Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]

Background Lassa fever (LF) is an endemic and immediately notifiable disease in Liberia, and one laboratory confirmed case constitutes an outbreak. We described the epidemiological characteristics and hospital outcomes of LF cases hospitalized during the 2022-2023 outbreak in Liberia. Methods A retr...

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Main Authors: Emmanuel Dwalu, Pryanka Relan, Julius S. M. Gilayeneh, Patrick N. Kpanyen, Peter Adewuyi, Godwin E. Akpan, Ibrahim Franklyn Kamara, George W. Goteh, Shermarke Hassan, Philip Owiti, Fahn Tarweh, Benjamin T. Vonhm, Bode I. Shobayo, Ralph W. Jetoh, Louis Ako-Egbe, Chukwuma D. Umeokonkwo, Darius B. Lehyen, Mher Beglaryan, Hannock Tweya
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Language:English
Published: F1000 Research Ltd 2025-05-01
Series:F1000Research
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Online Access:https://f1000research.com/articles/13-661/v2
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author Emmanuel Dwalu
Pryanka Relan
Julius S. M. Gilayeneh
Patrick N. Kpanyen
Peter Adewuyi
Godwin E. Akpan
Ibrahim Franklyn Kamara
George W. Goteh
Shermarke Hassan
Philip Owiti
Fahn Tarweh
Benjamin T. Vonhm
Bode I. Shobayo
Ralph W. Jetoh
Louis Ako-Egbe
Chukwuma D. Umeokonkwo
Darius B. Lehyen
Mher Beglaryan
Hannock Tweya
author_facet Emmanuel Dwalu
Pryanka Relan
Julius S. M. Gilayeneh
Patrick N. Kpanyen
Peter Adewuyi
Godwin E. Akpan
Ibrahim Franklyn Kamara
George W. Goteh
Shermarke Hassan
Philip Owiti
Fahn Tarweh
Benjamin T. Vonhm
Bode I. Shobayo
Ralph W. Jetoh
Louis Ako-Egbe
Chukwuma D. Umeokonkwo
Darius B. Lehyen
Mher Beglaryan
Hannock Tweya
author_sort Emmanuel Dwalu
collection DOAJ
description Background Lassa fever (LF) is an endemic and immediately notifiable disease in Liberia, and one laboratory confirmed case constitutes an outbreak. We described the epidemiological characteristics and hospital outcomes of LF cases hospitalized during the 2022-2023 outbreak in Liberia. Methods A retrospective cohort study was conducted using routine LF surveillance data from the 2022-2023 outbreak in Liberia. Descriptive statistics were used to summarize the data and log binomial regression to assess the association between epidemiological characteristics and mortality. Results A total of 439 suspected LF cases were reported. The median age was 22 (interquartile range (IQR): 10-33) years and 233 (53%) were females. The median number of days between symptom onset and admission was 4 (IQR 2-7). Of the 439 cases, 416 (95%) were tested for LF and 138 were confirmed with 33% positivity rate. The majority, 95 (69%), of confirmed cases were <30 years, 78 (57%) were females, and 81 (59%) were reported during the dry season (October – March). Contact with rodents, 95 (69%), was the commonest mode of exposure. Fever, 128 (93%), malaise, 121 (88%), headache, 114 (83%) and myalgia, 114 (83%) were the most common clinical characteristics. There were 83 (19%) deaths among hospitalized suspected LF cases - 42 deaths (15%) among 278 individuals who tested negative and 41 among confirmed cases with 30% case fatality rate (CFR). Age 40-49 years accounted for 8/12 (67%) and those aged≥50 reported 5/8 (63%) of the deaths among the confirmed cases. There was no significant association between epidemiological characteristics and LF mortality. Conclusions The outbreak highlighted a high disease burden of LF with young adults disproportionately infected, and mortality, even among those who tested negative for the virus. This underscores the urgent need for preventive measures like vaccines and health education campaigns.
