Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide







  • Last modified
  • 14 July 2018
  • Datasheet Type(s)
  • Invasive Species
  • Animal Disease
  • Preferred Scientific Name
  • Trichinella
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Nematoda
  •       Class: Adenophorea
  •         Subclass: Enoplia

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Trichinella sp. larva in striated muscle.
TitleTrichinella larva
CaptionTrichinella sp. larva in striated muscle.
Copyright©John W. McGarry
Trichinella sp. larva in striated muscle.
Trichinella larvaTrichinella sp. larva in striated muscle.©John W. McGarry


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Preferred Scientific Name

  • Trichinella

International Common Names

  • English: trichinae

Parasitoses name

  • trichinellosis

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Nematoda
  •             Class: Adenophorea
  •                 Subclass: Enoplia
  •                     Order: Enoplida
  •                         Suborder: Trichinellina
  •                             Family: Trichinellidae
  •                                 Genus: Trichinella


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The geographical distributions of the Trichinella species/genotypes have recently been described by Pozio (2000). All species/genotypes seem to have individual ecological niches for which they are adapted (Kapel, 2000). Thus, T. spiralis is found primarily in the domestic habitat in which environmental stress is limited and the high reproductive capacity has a selective advantage. For the sylvatic species/genotypes, tolerance to high and low temperatures and decomposition of host tissue might be more important than the reproductive capacity (Kapel, 2000).

Trichinella spiralis: Temperate regions in Europe, Asia, New Zealand, North and South America.

Trichinella nativa: Arctic and subarctic areas of the Holarctic region. The isotherm –5°C in January appears to be the southern limit of its geographical distribution (see Pozio et al., 1996, 1998).

Trichinella britovi: Temperate areas of the Palearctic region (Europe, Asia). The January isotherm –6°C appears to be the northern limit of its distribution (see Pozio et al., 1996, 1998).

Trichinella nelsoni: Africa south of Sahara.

Trichinella murrelli: Temperate areas of North America.

Trichinella pseudospiralis: This species has been sporadically detected in Europe, Asia, North America, and in the Australian region, however, due to the lack of muscle capsules, the larvae are very difficult to detect by trichinoscopy and this may, in part, explain the low numbers of records.

Trichinella papuae: This species has been recovered very recently in Papua New Guinea and the geographical distribution has yet to be determined.

Trichinella T6: Temperate regions of North America, but too little data are available for defining the exact distribution.

Trichinella T8: T8 has only been detected in South Africa and Namibia, and the geographical distribution has yet to be determined.

Trichinella T9: T9 has only been detected in Japan, and the geographical distribution has yet to be determined.

For selected references to geographical distributions, see Pozio (2000) and Murrell et al. (2000).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


AzerbaijanNo information availableOIE Handistatus, 2005
BahrainDisease never reportedOIE Handistatus, 2005
BhutanReported present or known to be presentOIE Handistatus, 2005
Brunei DarussalamNo information availableOIE Handistatus, 2005
-Hong KongDisease not reportedOIE Handistatus, 2005
Georgia (Republic of)Reported present or known to be presentOIE Handistatus, 2005
IndiaDisease never reportedOIE Handistatus, 2005
IndonesiaDisease not reportedOIE Handistatus, 2005
IranDisease never reportedOIE Handistatus, 2005
IraqDisease never reportedOIE Handistatus, 2005
IsraelNo information availableOIE Handistatus, 2005
JapanDisease not reportedOIE Handistatus, 2005
JordanDisease never reportedOIE Handistatus, 2005
KazakhstanDisease not reportedOIE Handistatus, 2005
Korea, DPRDisease not reportedOIE Handistatus, 2005
Korea, Republic ofDisease not reportedOIE Handistatus, 2005
KuwaitDisease never reportedOIE Handistatus, 2005
LebanonDisease not reportedOIE Handistatus, 2005
-Peninsular MalaysiaDisease not reportedOIE Handistatus, 2005
-SabahDisease never reportedOIE Handistatus, 2005
-SarawakDisease never reportedOIE Handistatus, 2005
MongoliaNo information availableOIE Handistatus, 2005
MyanmarDisease not reportedOIE Handistatus, 2005
NepalNo information availableOIE Handistatus, 2005
OmanDisease not reportedOIE Handistatus, 2005
PhilippinesDisease not reportedOIE Handistatus, 2005
QatarDisease not reportedOIE Handistatus, 2005
Saudi ArabiaDisease not reportedOIE Handistatus, 2005
SingaporeDisease never reportedOIE Handistatus, 2005
Sri LankaDisease not reportedOIE Handistatus, 2005
SyriaDisease not reportedOIE Handistatus, 2005
TaiwanDisease never reportedOIE Handistatus, 2005
TajikistanNo information availableOIE Handistatus, 2005
ThailandLast reported2002OIE Handistatus, 2005
TurkeyNo information availableOIE Handistatus, 2005
TurkmenistanNo information availableOIE Handistatus, 2005
United Arab EmiratesDisease never reportedOIE Handistatus, 2005
UzbekistanDisease not reportedOIE Handistatus, 2005
VietnamDisease never reportedOIE Handistatus, 2005
YemenNo information availableOIE Handistatus, 2005


