Schistosomiasis. Pathophysiology, diagnosis, and treatment

Fulminant Hepatitis and Ulcerative Colitis: Case Report of Ethiopian Child with Schistosomiasis and Amebiasis Co-Infection

Background

Schistosomiasis is a neglected tropical disease (NTD) that affects around 200 million people worldwide, the majority of whom are children aged 5 to 15 years. It is one of the most significant public health problems in tropical and subtropical regions. Entamoeba histolytica infection is common in areas where schistosomiasis is endemic because Schistosoma mansoni infection can reduce the host's immune response, resulting in increased morbidity.

Case Presentation

This is the story of a 12-year-old male adolescent from the Guji zone of the Oromia regional state of Ethiopia who presented to Hawassa University Comprehensive Specialized Hospital (HUCSH) complaining of bloody diarrhea of 1 week associated with vomiting of ingested matter of 2 weeks. He also had history of fever, chills, rigors, arthralgia, and weight loss during a 2 weeks period. Further questioning revealed that he had previously swum in a pond and had a self-limited itchy skin condition. The family said that similar cases had occurred in their town that resolved with medications provided at a local health center.

Conclusion

Schistosomiasis and amebiasis are major public health issues, especially in impoverished areas. Schistosomiasis presents differently clinically depending on the phase and clinical form in which it manifests, making diagnosis and management challenging. As a result, it necessitates an integrated collaboration involving clinicians, pathologists, and public health professionals. We describe ulcerative colitis (UC) ascribed to schistosomiasis and amoebiasis coinfection, and fulminant hepatitis due to schistosomiasis. As there was no report of liver abscess on sonographic scanning, hepatitis may not be due to coinfection. This case will be an alert to clinicians and public health personnel who are striving for the ultimate eradication of schistosomiasis and also teaches us that treating co-infections of both is beyond just giving praziquantel and antiamebics.

Portal venous pressure in non-cirrhotic bilharzial patients undergoing elective splenectomy, can it affect mortality? A prospective study

Background and study aims

To evaluate the impact of intraoperatively measured portal vein pressure (PVP) on mortality in non-cirrhotic bilharzial patients undergoing splenectomy.

Methods

The present study is a prospective study that was conducted in Egypt from April 2014 to April 2018. Adult patients with non-cirrhotic bilharziasis who were scheduled to undergo splenectomy were included. Studied cases were divided into a survival cohort and a non-survival cohort. The main objective was the correlation between the incidence of mortality and intraoperative PVP.

Results

The present work comprised 130 cases with a mean age of 51.8 ± 6.4 years old. The in-hospital mortality rate was 22.3%, with sepsis as a major cause of death (37.9%). In term of the association between preoperative variables and mortality, survivors had statistically significant lower portal vein diameter (13.6 ± 1.8 versus 15.2 ± 1.8mm; p<0.001) and higher portal vein velocity (14.2 ± 1.8 versus 10.4 ± 2.3 cm/sec; p<0.001) than nonsurvivors. The survived patients had significantly lower PVP (13.9 ± 1.1 versus 17.7 ± 2.7; p<0.001). A cut-off value of ≥14.5 mmHg, the PVP yielded a sensitivity of 86.2% and a specificity of 69% for the prediction of mortality. The association analysis showed a statistically significant association between mortality and postoperative liver function parameters.

Conclusions

High intraoperative PVP is linked to early postoperative death in non-cirrhotic cases undergoing splenectomy. Our study showed that PVP > 14.5mmHg was an independent predictor of death and showed good diagnostic performance for the detection of early postoperative mortality.

Schistosomiasis Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease of the lung blood vessels that results in right heart failure. PAH is thought to occur in about 5% to 10% of patients with hepatosplenic schistosomiasis, particularly due to S. mansoni. The lung blood vessel injury may result from a combination of embolization of eggs through portocaval shunts into the lungs causing localized Type 2 inflammatory response and vessel remodeling, triggering of autonomous pathology that becomes independent of the antigen, and high cardiac output as seen in portopulmonary hypertension. The condition is likely underdiagnosed as there is little systematic screening, and risk factors for developing PAH are not known. Screening is done by echocardiography, and formal diagnosis requires invasive right heart catheterization. Patients with Schistosoma-associated PAH show reduced functional capacity and can be treated with pulmonary vasodilators, which improves symptoms and may improve survival. There are animal models of this disease that might help in understanding disease pathogenesis and identify novel targets to screen and treatment. Pathogenic mechanisms include Type 2 immunity and activation and signaling in the TGF-β pathway. There are still major uncertainties regarding Schistosoma-associated PAH development, course and treatment.

Surveillance on schistosomiasis in five provincial-level administrative divisions of the People's Republic of China in the post-elimination era

Background

The People’s Republic of China (P. R. China) has made significant progress on schistosomiasis control. Among the 12 provincial-level administrative divisions (PLADs) with schistosomiasis endemic in P. R. China, Guangdong, Shanghai, Fujian, Guangxi and Zhejiang PLADs (following as five PLADs) had successively eliminated schistosomiasis during 1985–1995. However, consolidation of the schistosomiasis elimination in these five PLADs remains challenging. In the current study, we sought to understand the epidemic situation in these post-elimination areas and their surveillance capabilities on schistosomiasis.

