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Infectious & Epidemic Diseases

Detecting, diagnosing and understanding the pathogens behind fevers and outbreaks in Sierra Leone and across West Africa — from everyday undiagnosed fevers to epidemic arboviruses.

Overview

Turning undiagnosed fevers into actionable intelligence

Much of the disease burden in our region hides behind a single symptom: fever. In Sierra Leone, an estimated 65% of acute febrile illnesses test positive for malaria (SL DHS 2019) — but that leaves a large share of fevers undiagnosed, caused by viruses, bacteria, parasites or fungi that routine testing never identifies. Our work in this area builds the laboratory, surveillance and research capacity to find out what is actually making people sick, and to detect emerging and epidemic pathogens early — before they become outbreaks.

Why it matters

Preparedness, not just response

A regional hotspot

Climate change, urbanisation and mobility make West Africa increasingly prone to emerging and re-emerging outbreaks — Ebola, Lassa, arboviruses and more.

Hidden burden

Arboviral infections are underreported and often confused with malaria, so their true burden — and their risk — is poorly understood.

Local capacity

We strengthen in-country clinical, laboratory and genomic capacity so that detection and response can be led from within the region.

Flagship studies

Two studies driving this work

Acute Febrile Illness

Surveillance of Acute Febrile Illness (AFI) in Sierra Leone

Prof. Alhaji U. Njai — Principal Investigator · Co-PI: Prof. Jorge Osorio, Global Health Institute, UW–Madison

This study identifies and diagnoses the causes of undiagnosed fevers — fevers of unknown origin (FUO) — among patients attending designated sentinel health facilities in Freetown. Acute febrile illness can be driven by a wide range of pathogens, including dengue, typhoid, chikungunya, leptospirosis, influenza and many others, which frequently go unidentified when testing focuses on malaria alone.

Working with the Directorate of Health Security & Emergencies of the Ministry of Health and Sanitation, the study develops a mechanism to determine the etiologies of undiagnosed fevers, informing public-health programmes and strengthening the capacity to identify, monitor and assess pathogens of potential public-health importance — part of a global early-warning system for pandemic threats.

Objectives

  • Identify the pathogens causing fevers of unknown origin at designated sentinel sites.
  • Determine the proportion of fevers associated with FUO.
  • Guide operational research on acute febrile illness in Sierra Leone.

At a glance

LeadProf. Alhaji U. Njai (PI)
PartnerUW–Madison Global Health Institute, Africa One Health Center
NetworkAbbott Pandemic Defense Coalition (APDC)
Sentinel sitesConnaught, Ola During Children’s, 34 Military, Choithram Memorial & Rokupa hospitals
FocusFevers of unknown origin & emerging pathogen discovery
Arboviruses · SC-GRA

Strengthening Clinical & Genomic Research Capacity on Arboviruses (SC-GRA)

Prof. Alhaji Njai — Sierra Leone Country Principal Investigator · Lead PI: Prof. Seydou Doumbia, USTTB, Mali

West Africa is emerging as a potential hotspot for arboviral disease — dengue (DENV), Zika (ZIKV) and chikungunya (CHIKV), all transmitted by Aedes mosquitoes. Following the 2014 Ebola epidemic and the COVID-19 pandemic, the region continues to experience arboviral outbreaks that remain understudied, underreported, and easily confused with malaria.

SC-GRA is a prospective, observational, longitudinal study across five countries of the West African Consortium for Clinical Research on Epidemic Pathogens (WACCREP) — Mali, Côte d’Ivoire, Sierra Leone, Guinea and Liberia. Its principal aim is to advance sub-regional epidemic preparedness and response through integrated, collaborative clinical research and training, generating the evidence needed for surveillance and control of epidemic pathogens.

Asymptomatic arm

A population-based seroconversion survey estimating the seroprevalence and annual incidence of arboviral infection in the general population.

Symptomatic arm

Febrile-illness surveillance measuring the prevalence and distribution of DENV, ZIKV and CHIKV among febrile patients, and the risk factors for severe disease.

Specific objectives

  • Map the geographic and temporal distribution of asymptomatic and symptomatic arboviral pathogens across WACCREP sites.
  • Determine facility-based prevalence of arboviral infection among febrile patients.
  • Identify risk factors for disease severity and describe clinical phenotypes distinguishing mild from severe disease.
  • Estimate seroprevalence and annual incidence of seroconversion in the general population.

At a glance

SL LeadProf. Alhaji Njai (Country PI)
ConsortiumWACCREP — Mali, Côte d’Ivoire, Sierra Leone, Guinea, Liberia
SponsorScience for Africa Foundation (SFA) — EPSILON
CollaborationGlobal Alliance for the Prevention of Pandemics (GAPP), Columbia University; NIAID
PathogensDengue (DENV), Zika (ZIKV), Chikungunya (CHIKV)

Collaborate with us on epidemic preparedness

We welcome partners, students and collaborators interested in infectious-disease surveillance, diagnostics and genomic research in West Africa.

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