Trichinellosis (also known as trichinosis) is a parasitic zoonosis caused by nematodes of the Trichinella genus, with T. spiralis being the most frequently implicated species [1][4]. After ingestion of encysted larvae in undercooked meat, the parasites mature in the small intestine and produce new larvae that encyst in striated muscle [1].
Disease overview
ParasiticTrichinellosis
旋毛虫病
Evidence-backed informationEN 5/7 applicable sections · ZH 5/7 applicable sectionsUpdated Sep 3, 2026
Trichinellosis is a parasitic zoonosis caused by roundworms of the Trichinella genus, most commonly T. spiralis, that is transmitted to humans primarily through consumption of undercooked meat containing Trichinella cysts [1]. The disease is increasingly regarded as a re-emerging zoonosis in some regions, influenced by changing patterns of meat distribution, sylvatic transmission, climate, and sociopolitical shifts [1]. Although ranked among the most important food-borne parasites globally by public-health impact, country-level incidence and distribution data remain uneven, and human trichinellosis is often underreported [2][3].
Read the full clinical and epidemiological profile6
During the intestinal phase, large worm burdens can produce nausea, heartburn, dyspepsia, and diarrhea from two to seven days after infection, while light infections are often asymptomatic; eosinophilia appears early and rises rapidly [1]. About one week after infection, migrating larvae cause facial swelling, scleral inflammation, fever, myalgia, and rash, and possible complications include myocarditis, central nervous system involvement, and pneumonitis [1]. When the central nervous system is affected in severe cases (neurotrichinellosis), the dominant manifestations are encephalopathy, neuromuscular disturbance, and ocular involvement, with encephalopathy accounting for most fatalities, especially when T. spiralis is the etiologic agent [4].
Trichinellosis has been ranked among the most important food-borne parasites of humans in terms of public-health, socioeconomic, and trade impact, yet information from many countries remains scarce and fragmented, with local reports often inaccessible to the international research community [2]. The disappearance of the pathogen from domestic pigs in some settings has led to relaxed veterinary public-health controls, and the disease has been described as re-emerging, driven by increased meat-product distribution, climate change, political transitions, and growing sylvatic transmission; for example, the sociopolitical upheaval in Romania in the 1990s was followed by a rise in incidence [1]. Systematic review evidence from Vietnam indicates that trichinellosis occurs across multiple provinces alongside other food-borne zoonoses, and that underestimation of prevalence is likely because of imperfect diagnostic methods and poorly described sampling [2]. In Iran, published reports indicate that Trichinella spp. infections are documented mainly in wild animals, with most studies concentrated in northern regions and only a small proportion of at-risk humans testing positive for anti-Trichinella IgG [3].
Trichinellosis is primarily food-borne, acquired when humans eat undercooked meat containing Trichinella cysts; wild game carries a higher risk than domestically reared animals, and in North America bear meat is the most frequently implicated source, with pork, wild boar, and dog meat also reported [1]. After ingestion, the larvae are released from their cysts in the stomach, invade the intestinal wall where they mature into adults, and within approximately one week the females release larvae that migrate to voluntarily controlled muscles and encyst [1].
The principal preventive measure is to fully cook meat, with a food thermometer used to confirm that the internal temperature reaches a level sufficient to kill encysted larvae [1]. Public-health authorities emphasize sustained veterinary control of pork and wild-game production, given that relaxation of such measures has been linked to resurgence of Trichinella infections in swine and humans [1].
- 1Wikipedia contributors. Trichinosis - Wikipedia [Internet]. Wikipedia. cited 2 Sept 2026.Available from: https://en.wikipedia.org/wiki/Trichinosis
- 2Ng-Nguyen D et al. A systematic review of taeniasis, cysticercosis and trichinellosis in Vietnam. Parasit Vectors. 2017 Mar 21. PMID: 28320455. doi: 10.1186/s13071-017-2085-9.PubMed: https://pubmed.ncbi.nlm.nih.gov/28320455/
- 3Moazeni M et al. Epidemiology of taeniosis, cysticercosis and trichinellosis in Iran: A systematic review. Zoonoses Public Health. 2019 Feb. PMID: 30575317. doi: 10.1111/zph.12547.PubMed: https://pubmed.ncbi.nlm.nih.gov/30575317/
- 4Bruschi F et al. Neurotrichinellosis. Handb Clin Neurol. 2013. PMID: 23829915. doi: 10.1016/B978-0-444-53490-3.00019-4.PubMed: https://pubmed.ncbi.nlm.nih.gov/23829915/
Coverage
Reporting countries and regions
AustriaAT
BelgiumBE
BulgariaBG
CanadaCA
CroatiaHR
CyprusCY
CzechiaCZ
EstoniaEE
FinlandFI
FranceFR
GermanyDE
GreeceGR
HungaryHU
IcelandIS
IrelandIE
ItalyIT
LatviaLV
LiechtensteinLI
LithuaniaLT
LuxembourgLU
MaltaMT
NetherlandsNL
NorwayNO
PolandPL
PortugalPT
RomaniaRO
SlovakiaSK
SloveniaSI
SpainES
SwedenSE
SwitzerlandCH
United KingdomGB
United StatesUS
Trends by reporting country
Monthly patterns over time
Research Radar
Recent related research
Cultural drivers and health-seeking behaviours that impact on the transmission of pig-associated zoonoses in Lao People’s Democratic Republic
Infectious Diseases of Poverty
Literature links are provided for discovery and do not alter or validate the surveillance series above.