Methods

Annual data reflecting the interventions and surveillance on human beings, cattle and snails based on county level from 2005 to 2016 were collected through the national schistosomiasis reporting system and the data were analyzed to understand the epidemic status of schistosomiasis in the five PLADs. A standardized score sheet was designed to assess the surveillance capacity for schistosomiasis of selected disease control agencies in five PLADs and ten counties. Assessment on surveillance capacity including schistosomiasis diagnostic skills, identification of snails’ living and infection status and knowledge about schistosomiasis and its control were made. Descriptive analysis was used to analyze the epidemic status and evaluation results on surveillance capacities.

Results

The assessments showed that no local cases in humans and cattle or infected snail were found in these five PLADs since 2005. However, from 2005 to 2016, a total of 221 imported cases were detected in Zhejiang, Shanghai and Fujian, and 11.98 hm² of new snail habitats were found in Zhejiang, Shanghai and Guangxi. In addition, snail infestation reoccurred in 247.55 hm² of former snail habitats since 2011. For the surveillance capacity assessment, the accuracy rate of IHA and MHT were 100 and 89.3%, respectively. All participants could judge the living status of snails accurately and 98.1% on the infection status of snails. The accuracy rate of the questionnaire survey was 98.0%.

Conclusions

Elimination of schistosomiasis was consolidated successfully in five PLADs of P. R. China due to effective and strong post-elimination surveillance. Comprehensive consolidation strategies should be focused on the elimination of residual snails and the prevention of imported infection sources to consolidate the achievements of schistosomiasis control.

Colonic Polyps an Unusual Manifestation of Schistosomiasis

Patient: Male, 24-year-old

Final Diagnosis: Large rectal polyps secondary to Schistosoma infection • Unusual colonic polyp caused by Schistoma infection

Symptoms: Abdominal pain • bleeding per rectum

Medication: During the procedure: Xylocaine local gel • Midazolam inj • Fentanyl inj; For the disease: Praziquantel tab

Clinical Procedure: Colonoscopy with endoscopic submucosal resection (EMR) • endoscopic submucosal resection (EMR)

Specialty: Gastroenterology and Hepatology • Endoscopy

Gallbladder schistosomiasis - a rare presentation as gallbladder polyp: a case report

Background: Schistosomiasis is a neglected tropical disease second to malaria in prevalence with significant morbidity and mortality. Although, Schistosomiasis can affect multiple organs, gallbladder involvement is very rarely reported. We present a case of isolated gallbladder schistosomiasis in a 20-year-old female presenting as gallbladder polyp radiologically and also correlated the histopathological findings which to our knowledge has never been reported in the English literature. A high index of suspicion should be made for considering Schistosomiasis when an individual hailing from endemic region presents with gallbladder pathologies.

Systemic schistosomiasis and large bowel perforation: An unexpected surgical urgency. Report of a case and literature review

In the presence of suggestive clinical picture (high eosinophil count and multiple CT scan granuloma-like lesions), schistosomiasis should be taken into account in case of suspected bowel perforation even if common risk factors are not identified through anamnesis.

A Curious Case of Iron-Deficiency Anemia

A 49-year-old Brazilian male presented to the emergency department with a five-day history of abdominal pain, dark stools, and syncope. Physical examination did not reveal any melena on digital rectal examination and there were no stigmata of chronic liver disease. Laboratory results showed hemoglobin of 47 g/L, MCV of 80 fL, and ferritin of 6 ng/mL. Liver enzymes and liver function tests were normal. Abdominal ultrasound showed a cirrhotic liver with splenomegaly and varices suggestive of portal hypertension. His past history was significant for cirrhosis based on a previous variceal bleed but a workup for chronic liver disease was negative and a liver biopsy did not show steatosis, fibrosis, or cirrhosis. A gastroscopy in this admission showed large esophageal varices without high-risk stigmata and no overt bleeding was seen. A colonoscopy was subsequently completed to the terminal ileum and was normal aside from a 5 mm sessile polyp in the descending colon.

Multiple parasitic infections in a cardiac transplant recipient

Infectious complications represent an important cause of morbidity and death in patients with transplant. Parasitic infections are less frequent than viral and bacterial agents, and are often overlooked. We describe the case of a 13-year-old adolescent, born in São Tomé Island, who was under immunosuppressive therapy after a cardiac transplant. The patient had an intermittent course of diarrhoea, abdominal pain and vomiting. She was admitted dehydrated, and Strongyloides stercoralis, Schistosoma intercalatum and Cystoisospora belli were isolated in her stools. The patient was treated with ivermectin, albendazole, praziquantel and ciprofloxacin with clinical and microbiological resolution. Her immunosuppressive therapy was reduced during hospitalisation. We believe that the parasitic infection was a result of a recrudescence of dormant infections acquired in her homeland. To the best of our knowledge, there are no reports of cystoisosporiasis or schistosomiasis in heart transplant recipients.