AlgeriaDisease not reportedOIE Handistatus, 2005
AngolaNo information availableOIE Handistatus, 2005
BeninNo information availableOIE Handistatus, 2005
BotswanaNo information availableOIE Handistatus, 2005
Burkina FasoNo information availableOIE Handistatus, 2005
BurundiNo information availableOIE Handistatus, 2005
CameroonNo information availableOIE Handistatus, 2005
Cape VerdeDisease never reportedOIE Handistatus, 2005
Central African RepublicDisease not reportedOIE Handistatus, 2005
ChadNo information availableOIE Handistatus, 2005
Congo Democratic RepublicDisease not reportedOIE Handistatus, 2005
Côte d'IvoireNo information availableOIE Handistatus, 2005
DjiboutiDisease never reportedOIE Handistatus, 2005
EgyptReported present or known to be presentOIE Handistatus, 2005
EritreaDisease not reportedOIE Handistatus, 2005
EthiopiaDisease never reportedOIE Handistatus, 2005
GhanaDisease not reportedOIE Handistatus, 2005
GuineaDisease not reportedOIE Handistatus, 2005
Guinea-BissauNo information availableOIE Handistatus, 2005
KenyaCAB Abstracts data miningOIE Handistatus, 2005
LibyaDisease never reportedOIE Handistatus, 2005
MalawiNo information availableOIE Handistatus, 2005
MaliNo information availableOIE Handistatus, 2005
MauritiusDisease not reportedOIE Handistatus, 2005
MoroccoNo information availableOIE Handistatus, 2005
MozambiqueNo information availableOIE Handistatus, 2005
NamibiaDisease not reportedOIE Handistatus, 2005
NigeriaNo information availableOIE Handistatus, 2005
RéunionDisease never reportedOIE Handistatus, 2005
RwandaNo information availableOIE Handistatus, 2005
Sao Tome and PrincipeDisease not reportedOIE Handistatus, 2005
SenegalNo information availableOIE Handistatus, 2005
SeychellesDisease not reportedOIE Handistatus, 2005
SomaliaNo information availableOIE Handistatus, 2005
South AfricaNo information availableOIE Handistatus, 2005
SudanDisease never reportedOIE Handistatus, 2005
SwazilandNo information availableOIE Handistatus, 2005
TanzaniaNo information availableOIE Handistatus, 2005
TogoDisease never reportedOIE Handistatus, 2005
TunisiaDisease not reportedOIE Handistatus, 2005
UgandaLast reported2001OIE Handistatus, 2005
ZambiaNo information availableOIE Handistatus, 2005
ZimbabweNo information availableOIE Handistatus, 2005

North America

BermudaDisease not reportedOIE Handistatus, 2005
CanadaLast reported1996OIE Handistatus, 2005
MexicoOIE Handistatus, 2005
USAReported present or known to be presentOIE Handistatus, 2005

