Parasitic diseases of the biliary tract

Adult schistosomes have an epithelial bacterial population distinct from the surrounding mammalian host blood

Background

Schistosomiasis is a neglected tropical parasitic and chronic disease affecting hundreds of millions of people. Adult schistosomes reside in the blood stream of the definitive mammalian host. These helminth parasites possess two epithelial surfaces, the tegument and the gastrodermis, both of which interact with the host during immune evasion and in nutrient uptake.

Methods

Female ARC Swiss mice (4–6 weeks old) were infected percutaneously with Schistosoma japonicum cercariae freshly shed from Oncomelania hupensis quadrasi snails (Philippines strain). Fluorescent in situ hybridisation (FISH) was performed by using fresh adult S. japonicum perfused from those infected mice. Adult S. japonicum worms were processed to isolate the tegument from the carcass containing the gastrodermis; blood and bile were collected individually from infected and uninfected mice. Total DNA extracted from all those samples were used for microbiome profiling.

Results

FISH and microbiome profiling showed the presence of bacterial populations on two epithelial surfaces of adult worms, suggesting they were distinct not only from the host blood but also from each other. Whereas microbial diversity was reduced overall in the parasite epithelial tissues when compared with that of host blood, specific bacterial taxa, including Anoxybacillus and Escherichia, were elevated on the tegument. Minimal differences were evident in the microbiome of host blood during an active infection, compared with that of control uninfected blood. However, sampling of bile from infected animals identified some differences compared with controls, including elevated levels of Limnohabitans, Clostridium and Curvibacter.

Conclusions

Using FISH and microbial profiling, we were able to demonstrate, for the first time, that bacteria are presented on the epithelial surfaces of adult schistosomes. These schistosome surface-associated bacteria, which are distinct from the host blood microenvironment, should be considered as a new and important component of the host-schistosome interaction. The importance of individual bacterial species in relation to schistosome parasitism needs further elucidation.

Bile duct infestation with Enterobius vermicularis diagnosed after cholecystectomy: About two case reports

Intestinal infestation with Enterobius vermicularis is common, especially in the developing countries. However, its migration in the bile ducts is rare, often diagnosed after cholecystectomy. More investigations are needed to define its involvement in symptoms presented by patients and the likelihood of complications.

Typical imaging finding of hepatic infections: a pictorial essay

Hepatic infections are frequent in clinical practice. Although epidemiological, clinical and laboratory data may suggest hepatic infection in certain cases, imaging is nearly always necessary to confirm the diagnosis, assess disease extension and its complications, evaluate the response to treatment, and sometimes to make differential diagnoses such as malignancies. Ultrasound (US) is usually the first-line investigation, while computed tomography (CT) and magnetic resonance imaging (MRI) provide better characterization and a more precise assessment of local extension, especially biliary and vascular. The purpose of this article is to describe the typical features and main complications of common hepatic infections. Familiarity with the radiological features of this entity can help suggest the correct diagnosis and the need for further studies as well as determine appropriate and timely treatment.

Ascaris-mimicking common bile duct stone: A case report

BACKGROUND

In most cases, it is not difficult to differentiate common bile duct (CBD) stone from Ascaris infection because they are different disease entities and have different imaging findings. The two diseases usually demonstrate unique characteristic findings on computed tomography or magnetic resonance cholangiopancreatography. However, we report a rare case from our experience in which a CBD stone mimicked and was misdiagnosed as Ascaris.

CASE SUMMARY

A 72-year-old male presented with elevated serum liver enzymes. Computed tomography showed a hyper-attenuated, elongated lesion in the CBD lumen and associated biliary inflammation. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography revealed a linear filling defect in the bile duct. Moreover, elongated echogenic material with a central hypoechogenic area was seen on endoscopic ultrasound. Although the imaging findings caused us to suspect infection with the nematode Ascaris, the lesion was revealed to be a dark-brown-colored CBD stone through endoscopic extraction.