Neurologic manifestations of the neglected tropical diseases

BACKGROUND

The World Health Organization has identified 17 neglected tropical diseases (NTDs) that disproportionately affect the world's poorest populations. The neurologic aspects of many of these NTDs have received relatively little attention.

METHODS

A review was performed in PubMed (MedLine) for each NTD by disease name, name of its causative organism, and neurology, neurosurgery, neurologist, brain, spinal cord, peripheral nerve, muscle, nervous system, encephalitis, meningitis, encephalopathy, stroke, neuropathy, and myopathy (1968-Sept. 2013). The Oxford Center for Evidence-based Medicine guidelines were used to determine the level of evidence of neurological involvement and treatment based on the reports identified.

RESULTS

Neurologic manifestations were reported for all NTDs except yaws. Neurologic involvement was described in systematic reviews for four NTDs (Chagas disease, echinococcosis, rabies, cysticercosis) (levels 2a-3a), retrospective cohort studies for six (dengue, human African trypanosomiasis, leishmaniasis, leprosy, onchocerciasis, schistosomiasis) (levels 2b-3b), case series for one (foodborne trematodiasis) (level 4), and case reports for five (Buruli ulcer, dracunculiasis, filariasis, soil-transmitted helminthes, and trachoma). Level 1 evidence for treatment of neurologic manifestations of NTDs was found for human African trypanosomiasis, leprosy, and cysticercosis and level 2 evidence exists for treatment of neurologic involvement in Chagas disease. For the remaining NTDs, treatment of neurologic complications is described in case series and case reports only.

CONCLUSIONS

Neurologic manifestations of NTDs cause significant morbidity and mortality, although limited evidence exists on how best to treat these neurologic complications. Increased awareness of neurologic manifestations of the NTDs can increase their early identification and treatment, contributing to ongoing elimination and eradication campaigns.

Schistosomiasis manifesting as a colon polyp: a case report

INTRODUCTION

Schistosomiasis is a rare disease with a common intestinal involvement. However, colon polyps associated with Schistosoma in the absence of inflammation have rarely been reported, especially in young people; this is the first case with the following presentation.

CASE PRESENTATION

We describe the case of a 20-year-old Ethiopian woman living in Lebanon who presented with nonspecific abdominal symptoms. Her biochemical profile was normal in addition to the results of her stool and urine tests. A colonoscopy showed normal colonic mucosa but surprisingly a large pedunculated polyp was found in her ascending colon. Pathology revealed a hamartomatous polyp but it was full of partially calcified parasitic eggs of Schistosoma mansoni compatible with chronic schistosomiasis.

CONCLUSIONS

She was treated with two doses of praziquantel and showed immediate marked clinical improvement. This unusual case will give us the opportunity to discuss schistosomiasis, its occurrence in colon polyps, clinical significance and the various means of management.

Controversies and challenges in research on urogenital schistosomiasis-associated bladder cancer

Urogenital schistosomiasis, infection with Schistosoma haematobium, is linked to increased risk for the development of bladder cancer, but the importance of various mechanisms responsible for this association remains unclear, in part, owing to lack of sufficient and appropriate animal models. New advances in the study of this parasite, bladder regenerative processes, and human schistosomal bladder cancers may shed new light on the complex biological processes that connect S. haematobium infection to bladder carcinogenesis.

Hepatic and intestinal schistosomiasis: review

Schistosomiasis is an endemic disease in Egypt caused by the trematode Schistosoma which has different species. Hepatic schistosomiasis represents the best known form of chronic disease with a wide range of clinical manifestations. The pathogenesis of schistosomiasis is related to the host cellular immune response. This leads to granuloma formation and neo angiogenesis with subsequent periportal fibrosis manifested as portal hypertension, splenomegaly and esophageal varices. Intestinal schistosomiasis is another well identified form of chronic schistosomal affection. Egg deposition and granuloma formation eventually leads to acute then chronic schistosomal colitis and is commonly associated with polyp formation. It frequently presents as abdominal pain, diarrhea, tenesmus and anal pain. Definite diagnosis of schistosomiasis disease depends on microscopy and egg identification. Marked progress regarding serologic diagnosis occurred with development of recent PCR techniques that can confirm schistosomal affection at any stage. Many antischistosomal drugs have been described for treatment, praziquantel being the most safe and efficient drug. Still ongoing studies try to develop effective vaccines with identification of many target antigens. Preventive programs are highly needed to control the disease morbidity and to break the cycle of transmission.

A fibreoptic endoscopic study of upper gastrointestinal bleeding at Bugando Medical Centre in northwestern Tanzania: a retrospective review of 240 cases

Background

Upper gastrointestinal (GI) bleeding is recognized as a common and potentially life-threatening abdominal emergency that needs a prompt assessment and aggressive emergency treatment. A retrospective study was undertaken at Bugando Medical Centre in northwestern Tanzania between March 2010 and September 2011 to describe our own experiences with fibreoptic upper GI endoscopy in the management of patients with upper gastrointestinal bleeding in our setting and compare our results with those from other centers in the world.