Central America and Caribbean

BarbadosDisease never reportedOIE Handistatus, 2005
BelizeNo information availableOIE Handistatus, 2005
British Virgin IslandsDisease never reportedOIE Handistatus, 2005
Cayman IslandsDisease not reportedOIE Handistatus, 2005
Costa RicaNo information availableOIE Handistatus, 2005
CubaDisease never reportedOIE Handistatus, 2005
CuraçaoDisease not reportedOIE Handistatus, 2005
DominicaDisease not reportedOIE Handistatus, 2005
Dominican RepublicDisease never reportedOIE Handistatus, 2005
El SalvadorDisease never reportedOIE Handistatus, 2005
GuadeloupeDisease not reportedOIE Handistatus, 2005
GuatemalaDisease never reportedOIE Handistatus, 2005
HaitiDisease never reportedOIE Handistatus, 2005
HondurasDisease never reportedOIE Handistatus, 2005
JamaicaDisease never reportedOIE Handistatus, 2005
MartiniqueDisease not reportedOIE Handistatus, 2005
NicaraguaDisease never reportedOIE Handistatus, 2005
PanamaNo information availableOIE Handistatus, 2005
Saint Kitts and NevisDisease never reportedOIE Handistatus, 2005
Saint Vincent and the GrenadinesDisease not reportedOIE Handistatus, 2005
Trinidad and TobagoDisease not reportedOIE Handistatus, 2005

South America

ArgentinaReported present or known to be presentOIE Handistatus, 2005
BoliviaNo information availableOIE Handistatus, 2005
BrazilDisease never reportedOIE Handistatus, 2005
ChileOIE Handistatus, 2005
ColombiaDisease never reportedOIE Handistatus, 2005
EcuadorDisease never reportedOIE Handistatus, 2005
Falkland IslandsDisease never reportedOIE Handistatus, 2005
French GuianaDisease never reportedOIE Handistatus, 2005
GuyanaDisease not reportedOIE Handistatus, 2005
ParaguayDisease never reportedOIE Handistatus, 2005
PeruDisease never reportedOIE Handistatus, 2005
UruguayLast reported1932OIE Handistatus, 2005
VenezuelaDisease never reportedOIE Handistatus, 2005


AndorraReported present or known to be presentOIE Handistatus, 2005
AustriaNo information availableOIE Handistatus, 2005
BelarusReported present or known to be presentOIE Handistatus, 2005
BelgiumDisease not reportedOIE Handistatus, 2005
Bosnia-HercegovinaReported present or known to be presentOIE Handistatus, 2005
BulgariaReported present or known to be presentOIE Handistatus, 2005
CroatiaReported present or known to be presentOIE Handistatus, 2005
CyprusDisease never reportedOIE Handistatus, 2005
Czech RepublicLast reported2003OIE Handistatus, 2005
DenmarkLast reported1930OIE Handistatus, 2005
EstoniaReported present or known to be presentOIE Handistatus, 2005
FinlandReported present or known to be presentOIE Handistatus, 2005
FranceReported present or known to be presentOIE Handistatus, 2005
GermanyReported present or known to be presentOIE Handistatus, 2005
GreeceDisease not reportedOIE Handistatus, 2005
HungaryOIE Handistatus, 2005
IcelandDisease never reportedOIE Handistatus, 2005
IrelandDisease not reportedOIE Handistatus, 2005
Isle of Man (UK)Disease never reportedOIE Handistatus, 2005
ItalyNo information availableOIE Handistatus, 2005
JerseyDisease never reportedOIE Handistatus, 2005
LatviaReported present or known to be presentOIE Handistatus, 2005
LiechtensteinDisease not reportedOIE Handistatus, 2005
LithuaniaReported present or known to be presentOIE Handistatus, 2005
LuxembourgDisease not reportedOIE Handistatus, 2005
MacedoniaOIE Handistatus, 2005
MaltaDisease never reportedOIE Handistatus, 2005
MoldovaLast reported2000OIE Handistatus, 2005
NetherlandsReported present or known to be presentOIE Handistatus, 2005
NorwayLast reported1994OIE Handistatus, 2005
PolandNo information availableOIE Handistatus, 2005
PortugalDisease not reportedOIE Handistatus, 2005
RomaniaOIE Handistatus, 2005
Russian FederationOIE Handistatus, 2005
SlovakiaLast reported2003OIE Handistatus, 2005
SloveniaReported present or known to be presentOIE Handistatus, 2005
SpainOIE Handistatus, 2005
SwedenReported present or known to be presentOIE Handistatus, 2005
SwitzerlandReported present or known to be presentOIE Handistatus, 2005
UKLast reported1977OIE Handistatus, 2005
-Northern IrelandLast reported1979OIE Handistatus, 2005
UkraineOIE Handistatus, 2005
Yugoslavia (former)No information availableOIE Handistatus, 2005
Yugoslavia (Serbia and Montenegro)Reported present or known to be presentOIE Handistatus, 2005


