History

Fact Explanation
Diarrhea Metagonimiasis is a disease caused by an intestinal trematode known as Metagonimus yokagawai. The human becomes infected by ingesting undercooked or salted fish containing metacercariae. The metacercariae excyst, attachs to the mucosa of the small intestine after ingestion which then mature into adults. As they get attached to the intestinal mucosa, local inflammatory reactions take place. Most patients do not show any symptoms. Appearance of symptoms depends on the parasitic load. Watery type of mild diarrhea appears insidiously and is accompanied with nausea, vomiting and anorexia rarely. When present in large numbers, can cause chronic intermittent diarrhea. [1,2,3,4,5]
Abdominal pain Localized allergic reaction results in colicky type of intermittent abdominal pain. Heavy infection has also been associated with epigastric distress, fatigue, and malaise. [2,3,4]
Neurological manifestations Occasionally, flukes invade the mucosa and eggs deposited in tissue may gain access to circulation. This can then lead to eggs embolizing in the brain causing seizures and other neurological deficits. [1,2,3]
Chest pain Rarely, when the eggs of the flukes move into the heart, fatal valvular and myocardial damage may occur. The resultant arrhythmias may manifest as a chest pain. [3,4,5]
At risk population Metagonimiasis mostly occurs in the Far East, as well as Siberia, Manchuria, the Balkan states, Israel, and Spain. Ingestion of undercooked, salted, pickled, or smoked freshwater fish poses a greater risk. Incidences are higher in fishermen, fishmongers, workers in processing fish products, officials than in those with other occupations. [1,2,5]
References
  1. NZALAWAHE J, KASSUKU AA, STOTHARD JR, COLES GC, EISLER MC. Trematode infections in cattle in Arumeru District, Tanzania are associated with irrigation. Parasit Vectors [online] 2014 Mar 20:107 [viewed 14 August 2014] Available from: doi:10.1186/1756-3305-7-107
  2. CHAI JY. Praziquantel treatment in trematode and cestode infections: an update. Infect Chemother [online] 2013 Mar, 45(1):32-43 [viewed 14 August 2014] Available from: doi:10.3947/ic.2013.45.1.32
  3. LAN-ANH NT, PHUONG NT, MURRELL KD, JOHANSEN MV, DALSGAARD A, THU LT, KIM-CHI TT, THAMSBORG SM. Animal reservoir hosts and fish-borne zoonotic trematode infections on fish farms, Vietnam. Emerg Infect Dis [online] 2009 Apr, 15(4):540-6 [viewed 14 August 2014] Available from: doi:10.3201/eid1504.081147
  4. UPPAL B, WADHWA V. Rare case of Metagonimus yokogawai. Indian J Med Microbiol [online] 2005 Jan, 23(1):61-2 [viewed 14 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/15928427
  5. PORTES SANTOS C, LOPES KC, DA SILVA COSTA V, DOS SANTOS EG. Fish-borne trematodosis: potential risk of infection by Ascocotyle (Phagicola) longa (Heterophyidae). Vet Parasitol [online] 2013 Mar 31, 193(1-3):302-6 [viewed 14 August 2014] Available from: http://www.sciencedirect.com/science/article/pii/S0304401712006590

Examination

Fact Explanation
Abdominal tenderness Mild abdominal tenderness is possible due to the inflammation of the bowel mucosa. [1,2,3]
Cardiac murmers Very rarely cardiac murmurs may be auscultated owing to the myocarditis and eventual heart failure. [1,2,4]
Neurological signs In rare instances, neurological signs such as paresis can be found, depending on the extent that the cerebral emboli is affected. [1,3,4]
References
  1. NZALAWAHE J, KASSUKU AA, STOTHARD JR, COLES GC, EISLER MC. Trematode infections in cattle in Arumeru District, Tanzania are associated with irrigation. Parasit Vectors [online] 2014 Mar 20:107 [viewed 14 August 2014] Available from: doi:10.1186/1756-3305-7-107
  2. LAN-ANH NT, PHUONG NT, MURRELL KD, JOHANSEN MV, DALSGAARD A, THU LT, KIM-CHI TT, THAMSBORG SM. Animal reservoir hosts and fish-borne zoonotic trematode infections on fish farms, Vietnam. Emerg Infect Dis [online] 2009 Apr, 15(4):540-6 [viewed 14 August 2014] Available from: doi:10.3201/eid1504.081147
  3. PORTES SANTOS C, LOPES KC, DA SILVA COSTA V, DOS SANTOS EG. Fish-borne trematodosis: potential risk of infection by Ascocotyle (Phagicola) longa (Heterophyidae). Vet Parasitol [online] 2013 Mar 31, 193(1-3):302-6 [viewed 14 August 2014] Available from: http://www.sciencedirect.com/science/article/pii/S0304401712006590
  4. UPPAL B, WADHWA V. Rare case of Metagonimus yokogawai. Indian J Med Microbiol [online] 2005 Jan, 23(1):61-2 [viewed 14 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/15928427