Findings

A total of 240 patients representing 18.7% of all patients (i.e. 1292) who had fibreoptic upper GI endoscopy during the study period were studied. Males outnumbered female by a ratio of 2.1:1. Their median age was 37 years and most of patients (60.0%) were aged 40 years and below. The vast majority of the patients (80.4%) presented with haematemesis alone followed by malaena alone in 9.2% of cases. The use of non-steroidal anti-inflammatory drugs, alcohol and smoking prior to the onset of bleeding was recorded in 7.9%, 51.7% and 38.3% of cases respectively. Previous history of peptic ulcer disease was reported in 22(9.2%) patients. Nine (3.8%) patients were HIV positive. The source of bleeding was accurately identified in 97.7% of patients. Diagnostic accuracy was greater within the first 24 h of the bleeding onset, and in the presence of haematemesis. Oesophageal varices were the most frequent cause of upper GI bleeding (51.3%) followed by peptic ulcers in 25.0% of cases. The majority of patients (60.8%) were treated conservatively. Endoscopic and surgical treatments were performed in 30.8% and 5.8% of cases respectively. 140 (58.3%) patients received blood transfusion. The median length of hospitalization was 8 days and it was significantly longer in patients who underwent surgical treatment and those with higher Rockall scores (P < 0.001). Rebleeding was reported in 3.3% of the patients. The overall mortality rate of 11.7% was significantly higher in patients with variceal bleeding, shock, hepatic decompensation, HIV infection, comorbidities, malignancy, age > 60 years and in patients with higher Rockall scores and those who underwent surgery (P < 0.001).

Conclusion

Oesophageal varices are the commonest cause of upper gastrointestinal bleeding in our environment and it is associated with high morbidity and mortality. The diagnostic accuracy of fibreoptic endoscopy was related to the time interval between the onset of bleeding and endoscopy. Therefore, it is recommended that early endoscopy should be performed within 24 h of the onset of bleeding.

Identification and profiling of circulating antigens by screening with the sera from schistosomiasis japonica patients

Background

Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma. The disease remains a serious public health problem in endemic countries and affects at least 207 million people worldwide. A definite diagnosis of the disease plays a key role in the control of schistosomiasis. The detection of schistosome circulating antigens (CAs) is an effective approach to discriminate between previous exposure and current infection. Different methods have been investigated for detecting the CAs. However, the components of the schistosome CAs remain unclear. In this study, we analyzed the CAs in sera of patients infected with Schistosoma japonicum.

Methods

The parasites were collected from the infected rabbits for preparing the adult worm antigen (AWA). The hyline hens were immunized subcutaneously with AWA to produce anti-AWA IgY. The IgY was purified by water-dilution and ammonium sulfate precipitation method and identified by ELISA and Western blotting. After purification and characterization, IgY was immobilized onto the resin as a capture antibody. The circulating antigens were immune-precipitated from patients′ serum samples by direct immunoprecipitation. The precipitated proteins were separated by one-dimensional electrophoresis and analyzed by LC-MS/MS.

Results

Firstly, the IgY against AWA was produced from the eggs of immunized hens by AWA, which gave a titer of 1:12800. The purified IgY was used as the capture antibody to enrich the CAs in sera of S. japonicum infected patients through immunoprecipitation. The CAs were determined by LC-MS/MS. There were four proteins, including protein BUD31 homolog, ribonuclease, SJCHGC06971 protein and SJCHGC04754 protein, which were identified among the CAs.

Conclusions

We developed a novel method based on IgY for identification and profiling CAs in sera of S. japonicum infected patients. Four new CAs were identified and have potential value for further development of an antigen assay.

Hepatic schistosomiasis

Praziquantel is the treatment of choice for schistosomiasis because of its efficacy, ease of administration, limited side effects, and low cost. Praziquantel has been so effective that alternative therapies are increasingly difficult to obtain, and the development of novel medications has been limited. The possibility of praziquantel resistance is a grave concern. Low cure rates for praziquantel have been reported in several countries, but despite widespread use, no significant loss of efficacy has occurred to date. The primary goal of antischistosomal therapy is parasite eradication, which reduces the likelihood of chronic complications, including advanced hepatic fibrosis. Mild to moderate hepatic fibrosis results from the immune response to schistosome eggs deposited in the portal venules and reverses with successful treatment. Most individuals clear schistosomiasis with a single course of therapy. Repeat doses cure the majority of patients in whom eradication does not occur after the initial dose. A secondary goal of therapy for patients with persistent or recurrent infection is egg burden reduction, which also reduces the risk of hepatic fibrosis and lowers community spread. Community eradication programs in highly endemic regions use periodic retreatment to limit chronic schistosomiasis' morbidity. Advanced liver fibrosis and portal hypertension due to chronic schistosomiasis are irreversible. Variceal bleeding is the primary cause of death in hepatic schistosomiasis. The bleeding risk is best reduced through use of beta-blocker prophylaxis or endoscopic banding or sclerotherapy. Surgical management of varices, including splenectomy with esophagogastric devascularization or selective shunts such as the distal splenorenal, is effective in patients with recalcitrant bleeding. Because hepatic synthetic function is normal in patients with schistosomiasis, procedures that reduce portal pressures may lower hepatic perfusion and cause hepatic impairment. The risk of encephalopathy after shunt surgery is higher in patients with schistosomiasis than in those with cirrhosis. For these reasons, nonselective shunt surgery such as the proximal splenorenal or the transjugular intrahepatic portosystemic shunt should not be performed in patients with advanced hepatic schistosomiasis.