AustraliaDisease not reportedOIE Handistatus, 2005
French PolynesiaDisease not reportedOIE Handistatus, 2005
New CaledoniaSerological evidence and/or isolation of the agentOIE Handistatus, 2005
New ZealandReported present or known to be presentOIE Handistatus, 2005
SamoaDisease not reportedOIE Handistatus, 2005
VanuatuDisease never reportedOIE Handistatus, 2005
Wallis and Futuna IslandsNo information availableOIE Handistatus, 2005

Pathogen Characteristics

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The various species/genotypes of Trichinella are morphologically very similar. This is the main reason why the 10 species/genotypes have been recognized only very recently (see Murrell, 2000).

The males are 1-2 mm and the females 1-4 mm. The body is slender and the oesophageal region is not very much longer than the posterior part of the worm. The male has no spicules but a pair of lateral flaps. The muscle larvae measure 0.6-1.4 mm. See table in Murrell et al. (2000).

Hosts/Species Affected

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The infectivity to pigs and the resulting numbers of larvae per gram of muscle have been compared for some of the Trichinella species (Kapel and Gamble, 2000):

Trichinella spiralis - Highly infective (171.5 larvae/g)

Trichinella nativa - Lightly infective (0.15 larvae/g)

Trichinella britovi - Moderately infective (30.6 larvae/g)

Trichinella nelsoni - Moderately infective (58.6 larvae/g)

Trichinella murrelli - Lightly infective (2.4 larvae/g)

Trichinella pseudospiralis - Moderately infective (23.9 larvae/g)

Trichinella papuae - Not known, however, the worms were originally isolated from wild boars from Papua New Guinea (Pozio et al., 1999)

Host Animals

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Animal nameContextLife stageSystem
Aves (birds)
Mammalia (mammals)
Sus scrofa (pigs)Domesticated host, Wild hostPigs: All Stages

Economic Impact

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Trichinella rarely cause clinical infections in pigs or other domestic animals, however, due to the zoonotic behaviour and the serious or even fatal course of Trichinella infections in man, the most important economical losses are caused by the intensive Trichinella preventive programmes and routine meat inspections (see Pozio, 2000).


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The detection of Trichinella infections in food animals has recently been reviewed by Nöckler et al. (2000). They also discussed important issues like sample size and sample location. The most simple method is trichinoscopy, which is direct microscopy of small muscle samples pressed between two glass plates (see Roepstorff and Nansen, 1998). This method is rather insensitive, has difficulties in recovering larvae of non-encapsulated species, and is time-consuming. Digestion with pepsin-HCl (see Roepstorff and Nansen, 1998; Nöckler et al., 2000) of pooled samples, is better but still rather time-consuming. Serodiagnostic methods (such as ELISA) have been developed, and are discussed by Nöckler et al. (2000).

Prevention and Control

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Infection of domestic pigs with Trichinella spp. may be due to ingestion of raw or inadequately cooked flesh (culinary waste) containing infective trichinae or accidental ingestion of infected rodents, such as rats (see Gajadhar and Gamble, 2000). Control of trichinellosis by inspection and farm management, the use of computerized databases in Trichinella control and international recommendations on control have been reviewed by Knapen (2000), Polley et al. (2000), and Gamble et al. (2000), respectively.


