Endoscopic and histopathological study on the duodenum of Strongyloides stercoralis hyperinfection

AIM:To investigate endoscopic and histopathological findings in the duodenum of patients with Strongyloides stercoralis(S.stercoralis)hyperinfection. METHODS:Over a period of 23 years(1984-2006),we investigated 25 patients withS.stercoralis hyperinfection who had had an esophagogastroduodenoscopy before undergoing treatment for strongyloidiasis.The clinical and endoscopic findings were analyzed retrospectively. RESULTS:Twenty-four(96%)of the patients investigated were under immunocompromised condition which was mainly due to a human T lymphotropic virus type 1(HTLV-1)infection.The abnormal endoscopic findings,mainly edematous mucosa,white villi and erythematous mucosa,were observed in 23(92%) patients.The degree of duodenitis including villous atrophy/destruction and inflammatory cell infiltration corresponded to the severity of the endoscopic findings. The histopathologic yield for identifying larvae was 71.4% by duodenal biopsy.The endoscopic findings of duodenitis were more severe in patients whose biopsies were positive for larvae than those whose biopsies were negative(Endoscopic severity score:4.86±2.47vs 2.71 ±1.38,P<0.05). CONCLUSION:Our study clearly demonstrates that,in addition to stool analysis,endoscopic observation and biopsies are very important.We also emphasize that S.stercoralis and HTLV-1 infections should be ruled out before immunosuppressive therapy is administered in endemic regions.

Strongyloides stercoralis in an immunocompetent adult:An unexpected cause of weight lost

Strongyloides stercoralis infects at least 100 million humans worldwide each year, but its prevalence is underestimated. It is endemic in hot and humid climates as well as resource poor countries with inadequate sanitary conditions. The rise of international travel and immigration has a positive impact in strongyloidiasis. Due to its unique auto infection life-cycle, Strongyloides may lead to chronic infections remaining undetected for decades. Strongyloidiasis is most often asymptomatic but it has a wide range of clinical presentations. The two most severe forms of strongyloidiasis are hyperinfection and disseminated syndromes. These occur most often in patients with impaired cell mediated immunity. A 42-year-old immunocompetent man presented with chronic watery diarrhea, malaise, upper abdominal pain, anorexia and weight lost. Strongyloides stercoralis was identified in stool samples and duodenal biopsy. The patient was successfully treated with albendazole. The authors report a case of strongyloidiasis hyperinfection in an immunocompetent host 20 years away from an endemic area and make a literature review.

Alive Strongyloides stercoralis in biliary fluid in patient:A case report

BACKGROUND Strongyloides stercoralis(S.stercoralis),is a prevalent parasitic worm that infects humans.It is found all over the world,particularly in tropical and subtropical areas.Strongyloidiasis is caused mostly by the parasitic nematode S.stercoralis.Filariform larvae typically infest humans by coming into contact with dirt,such as by walking barefoot or through exposure to human waste or sewage.CASE SUMMARY A 35-year-old male presented to our department with a 10-year history of abdominal pain and diarrhea,which had recently recurred for the past 3 months.A computed tomography(CT)scan revealed acute cholecystitis accompanied by a gallbladder stone.Additionally,a 5 mm stone was found obstructing the lower portion of the common bile duct,resulting in dilatation of both the intrahepatic and extrahepatic bile ducts to 8 mm,in contrast to a previous CT scan.Endoscopic ultrasonography revealed a prominent echogenicity in the lower portion of the common bile duct.Consequently,an endoscopic retrograde cholangiopancreatography was conducted via endoscopic sphincterotomy and balloon dilatation.The microscope revealed the presence of viable S.stercoralis rhabditiform larvae in the biliary fluid.We documented an uncommon instance of S.stercoralis infection in the biliary fluid of a patient suffering from gallstones and cholangitis.CONCLUSION The film we created provides a visual representation of the movement of the living S.stercoralis in biliary fluid.

Strongyloides stercoralis prevalence and diagnostics in Vientiane, Lao People’s Democratic Republic

Background:Despite the high prevalence of strongyloidiasis in the Laotian population,Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides stercoralis infections.This cross-sectional hospital-based study was conducted to assess the prevalence of Strongyloides stercoralis infection among hospitalized patients treated at Mahosot Hospital,the primary reference hospital of Lao People’s Democratic Republic(Lao PDR),and to validate feasible methods for diagnosing S.stercoralis infection at hospital’s laboratory.Methods:Between September and December 2018,stool samples of 104 inpatients were investigated for S.stercoralis infection by wet smear,Baermann technique,Koga Agar plate culture(KAPC),and real-time detection polymerase chain reaction(RTD-PCR)at the Infectious Diseases Ward of the Mahosot Hospital in Vientiane.The sensitivity,the specificity,the negative predictive value(NPV)of each diagnostic test,as well as their combination(s)was calculated using a composite reference standard(CRS).The correlation of the different test methods was assessed by chi-square or Fisher’s exact test.Cohen’s kappa coefficient was used to assess the diagnostic agreement of the different test methods.Results:The overall prevalence of S.stercoralis infections among the study population was 33.4%.The cumulative infection prevalence statistically significantly increased from the lowest age group of 40 years and below(22.4%),to the medium(40.0%)and to the oldest age group of 61 year and above(72.7%)(P=0.003).The cumulative infection prevalence of CRS was considerably higher in male(40.4%)compared to female patients(28.1%),but not statistically different(P=0.184).The diagnostic sensitivity of Baermann technique,KAPC,RTD-PCR,and the combination of Baermann technique and KAPC were 60.0,60.0,74.3,and 77.1%,respectively.Only 13 patients(37.1%)of the total 35 S.stercoralis patients diagnosed with any technique had a simultaneously positive diagnostic test with Baermann,KAPC and RTD-PCR.Conclusions:We identified Baermann technique and KAPC to be currently the most feasible and implementable standard methods for diagnosing S.stercoralis at a hospital setting such as Mahosot Hospital and provincial and district hospitals in Lao PDR and other low-and middle income countries in Southeast Asia.Trial registration:This study was approved by the National Ethics Committee for Health Research in Lao PDR(reference no.083/NECHR)and by the Ethics Committee Northwest and Central Switzerland(reference no.2018–00594).