CONCLUSION

We report a rare case of a CBD stone that mimicked Ascaris. We also review the literature for side-by-side comparisons of the imaging features of CBD stones and ascariasis.

Parasitic diseases as a cause of acute abdominal pain: imaging findings

Acute abdominal pain can be seen in cases with parasitic diseases delivered to emergency departments. The diagnosis of the parasitic disease can be delayed because of the similar clinical signs encountered in other frequently seen causes of acute abdomen. Nevertheless, the features detected in imaging scans can be helpful in the diagnosis. The present study aims to raise awareness about abdominal parasitosis in emergency conditions and also to underline the association between imaging findings and the life cycle of parasites with illustrative cases.

The hepatoduodenal ligament revisited: cross-sectional imaging spectrum of non-neoplastic conditions

INTRODUCTION

The hepatoduodenal ligament is frequently involved by conditions affecting the portal triad and surrounding structures, including a vast array of non-neoplastic conditions. Due its unique location between the retroperitoneum and the peritoneal space, the hepatoduodenal ligament is also targeted by inflammatory conditions involving the retroperitoneum and the liver. Finally, the presence of lymphatics and of the biliary tracts makes the hepatoduodenal ligament a route of spread for a variety of infections. The purpose of this pictorial essay is twofold: to review the cross-sectional radiological anatomy and variants of the structures within the hepatoduodenal ligament, and to illustrate the non-neoplastic conditions that may arise within the hepatoduodenal ligament.

CONCLUSION

Familiarity with these specific entities and their cross-sectional imaging findings is fundamental for a more accurate diagnosis.

Catastrophic health expenditure of Vietnamese patients with gallstone diseases - a case for health insurance policy revaluation

Purpose

Despite gallstone diseases (GSDs) being a major public health concern with both acute and chronic episodes, none of the studies in Vietnam has been conducted to investigate the household expenditure for the GSD treatment. The objective of this study was to estimate the costs of managing GSD and to explore the prevalence and determinants of catastrophic health expenditure (CHE) among Vietnamese patients.

Materials and methods

A cross-sectional study was conducted from June 2016 to March 2017 in the Department of Hepatobiliary and Pancreatic Surgery, Viet Duc Hospital in Hanoi, Vietnam. A total of 206 patients were enrolled. Demographic and socioeconomic data, household income, and direct and indirect medical costs of patients seeking treatment for GSD were collected through face-to-face interview. Multivariate logistic regression was used to explore factors associated with CHE.

Results

The prevalence of CHE in patients suffering from GSD was 35%. The percentage of patients who were covered by health insurance and at risk for CHE was 41.2%, significantly higher than that of those noninsured (15.8%). Proportions of patients with and without health insurance who sought outpatient treatment were 30.6% and 81.6%, respectively. Patients who were divorced or widowed and had intrahepatic gallstones were significantly more likely to experience CHE. Those who were outpatients, were women, had history of pharmacological treatment to parasitic infection, and belong to middle and highest monthly household income quantile were significantly less likely to experience CHE.

Conclusion

The findings suggested that efforts to re-evaluate health insurance reimbursement capacity, especially for acute diseases and taking into account the varying preferences of people with different disease severity, should be conducted by health authority. Further studies concerning CHE of GSD in the context of ongoing health policy reform should consider utilizing WHO-recommended measures like the fairness in financial contribution index, as well as taking into consideration the behavioral aspects of health care spending.

Parasitic infections of the gut in children

Parasitic infections of the gut have major implications for child health, but many questions remain unanswered. Protozoal parasites, especially cryptosporidiosis and giardiasis, cause diarrhoea and contribute to impaired growth, neurocognitive development and mortality. Entamoeba histolytica causes dysentery and may have more subtle effects on child growth. Helminth infections are mostly asymptomatic, and untargeted mass deworming has not been shown to be beneficial. However, children with heavy infections certainly benefit from antihelminthic treatment. Hepatosplenic schistosomiasis is a neglected problem on a massive scale, which causes portal hypertension and lifelong morbidity in individuals who get infected in childhood. Neurocysticercosis causes epilepsy and is a significant consequence of taeniasis solium, another neglected disease which is entirely preventable. Parasitic infections of the gut contribute to child health problems on a large scale. Fresh approaches are needed to prevention and treatment.

