Liver parasites: A global endemic and journey from infestation to intervention

Table 1 Clinical features of cestodes

Parasite	Ref.	Global distribution	Hosts	Symptoms and complications	Diagnosis	Treatment
Echinococcus granulosus	Rinaldi et al[7]	Eurasia, Africa, Australia, South America	Dogs, herbivores, humans	Abdominal pain, hepatic cysts commonly, rarely pulmonary cysts	US, CT scan, ELISA and indirect hemagglutination, newer cystic fluid lipoprotein antigen	Albendazole 15 mg/kg/day in 2 divided doses, praziquantel once/week 40 mg/kg surgery, puncture, aspiration, instillation, reaspiration
Echinococcus multilocularis	Nunnari et al[6]	North America, Asia	Carnivores	Early symptoms of fatigue, weight loss, followed by portal hypertension, ascites splenomegaly	US, CT, IHA, ELISA, raised levels of IgG1 and IgG4 antibodies	Surgical resection, albendazole 15 mg/kg/day and mebendazole 40 mg/kg/day

CT: Computed tomography; ELISA: Enzyme-linked immunosorbent assay; IHA: Indirect hemagglutination; US: Ultrasound.

Table 2 Clinical features of trematodes

Parasite	Ref.	Global distribution	Hosts	Symptoms and complications	Diagnosis	Treatment
Fasciola hepatica	Peters et al[4]; Bargues and Mas-Coma[16]	Asia, Americas, Africa, Europe, Oceania	Lymnaea galba (water snail)	Abdominal pain, fever, nausea, urticaria, biliary tract obstruction, eosinophilia, jaundice, focal hepatic lesion	Stool microscopy, CT, antibodies, US, ERCP	Triclabendazole 10 mg/kg × 2 doses 12 hours apart, nitazoxanide 500 mg twice a day for 7 days
Fasciola gigantica	Peters et al[4]; Bargues and Mas-Coma[16]	Asia, Africa[4]	Lymnaea radix (water snail)[16]	Constitutional and hepatobiliary symptoms the same as Fasciola hepatica	Stool microscopy, CT, antibodies, US, ERCP	Triclabendazole 10 mg/kg × 2 doses 12 hours apart, nitazoxanide 500 mg twice a day for 7 days
Clonorchis sinesis	Locke et al[17]	East Asia	Freshwater fish (mainly cyprinidae family)	Calcium carbonate gallstones, pancreatitis, liver abscess, recurrent ascending cholangitis, cholangiocarcinoma	Stool microscopy, bile and serum IgG4, ERCP, ELISA, CT	Praziquantel 25 mg/kg orally 3 times a day, tribendimidine single dose of 400 mg, surgery or biliary stenting in case of cholangiocarcinoma
Ophisthorchis viverrine	Liau et al[18]	Southeast Asia	Freshwater snails (bithynia), Freshwater fish (cyprinidae)	Cholangitis, cholecystitis, periductal fibrosis, cholangiocarcinoma	Stool microscopy, urine antigen detection, US, CT, ERCP	Praziquantel 25 mg/kg orally 3 times a day, tribendimidine single dose of 400 mg
Schistosoma manson	Colley et al[19]	Africa, Middle East, Americas	Freshwater snails (biomphalaria species)	Symmers pipestem liver fibrosis, portal hypertension, gastroesophageal varices	Stool microscopy, US, circulating cathodic antigen assay	Praziquantel 20 mg/kg PO TID for 1 day
Schistosoma japonicum	Colley et al[19]	Asia	Freshwater snails (oncomelania species)	Periportal fibrosis, rectal bleeding, cerebral schistosomiasis (meningoencephalitis)	Stool microscopy, circulating cathodic antigen assay	Praziquantel 20 mg/kg PO TID for 1 day

CT: Computed tomography; ELISA: Enzyme-linked immunosorbent assay; ERCP: Endoscopic retrograde cholangiopancreatography; PO: Per oral; TID: Three times a day; US: Ultrasound.

Table 3 Clinical features of nematodes

Parasite	Ref.	Global distribution	Host	Symptoms and complications	Diagnosis	Treatment
Ascaris Lumbricoides	de lima et al[21]; Ali et al[22]	Sub-Saharan Africa, Latin America, China, East Asia	Humans (transmitted by fecal oral route)	Anorexia, diarrhea, pneumonitis and, cholangitis, small bowel obstruction, intussusception	Stool microscopy (can be negative in early infection), CBC, sputum analysis, US, CT, ERCP	Albendazole 400 mg PO once, mebendazole 100 mg PO 12 hours for 3 days, ivermectin 150-200 μg/kg, laparotomy if bowel obstruction present

CBC: Complete blood count; CT: Computed tomography; ERCP: Endoscopic retrograde cholangiopancreatography; PO: Per oral; US: Ultrasound.

Table 4 Clinical features of protozoas

Parasite	Ref.	Global distribution	Host	Symptoms and complications	Diagnosis	Treatment
Entamoeba Histolytica	Guillén[26]; Chou and Austin[27]	Central and South America, Africa, Asia	Humans	Asymptomatic, dysentery, liver abscess, amoebic brain abscess	Stool microscopy, stool antigen detection, stool molecular studies, colonoscopy, abscess drain aspirate culture and sensitivity	Metronidazole 500-750 mg PO TID for 5-10 days, luminal agents such as paromomycin 25-35 mg/kg/day PO 6 hourly, Drain placement in liver abscess

PO: Per oral; TID: Three times a day.