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Despommier DD, 1998. How does Trichinella spiralis make itself at home?. Parasitology Today, 14(8):318-323; 48 ref.

Gajadhar AA; Gamble HR, 2000. Historical perspectives and current global challenges of Trichinella and trichinellosis. Veterinary Parasitology, 93:183-189.

Gamble HR et al., 2000. International Commission on Trichinellosis: recommendations on methods for the control of Trichinella in domestic and wild animals intended for human consumption. Veterinary Parasitology, 93:393-408.

Kapel CMO, 2000. Host diversity and biological characteristics of the Trichinella genotypes and their effect on transmission. Veterinary Parasitology, 93:263-278.

Kapel CMO; Gamble HR, 2000. Infectivity, persistence, and antibody response to domestic and sylvatic Trichinella spp. in experimentally infected pigs. International Journal for Parasitology, 30(2):215-221; 35 ref.

Knapen F van, 2000. Control of trichinellosis by inspection and farm management practices. Veterinary Parasitology, 93:385-392.

Murrell KD; Lichtenfels JR; Zarlenga DS; Pozio E, 2000. The systematics of the genus Trichinella with a key to species. Veterinary Parasitology, 93:293-307.

Nöckler K; Pozio E; Voigt WP; Heidrich J, 2000. Detection of Trichinella infection in food animals. Veterinary Parasitology, 93:335-350.

OIE Handistatus, 2002. World Animal Health Publication and Handistatus II (dataset for 2001). Paris, France: Office International des Epizooties.

OIE Handistatus, 2003. World Animal Health Publication and Handistatus II (dataset for 2002). Paris, France: Office International des Epizooties.

OIE Handistatus, 2004. World Animal Health Publication and Handistatus II (data set for 2003). Paris, France: Office International des Epizooties.

OIE Handistatus, 2005. World Animal Health Publication and Handistatus II (data set for 2004). Paris, France: Office International des Epizooties.

Polley L; Gaschler C; Gajadhar A, 2000. National occurrence reporting of Trichinella and trichinellosis using a computerized database. Veterinary Parasitology, 93(3/4):351-363; 17 ref.

Pozio E, 2000. Factors affecting the flow among domestic, synanthropic and sylvatic cycles of Trichinella. Veterinary Parasitology, 93(3/4):241-262; many ref.

Pozio E; La Rosa G; Amati M, 1994. Factors influencing the resistance of Trichinella muscle larvae to freezing. In: Campbell WC, Pozio E, Bruschi F, eds. Trichinellosis. Rome, Italy: Instituto Superiore di Sanita Press, 173-178.

Pozio E; La Rosa G; Yamaguchi T; Saito S, 1996. Trichinella britovi from Japan. Journal of Parasitology, 82:847-849.

Pozio E; Miller I; Järvis T; Kapel CMO; Rosa Gla, 1998. Distribution of sylvatic species of Trichinella in Estonia according to climate zones. Journal of Parasitology, 84(1):193-195; 10 ref.

Pozio E; Owen IL; Rosa Gla; Sacchi L; Rossi P; Corona S, 1999. Trichinella papuae n.sp. (Nematoda), a new non-encapsulated species from domestic and sylvatic swine of Papua New Guinea. International Journal for Parasitology, 29(11):1825-1839; 31 ref.

Roepstorff A; Nansen P, 1998. The epidemiology, diagnosis and control of helminth parasites of swine. An FAO handbook. Rome, Italy: FAO.

Soulsby EJL, 1982. Helminths, arthropods and protozoa of domesticated animals. Helminths, arthropods and protozoa of domesticated animals., Ed. 7:xi + 809 pp.44; [many fig., 260 x 195 mm]; many ref.

Zarlenga DS; Rosa G La, 2000. Molecular and biochemical methods for parasite differentiation within the genus Trichinella. Veterinary Parasitology, 93:279-292.

Distribution Maps

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