Ultrasonographic investigation of cholangiocarcinoma in Lao PDR

Opisthorchis viverrini is a group 1 carcinogen that causes cholangiocarcinoma (CCA). Although opisthorchiasis is known to be severely endemic to several areas along the Mekong River in Lao PDR, the CCA status of residents of this region is still under investigation. In this study, we analyzed the results of abdominal ultrasonography (US) performed on 6113 residents in 9 provinces (Vientiane Municipality, Savannakhet, Phongsaly, Khammouane, Saravane, Champasak, Vientiane, Xieng Khuouang, and Luang Prabang provinces) of Lao PDR from 2007 to 2011. Overall, 51 cases (0.83%) were detected with suspected CCA. The CCA rates in Vientiane Municipality and in Savannakhet and Khammouane provinces were 1.45%, 1.58%, and 1.09%, respectively. However, in the other 6 provinces, the rate of CCA averaged only 0.26%. In the 3 provinces with higher rates of CCA, bile duct dilatation (grade ≥ 2) was also significantly more prevalent (P < 0.0001). These results are concordant with previous reports showing a higher endemicity of opisthorchiasis in Vientiane Municipality and in Savannakhet and Khammouane provinces.

Unexpected hosts: imaging parasitic diseases

Radiologists seldom encounter parasitic diseases in their daily practice in most of Europe, although the incidence of these diseases is increasing due to migration and tourism from/to endemic areas. Moreover, some parasitic diseases are still endemic in certain European regions, and immunocompromised individuals also pose a higher risk of developing these conditions. This article reviews and summarises the imaging findings of some of the most important and frequent human parasitic diseases, including information about the parasite's life cycle, pathophysiology, clinical findings, diagnosis, and treatment. We include malaria, amoebiasis, toxoplasmosis, trypanosomiasis, leishmaniasis, echinococcosis, cysticercosis, clonorchiasis, schistosomiasis, fascioliasis, ascariasis, anisakiasis, dracunculiasis, and strongyloidiasis. The aim of this review is to help radiologists when dealing with these diseases or in cases where they are suspected. Teaching Points • Incidence of parasitic diseases is increasing due to migratory movements and travelling. • Some parasitic diseases are still endemic in certain regions in Europe. • Parasitic diseases can have complex life cycles often involving different hosts. • Prompt diagnosis and treatment is essential for patient management in parasitic diseases. • Radiologists should be able to recognise and suspect the most relevant parasitic diseases.

Sonographic images of hepato-pancreatico-biliary and intestinal ascariasis: A pictorial review

Abstract

Despite advancement in the diagnosis and treatment of intestinal helminthiasis, ascariasis remains the most common cause of helminthic infections in the developing countries. Ultrasound offers a rapid, safe, and noninvasive approach to the diagnosis of intestinal ascariasis. Ultrasound is also the modality of choice for diagnosis of hepatobiliary ascariasis, which is relatively rare and is due to migration of intestinal worms through the papilla of Vater. We present an imaging spectrum of hepato-pancreatico-biliary and intestinal ascariasis.

Main messages

• Ascariasis refer to infestation by the round worm ascaris lumbricoides.

• Ascaris eggs are excreted in faeces and are infective to humans.

• Eggs hatch to larva, travel to the lungs and mature to adult worms.

• Intestinal obstruction can be caused by multiple ascariasis forming bag of worms.

Three Living Fasciola Hepatica in the Biliary Tract of a Woman

Fasciola hepatica (F. hepatica) as a foodborne trematode can occasionally cause hepatobiliary diseases. We report a 67-year-old woman who was referred to our center because of the diagnosis of cholangitis. She was a resident of mountainous area with the history of unsafe water and contaminated vegetables. Endoscopic retrograde cholangiopancreatography (ERCP) was performed as a diagnostic and therapeutic modality for her. Three living F. hepatica was removed from biliary tract with a basket via ERCP. Clinical and laboratory condition of the patient improved after therapy of antibiotics and triclabendazole.