Schistosoma mansoni infection: an immune complex disease presenting with polyarthritis

Schistosomiasis or bilharzia is a parasitic disease found in tropical countries. Most infections are subclinical but may progress to chronic form characterized most frequently by the presence of liver involvement and portal hypertension. We report a patient that presented chronic polyarthritis with positive rheumatoid factor. During investigation, increased liver enzymes, negative hepatitis serologies and signs of portal hypertension on an ultrasound examination raised suspicion of S. mansoni infection. We will discuss pathophysiology and clinical manifestations of S. mansoni infection with special attention to articular involvement.

Acute bloody diarrhea: a medical emergency for patients of all ages

Acute bloody diarrhea should be considered a medical emergency. Its causes are frequently serious or actionable or both and are usually identified. However, acute bloody diarrhea as a stand-alone clinical presentation has received little scholarly attention in the past several decades. Although the range of possible causes of acute bloody diarrhea is broad, infectious considerations are paramount and should always be prioritized in the evaluation of such patients. History, examination, and laboratory testing should be focused on minimizing time to diagnosis (and, by extension, to implementing appropriate therapy). Strategically chosen tests and imaging, avoidance of extraneous diagnostic pursuits, and provision of supportive care while awaiting diagnostic clarity are central to the adroit management of patients with acute bloody diarrhea. Diagnostic considerations differ somewhat between adults and children but have many elements in common, including the need for vigilance in detecting Escherichia coli O157:H7 infection. In this review, we discuss diagnostic approaches (emphasizing the importance of rapid, accurate, and thorough microbiologic investigation) and measures that can be taken to support patients while awaiting information that determines the cause of their disease. These topics are discussed in the context of the medical care that is available to children and adults with bloody diarrhea in most institutions in developed nations.

Schistosomiasis: an unexpected finding in an inguinal hernia sac

We report an 11-year-old boy who was diagnosed with schistosomiasis based on histopathologic examination of an inguinal hernia sac specimen. The child was an immigrant from Liberia and presented to our institution with inguinal and scrotal swelling. His past medical history was remarkable for previous ipsilateral hernia sac repair in West Africa, and at the time of his recurrent hernia repair, he was noted to have a peculiar loculated fluid-filled hernia sac, which was sent for pathologic examination because of its unusual appearance. Histologic examination revealed an intense infiltrate of eosinophils and numerous granulomas with ova of Schistosoma mansoni, and this speciation was confirmed with a stool wet prep examination for ova and parasites. Review of the English-language literature uncovered no prior cases of schistosomiasis presenting as an inguinal hernia. This unusual finding in a "routine" specimen, otherwise destined for the incinerator without pathologic evaluation, reinforces the importance of surgical vigilance in recognizing unusual or atypical features in these specimens.

Intrahepatic Cholangiocarcinoma with Old Infestation of Schistosoma japonicum: Report of a Case

We report a rare case of intrahepatic cholangiocarcinoma associated with old infestation of Schistosoma japonicum. The patient was a 76-year-old Japanese man who had lived his childhood in an endemic area of this parasite. He presented with jaundice and computed tomography showed a 4-cm, hypodense tumor in segment VIII of the liver. Microscopically, the resected mass was composed of well-differentiated adenocarcinoma cells. Fibrosis and inflammation were seen around the dilated peripheral portal veins embolized with dead S. japonicum eggs. Our search of the literature found only one other case of cholangiocarcinoma coincident with S. japonicum, suggesting that it is not a risk factor for cholangiocarcinoma, although the inflammation and fibrosis caused by the S. japonicum eggshells may predispose to carcinogenesis. However, there is no evidence supporting this hypothesis. More data are necessary to evaluate the differences in clinicopathological findings between cholangiocarcinoma concomitant with S. japonicum and the usual type of cholangiocarcinoma.

Parasitic colitides

Parasitic infections are a major worldwide health problem, and they account for millions of infections and deaths each year. Most of the infections as well as the morbidity and mortality from these diseases occur in the developing world in rural regions. However, these diseases have become more common in Western countries and in big cities over the past 25 years. These changing disease patterns can be attributed to emigration from the third world to developed countries and migration of rural populations to the big cities in developing nations. These parasitic infections have protean manifestations and consequences. The medical problems range from chronic asymptomatic carrier to fulminant infections and even death. Several factors such as the host immune status, the infecting organism, and the availability of treatment all play key roles in the outcomes of parasitic colitides. The two major classes of parasites causing these infections are the helminthes (ascariasis, strongyloidiasis, enterobiasis, trichuriasis, and schistosomiasis) and the protozoa (Isospora, Cryptosporidium, Cyclospora, Trypanosoma cruzi, Giardia lamblia, and Balantidium coli). This article summarizes the salient features of each parasite with respect to epidemiology, transmission, pathogenesis, clinical features, diagnosis, and treatment. The vast majority of these infections have a self-limited clinical course or are easily treated with medical management, and surgery is rarely needed.

