Table 1 Classification (Order, Family and Species) of zoonotic helminths causing human blindness divided according their route of transmission (Vector borne zoonosis, VbZ, food consumption, FbZ, and those at direct transmission from the environment, EbZ), geographical distribution, localization in the eyes and zoonotic relevance.
OrderOrder (Family) | Species (common name) | Route of transmission | Geographical distribution | Localization | Definitive host | REF |
|---|---|---|---|---|---|---|
HELMINTHS | Â | Â | Â | Â | Â | Â |
Strongylida | Â | Â | Â | Â | Â | Â |
| Â | Angiostrongylus cantonensis (rat lungworm) | Ingestion of snails, slugs, shellfish and crustacean (FbZ) | Asia, Australia, Africa, USA, Pacific Islands, Caribbean Islands, and South America | Anterior chamber, vitreous | Rat | 131,137 |
Ascaridida (Ascarididae) | Â | Â | Â | Â | Â | Â |
| Â | Toxocara canis (dog roundworm) | Dog faeces (EbZ) | Worldwide | Eyebrows and eyelds, aqueous humor and vitreous | Dog | 11 |
| Â | Toxocara cati (feline roundworm) | Cat faeces (EbZ) | Worldwide | Aqueous humor and vitreous | Cat | 11 |
| Â | Baylisascaris procyonis (raccoon roundworm) | Raccoon faeces (EbZ) | North America, Europe, Japan | Vitreous | Raccoon | 46 |
Spirurida Suborder Spirurina | Â | Â | Â | Â | Â | Â |
| Â | Gnathostoma spinigerum, G. hispidum, | Ingestion of crustacean (cyclops), | Worldwide | Anterior chamber, eye lid | Dog, cat, wild carnivores, | 49 |
| Â | G. doloresi and G. nipponicum | infected fish, frogs (FbZ) | Â | Â | raccoon, opossum | Â |
(Onchocercidae) | Â | Â | Â | Â | Â | Â |
| Â | Dirofilaria repens | Aedes, Anopheles, Culex (VbZ) | Europe, Asia, Africa | Subconjunctival | Dog | 8, 197 |
| Â | D. immitis | Aedes, Anopheles, Culex (VbZ) | Worldwide | Anterior chamber | Dog, cat | 8,76 |
| Â | D. tenuis | Aedes, Anopheles, (VbZ) | Canada, USA | Subconjunctival | Raccon | 8 |
| Â | Acanthocheilonema arbuta | Aedes, Taeniorhynchus (VbZ) | Canada, USA | Anterior chamber | Porcupine | 198 |
| Â | A. sprenti | Mosquitoes (VbZ) | Canada, Oregon, USA | Anterior chamber | Beaver | 8 |
| Â | A. reconditum | Fleas, louses (VbZ) | Worldwide | Subconjunctival | Dog | 79 |
| Â | Onchocerca gutturosa | Simulium spp. (VbZ) | Worldwide | Subconjunctival, cornea | Cattle | 8 |
| Â | O. cervicalis | Culicoides spp. (VbZ) | Worldwide | Subconjunctival, cornea | Horse | 169 |
| Â | Onchocerca jakutensis | Culicoides spp. (VbZ) | Europe, Austria | Subconjunctival, cornea | Red deer | 199 |
| Â | O. reticulata | Culicoides spp. (VbZ) | Europe, Asia, Africa | Subconjunctival, cornea | Horse | 170 |
| Â | O. dewittei japonica | Simulium spp. (VbZ) | Japan | Subconjunctival, cornea | Bear | 167 |
| Â | O. lupi | Simulium spp. (VbZ) | Europe | Subconjunctival | Dog | 172 |
| Â | Loaina uniformis | Aedes, Anopheles, Culex | North America | Subconjunctival | Lagomorphs | 8,62,64,83 |
| Â | P. (Loaina) scapiceps | Aedes, Mansonia | North America | Subconjunctival | Lagomorphs | 8,62,83 |
(Thelaziidae) | Â | Â | Â | Â | Â | Â |
| Â | Thelazia callipaeda T. californiensis | Phortica spp. (VbZ) | China, Southeastern Asia, Europe, USA | Subconjunctival, intraocular | Dogs, cats, rabbits and wild carnivores | 160 |
Enoplida | Â | Â | Â | Â | Â | Â |
(Trichuridae) | Trichinella spp. | Ingestion of raw meat (FbZ) | Worldwide | Orbit, Ocular muscles | Numerous, domestic and wild animals | 15 |
CESTODA | Â | Â | Â | Â | Â | Â |
Pseudophyllidea (Diphyllobothriidae) | Â | Â | Â | Â | Â | Â |
| Â | Spirometra erinaceieuropaei (Sparganosis) | Ingestion of crustacean, frogs, birds, snakes (FbZ) | Middle East, Australia | Subconjunctival | Carnivores | 102,109 |
| Â | Spargana (other species) | Ingestion of crustacean, frogs, birds, snakes (FbZ) | South America, Asia | Subconjunctival | Carnivores | 102,109 |
Cyclophyllidea (Teniidae) | Â | Â | Â | Â | Â | Â |
| Â | Taenia crassiceps | Food contaminated by dog faeces (EbZ) | USA and Europe | Anterior chamber | Carnivores | 89 |
| Â | Echinococcus granulosus | Food contaminated by dog faeces (EbZ) | Worldwide | Intraocular | Dog | 112 |
| Â | E. multilocularis | Food contaminated by wild carnivores dog faeces (EbZ) | Worldwide | Intraocular | Wolf, jackal, coyote | 115 |
| Â | E. oligharthrus | Food contaminated by wild carnivores dog faeces (EbZ) | South and Central America | Orbit | Wild felids | Wild felids |
| Â | Coenurus cerebralis (Multiceps multiceps) | dog faeces (EbZ) | Worldwide | Intraocular | Dog | 95 |
TREMATODA | Â | Â | Â | Â | Â | Â |
(Fluke) | Â | Â | Â | Â | Â | Â |
| Â | Fasciola hepatica | water plants (FbZ) | Worldwide | Anterior chamber | Domestic and wild ruminants, horse | 120 |
| Â | Alaria mesocercaria, A. americana | Frogs (FbZ) | Asia, USA, Canada | Intraocular | Canids | 122 |
| Â | Philophthalmus lacrimosus | Contaminated food or direct contact with the eye mucosa (EbZ) | Europe, Asia, and America | Conjunctival | Birds | 124 |