Paragonimiasis

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Paragonimiasis
Paragonimiasis - Case 285.jpg
Photomicrograph showing ova within lung parenchyma
Specialty Infectious diseases, helminthology   OOjs UI icon edit-ltr-progressive.svg
Symptoms Fever, malaise, cough, chest pain [1]
Complications Seizures [1]
Durationmonths or years [2]
Causes Paragonimus flatworms
Risk factors Eating undercooked crabs and crawfish
Diagnostic method Blood test, CT scan, serologic test
Differential diagnosis Tuberculosis
PreventionEating thoroughly cooked crustaceans
Medication Praziquantel, Triclabendazole
Frequency23 million [3]

Paragonimiasis is a food-borne parasitic disease caused by several species of lung flukes belonging to genus Paragonimus . [4] Infection is acquired by eating crustaceans such as crabs and crayfishes which host the infective forms called metacercariae, or by eating raw or undercooked meat of mammals harboring the metacercariae from crustaceans. [5]

Contents

More than 40 species of Paragonimus have been identified; 10 of these are known to cause disease in humans. [6] The most common cause of human paragonimiasis is P. westermani , the oriental lung fluke. [7]

About 22 million people are estimated to be affected yearly worldwide. [8] It is particularly common in East Asia. Paragonimiasis is easily mistaken for other diseases with which it shares clinical symptoms, such as tuberculosis and lung cancer. [5]

Background

The first human case was seen in 1879 in Taiwan. An autopsy was done and adult trematodes were found in the lungs. The adult flukes are reddish-brown in color with an ovoid shape. They have two muscular suckers, the first an oral sucker located anteriorly and the second a ventral sucker located mid-body. The adult flukes can live up to 20 years. The eggs are golden brown in color and are asymmetrically ovoid. They have a very thick shell. [9]

These trematodes have a very complex life cycle with seven distinct phases involving intermediate hosts and humans. [9] These seven phases are outlined as follows: eggs reach fresh water where they develop into miracidia. These penetrate many species of aquatic snails (first intermediate host) where they go through three distinct stages: first sporocysts, then rediae, and finally cercariae, also referred to as the larvae. These larvae released into water and penetrate crabs, crayfish and other crustaceans (second intermediate host). The cercariae situate themselves into the gills, liver and muscles where they further develop into metacercariae. When the parasite-filled crustacean is eaten, the metacercariae hatch in the intestine. These young worms penetrate intestinal wall, peritoneum, the diaphragm and the pleura where they finally reach the lungs. Here they live in pairs and lay eggs that are coughed up in sputum to restart the cycle. [10]

Life cycle

Not all Paragonimus species infect humans. However, all of them target mammals as their final (definitive) hosts. In mammalian lung tissue, the adult flukes live as encapsulated pairs. As hermaphrodites, they produce and fertilise their own eggs that are released through the respiratory tract. The eggs are excreted to the environment either through the sputum or by being swallowed and passed out along with the faeces. [5]

In the external environment, the eggs remain unembryonated until ideal conditions of temperature and humidity are encountered. Then, they embryonate and develop into ciliated larvae called miracidia. As the egg shells disintegrate, the motile miracidia hatch and swim to seek the first intermediate host, a snail, and penetrate its soft tissues. Each miracidium goes through several developmental stages inside the snail: firstly into a series of daughter cells called sporocysts and then into rediae, which give rise to many worm-like larvae called cercariae. The cercariae penetrate through the body of the snail, emerging into the water. [7] Development in the snail takes about 9 to 13 weeks. [11]

The cercariae then infect the second intermediate host, a crustacean such as a crab or crayfish, where they encyst and become metacercariae. Encystment occurs in the liver, gills, intestine, skeletal muscles and sometimes in the heart. These cysts are the infective stage for the mammalian host. Freshwater crab species of genera Potamiscus, Potamon, Paratelphusa, Eriocheir, Geothelphusa, Barytelphusa, crayfish species of genus Camberoides and shrimps of genera Acrohrachium and Caridina commonly serve as the secondary intermediate hosts. The secondary intermediate hosts are infected either by directly eating the snail or penetration of the body by free-swimming cercariae. [11]