Differential liver protein expression during schistosomiasis

The arrival of eggs in the liver during Schistosoma mansoni infection initiates a protective granulomatous response; however, as the infection progresses, this response results in chronic liver fibrosis. To better understand the impact of schistosomiasis on liver function, we used a proteomic approach to identify proteins whose expression was significantly altered in schistosome-infected mice 8 weeks postinfection. Identification of differentially expressed proteins by mass fingerprinting revealed that schistosome infection markedly reduced the abundance of proteins associated with several normal liver functions (i.e., citric acid cycle, fatty acid cycle, and urea cycle), while proteins associated with stress responses, acute phase reactants, and structural components were all significantly more abundant. The expression patterns of several immunity-related proteins (peroxiredoxin 1, arginase 1, and galectin 1) suggested that different protein forms are associated with schistosome infection. These findings indicate that acute schistosomiasis has a significant impact on specific liver functions and, moreover, that the alterations in specific protein isoforms and upregulation of unique proteins may be valuable as new markers of disease.

Assessment of portal hemodynamics by Doppler ultrasound and of liver morphology in the hepatosplenic and hepatointestinal forms of schistosomiasis mansoni

The aim of this study was to compare portal and splenic blood flows and the liver morphology in hepatosplenic (HS) and hepatointestinal (HI) schistosomiasis. Doppler ultrasound measurements were performed in 48 adult patients with schistosomiasis, according to the criteria of the World Health Organization, and compared with those performed in 20 healthy controls. Portal flow was significantly higher (P < 0.0001) in both HS and HI (2481 +/- 1467 and 2159 +/- 1446 ml/min, respectively) than in normal individuals (842 +/- 322 ml/min). There was no difference in splenic blood flow (822 +/- 685 and 458 +/- 292 ml/min, respectively) between HS and HI, but these values were significantly higher than those of normal controls (243 +/- 94 ml/min). Portal and splenic overflow are found in both the HS and the HI forms of schistosomiasis.

High-Throughput GoMiner, an 'industrial-strength' integrative gene ontology tool for interpretation of multiple-microarray experiments, with application to studies of Common Variable Immune Deficiency (CVID)

BACKGROUND

We previously developed GoMiner, an application that organizes lists of 'interesting' genes (for example, under-and overexpressed genes from a microarray experiment) for biological interpretation in the context of the Gene Ontology. The original version of GoMiner was oriented toward visualization and interpretation of the results from a single microarray (or other high-throughput experimental platform), using a graphical user interface. Although that version can be used to examine the results from a number of microarrays one at a time, that is a rather tedious task, and original GoMiner includes no apparatus for obtaining a global picture of results from an experiment that consists of multiple microarrays. We wanted to provide a computational resource that automates the analysis of multiple microarrays and then integrates the results across all of them in useful exportable output files and visualizations.

RESULTS

We now introduce a new tool, High-Throughput GoMiner, that has those capabilities and a number of others: It (i) efficiently performs the computationally-intensive task of automated batch processing of an arbitrary number of microarrays, (ii) produces a human-or computer-readable report that rank-orders the multiple microarray results according to the number of significant GO categories, (iii) integrates the multiple microarray results by providing organized, global clustered image map visualizations of the relationships of significant GO categories, (iv) provides a fast form of 'false discovery rate' multiple comparisons calculation, and (v) provides annotations and visualizations for relating transcription factor binding sites to genes and GO categories.

CONCLUSION

High-Throughput GoMiner achieves the desired goal of providing a computational resource that automates the analysis of multiple microarrays and integrates results across all of the microarrays. For illustration, we show an application of this new tool to the interpretation of altered gene expression patterns in Common Variable Immune Deficiency (CVID). High-Throughput GoMiner will be useful in a wide range of applications, including the study of time-courses, evaluation of multiple drug treatments, comparison of multiple gene knock-outs or knock-downs, and screening of large numbers of chemical derivatives generated from a promising lead compound.

Schistosomiasis mansoni -- clinical features

In the present review, we will discuss the Schistosoma mansoni form, which is the most widely distributed schistosome in humans and is found both in the Old and New Worlds. The main features of the natural history of mansonic schistosomiasis are reviewed, with emphasis on the clinical forms of the disease, their diagnosis and treatment.

Antiparasitic therapy in children

Treatment of parasitic infections in children presents many challenges for the clinician. Although parasitic infections are ubiquitous on a worldwide basis, with an estimated 1 billion persons infected with intestinal helminthes alone, physicians in the United States and other developed countries are often unfamiliar with the management of these diseases. Children are traveling internationally in larger numbers than ever before, however, and emigration from developing countries to the United States and other Western countries is increasing, so clinicians in these countries are confronted more frequently with parasitic diseases from the tropics. This article describes current approaches to antiparasitic therapy. Drugs used in the treatment of more than one type of parasite are presented once in detail, with reference to the detailed description in subsequent sections.

