ORPHA:99824
Lassa fever
Also known as: LF · Lassa hemorrhagic fever
Clinical definition (Orphanet)
Lassa fever (LF) is a potentially severe viral hemorrhagic disease caused by Lassa virus and characterized by initial fever and malaise followed by gastrointestinal symptoms and, in severe cases, bleeding, shock and multi-organ system failure.
How rare: How common this is has not been clearly measured.
Is anyone studying this?
5,590
5,590 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=183) is 38.
5,590 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 38 (publications denominator n=183).
3,291 in the last 10 years · low confidence
Is a treatment being tested?
11
trials for this specific condition
11 interventional trials matched this specific condition name; 3 currently recruiting in our sample.
Data as of 26 July 2026
11 interventional trials — more than 59.2% of diseases in the trials denominator have none at all (151 of 255; this disease is at the 87.3th percentile).
low confidence · 87.3th percentile (trials denominator)
Do we know what causes it?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
Who's working on it?
1,589
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.
- 01Günther S13 papers · 2026
Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Papers in Europe PMC - 02
- 03Asogun D10 papers · 2026
Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria.
Papers in Europe PMC - 04Okogbenin S9 papers · 2026
Institute of Lassa Fever Research and Control, Irrua Specialist Teaching Hospital, Irrua, Nigeria.
Papers in Europe PMC - 05Saka SA7 papers · 2025
Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria.
Papers in Europe PMC - 06
- 07
- 08Fichet-Calvet E6 papers · 2026
Zoonoses Control Research Group, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Papers in Europe PMC - 09
- 10Hinrichs M6 papers · 2026
Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Papers in Europe PMC
Recruiting interventional trials
Trials testing a treatment from the matched ClinicalTrials.gov set
11 interventional trials matched after quoted-phrase search and title/condition post-filter.
Observational and natural-history studies
5 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.
Recruiting or not-yet-recruiting
Where to find support
We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:
India — NPRD
Last verified 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored below but are not added to the query string.
"Lassa fever" OR "Lassa hemorrhagic fever"
MeSH descriptor terms unioned into the query: Lassa Fever
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Lassa fever" OR "Lassa hemorrhagic fever" OR "arenavirus hemorrhagic fever" OR "lassa virus infectious disease" OR "viral hemorrhagic fever"
Interventional trials matched via: both, phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).
Study-type breakdown: 11 interventional · 5 observational · 0 expanded access. Only interventional studies enter the trial headline.
Cross-references (from Mondo): MESH:D007835 UMLS:C0023092 NCIT:C128418
Query health: ok — strategies attempted: phrase, mesh, recall-expansion; with hits: phrase, mesh, recall-expansion
Run this search on ClinicalTrials.gov
Synonyms dropped by stoplist: LF
Confidence reasoning
- Preferred label is short or not clearly distinctive
- 1 synonym(s) dropped by stoplist (may under-count)
- No label/synonym collisions with other diseases in this corpus