Human infection with P. westermani —the best understood species—occurs by eating inadequately cooked or pickled crab or crayfish that harbour metacercariae of the parasite. The metacercariae excyst in the duodenum, penetrate through the intestinal wall into the peritoneal cavity, then through the abdominal wall and diaphragm into the lungs, where they become encapsulated and develop into adults (7.5 to 12 mm by 4 to 6 mm). [7] Unlike most other trematodes, after they migrate from the intestine, they remain in the peritoneal cavity until they find a suitable partner. Only then do the couples enter the lung tissues to form capsules. [5] The flukes can also reach other organs and tissues, such as the brain and skeletal muscles. However, when this takes place completion of the life cycles is not achieved, because the eggs laid cannot exit these sites. Time from infection to laying of eggs is 65 to 90 days. Infections may persist for 20 years in humans. Animals such as pigs, dogs, and a variety of feline species can also harbor P. westermani. [7] For other species, rodents and deer are also additional (paratenic) hosts. By consuming infected animals of these reservoir species, even animals and humans that do not eat crustaceans directly can become infected. [5]

Geographic distribution

There are more than 30 known species of Paragonimus. Species of Paragonimus are widely distributed in Asia, Africa, and North and South America. P. westermani is found in southeast Asia and Japan, while P. kellicotti is endemic to North America. [7] P. africanus is found in Africa and P. mexicanus is found in central and South America. [7] Just as the species names imply, paragonimiasis is more prominent in Asians, Africans and Hispanics because of their habitats and cultures. [9] Prominence increases with age from older children to young adults then decreases with age. It is also higher among the female populations. [9] This is a very common parasite of crustacean-eating mammals. [10]

Symptoms and diagnosis

Paragonimiasis causes pneumonia with characteristic symptoms including prolonged cough, chest pain, shortness of breath, and hemoptysis. [12] Owing to the diverse symptoms it presents, the disease is variously known as endemic haemoptysis, oriental lung fluke infection, pulmonary distomiasis, parasitical haemoptysis, and parasitare haemopte. Pulmonary paragonimiasis is the most common clinical manifestation, accounting for 76–90% of all infections. It has the classic symptoms of pneumonia. Extra-pulmonary infection is due to migration of the young worms away from the normal route to the lungs. In such case, any other part of the body can be infected. Cutaneous paragonimiasis is common in children and is generally indicated by skin nodules that move from one place to another. [11] Cerebral paragonimias is most severe extra-pulmonary symptoms that affect the brain and leads to seizure, headache, visual disturbance, and motor and sensory disturbances. [4]

The acute phase (invasion and migration) may be marked by diarrhea, abdominal pain, fever, cough, urticaria, hepatosplenomegaly, pulmonary abnormalities, and eosinophilia. During the chronic phase, pulmonary manifestations include cough, expectoration of discolored sputum containing clumps of eggs, [7] hemoptysis, and chest radiographic abnormalities. Extrapulmonary locations of the adult worms result in more severe manifestations, especially when the brain is involved. [13] Diagnosis is based on microscopic demonstration of eggs in stool or sputum, but these are not present until 2 to 3 months after infection. (Eggs are also occasionally encountered in effusion fluid or biopsy material.) Concentration techniques may be necessary in patients with light infections. Biopsy may allow diagnostic confirmation and species identification when an adult or developing fluke is recovered. [13]

Diagnosis is done by microscopic examination of sputum and stool samples, and presence of the eggs is a confirmation. However, eggs are not always to be found. In such case, serological tests based on antibody detection using ELISA is a better method. [12] A more arduous method like immunoblotting is also used. For brain infection, radiological examinations including plain skull x-rays, brain CT, and MR scans are used. [4] A rapid antibody detection kit, dot-immunogold filtration assay (DIGFA), was developed for P. wertermani in China in 2005. [14]

Misdiagnosis is a serious issue in paragonimiasis. It is commonly misdiagnosed as tuberculosis because it presents similar symptoms. [15] In China, 69–89% of cases from 2009 to 2019 were misdiagnosed. [5] It is also frequently misidentified as malignancy or chronic obstructive pulmonary disease. [16]

Treatment

The drug of choice to treat paragonimiasis is praziquantel, although bithionol may also be used. [13] Triclabendazole is useful in P. uterobilateralis, P. mexicanus, and P. skrjabini infections but not in P. westermani infection. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Trematoda</span> Class of parasitic flatworms

Trematoda is a class of flatworms known as flukes or trematodes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish.