Data access
Page dataset index with source links and update metadata.
Official sourcesAuthority, cadence, notes39
Austria AGES Radar for Infectious Diseases
Austria
AGES Radar monthly national source. Internal ingestion retains native categories; public release is disabled pending licence review.
ECDC Surveillance Atlas — Belgium Annual Baseline
Belgium
Belgium annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Bulgaria Annual Baseline
Bulgaria
Bulgaria annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
Canada PHAC CNDSS Annual
Canada
Canada is the national jurisdiction; subdivision feeds are registered separately.
Public Health Ontario IDTO Monthly
Ontario, Canada
Ontario-level current-year preliminary monthly case counts from Public Health Ontario's IDTO report.
Switzerland FOPH IDD
Switzerland
Switzerland FOPH/BAG IDD mandatory reporting API normalized to national case rows. Monthly series may use the dashboard CHFL aggregate where CH-only monthly series are not exposed.
ECDC Surveillance Atlas — Cyprus Annual Baseline
Cyprus
Cyprus annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Czechia Annual Baseline
Czechia
Czechia annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
Germany RKI SurvStat 2.0
Germany
RKI SurvStat national weekly notification export; raw ZIP exports are retained and recent weeks are overwritten for revisions.
ECDC Surveillance Atlas — Estonia Annual Baseline
Estonia
Estonia annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Spain Annual Baseline
Spain
Spain annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
Finland THL Infectious Diseases Register
Finland
Finland THL Infectious Diseases Register national monthly case counts. The current month is ingested as provisional and the latest three months are refreshed for source revisions.
ECDC Surveillance Atlas — France Annual Baseline
France
France annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — United Kingdom Annual Baseline
United Kingdom
United Kingdom annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Greece Annual Baseline
Greece
Greece annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Croatia Annual Baseline
Croatia
Croatia annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Hungary Annual Baseline
Hungary
Hungary annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
Ireland HPSC Notifiable Diseases Hub
Ireland
Ireland HPSC national weekly notifiable-disease totals from the official ArcGIS FeatureServer. Internal ingestion is enabled; public release remains disabled pending written redistribution permission.
Iceland Directorate of Health Annual Dashboard
Iceland
National annual case notifications by disease. Published values can be revised retrospectively and remain annual period totals.
Iceland Directorate of Health STI Dashboard
Iceland
Monthly STI diagnosis facts from laboratory and registry surveillance; the official dashboard is published on a quarterly schedule.
Iceland Directorate of Health Respiratory Dashboard
Iceland
ISO-week respiratory diagnosis counts. Hospitalizations, samples, and vaccination indicators are separate measures and are not counted as diagnoses.
Iceland Directorate of Health Historical Registry
Iceland
Historical official registry tables for 1997–2021, with annual totals and disease-specific monthly notification facts retained at source grain.
Iceland Directorate of Health Legacy ICD Monthly
Iceland
Historical Saga EHR ICD encounter counts for 1997–2020. This clinical measure is non-comparable with registry notifications and is kept separate.
ECDC Surveillance Atlas — Italy Annual Baseline
Italy
Italy annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Liechtenstein Annual Baseline
Liechtenstein
Liechtenstein annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Lithuania Annual Baseline
Lithuania
Lithuania annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Luxembourg Annual Baseline
Luxembourg
Luxembourg annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Latvia Annual Baseline
Latvia
Latvia annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Malta Annual Baseline
Malta
Malta annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Netherlands Annual Baseline
Netherlands
Netherlands annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
Norway FHI MSIS Statistics Bank
Norway
Norway FHI MSIS national monthly notifications from the official Allvis frontend API; adapter contract checks guard the unversioned endpoint.
ECDC Surveillance Atlas — Poland Annual Baseline
Poland
Poland annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Portugal Annual Baseline
Portugal
Portugal annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Romania Annual Baseline
Romania
Romania annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
Sweden Public Health Agency SmiNet
Sweden
Sweden SmiNet national monthly reported cases from the official Public Health Agency statistics pages; public release is enabled with closed-month publication and revisable recent-month refreshes.
ECDC Surveillance Atlas — Slovenia Annual Baseline
Slovenia
Slovenia annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
ECDC Surveillance Atlas — Slovakia Annual Baseline
Slovakia
Slovakia annual Member-State reported case counts from the ECDC Surveillance Atlas. Missing topic/year cells remain unknown and published zeroes are preserved. Data provided by ECDC based on data reported by EU/EEA Member States.
US CDC NNDSS
United States
CDC National Notifiable Diseases Surveillance System provisional data.
US CDC NHSS HIV
United States
CDC NNDSS weekly data plus NHSS annual national HIV diagnoses