Schistosomiasis

Schistosomiasis ranks second, behind malaria, among human parasitic diseases in terms of public health and socioeconomic importance in tropical and sub-tropical areas. Worldwide, 1 of 30 people has schistosomiasis. Up to 300 million people are infected, and 600 million live in environments where infection is a risk. Tourists from non-endemic areas are contracting schistosomiasis due to the rise in "off-the-beaten-track" tourism. Praziquantel is effective against all species of schistosomes and early treatment is curative. Schistosomiasis is an insidious disease, however, so worldwide the disease is not diagnosed early. The most frequent and dangerous complication of the disease is variceal hemorrhage due to hepatic fibrosis. Variceal hemorrhage is the first symptom in 58% of cases. A variety of treatments for variceal hemorrhage are available. Exsanguination from variceal hemorrhage is possible; therefore, aggressive stabilization of the patient by the use of multiple therapies is appropriate. Most patients treated after esophageal hemorrhages do not experience reversal of hepatic fibrosis. For this reason, healthcare providers need an increased awareness of schistosomiasis to enable earlier detection and treatment in world travelers.

Hematologic problems in immigrants from Southeast Asia

An increasing number of Southeast Asian immigrants have come to North America. Physicians who care for this population should be aware of the high prevalence of hematologic disorders and develop an approach to their diagnosis and management. Malaria and the hematologic sequelae, glucose-6-phophate dehydrogenase deficiency, the thalassemia syndromes, Southeast Asian ovalocytosis, visceral leishmaniasis, HIV infection, and iron-deficiency anemia, all of which may pertain to these patients, are reviewed in this article.

IFN-gamma polymorphisms (IFN-gamma +2109 and IFN-gamma +3810) are associated with severe hepatic fibrosis in human hepatic schistosomiasis (Schistosoma mansoni)

Schistosome infection is a major public health concern affecting millions of people living in tropical regions of Africa, Asia, and South America. Schistosomes cause mild clinical symptoms in most subjects, whereas a small proportion of individuals presents severe clinical disease (as periportal fibrosis (PPF)) that may lead to death. Severe PPF results from an abnormal deposition of extracellular matrix proteins in the periportal spaces due to a chronic inflammation triggered by eggs and schistosome Ags. Extracellular matrix protein production is regulated by a number of cytokines, including IFN-gamma. We have now screened putative polymorphic sites within this gene in a population living in an endemic area for Schistosoma mansoni. Two polymorphisms located in the third intron of the IFN-gamma gene are associated with PPF. The IFN-gamma +2109 A/G polymorphism is associated with a higher risk for developing PPF, whereas the IFN-gamma +3810 G/A polymorphism is associated with less PPF. The polymorphisms result in changes in nuclear protein interactions with the intronic regions of the gene, suggesting that they may modify IFN-gamma mRNA expression. These results are consistent with the results of previous studies. Indeed, PPF is controlled by a major locus located on chromosome 6q22-q23, closely linked to the gene encoding the alpha-chain of the IFN-gamma receptor, and low IFN-gamma producers have been shown to have an increased risk of severe PPF. Together, these observations support the view that IFN-gamma expression and subsequent signal transduction play a critical role in the control of PPF in human hepatic schistosome infection (S. mansoni).

Administration of praziquantel to pregnant and lactating women

Praziquantel (PZQ) is the safest of all anti-helminthics and now forms the backbone for all national control programs against schistosomiasis (Med. Res. Rev. 3 (1983) 147-200; Bull. WHO 57 (1979) 767-771; Wegner, D.H.G, Therapeutic Drugs (1991), Churchill Livingstone; Adv. Intern. Med. 32 (1987) 193-206; Drugs 42 (1991) 379-405; Pharmac. Ther. 68 (1995) 35-85; Ann. Intern. Med. 110 (1989) 290-296). Despite its lack of known toxicity, the drug was not tested on pregnant or lactating women prior to release. It is currently listed as Pregnancy Category B by the US FDA, which is a drug presumed safe based in animal studies. Unfortunately, this has been interpreted by most national control programs and WHO (1998) to exclude lactating and pregnant women from treatment. In fact, some experts advocate excluding adolescent girls from mass treatment campaigns over this issue. As a result, a large number of women living in endemic countries are currently left untreated or have treatment significantly delayed. A review of the current known toxicology of PZQ, combined with over two decades of clinical experience with this drug, suggest very low potential for adverse effects on either the mother or her unborn child. In contrast, significant animal and human data are presented in this review that suggest both the pregnant woman and her unborn fetus suffer morbid sequella from schistosomiasis. A double-blind placebo-controlled trial that could resolve this issue would require a very large and expensive study and in light of the above facts might not now be ethically appropriate. The author concludes that pregnant women should be treated with PZQ, that women of childbearing age should be included in all mass treatment programs and that lactating women are not systematically excluded from treatment.