<i>Fasciola hepatica</i> Species of fluke

Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic trematode of the class Trematoda, phylum Platyhelminthes. It infects the livers of various mammals, including humans, and is transmitted by sheep and cattle to humans all over the world. The disease caused by the fluke is called fasciolosis or fascioliasis, which is a type of helminthiasis and has been classified as a neglected tropical disease. Fasciolosis is currently classified as a plant/food-borne trematode infection, often acquired through eating the parasite's metacercariae encysted on plants. F. hepatica, which is distributed worldwide, has been known as an important parasite of sheep and cattle for decades and causes significant economic losses in these livestock species, up to £23 million in the UK alone. Because of its relatively large size and economic importance, it has been the subject of many scientific investigations and may be the best-known of any trematode species. F. hepatica's closest relative is Fasciola gigantica. These two flukes are sister species; they share many morphological features and can mate with each other.

<i>Fasciola</i> Genus of flukes

Fasciola, commonly known as the liver fluke, is a genus of parasitic trematodes. There are three species within the genus Fasciola: Fasciola nyanzae,Fasciolahepatica and Fasciolagigantica. Fasciola hepatica and F. gigantica are known to form hybrids. Both F. hepatica and F. gigantica and their hybrids infect the liver tissue of a wide variety of mammals, including humans, in a condition known as fascioliasis. F. hepatica measures up to 30 mm by 15 mm, while F. gigantica measures up to 75 mm by 15 mm. Fasciola nyanzae is thought to exclusively infect the common hippopotamus, Hippopotamus amphibius.

<span class="mw-page-title-main">Trematode life cycle stages</span>

Trematodes are parasitic flatworms of the class Trematoda, specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions.

<i>Paragonimus westermani</i> Species of fluke

Paragonimus westermani is the most common species of lung fluke that infects humans, causing paragonimiasis. Human infections are most common in eastern Asia and in South America. Paragonimiasis may present as a sub-acute to chronic inflammatory disease of the lung. It was discovered by Coenraad Kerbert (1849–1927) in 1878.

<i>Echinostoma</i> Genus of flukes

Echinostoma is a genus of trematodes (flukes), which can infect both humans and other animals. These intestinal flukes have a three-host life cycle with snails or other aquatic organisms as intermediate hosts, and a variety of animals, including humans, as their definitive hosts.

<i>Paragonimus</i> Genus of flukes

Paragonimus is a genus of flukes (trematodes) and is the only genus in the monotypic family Paragonimidae. Some tens of species have been described, but they are difficult to distinguish, so it is not clear how many of the named species may be synonyms. The name Paragonimus is derived from the combination of two Greek words, “para” and “gonimos”. Several of the species are known as lung flukes. In humans some of the species occur as zoonoses; the term for the condition is paragonimiasis. The first intermediate hosts of Paragonimus include at least 54 species of freshwater snails from superfamilies Cerithioidea and Rissooidea.

Metagonimoides oregonensis is a trematode, or fluke worm, in the family Heterophyidae. This North American parasite is found primarily in the intestines of raccoons, American minks, frogs in the genus Rana, and freshwater snails in the genus Goniobasis. It was first described in 1931 by E. W. Price. The parasite has a large distribution, from Oregon to North Carolina. Adult flukes vary in host range and morphology dependent on the geographical location. This results in different life cycles, as well as intermediate hosts, across the United States. On the west coast, the intermediate host is freshwater snails (Goniobasis), while on the east coast the intermediate host is salamanders (Desmognathus). The parasites on the west coast are generally much larger than on the east coast. For example, the pharynx as well as the body of the parasite are distinctly larger in Oregon than in North Carolina. The reverse pattern is observed on the east coast for uterine eggs, which are larger on the west coast. In snails, there is also a higher rate of infection in female snails than in males. Research on the life history traits of the parasites have been performed with hamsters and frogs as model species.

<i>Nanophyetus</i> Genus of flukes

Nanophyetus salmincola is a food-borne intestinal trematode parasite prevalent on the Pacific Northwest coast. The species may be the most common trematode endemic to the United States.

Echinostoma hortense is an intestinal fluke of the class Trematoda, which has been found to infect humans in East Asian countries such as Korea, China, and Japan. This parasite resides in the intestines of birds, rats and other mammals such as humans. While human infections are very rare in other regions of the world, East Asian countries have reported human infections up to about 24% of the population in some endemic sub-regions. E. hortense infections are zoonotic infections, which occurs from eating raw or undercooked freshwater fish. The primary disease associated with an E. hortense infection is called echinostomiasis, which is a general name given to diseases caused by Trematodes of the genus Echinostoma.

