Linguatulosis is a condition associated with the organism ''

Linguatula serrata ''Linguatula serrata'' is a species of cosmopolitan zoonotic parasite, belonging to the tongueworm order Pentastomida. They are wormlike parasites of the respiratory systems of vertebrates. They live in the nasopharyngeal region of mammals. Cat ...

''. The usual final host for ''

'' is a carnivore, like a dog or jackal, and the species is sometimes known as the dog tongueworm for this reason. More generally, linguatulosis can be considered a form of "pentastomiasis", which refers to all diseases caused by

pentastomid The Pentastomida are an enigmatic group of parasitic arthropods commonly known as tongue worms due to the resemblance of the species of the genus ''Linguatula'' to a vertebrate tongue; molecular studies point to them being degenerate crustaceans. ...

s, including

porocephaliasis Porocephaliasis is a condition associated with species in the closely related genera ''Porocephalus'' and ''Armillifer''. (The term "pentastomiasis" encompasses all diseases of Pentastomida, which includes porocephaliasis and linguatulosis.) Poroc ...

. This disease is often accidentally identified during autopsy because of its asymptomatic effect on the body. Human infestation by ''Linguatula'' was historically more commonplace than is sometimes realised. Human liver autopsies in Berlin from the early part of the 20th century revealed an infection rate of nearly 12%.

Signs and symptoms

It is usually asymptomatic unless the complication and infection is severe. But in some recorded cases, symptoms include

nasopharyngitis The common cold or the cold is a viral infectious disease of the upper respiratory tract that primarily affects the respiratory mucosa of the nose, throat, sinuses, and larynx. Signs and symptoms may appear fewer than two days after exposu ...

accompanied by pain, itching of throat and ears. Coughing,

hemoptysis Hemoptysis is the coughing up of blood or blood-stained mucus from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia, a ...

and vomiting are verifiable indications as well as sneezing, bleeding,

dyspnea Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...

, and inflammation.

Visceral and nasopharyngeal

Humans can become infected in two ways: either as an intermediate host (visceral linguatuliasis) or as an accidental final host (nasopharyngeal linguatuliasis). * In visceral linguatuliasis ''Linguatula'' eggs are sneezed or defecated out by the primary host. Normally they would be eaten by a herbivorous mammal (the intermediate host), including various domestic animals . The eggs hatch in the intestines and the resulting larvae burrow their way into the visceral cavity of the body. Here they form cysts or granulomas, typically in the liver or the lymph nodes. This can also occur in humans if the eggs are accidentally swallowed, although the victim may not be aware of the infestation and misdiagnosis as liver disease can even occur . Rarely, the larvae of both ''Lingulatula'' and ''Armillifer'' can enter the eye accidentally * In nasopharyngeal linguatuliasis it is the encysted larvae which are consumed, usually via raw or poorly cooked meat. Once in the stomach, the larvae become liberated from their cysts within a couple of hours and then crawl up the oesophagus and establish themselves in the nose, pharynx or lungs — holding themselves in place with the hooks flanking the mouth . Presence of the parasite can induce headaches, coughing and nasal discharge which obviously helps to spread the infection. Nasopharyngeal linguatuliasis appears to be quite prevalent throughout the Middle East where it is often known as the Halzoun syndrome after religious festivals in which infected raw meat is consumed . In Sudan nasopharyngeal linguatuliasis is known as Marrara syndrome; Marrara is a popular local dish prepared from raw

offal Offal (), also called variety meats, pluck or organ meats, is the organs of a butchered animal. The word does not refer to a particular list of edible organs, which varies by culture and region, but usually excludes muscle. Offal may also refe ...

. It has been suggested that up to 20% of the population in some parts of Sudan may be affected by this syndrome at some stage of their lives .

Transmission

Eating raw or semi-cooked infected liver or lymph nodes infected with nymphal ''L. serrata'' causes severe symptoms in the human

nasopharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...

. Submaxillary and cervical lymph nodes sometimes enlarge and the neck is swollen. Complications include abscesses in the auditory canals, facial paralysis, and enlarged tonsils producing asphyxiation. These symptoms are well recognized as a disease called “ halzoun syndrome” in

Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to Lebanon–Syria border, the north and east and Israel to Blue ...

and nearby countries. In Egypt, infected camels and buffalo may also be a source of infection for dogs, which are companions of man in desert and semi-desert areas where grazing is a major profession, and in villages, where dogs are also common. Infected dogs, in turn, are a source of infection to man who may be an intermediate host.

Treatment

An antibiotic therapy for secondary infections caused by the parasite is available, but surgical removal is usually the only way to get rid of the parasites.

References

External links

{{Arthropod infestations Arthropod infestations