Parasitic liver disease in travelers

Liver disease is an important source of morbidity among ill returning travelers. Jaundice is one of the most common and obvious symptoms of liver disease, the differential diagnosis of which is extensive, especially in travelers. Jaundice in travelers can arise from both infectious and noninfectious causes. We herein summarize the most common parasitic etiologies that may lead to jaundice in the returned traveler, visitors of friends and relatives, or new immigrants, and describe the etiology, epidemiology, and pathogenesis of clinical features of each.

Infections and infestations of the gastrointestinal tract. Part 2: parasitic and other infections

The purpose of this article is to provide a comprehensive review of the imaging findings of various parasitic infestations and other miscellaneous infections affecting the gastrointestinal tract. Barium examinations play an important role in the diagnostic workup of parasitic intestinal infections. Knowledge of differential diagnosis, sites of involvement, and imaging features of different infections and infestations can help in accurate diagnosis and guide treatment.

[Tomato peel: rare cause of biliary tract obstruction]

Foreign bodies in the biliary tree are rare causes of obstructive jaundice. Food bezoars are infrequent as well. They can cause biliary obstruction after biliary tract interventions, or in the presence of biliary-bowel fistula or duodenum diverticulum. Food bezoars usually pass the gastrointestinal tract without any symptoms, but they can cause abdominal pain and obstructive jaundice in the case of biliary tract obstruction. Endoscopic retrograde cholangio-pancreatography has the major role in the diagnosis and the treatment of the disease. Authors summarize the medical history of a 91-year-old female patient, who developed vomiting and right subcostal pain due to the presence of tomato peel within the ductus choledochus.

Role of the apparent diffusion coefficient measurement by diffusion weighted magnetic resonance imaging in the diagnosis of Fasciola hepatica in the liver

PURPOSE

The aim of this study was to investigate the diagnostic role of the apparent diffusion coefficient (ADC) measurement in the diagnosis of focal parenchymal lesions and to understand the discriminating role of the ADC value for differentiating Fasciola lesions from other focal liver lesions.

MATERIALS AND METHODS

We measured ADC values of parenchymal lesions and liver parenchyma in 18 patients with Fasciola hepatica infestation at b 100, b 600, and b 1000 s/mm(2) gradients. We further measured average ADC values of hepatic metastases (n = 21), hepatocellular carcinomas (n = 21), cholangiocarcinomas (n = 7), hydatid cysts (n = 12), and focal nodular hyperplasia (FNH) (n = 12) and compared them with average ADC values for Fasciola hepatica.

RESULTS

The differences between average ADC values of lesions (2.16 ± 0.36 × 10(-3) mm(2)/s) and parenchyma (1.64 ± 0.2 × 10(-3) mm(2)/s) at three gradients were statistically significant (P < 0.05). Mean ADC values of Fasciola hepatica lesions were significantly different from most of the other focal hepatic lesions, except FNH at all gradients and hydatid cyst at only the b 100 gradient.

CONCLUSION

ADC measurement may be a complementary method in the diagnosis of Fasciola hepatica, and it may be used to differentiate these lesions from other focal liver lesions.

Ascariasis of gall bladder associated with xanthogranulomatous inflammation and cholelithiasis

We report a rare case of ascariasis of gall bladder. The unusual features in this case were the presence of eggs of Ascaris lumbricoides in the lumen. Some of the eggs had evoked a foreign body reaction indicating chronicity. The bladder wall was unevenly thickened with yellowish white nodules and showed maximum thickness around the neck region. Microscopy showed predominantly xanthogranulomatous inflammation in the thickened parts of the wall.