Differential Diagnoses

Fact Explanation
Amoebiasis Amoebiasis, or Amebiasis, refers to infection caused by the amoeba Entamoeba histolytica. Most infected people are asymptomatic. Severe amoebiasis infections (known as invasive or fulminant amoebiasis) occur in two major forms. Invasion of the intestinal lining causes amoebic dysentery or amoebic colitis. Symptoms can range from mild diarrhea to severe dysentery with blood and mucus. [1]
Ascariasis Ascariasis is caused by Ascaris lumbricoides (large roundworm of humans) It is extremely common infection worldwide and associated with poor sanitation (lack of latrines) in slum areas and estate line rooms. Ascariasis affects more in children than in adults. Mild infection of adult worms does not show symptoms or signs. Increasing worm loads result in worsening of chronic malnutrition especially in children with a poor diet, poor weight gain and stunting. Symptoms may include shortness of breath and fever in the beginning of the disease. These may be followed by symptoms of abdominal swelling, abdominal pain and diarrhea. [2]
Fascioliasis Fasciola hepatica or the sheep liver fluke is a common parasite of sheep and cattle kept on damp pastures in many parts of the world, but is only occasionally found in men. Most cases have been reported from from sheep rearing countries such as South America, Europe and North America. The major symptoms includes fever, abdominal pain, gastrointestinal disturbances such as loss of appetite, flatulence, nausea, diarrhea and urticaria. [3]
Viral gastroenteritis Viral gastroenteritis is the most common cause of watery diarrhea.It is associated with abdominal pain,nausea and vomiting. Bacterial gastroenteritis usually results in watery diarrhea and sometimes blood and mucous diarrhea.Dehydration is common . Bacterial disease responds to antibacterial agents. [4]
Giardiasis Giardiasis is caused by Giardia intestinalis, a flagellate protozoan which decreases expression of brush-border enzymes namely disaccharidases and lipase. It causes impairment of carbohydrate and lipid digestion resulting osmotic diarrhea.Travelers to countries where giardiasis is common, People in child care settings, those who are in close contacts with patients, people who swallow contaminated or untreated water,men who have sex with men have a greater risk of becoming infected. Diarrhea is the most common symptom in acute giardiasis. It is more specifically, a steatorrhoea which contains pale, bulky, frothy, foul smelling stools which are floating in the lavatory pan due to fat content. [5]
References
  1. ARCHAMPONG EQ, CLARK CG. Surgical problems in amoebiasis. Ann R Coll Surg Engl [online] 1973 Jan, 52(1):36-48 [viewed 27 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/4568445
  2. WANG J, PAN YL, XIE Y, WU KC, GUO XG. Biliary ascariasis in a bile duct stones-removed female patient. World J Gastroenterol [online] 2013 Sep 28, 19(36):6122-4 [viewed 27 July 2014] Available from: doi:10.3748/wjg.v19.i36.6122
  3. ARADAğ-ÖNCEL E, OZSüREKçI Y, OZKAYA-PARLAKAY A, CELIK M, CENGIZ AB, HALILOğLU M, CEYHAN M, KARA A. Fasciola hepatica infection: clinical and radiological findings in pediatric patients. Turk J Pediatr [online] 2012 Jul-Aug, 54(4):362-7 [viewed 27 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23692716
  4. GODANA W, MENGISTIE B. Determinants of acute diarrhoea among children under five years of age in Derashe District, Southern Ethiopia. Rural Remote Health [online] 2013, 13(3):2329 [viewed 27 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/24016301
  5. VESY , PETERSON . Review article: the management of Giardiasis. Aliment Pharmacol Ther [online] 1999 July, 13(7):843-850 [viewed 27 July 2014] Available from: doi:10.1046/j.1365-2036.1999.00537.x

