Parasites encompasses fungi, protozoa, including amoebae and flagellates, as well as multicellular parasites such as (roundworms) and platyhelminthes (flatworms).

Lice

Lice are parasites that can be found on the body. See CDC

Head Lice: Pediculus humanus capitis causes head lice. Benzyl alcohol is used effectively for treating lice infestations as the active ingredient in lotion shampoo with 5% benzyl alcohol. (sold under the brane name Ulesfia)

Crabs: is caused by Pthirus pubis, 

Fungi

Ringworm: These mycoses are strictly confined to the nonliving epidermal tissues (statum corneum) and thei rderivatives (hair and nails). All these conditions have different names that begin with the word “tinea”.. Tinea Capitis results from the fungal invasion of the scalp and the hair of the head, eyebrows and eyelashes. Tinea Corporis is extremely prevalent infection that can apepar nearly anywhere on the body’s glabrous (smooth and bare) skin. Tinea Cruris also known as “jock itch” is a crutal ringworm that occurs mainly in males on the groin, preianal skin, scrotum and accoasinally the penis. The fungus thrives under conditions of mositure and humidity created by sweating. Tinea Pedis is ringword of the foot.

Protozoa (see outline)

Toxoplasma gondii 

Toxoplasma is a globally distributed pathogen of humans and animals. Between 30-80% of the human population carries latent infeciton with this opportunisitc parasite. T. Gondii develops in the intestinal cells of cats. Humans can become infected by ingestion of infective ooxycts from cat fecal contamination or by ingestion of improperly cooked meat from an intermediate host. Infection can be serious in immunocompromised people. This is a risk in AIDS patietns, where about 25% of those carring latent T. gondii infection undergo reactivating toxoplasmosis in the central nervous system.

Trypanosomes 

Trypanosomes are microscopic unicellular protozoa that are ubiqitous parasites of insects, plants and birds.  Trypanosomes differ from most other cells with respect to their mitochondrial DNA which is present in large amount, is condensed in the kinetoplast and called the kinetoplast DNA. It consists of thousands of interlocked circular molecules that seem to be held together by catenation.

Trypanosomes include include the following:

African trypanosomiasis which cause sleeping sickness

Trypanosoma cruzi is the causative agent of Chagas’ disease.

It is transitted by the reduuviid bug (kissing bug). After the bug bites on the face it deposits its feces which transmits the infection. It causes chagas disease and occurs mainly in children under 5. Trypanosoma is endemic in Central and South America, as well as in Mexico. In endemic areas, T. cruzi is transmitted mainly by blood-sucking triatomine insects. The disease can also be spread by blood transfusion, intravenous drug use, congenital transmission, by sexual activity, organ transplant or through breast milk.

After a mild acute phase, most infected people enter an indeterminate phase that is characterized by a lack of symptoms, low parasite count, and low titers of anti-T. cruzi antibodies. About 10-30% of persons with chronic T. cruzi infections, develop cardiac or gastrointestinal dysfunction.

Diagnosis of chronic T. cruzi infection refllects the complexity of the parasites’ lfie cycle. During period of high fever, diagnosis consists simply of identifying the parasites in blood, crebrospinal fluid, fixed tissue or lymph nodes. However, during latency the bug is difficult to detect. Serologic assays for antibodies to T. cruzi are well suited for rapid and inexpensive diagnosis. Brophy (US 2017/0023568) discloses antibodies that specifically bind Trypanosoma cruzi antigens and uses thereof.

An antibody has been generated that specifically inhibits the differentiation of one form of the parasite to another (epimastigote to trypomastigote stage) in vitro and which reacts with a cell surface glycoportein, however, this antigen is abesent form the mammalian bloodstream forms of the parasite (Sher, Nature, 300: 639-640, 1982).

To kill the parasite, Chagas disease can be treated with benznidazole or nifurtimox. Both medicines are nearly 100% effective in curing the disease if given soon after infection at the onset of the acute phase, including the cases of congenital transmission. The efficacy of both diminishes, however, the longer a person has been infected and the adverse reactions are more frequent at older age. See WHO

Treatment for Parasitic Infections Generally:

–—Fenbendazole, [5-(phenylthio)-1H-benzimidazol-2-yl]carbamic acid methyl ester, is widely used to treat pinworms, other helminthes, and a variety of parasitic infections in laboratory animals, livestock, companion animals, and people. Fenbendazole (brand names Panacur®, Safe-Guard®) is a medication used to treat a variety of parasites (e.g., roundworms, hookworms, lungworm, whipworm, and certain types of tapeworms) in dogs. Its use in cats for the treatment of parasites is ‘off label’. The mode of action works at the sub-cellular level, preventing cell division. Benzimidazoles binds to β-tubulin, 69 inhibiting the cell’s microtubule assembly responsible for intracellular transport and required for mitotic 70 cellular division.

—-Ivermectin: is a broad FDA approved anti-parasitic drug. Interesting it has also showed to be helpful for the Coronavirus.