Gastrointestinal complications of schistosomiasis

Schistosomiasis is an important disease in many parts of the world and has affected the course of human history many times over. The parasitic infection is acquired during contact with infected water. A chronic inflammatory response to schistosome eggs, mediated by both cellular and humoral mechanisms, is the root of the pathology seen in schistosomiasis. Hepatosplenic disease results in intrahepatic presinusoidal portal hypertension. The resultant esophageal and gastric varices are an important cause of morbidity and mortality. Standard treatment guidelines for managing varices can be applied to patients with schistosomiasis. Coinfection with viral hepatitis results in liver disease that progresses more rapidly and is more difficult to treat. Intestinal schistosomiasis may be confused with other disease states and can be an important cause of morbidity, especially in heavily infected patients. Diagnosis relies on demonstration of schistosome eggs in feces or tissue. Praziquantel is the treatment of choice. The development of a vaccine for schistosomiasis is an important goal in the attempt to control this disease.

Recent Advances in Schistosomiasis

Schistosomiasis is a major parasitic disease, affecting nearly 200 million persons, worldwide. Major advances in our knowledge-in terms of pathogenesis, improved diagnosis, therapeutics (both drugs and strategies), and morbidity assessment-now make schistosomiasis a curable, often preventable disease. In contrast to most other illnesses, most schistosomiasis pathology appears to be reversible over time. For the future, several promising vaccine candidates are already in phase-I or phase-II testing. On the other hand, the range of this disease has been increasing, as water resources are developed in several newly industrialized countries and much of schistosomiasis in sub-Saharan Africa remains largely untreated.

Does the failure to acquire helminthic parasites predispose to Crohn's disease?

Two polarized patterns (Th1 and Th2) of cytokines regulate inflammatory responses. Each cytokine pattern inhibits production of the opposing pattern. Lymphocytes from inflamed intestine due to Crohn's disease secrete a Th1 pattern of cytokines. Crohn's disease is most prevalent in highly industrialized countries with temperate climates. It occurs rarely in tropical third world countries with poor sanitation. We propose that exposure to an environmental agent predisposes individuals to Crohn's disease. Parasitic worms (helminths) are common in tropical climates and in populations subject to crowding and poor sanitation. Children are most subject to helminthic colonization. Many helminths live within or migrate through the human gut where they interact with the mucosal immune system. The host mounts a mucosal response that includes Th2 cytokine production limiting helminthic colonization. Helminths and their eggs probably are the most potent stimulators of mucosal Th2 responses. The Th2 response provoked by parasitic worms can modulate immune reactions to unrelated parasitic, bacterial, and viral infections. Many people in developed countries now live in increasingly hygienic environments, avoiding exposure to helminths. Perhaps failure to acquire these parasites and experience mucosal Th2 conditioning predisposes to Crohn's disease, which is an overly active Th1 inflammation.

[A case of hepatic Loeffler's syndrome]

INTRODUCTION

During nematode infection transit of the microorganism in the lung may be associated with transient infiltration lesions accompanied by marked eosinophilia. In the invasion stage of the disease maturation and sexual differentiation of schistosomules is restricted to portal vessels. Liver ultrasonography may show concomitant abnormalities.

EXEGESIS

Eosinophilia was diagnosed in a 36-year-old man residing in Central Africa. Clinical examination, chest X-ray and biology were normal. Liver ultrasonography showed numerous hypoechoic lesions, up to 3 cm in diameter. Ultrasonography-directed biopsy demonstrated infiltration of both portal vessels and liver sinusoids, with sometimes microabcesses. No parasite was found in either blood, stool, or rectal biopsy. Immunoelectrophoresis and hemagglutination showed positive bilharziosis serology, whereas serology for other helminthiases was negative. Four months after treatment eosinophilia was still high, liver ultrasonography was normal, and hemagglutination was negative.

CONCLUSION

The transient shistosomules maturation-related liver abnormalities detected by ultrasonography should be differentiated from the laying phase of the disease.

Parasitic infections of the gastrointestinal tract

Parasitic infections of the gastrointestinal tract are a major cause of morbidity and mortality worldwide. Increased international travel means that gastroenterologists are now more likely to care for patients with parasitic diseases. This article reviews various aspects of the more common intestinal parasites and their infections, including epidemiology, life cycle, pathogenesis, clinical manifestations, diagnosis, and treatment.

The substance P and somatostatin interferon-gamma immunoregulatory circuit

Murine schistosomiasis mansoni is a parasitic disease in which flukes living in the portal vein of the host produce ova that deposit in the liver and intestines. In these organs, ova release antigens that induce chronic, focal granulomatous inflammation. IFN-gamma is an inflammatory cytokine important in macrophage activation and B-cell differentiation. A substance P (SP)/somatostatin (SOM) neurokine immunoregulatory circuit controls IFN-gamma production in schistosome granulomas. SP stimulates, while SOM inhibits IFN-gamma release, modulating IFN-gamma-dependent circuitry. SP and SOM function through interaction with authentic SP and SOM receptors located on granuloma T cells. Also, the granulomas produce authentic SP and SOM14, as evidenced by the presence of mRNA and product. The granulomas have no nerves. This, and other data suggest that the inflammatory cells make these neurokines. Granuloma macrophages produce SOM. Macrophages from various sources express SOM mRNA in response to LPS, IFN-gamma, IL-10 or several other inflammatory mediators. Thus, the inflammation of murine schistosomiasis has a complete SP/SOM immunoregulatory circuit, which in turn is subject to immunoregulation.