<i>Clinostomum marginatum</i> Species of fluke

Clinostomum marginatum is a species of parasitic fluke. It is commonly called the "Yellow grub". It is found in many freshwater fish in North America, and no fish so far is immune to this parasite. It is also found in frogs. Clinostomum marginatum can also be found in the mouth of aquatic birds such as herons and egrets. They are commonly present in the esophagus of fish-eating birds and reptiles. Eggs of these trematodes are shed in the feces of aquatic birds and released into water. Aquatic birds become hosts of this parasite by ingesting infected freshwater fish. The metacercariae are found right beneath the skin or in the muscles of host fish.

Megalodiscus temperatus is a Digenean in the phylum Platyhelminthes. This parasite belongs to the Cladorchiidae family and is a common parasite located in the urinary bladder and rectum of frogs. The primary host is frogs and the intermediate hosts of Megalodiscus temeperatus are freshwater snails in the genus Helisoma.

<i>Alaria</i> (flatworm) Genus of flukes

Alaria is a genus of flatworms, or trematodes, in the family Diplostomidae.

Paragonimus kellicotti, the North American lung fluke, is a species of parasitic trematode in the genus Paragonimus. This species of Paragonimus has an intricate lifecycle, and although its name may suggest that it is only a health concern in North America, it is also prominent in Southeast Asia and China.

<span class="mw-page-title-main">Bivitellobilharzia nairi</span> Species of fluke

Bivitellobilharzia nairi is a species of trematodes, part of the family Schistosomatidae. This is a fairly new identified endoparasite that was found in 1945 by Mudaliar and Ramanujachari, who first recorded the parasite in India. Researchers collected fecal samples of the Indian rhinoceros and were startled to find B. nairi eggs.

Paragonimus skrjabini is classified as a species in the genus Paragonimus, which consists of many species of lung flukes that result in the food-borne parasitic disease paragonimiasis.

<i>Metagonimus yokogawai</i> Species of fluke

Metagonimus yokogawai, or the Yokogawa fluke, is a species of a trematode, or fluke worm, in the family Heterophyidae.

<span class="mw-page-title-main">Trematodiasis</span> Medical condition

Trematodiasis is a group of parasitic infections due different species of flukes, the trematodes. Symptoms can range from mild to severe depending on the species, number and location of trematodes in the infected organism. Symptoms depend on type of trematode present, and include chest and abdominal pain, high temperature, digestion issues, cough and shortness of breath, diarrhoea and change in appetite.

<span class="mw-page-title-main">Trematoda in Kuwait</span>

Trematoda is a whole-living worm that lives in different parts of the host's body, some of which live in bile ducts. These are called hepatic worms such as Fasciola species, including species that live in the intestines such as the genus Heterophyes, including those living in blood vessels such as the genus that causes schistosomiasis, the genus of Schistosoma. Including what lives in the lung such as the genus of Paragonimus.

<span class="mw-page-title-main">Gastropod-borne parasitic disease</span> Medical condition

Gastropod-borne parasitic diseases (GPDs) are a group of infectious diseases that require a gastropod species to serve as an intermediate host for a parasitic organism that can infect humans upon ingesting the parasite or coming into contact with contaminated water sources. These diseases can cause a range of symptoms, from mild discomfort to severe, life-threatening conditions, with them being prevalent in many parts of the world, particularly in developing regions. Preventive measures such as proper sanitation and hygiene practices, avoiding contact with infected gastropods and cooking or boiling food properly can help to reduce the risk of these diseases.

