setariasis

Setariasis is a filariasis that involves parasitic infection of the abdomen in cattle, horses, and sheep by nematodes of the genus Setaria [9]. This condition is usually seen in cattle and equines and is of little pathogenic significance, although migration of the worm to the eye may lead to blindness [12].

The adult parasites typically reside in the peritoneal cavity of ungulates, but immature forms may aberrantly migrate to the eyes of cattle, buffalo, goats, horses, and several other hosts, leading to corneal opacity and blindness [13]. Setariasis is a relatively rare condition, and its incidence can vary depending on the region and host population.

In terms of anatomy, adult Setaria worms are slender, milky-white, and translucent, with a length of up to 15 cm. They have a tubular digestive system with two openings, the mouth and the anus [11]. The body of these worms is covered with a flexible but tough cuticle, which tapers towards the tail that is coiled.

It's worth noting that Setariasis is not typically considered a serious or life-threatening condition in most domestic animals, although it can cause some discomfort and potentially lead to more severe complications if left untreated.

Setariasis, also known as Setaria infection, is a parasitic disease caused by the Setaria parasite. The signs and symptoms of setariasis can vary depending on the severity of the infection and the individual's overall health.

Common symptoms:

• Lacrimation (tearing)
• Serous ocular discharge
• Watery eyes
• Corneal opacity
• Conjunctivitis (inflammation of the conjunctiva, the thin membrane covering the white part of the eye)

These symptoms can occur in both terrestrial animals and humans who are infected with Setaria parasites.

Other signs:

• Photophobia (sensitivity to light)
• Inflammatory reactions in the eyes, liver, and lungs
• Migrating larvae in the central nervous system

It's worth noting that setariasis is typically transmitted by mosquito bites, and the disease can be more severe in certain seasons, such as summer and autumn.

References:

• [11] Setariasis is transmitted by mosquito Armigeres sp. and a large proportion of humans can be exposed to an infestation with Setaria spp.
• [13] The disease occurs mostly in summer and autumn seasons and it displays signs of lacrimation, photophobia, corneal opacity, conjunctivitis and ...
• [14] Eye worm movement in the anterior chamber may lead to varying degrees of corneal opacity and most of the affected animals are presented with clinical signs such as lacrimation, serous ocular discharge, watery eyes, and conjunctivitis.

Diagnostic Tests for Setariasis

Setariasis, also known as ocular setariasis, is a vision-threatening disease caused by the filarial worm Setaria spp. in equines. Diagnosing this condition requires a combination of clinical examination and laboratory tests.

• Clinical Examination: A thorough eye examination can reveal signs of setariasis, such as conjunctival hemorrhages, corneal ulcers, and blepharospasm (eye spasms). Close inspection of the eye is crucial in diagnosing this condition [13].
• Hematological Tests: Full blood count, microscopic examination of wet blood films, and Knott's test can be used as supplementary diagnostic tests to confirm the presence of Setaria spp. in the equine's bloodstream [11][13].
• Microscopic Examination: Wet blood films and Knott's test can also be used to detect the presence of microfilariae (young filarial worms) in the equine's blood, which is a key diagnostic feature of setariasis [11].

It's worth noting that while these tests can help diagnose setariasis, they are not definitive and may require further investigation. A combination of clinical examination and laboratory tests should be used to confirm the diagnosis.

References: [11] Rafee and Amarpal (2016) - "Diagnostic possibilities; tests like pupillary light response and menace reflex are commonly used as ophthalmic diagnostic tests." [13] Nabie R, Spotin A, Rouhani S (2017) - "Subconjunctival setariasis due to Setaria equina infection; a case report and a literature review."

Medical Treatment Options for Setariasis

Setariasis, also known as ocular equine microfilariasis, can be treated with various medical options. According to the available information, one of the most advocated drugs for treating ocular equine setariasis is Ivermectin [6][9]. Ivermectin has been shown to be effective in treating this condition, and it is often recommended as a first-line treatment.

However, medical treatment alone may not always be sufficient due to the slow resorption of dead parasites and the attendant antigenicity leading to uveitis [3][14]. In such cases, surgical intervention may be necessary to remove the parasite from the eye.

Surgical Treatment Options

Surgical removal of the parasite is often considered the best treatment option for setariasis. This can be done through various methods, including:

• Anterior chamber paracentesis: This involves removing the dead parasites and other debris from the anterior chamber of the eye [5][8].
• Needle paracentesis: This involves using a needle to remove the parasite from the eye [13].
• Surgical removal under regional/general anesthesia: This is considered the most effective method for removing the parasite and preventing further complications [7][10][12].

It's worth noting that surgical treatment options may be more invasive than medical treatment, but they can provide quicker relief and better outcomes in many cases.

References

[1] Gangwar et al. [3] Moore et al., 1983 [5] WMNK Jayathilake, 2019 [6] N Tuntivanich, 2011 [7] Jul 17, 2020 [8] N Tuntivanich, 2011 [9] Jan 9, 2007 [10] The best treatment is the surgical removal of the parasite under regional/general anesthesia. [12] Ocular setariasis is a common vision threatening ophthalmic condition in equine resulting from ectopic parasitism by Setaria digitata, Setaria equina and Thelazia lacrymalis.

The differential diagnosis for scabies, also known as setariasis, includes a variety of pruriginous skin diseases that can mimic the symptoms of scabies. Some of these conditions include:

• Atopic dermatitis
• Contact dermatitis
• Papular urticaria
• Folliculitis
• Dermatitis herpetiformis
• Prurigo nodularis
• Bites from mosquitoes, fleas, bed bugs, and chiggers or other mites

These conditions can present with similar symptoms to scabies, such as intense itching and skin lesions. It's essential to consider these differential diagnoses when diagnosing scabies, especially in cases where the clinical presentation is not typical.

According to [3], scabies often gets misdiagnosed as eczema, dermatitis prurigo nodularis, or lupus erythematosus. Additionally, crusted scabies can be mistaken for other conditions such as psoriasis and seborrheic dermatitis [9].

The 2020 IACS Criteria aim to standardize the diagnosis of common scabies, taking into account these differential diagnoses [10]. A diagnosis of clinical or suspected scabies should only be made if other differential diagnoses are considered less likely than scabies [11].

In some cases, the differential diagnosis for scabies may also include other infestations such as pubic lice, which can present with itchy, red papules in any course body hair [15].