for Lassa fever should focus on the hospitalised patient.
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Affiliation(s)
- Deborah U Ehichioya
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
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Abstract
Recent Lassa virus strains from Nigeria were completely or partially sequenced. Phylogenetic analysis revealed the predominance of lineage II and III strains, the existence of a previously undescribed (sub)lineage in Nigeria, and the directional spread of virus in the southern part of the country. The Bayesian analysis also provided estimates for divergence times within the Lassa virus clade.
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