Investigations - for Diagnosis

Fact Explanation
Full blood count Parasitic infestation is characterized by high degree of eosinophilia. Leukocytosis and anemia (rarely) may also occur. [1,2,3]
Stool examination The diagnosis depends on the demonstration of eggs in stool specimens. Concentration techniques and repeated examinations will increase the likelihood of detecting light infections. However, the eggs are indistinguishable from those of Heterophyes and resemble those of Clonorchis and Opisthorchis. The eggs from Heterophyes are small, oval and brown, with embryo and operculum / lid. They are 28 to 30 microns long and 15 to 17 microns wide. Specific diagnosis is based on identification of the adult fluke evacuated after antihelminthic therapy, or found at autopsy. [1,2,3,4]
References
  1. NZALAWAHE J, KASSUKU AA, STOTHARD JR, COLES GC, EISLER MC. Trematode infections in cattle in Arumeru District, Tanzania are associated with irrigation. Parasit Vectors [online] 2014 Mar 20:107 [viewed 14 August 2014] Available from: doi:10.1186/1756-3305-7-107
  2. UPPAL B, WADHWA V. Rare case of Metagonimus yokogawai. Indian J Med Microbiol [online] 2005 Jan, 23(1):61-2 [viewed 14 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/15928427
  3. PORTES SANTOS C, LOPES KC, DA SILVA COSTA V, DOS SANTOS EG. Fish-borne trematodosis: potential risk of infection by Ascocotyle (Phagicola) longa (Heterophyidae). Vet Parasitol [online] 2013 Mar 31, 193(1-3):302-6 [viewed 14 August 2014] Available from: http://www.sciencedirect.com/science/article/pii/S0304401712006590
  4. LAN-ANH NT, PHUONG NT, MURRELL KD, JOHANSEN MV, DALSGAARD A, THU LT, KIM-CHI TT, THAMSBORG SM. Animal reservoir hosts and fish-borne zoonotic trematode infections on fish farms, Vietnam. Emerg Infect Dis [online] 2009 Apr, 15(4):540-6 [viewed 14 August 2014] Available from: doi:10.3201/eid1504.081147

Management - General Measures

Fact Explanation
Prevention Avoidance from having raw, undercooked or pickled wish is the best preventive method. Using molluscicides for snail (a host) control have been successful. [1,2,3]
References
  1. UPPAL B, WADHWA V. Rare case of Metagonimus yokogawai. Indian J Med Microbiol [online] 2005 Jan, 23(1):61-2 [viewed 14 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/15928427
  2. LAN-ANH NT, PHUONG NT, MURRELL KD, JOHANSEN MV, DALSGAARD A, THU LT, KIM-CHI TT, THAMSBORG SM. Animal reservoir hosts and fish-borne zoonotic trematode infections on fish farms, Vietnam. Emerg Infect Dis [online] 2009 Apr, 15(4):540-6 [viewed 14 August 2014] Available from: doi:10.3201/eid1504.081147
  3. CHAI JY. Praziquantel treatment in trematode and cestode infections: an update. Infect Chemother [online] 2013 Mar, 45(1):32-43 [viewed 14 August 2014] Available from: doi:10.3947/ic.2013.45.1.32

Management - Specific Treatments

Fact Explanation
Praziquantel Praziquantel as a single dose (25 mg/kg or less) is the current treatment of choice. Frequently occurring side effects are dizziness, headache, and malaise. Approximately 90% of all patients have abdominal pain or cramps with or without nausea and vomiting. [1,2]
References
  1. LAN-ANH NT, PHUONG NT, MURRELL KD, JOHANSEN MV, DALSGAARD A, THU LT, KIM-CHI TT, THAMSBORG SM. Animal reservoir hosts and fish-borne zoonotic trematode infections on fish farms, Vietnam. Emerg Infect Dis [online] 2009 Apr, 15(4):540-6 [viewed 14 August 2014] Available from: doi:10.3201/eid1504.081147
  2. CHAI JY. Praziquantel treatment in trematode and cestode infections: an update. Infect Chemother [online] 2013 Mar, 45(1):32-43 [viewed 14 August 2014] Available from: doi:10.3947/ic.2013.45.1.32