Entomological investigations into yellow fever outbreak in northern Ghana
11 affiliations
- 1Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
- 2Biomedical and Public Health Research Unit, Water Research Institute, Council for Scientific and Industrial Research, Accra, Ghana
- 3Department of Biological, Environmental and Occupational Health, School of Public Health, College of Health Sciences, University of Ghana, Legon, Ghana
- 4Department of Animal Biology and Conservation Science, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- 5Acute Febrile Laboratory, Naval Medical Research Unit 3, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
- 6Department of Molecular Medicine, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- 7Department of Virology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
- 8Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- 9Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- 10Department of Applied Biology, School of Environment and Life Sciences, University of Technology and Applied Sciences, Navrongo, Ghana
- 11Savannah Regional Health Directorate, Damongo, Ghana
Abstract
Arboviruses are pathogens of emerging/re-emerging infectious diseases. Half the world’s population is at risk. Recent African epidemics confirmed 19,569 cases with 820 deaths. In Ghana, Savannah Region had yellow fever (YF) outbreak in 2021. Reports revealed 35 deaths, 202 suspected cases (case fatality rate (CFR) = 17%), and 70 confirmed cases (CFR = 50%). This paper presents YF outbreak entomological investigations findings. A team with expertise in YF outbreak response were assembled and tasked to assess, contain and/or control the rapid spread of YF. Immature Aedes aegypti were collected in/around houses, and adult sampled using BG-Sentinel traps, oral aspirators and Prokopack. The chikungunya, dengue fever, YF, and Zika viruses screening using real time reverse-transcription PCR (detection limit <10 RNA copies/reaction) followed mosquitoes morphological identification. Breeding containers (12,264) were examined. Larvae (3,885) and pupae (1,186) were obtained from 173 containers (positivity rate = 1.26%). Larvae were identified with short and stout siphons. Pupae had short but distinct serrated spicules on paddle fringe and branched/fanlike (6–7 branches) seta 9-VIII. Out of 1,001 houses surveyed, 130 were positive for larvae/pupae (positivity rate = 12.99%). Receptacles included plastic [46.95% (6,529)], metallic [43.32% (6,024)], clay jar [5.42% (753)], tire [4.06% (565)], and well [0.24% (34)]. WHO larval indices thresholds (BI, CI, HI, and PDI) were used to assess risk. Exactly 1,571 adults were identified [Aedes aegypti aegypti (35), Aedes aegypti formosus (619), and Culex sp. (917)]. Outdoor collection were higher (86.4%) than indoors (13.6%). No arboviruses were detected. Generally, vector indices/densities suggested high-risk arbovirus transmission although vectors were not arbovirus positive. Aedes aegypti formosus was dominant. They are bridge vectors maintaining sylvatic YF cycles and spillover transmission. High risk for YF poses public health threat that calls for Aedes mosquito surveillance systems and vector control strategies. Ae. ae. formosus might be drivers for outbreak and/or YF transmission.
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BibTeX
@article{osei2026entomological,
title = {{Entomological investigations into yellow fever outbreak in northern Ghana}},
author = {Joseph Harold Nyarko Osei and Sellase Pi-Bansa and Kwadwo Kyereme Frempong and Mavis Ofei and Helena Anokyewaa Boakye and Jane Ansah-Owusu and Sandra-Candys Adwirba Akorful and Richard Odoi-Teye Malm and Christopher Nii Laryea Tawiah-Mensah and Mufeez Abudu and Andy Asafu-Adjaye and Seth Offei Addo and Bright Agbodzi and Ronald Bentil and Deborah Pratt and Shirley Nimo-Paintsil and Joseph Humphrey Kofi Bonney and Maxwell Alexander Appawu and Millie-Cindy Aba Aude Koffi and Sylvester Coleman and Millicent Captain-Esoah and Chrysantus Kubio and Daniel Adjei Boakye and Samuel Kweku Dadzie},
journal = {PLOS Global Public Health},
year = {2026},
month = oct,
doi = {10.1371/journal.pgph.0007346},
url = {https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0007346},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Entomological investigations into yellow fever outbreak in northern Ghana
AU - Joseph Harold Nyarko Osei
AU - Sellase Pi-Bansa
AU - Kwadwo Kyereme Frempong
AU - Mavis Ofei
AU - Helena Anokyewaa Boakye
AU - Jane Ansah-Owusu
AU - Sandra-Candys Adwirba Akorful
AU - Richard Odoi-Teye Malm
AU - Christopher Nii Laryea Tawiah-Mensah
AU - Mufeez Abudu
AU - Andy Asafu-Adjaye
AU - Seth Offei Addo
AU - Bright Agbodzi
AU - Ronald Bentil
AU - Deborah Pratt
AU - Shirley Nimo-Paintsil
AU - Joseph Humphrey Kofi Bonney
AU - Maxwell Alexander Appawu
AU - Millie-Cindy Aba Aude Koffi
AU - Sylvester Coleman
AU - Millicent Captain-Esoah
AU - Chrysantus Kubio
AU - Daniel Adjei Boakye
AU - Samuel Kweku Dadzie
PY - 2026
DA - 2026/10/15
JO - PLOS Global Public Health
DO - 10.1371/journal.pgph.0007346
UR - https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0007346
AB - Arboviruses are pathogens of emerging/re-emerging infectious diseases. Half the world’s population is at risk. Recent African epidemics confirmed 19,569 cases with 820 deaths. In Ghana, Savannah Region had yellow fever (YF) outbreak in 2021. Reports revealed 35 deaths, 202 suspected cases (case fatality rate (CFR) = 17%), and 70 confirmed cases (CFR = 50%). This paper presents YF outbreak entomological investigations findings. A team with expertise in YF outbreak response were assembled and tasked to assess, contain and/or control the rapid spread of YF. Immature Aedes aegypti were collected in/around houses, and adult sampled using BG-Sentinel traps, oral aspirators and Prokopack. The chikungunya, dengue fever, YF, and Zika viruses screening using real time reverse-transcription PCR (detection limit <10 RNA copies/reaction) followed mosquitoes morphological identification. Breeding containers (12,264) were examined. Larvae (3,885) and pupae (1,186) were obtained from 173 containers (positivity rate = 1.26%). Larvae were identified with short and stout siphons. Pupae had short but distinct serrated spicules on paddle fringe and branched/fanlike (6–7 branches) seta 9-VIII. Out of 1,001 houses surveyed, 130 were positive for larvae/pupae (positivity rate = 12.99%). Receptacles included plastic [46.95% (6,529)], metallic [43.32% (6,024)], clay jar [5.42% (753)], tire [4.06% (565)], and well [0.24% (34)]. WHO larval indices thresholds (BI, CI, HI, and PDI) were used to assess risk. Exactly 1,571 adults were identified [Aedes aegypti aegypti (35), Aedes aegypti formosus (619), and Culex sp. (917)]. Outdoor collection were higher (86.4%) than indoors (13.6%). No arboviruses were detected. Generally, vector indices/densities suggested high-risk arbovirus transmission although vectors were not arbovirus positive. Aedes aegypti formosus was dominant. They are bridge vectors maintaining sylvatic YF cycles and spillover transmission. High risk for YF poses public health threat that calls for Aedes mosquito surveillance systems and vector control strategies. Ae. ae. formosus might be drivers for outbreak and/or YF transmission.
SN - 2767-3375
ER -