EYEWORMS (THELAZIASIS) ~ Life Cycle & Treatment

Thelaziasis (Eyeworms):

Thelaziasis is the term for infestation with parasitic nematodes of the genus Thelazia. 

Thelazia worms parasitize the eyes & associated tissues of various bird & mammal hosts, including humans.  They are often called "eyeworms".

                      

Adults are found in the eyelids, tear glands, tear ducts, or so-called "third eyelid" (nictitating membrane). 

Occasionally, they're found in the eyeball itself, under the conjunctiva (the membrane that covers the white part of the eye), or in the vitreous cavity. 

All species of Thelazia are transmitted by fly species of Diptera which do not bite but feed on tears.

General Life Cycle:

In the uterus of the adult female, embryos develop into first-stage larva, which remain in an eggshell (sheath).  The female deposits these sheathed larva in the tears of the mammal or bird definitive host, & the larva are ingested by tear-feeding flies. 

In the fly, the larva hatch, penetrate the gut wall, & migrate to the body, testes, or egg follicles.

They develop into third-stage larva & migrate to the head of the fly.  They wiggle out of the straw-like feeding apparatus of the fly when it feeds on the tears of another mammal or bird host.  They develop into adults in the eye or surrounding tissues of the host, where they may live for over one year.

Thelazia are found in various tissues of the orbit (socket) of the host's eye, within the eyelids, in the tear glands, tear ducts, so-called "third eyelid," or within the eyeball.

Hosts & Geographic Range Of Thelaziasis:

A few dozen species of Thelazia are described in literature.  Only 2 are reported to infest humans and 7 are reported in veterinary contexts.  The remaining species are found in birds or wild mammals.

In humans, dogs, & cats, thelaziasis cases due to T.callipaeda (Asia & Europe) & T. californiensis (western North America) have been reported.

Horses are infested by T. lacrymalis (worldwide) & T. rhodesii (Africa, Asia, Europe).

In cattle, T. gulosa (Asia, Europe, North America), T. rhodesii (Africa, Asia, Europe), & T. skrjabini (Europe & North America) are the primary species.

In camels, T. leesei infestations have been reported from post-Soviet states & India.

The intermediate hosts of several Thelazia species are tear-feeding flies of the genera Musca (family Muscidae), Phortica (family Drosophilidae), or Fannia (family Fannidae).

Symptoms & Diagnosis:

Diagnosis involves examining the eyes & nearby tissues for the worms.  In animal & human hosts, Thelazia infestation may be asymptomatic, though it frequently causes watery eyes (epiphora), conjunctivitis, corneal opacity, or corneal ulcers (ulcerative keratitis). 

Infested humans have also reported "foreign body sensation" – the feeling that something is in the eye.

Adult Thelazia are very active & one author described T. californiensis as a "short lively piece of nylon fishing line about 10 mm long."

Prevalence:

By one author's count, 257 human cases of Thelazia callipaeda were reported worldwide by the year 2000, though thelaziasis is still considered to be a rare disease.

Various livestock & wildlife surveys suggest that thelaziasis is quite common among animals.

A slaughterhouse survey in Canada found about one-third (32%) of cattle over an 8-month period were infested with eyeworms.

A survey of horses in Kentucky revealed a 42% rate of infestation with Thelazia lacrymalis.

In Wyoming and Utah, a survey of hunter-harvested mule deer found 15% to be infested by Thelazia californiensis.

A survey of various sites in Italy found 23-60% of dogs, 5% of foxes, & 100% of cats were infested with Thelazia callipaeda.

Treatment & Control:

Because they live so close to the outside of the body, Thelazia is one of the few nematode infections which can be treated topically.

Topical treatment of livestock, dogs, & cats with organophosphates (such as ecothiopate iodide or isofluorophate) & systemic treatment with antihelmintics (ivermectin, levamisole, & doramectin) are recommended by the Merck Veterinary Manual.  Other sources reported positive results treating dogs with moxidectin, imidacloprid, or milbemycin oxime.

For treatment of human cases, removal of the worm is suggested. Topical treatment with thiabendazole has also been reported to kill the worms.

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Treatment: 

A forum member (Getout) recently ordered Dectomax from jefferslivestock.com to treat this infection in a family member (http://curezone.com/forums/fm.asp?i=1757157),

Ordering info for Ivermectin (tablets, suspension, & paste) is in the Albendazole & Ivermectin Protocol ~ Morgellons, Strongyloides, & Filariasis:  http://curezone.com/forums/fm.asp?i=1586882#i. 

Other topical treatment remedies for parasites in skin & soft tissue:  http://curezone.com/forums/fm.asp?i=1750708#i.

Cheers ~~ ICU

    

Parasite Drug Protocols:  Roundworms, Tapeworms, Flukes, Strongyloides, Filariasis, Morgellons, & Protozoa:  http://curezone.com/forums/fm.asp?i=1574645#i