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spelling doaj-art-54ce2d01ee774d0893ab2b985b40c3a52025-08-20T03:07:44ZengF1000 Research LtdF1000Research2046-14022025-05-011310.12688/f1000research.150743.2181955Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]Emmanuel Dwalu0https://orcid.org/0000-0003-2875-4130Pryanka Relan1https://orcid.org/0000-0002-9543-7891Julius S. M. Gilayeneh2Patrick N. Kpanyen3Peter Adewuyi4Godwin E. Akpan5https://orcid.org/0000-0001-8204-9219Ibrahim Franklyn Kamara6https://orcid.org/0000-0003-1454-4650George W. Goteh7Shermarke Hassan8Philip Owiti9Fahn Tarweh10Benjamin T. Vonhm11Bode I. Shobayo12https://orcid.org/0000-0002-4864-0248Ralph W. Jetoh13Louis Ako-Egbe14https://orcid.org/0000-0002-3269-8509Chukwuma D. Umeokonkwo15Darius B. Lehyen16https://orcid.org/0009-0008-9894-7409Mher Beglaryan17Hannock Tweya18National Public Health Institute of Liberia, Monrovia, LiberiaHealth Emergencies Programme, World Health Organization, Geneva, SwitzerlandNational Public Health Institute of Liberia, Monrovia, LiberiaNational Public Health Institute of Liberia, Monrovia, LiberiaAfrican Field Epidemiology Network, Monrovia, LiberiaAfrican Field Epidemiology Network, Monrovia, LiberiaReproductive Maternal Newborn Child and Adolescent Health Unit, World Health Organization Country Office, Freetown, Sierra LeoneNational Public Health Institute of Liberia, Monrovia, LiberiaInfectious Diseases Data Observatory, University of Oxford, Oxford, UKMinistry of Health, Nairobi, KenyaNational Public Health Institute of Liberia, Monrovia, LiberiaNational Public Health Institute of Liberia, Monrovia, LiberiaNational Public Health Institute of Liberia, Monrovia, LiberiaNational Public Health Institute of Liberia, Monrovia, LiberiaWorld Health Organization Country Office, Monrovia, LiberiaAfrican Field Epidemiology Network, Kampala, Central Region, UgandaNational Public Health Institute of Liberia, Monrovia, LiberiaTuberculosis Research and Prevention Centre, Yerevan 0014, ArmeniaInternational Training and Education Center for Health (I-TECH), Lilongwe, MalawiBackground Lassa fever (LF) is an endemic and immediately notifiable disease in Liberia, and one laboratory confirmed case constitutes an outbreak. We described the epidemiological characteristics and hospital outcomes of LF cases hospitalized during the 2022-2023 outbreak in Liberia. Methods A retrospective cohort study was conducted using routine LF surveillance data from the 2022-2023 outbreak in Liberia. Descriptive statistics were used to summarize the data and log binomial regression to assess the association between epidemiological characteristics and mortality. Results A total of 439 suspected LF cases were reported. The median age was 22 (interquartile range (IQR): 10-33) years and 233 (53%) were females. The median number of days between symptom onset and admission was 4 (IQR 2-7). Of the 439 cases, 416 (95%) were tested for LF and 138 were confirmed with 33% positivity rate. The majority, 95 (69%), of confirmed cases were <30 years, 78 (57%) were females, and 81 (59%) were reported during the dry season (October – March). Contact with rodents, 95 (69%), was the commonest mode of exposure. Fever, 128 (93%), malaise, 121 (88%), headache, 114 (83%) and myalgia, 114 (83%) were the most common clinical characteristics. There were 83 (19%) deaths among hospitalized suspected LF cases - 42 deaths (15%) among 278 individuals who tested negative and 41 among confirmed cases with 30% case fatality rate (CFR). Age 40-49 years accounted for 8/12 (67%) and those aged≥50 reported 5/8 (63%) of the deaths among the confirmed cases. There was no significant association between epidemiological characteristics and LF mortality. Conclusions The outbreak highlighted a high disease burden of LF with young adults disproportionately infected, and mortality, even among those who tested negative for the virus. This underscores the urgent need for preventive measures like vaccines and health education campaigns.https://f1000research.com/articles/13-661/v2Liberia Lassa fever positivity rate case fatality rate outbreak Integrated Disease Surveillance and Responseeng
spellingShingle Emmanuel Dwalu
Pryanka Relan
Julius S. M. Gilayeneh
Patrick N. Kpanyen
Peter Adewuyi
Godwin E. Akpan
Ibrahim Franklyn Kamara
George W. Goteh
Shermarke Hassan
Philip Owiti
Fahn Tarweh
Benjamin T. Vonhm
Bode I. Shobayo
Ralph W. Jetoh
Louis Ako-Egbe
Chukwuma D. Umeokonkwo
Darius B. Lehyen
Mher Beglaryan
Hannock Tweya
Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]
F1000Research
Liberia
Lassa fever
positivity rate
case fatality rate
outbreak
Integrated Disease Surveillance and Response
eng
title Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]
title_full Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]
title_fullStr Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]
title_full_unstemmed Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]
title_short Epidemiological characteristics and hospital outcomes of hospitalized Lassa fever cases during the 2022-2023 outbreak in Liberia [version 2; peer review: 1 approved, 2 approved with reservations]
title_sort epidemiological characteristics and hospital outcomes of hospitalized lassa fever cases during the 2022 2023 outbreak in liberia version 2 peer review 1 approved 2 approved with reservations
topic Liberia
Lassa fever
positivity rate
case fatality rate
outbreak
Integrated Disease Surveillance and Response
eng
url https://f1000research.com/articles/13-661/v2
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