Paediatric mpox during Sierra Leone’s 2024 to 2025 clade IIb outbreak: A national surveillance and outbreak-investigation study of 415 children
- 1National Public Health Agency (NPHA), Freetown, Sierra Leone.
- 2School of Professional Counseling, Lindsey Wilson University, Columbia, Kentucky, United States of America.
Abstract
Background: Evidence on paediatric mpox during contemporary African clade IIb outbreaks remains limited. We described paediatric cases in Sierra Leone’s 2024–2025 clade IIb G.1 outbreak by person, time, and place and examined clinical care, outcomes, vaccination records, and documented exposures. Methodology/Principal findings: We conducted a retrospective descriptive study using the national District Health Information Software 2 (DHIS2) mpox database, supplemented by patient charts and outbreak-investigation forms. Among 5,466 cases with recorded age, 415 (7.6%) were children younger than 15 years; 188 (45.3%) were aged 0–4 years, 121 (29.2%) were aged 5–9 years, and 106 (25.5%) were aged 10–14 years. Of 415 paediatric cases, 411 (99.0%) were laboratory-confirmed. Outcome was recorded for 261 children (62.9%); three died (1.1%, exact 95% CI 0.2 to 3.3). Care location was recorded for 285 children; 216 (75.8%) received hospital care for isolation, clinical management, or both. Three sporadic paediatric cases of mpox-like illness were reported from 2017 through 2024; notifications then rose rapidly from April 2025 and peaked in May. Western Area Urban accounted for 195/413 cases with known district (47.2%); crude notified paediatric rates were highest in Western Area Urban, Koinadugu, and Falaba. Household or caregiving contact was the most common documented exposure among 246 classifiable investigation forms (141, 57.3%). Mpox vaccination status was recorded for 27/54 cases aged 12–14 years; six were vaccinated. Conclusions/Significance: Children were not spared during Sierra Leone’s clade IIb outbreak. Response plans should include children in case finding, contact follow-up, clinical care, and vaccination assessment. DHIS2 should capture epidemiological links, clinical outcomes, vaccine eligibility and status, and potential exposure settings through standardised fields. Author summary: The 2022 global mpox outbreak focused attention on adults, who comprised most reported cases. We analysed Sierra Leone’s national surveillance database, patient charts, and outbreak-investigation forms to describe paediatric mpox during the country’s 2024–2025 clade IIb outbreak. Children accounted for 415 of 5,466 cases with recorded age, and almost half of paediatric cases occurred in children younger than 5 years. Three children died among those with recorded outcomes. National records documented three sporadic paediatric cases of mpox-like illness from 2017 through 2024. Notifications then rose rapidly from April 2025 and peaked in May. Western Area Urban recorded the most paediatric cases, while crude notified rates were also high in Koinadugu and Falaba. Household or caregiving contact was the most common documented exposure in available investigation forms, but the records could not establish how individual children acquired infection. Mpox response should identify child contacts early, investigate local exposure patterns, and record linked cases, clinical outcomes, and vaccine eligibility consistently. Prospective contact studies can clarify transmission pathways and guide age-appropriate prevention.
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BibTeX
@article{ikoona2026paediatric,
title = {{Paediatric mpox during Sierra Leone’s 2024 to 2025 clade IIb outbreak: A national surveillance and outbreak-investigation study of 415 children}},
author = {Eric Nzirakaindi Ikoona and Lucy Namulemo and Mary Magdalene Sinnah and Mohamed Alex Vandi and Foday Sahr},
journal = {PLOS Neglected Tropical Diseases},
year = {2026},
month = oct,
doi = {10.1371/journal.pntd.0014785},
url = {https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014785},
note = {CC BY},
}
RIS
TY - JOUR
TI - Paediatric mpox during Sierra Leone’s 2024 to 2025 clade IIb outbreak: A national surveillance and outbreak-investigation study of 415 children
AU - Eric Nzirakaindi Ikoona
AU - Lucy Namulemo
AU - Mary Magdalene Sinnah
AU - Mohamed Alex Vandi
AU - Foday Sahr
PY - 2026
DA - 2026/10/07
JO - PLOS Neglected Tropical Diseases
DO - 10.1371/journal.pntd.0014785
UR - https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014785
AB - Background: Evidence on paediatric mpox during contemporary African clade IIb outbreaks remains limited. We described paediatric cases in Sierra Leone’s 2024–2025 clade IIb G.1 outbreak by person, time, and place and examined clinical care, outcomes, vaccination records, and documented exposures. Methodology/Principal findings: We conducted a retrospective descriptive study using the national District Health Information Software 2 (DHIS2) mpox database, supplemented by patient charts and outbreak-investigation forms. Among 5,466 cases with recorded age, 415 (7.6%) were children younger than 15 years; 188 (45.3%) were aged 0–4 years, 121 (29.2%) were aged 5–9 years, and 106 (25.5%) were aged 10–14 years. Of 415 paediatric cases, 411 (99.0%) were laboratory-confirmed. Outcome was recorded for 261 children (62.9%); three died (1.1%, exact 95% CI 0.2 to 3.3). Care location was recorded for 285 children; 216 (75.8%) received hospital care for isolation, clinical management, or both. Three sporadic paediatric cases of mpox-like illness were reported from 2017 through 2024; notifications then rose rapidly from April 2025 and peaked in May. Western Area Urban accounted for 195/413 cases with known district (47.2%); crude notified paediatric rates were highest in Western Area Urban, Koinadugu, and Falaba. Household or caregiving contact was the most common documented exposure among 246 classifiable investigation forms (141, 57.3%). Mpox vaccination status was recorded for 27/54 cases aged 12–14 years; six were vaccinated. Conclusions/Significance: Children were not spared during Sierra Leone’s clade IIb outbreak. Response plans should include children in case finding, contact follow-up, clinical care, and vaccination assessment. DHIS2 should capture epidemiological links, clinical outcomes, vaccine eligibility and status, and potential exposure settings through standardised fields. Author summary: The 2022 global mpox outbreak focused attention on adults, who comprised most reported cases. We analysed Sierra Leone’s national surveillance database, patient charts, and outbreak-investigation forms to describe paediatric mpox during the country’s 2024–2025 clade IIb outbreak. Children accounted for 415 of 5,466 cases with recorded age, and almost half of paediatric cases occurred in children younger than 5 years. Three children died among those with recorded outcomes. National records documented three sporadic paediatric cases of mpox-like illness from 2017 through 2024. Notifications then rose rapidly from April 2025 and peaked in May. Western Area Urban recorded the most paediatric cases, while crude notified rates were also high in Koinadugu and Falaba. Household or caregiving contact was the most common documented exposure in available investigation forms, but the records could not establish how individual children acquired infection. Mpox response should identify child contacts early, investigate local exposure patterns, and record linked cases, clinical outcomes, and vaccine eligibility consistently. Prospective contact studies can clarify transmission pathways and guide age-appropriate prevention.
SN - 1935-2735
SN - 1935-2727
ER -