References

  1. 1 2 Ratini, Melinda, ed. (2019-04-02). "Paragonimiasis: Causes, Symptoms, and Treatment - WebMD". WebMD . Archived from the original on 2019-11-12. Retrieved 2019-04-02.
  2. ↑ Fischer, Peter U.; Weil, Gary J.; Wilkins, Patricia P.; Marcos, Luis A.; Folk, Scott M.; Curtis, Kurt C. (2013). "Serological Diagnosis of North American Paragonimiasis by Western Blot Using Paragonimus kellicotti Adult Worm Antigen". The American Journal of Tropical Medicine and Hygiene. 88 (6): 1035–1040. doi:10.4269/ajtmh.12-0720. PMC   3752799 . PMID   23589531.
  3. ↑ Fischer, P. U.; Weil, G. J. (2015). "North American paragonimiasis: epidemiology and diagnostic strategies - National Library of Medicine". Expert Review of Anti-Infective Therapy. 13 (6). Peter U. Fisher, Gary J. Weil: 779–86. doi:10.1586/14787210.2015.1031745. PMID   25835312. S2CID   11364754.
  4. 1 2 3 4 Chai, Jong-Yil (2013). "Paragonimiasis". Neuroparasitology and Tropical Neurology. Handbook of Clinical Neurology. Vol. 114. pp. 283–296. doi:10.1016/B978-0-444-53490-3.00023-6. ISBN   9780444534903. ISSN   0072-9752. PMID   23829919. S2CID   243875468.
  5. 1 2 3 4 5 6 Blair, David (2022). "Lung flukes of the genus Paragonimus: ancient and re-emerging pathogens". Parasitology. 149 (10): 1286–1295. doi: 10.1017/S0031182022000300 . PMC   10090773 . PMID   35292126. S2CID   247474931.
  6. ↑ Cong, Cung-Van; Anh, Tran-Thi Tuan; Ly, Tran-Thi; Duc, Nguyen Minh (2022). "Paragonimiasis diagnosed by CT-guided transthoracic lung biopsy: Literature review and case report". Radiology Case Reports. 17 (5): 1591–1597. doi:10.1016/j.radcr.2022.02.046. ISSN   1930-0433. PMC   8927937 . PMID   35309377.
  7. 1 2 3 4 5 6 7 "Paragonimiasis". Center for Global Health, U.S. Centers for Disease Control and Prevention (CDC). 2010-10-13. Archived from the original on 2013-12-16. Retrieved 2012-09-06.
  8. ↑ Haswell-Elkins MR, Elkins DB (1998). "Lung and liver flukes". In Collier L, Balows A, Sussman M (eds.). Topley and Wilson's Microbiology and Microbial Infections. Vol. 5 (9th ed.). New York: Oxford University Press. pp. 507–520. ISBN   978-0340663202.
  9. 1 2 3 4 Rosenbaum, Seth D.; Reboli, Annette C. (2019-10-11). Steele, Russell W.; Windle, Mary L. (eds.). "Paragonimiasis". Medscape. WebMD LLC. Retrieved 10 June 2024.
  10. 1 2 "Foodborne trematode infections". World Health Organization. 2016. Archived from the original on May 11, 2013. Retrieved November 11, 2016.
  11. 1 2 3 Singh, T. Shantikumar; Sugiyama, Hiromu; Rangsiruji, Achariya (2012). "Paragonimus & paragonimiasis in India". The Indian Journal of Medical Research. 136 (2): 192–204. ISSN   0971-5916. PMC   3461730 . PMID   22960885.
  12. 1 2 Diaz, James H. (2013). "Paragonimiasis Acquired in the United States: Native and Nonnative Species". Clinical Microbiology Reviews. 26 (3): 493–504. doi:10.1128/CMR.00103-12. ISSN   0893-8512. PMC   3719489 . PMID   23824370.
  13. 1 2 3 "Paragonimiasis, Clinical Features". CDC. 2010-10-13. Archived from the original on 2013-12-16. Retrieved 2012-09-06.
  14. ↑ Su-e, Zhang (2005). "Development of rapid diagnostic Kit(Dot Immunogold Filtration Assay) for detection of antibodies angainst Paragonimus westermani". Chinese Journal of Zoonoses. 21: 988–990. S2CID   88329798.
  15. ↑ Lane MA, Barsanti MC, Santos CA, Yeung M, Lubner SJ, Weil GJ (2009). "Human Paragonimiasis in North America following Ingestion of Raw Crayfish". Clinical Infectious Diseases. 49 (6): e55–e61. doi: 10.1086/605534 . PMID   19681705.
  16. ↑ Ahn, Chun-Seob; Shin, Jong Wook; Kim, Jeong-Geun; Lee, Weon-Young; Kang, Insug; Im, Jung-Gi; Kong, Yoon (2021). "Spectrum of pleuropulmonary paragonimiasis: An analysis of 685 cases diagnosed over 22 years". The Journal of Infection. 82 (1): 150–158. doi:10.1016/j.jinf.2020.09.037. ISSN   1532-2742. PMID   33017628. S2CID   222152193.
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