Systems parasitology: effects of Fasciola hepatica on the neurochemical profile in the rat brain

We characterize the integrated response of a rat host to the liver fluke Fasciola hepatica using a combination of ¹H nuclear magnetic resonance spectroscopic profiles (liver, kidney, intestine, brain, spleen, plasma, urine, feces) and multiplex cytokine markers of systemic inflammation. Multivariate mathematical models were built to describe the main features of the infection at the systems level. In addition to the expected modulation of hepatic choline and energy metabolism, we found significant perturbations of the nucleotide balance in the brain, together with increased plasma IL-13, suggesting a shift toward modulation of immune reactions to minimize inflammatory damage, which may favor the co-existence of the parasite in the host. Subsequent analysis of brain extracts from other trematode infection models (i.e. Schistosoma mansoni, and Echinostoma caproni) did not elicit a change in neural nucleotide levels, indicating that the neural effects of F. hepatica infection are specific. We propose that the topographically extended response to invasion of the host as characterized by the modulated global metabolic phenotype is stratified across several bio-organizational levels and reflects the direct manipulation of host–nucleotide balance.

Courvoisier's gallbladder: law or sign?

BACKGROUND

Variously described as Courvoisier's law, sign, or even gallbladder, this eponymous "law" has been taught to medical students since the publication of Courvoisier's treatise in 1890.

METHODS

We reviewed Courvoisier's original "law," the modern misconceptions surrounding it, and the contemporary evidence supporting and explaining his observations.

RESULTS

Courvoisier never stated a "law" in the context of a jaundiced patient with a palpable gallbladder. He described 187 cases of common bile duct obstruction, observing that gallbladder dilatation seldom occurred with stone obstruction of the bile duct. The classic explanation for Courvoisier's finding is based on the underlying pathologic process. With the presence of gallstones come repeated episodes of infection and subsequent fibrosis of the gallbladder. In the event that a gallstone causes the obstruction, the gallbladder is shrunken owing to fibrosis and is unlikely to be distensible and, hence, palpable. With other causes of obstruction, the gallbladder distends as a result of the back-pressure from obstructed bile flow. However, recent experiments show that gallbladders are equally distensible in vitro, irrespective of the pathology, suggesting that chronicity of the obstruction is the key. Chronically elevated intraductal pressures are more likely to develop with malignant obstruction owing to the progressive nature of the disease. Gallstones cause obstruction in an intermittent fashion, which is generally not consistent enough to produce such a chronic rise in pressure.

CONCLUSION

We hope that reminding clinicians of Courvoisier's actual observations will reestablish the usefulness of this clinical sign in the way he intended.

Biliary ascariasis on magnetic resonance cholangiopancreatography

A 17-year-old girl presented with features of biliary obstruction. Magnetic resonance cholangi-pancreatography revealed typical linear signals in common bile duct, which appears like Ascaris lumbricoides. The diagnosis was confirmed by endoscopic removal of the worm.

Changes in sonographic findings after treatment of patients with clonorchiasis in a heavy endemic area

We measured changes in sonographic findings of patients with clonorchiasis after a treatment in a highly endemic area. A total of 347 residents showed positive stool results for Clonorchis sinensis eggs in a village in northeastern China, and were treated with praziquantel. Of them, 132 patients underwent abdominal sonography both before and 1 year after treatment, and the changes in sonographic findings of 83 cured subjects were compared. Diffuse dilatation of intrahepatic bile ducts (DDIHD) was found in 82 patients (98.2%) before and 80 (96.4%) after treatment, which was improved in 3, aggravated in 1, and unchanged in 79 patients. Increased periductal echogenicity (IPDE) was observed in 42 patients (50.6%) before and 45 (54.2%) after treatment, which was improved in 5, aggravated in 8, and unchanged in 70 patients. Floating echogenic foci in the gallbladder (FEFGB) was detected in 32 patients (38.6%) before and 17 (20.5%) after treatment, which was improved in 20, aggravated in 5, and unchanged in 58 patients. Improvement of FEFGB only was statistically significantly (P = 0.004). The present results confirm that DDIHD and IPDE persist but FEFGB decreases significantly at 1 year after treatment. In a heavy endemic area, the sonographic finding of FEFGB may suggest active clonorchiasis 1 year after treatment.