Strongyloides hyper-infection causing life-threatening gastrointestinal bleeding

A 55-year old male patient was diagnosed with strongy- loides hyper-infection with stool analysis and intestinal biopsy shortly after his chemotherapy for myeloma. He was commenced on albendazole anthelmintic therapy. After initiation of the treatment he suffered life- threatening gastrointestinal (GI) bleeding. Repeated endoscopies showed diffuse multi-focal intestinal bleeding. The patient required huge amounts of red blood cells and plasma transfusions and correction of haemostasis with recombinant activated factor Ⅶ. Abdominal aorto-angiography showed numerous micro- aneurysms (‘berry aneurysms’) in the superior and inferior mesenteric arteries’ territories. While the biopsy taken prior to the treatment with albendazole did not show evidence of vasculitis, the biopsy taken after initiation of therapy revealed leukoclastic aggregations around the vessels. These findings suggest that, in addition to direct destruction of the mucosa, vasculitis could be an important additive factor causing the massive GI bleeding during the anthelmintic treatment. This might result from substances released by the worms that have been killed with anthelmintic therapy. Current guidelines advise steroids to be tapered and stopped in case of systematic parasitic infections as they might reduce immunity and precipitate parasitic hyper-infection. In our opinion, steroid therapy might be of value in the management of strongyloides hyper- infection related vasculitis, in addition to the anthelmintic treatment. Indeed, steroid therapy of vasculitis with other means of supportive care resulted in cessation of the bleeding and recovery of the patient.

Disseminated strongyloidiasis in an immunocompromised host:A case report

Infections caused by Strongyloides stercoralis(S.stercoralis) in human are generally asymptomatic,however in immunocompromised individual,hyperinfection may develop with dissemination of larvae to extra-intestinal organs.The diagnosis could be easily missed due to asymptomatic presentation and insufficient exposure towards the infection itself,which may lead to low index of suspicion as a consequence.In this report,a case of a Malaysian male with underlying diabetes mellitus,hypertension,cerebrovascular accident,bullous pemphigus and syndrome of inappropriate antidiuretic hormone secretion who initially complained of generalized body weakness and poor appetite without any history suggestive of sepsis is presented.However,he developed septicemic shock later,and S.stercoralis larvae was incidentally found in the tracheal aspirate that was sent to look for acid fast bacilli.Regardless of aggressive resuscitation,the patient succumbed due to pulmonary hemorrhage and acute respiratory distress syndrome.It was revealed that the current case has alarmed us via incidental finding of S.stercoralis larvae in the tracheal aspirate,indicating that the importance of the disease should be emphasized in certain parts of the world and population respectively.

A study implementing real-time PCR to identify Strongyloides species of third-stage larvae in human stool samples from Southern Vietnam

Background:Strongyloidiasis,a neglected disease caused by intestinal nematodes of the genus,is endemic to tropical and subtropical areas such as Vietnam.Morphological methods only identify the genus,while DNA-molecular techniques are susceptible in Strongyloides spp.detection.The study aims to determine the prevalence of dominant Strongyloides species among the population in Duc Hoa district,Long An,Vietnam.Methods:A cross-sectional study used 1190 stool specimens collected from July 2017 to November 2018.All samples were transported within 2 h,stored at 2-8℃,and processed within 48 h for microscopy smear and culture at the Laboratory of Medical Parasitology,Pham Ngoc Thach University of Medicine(PNT).Then all positive samples with the above 2 methods were verified by real-time PCR technique.Real-time PCR amplification was conducted at the Laboratory of Molecular Biology,PNT.Results:Direct microscopy and modified Harada-Mori culture detected Strongyloides spp.larvae in 79/1190 sam-ples(6.6%).About 94.2%of the DNA samples were Strongyloides stercoralis,2.9%were co-infections with Strongy-loides ratti and S.stercoralis,and 2.9%were patients with S.ratti.The identity of 12/14 sequences was confirmed as S.stercoralis with a high level of similarity(91.3%-100%)and over 98%for S.ratti.Conclusion:DNA-molecular techniques and sequence analysis are highly suitable for identifying Strongyloides species isolated from stool samples.It is remarkable evidence of the presence of zoonosis S.ratti disease in human,not just the known S.stercoralis.It is likely to result in a certain proportion of people being infected by this animal-borne infectious pathogen.

Strongyloidiasis in Ethiopia:systematic review on risk factors,diagnosis,prevalence and clinical outcomes

Background:Strongyloidiasis is a gastrointestinal infection caused by the parasitic nematode Strongyloides stercorolis.It is estimated to infea up to 370 million people globally and is predominately found in tropical and subtropical areas of socioeconomic disadvantage.Main body:This systematic literature review identified studies published in the last ten years on the risk factors,diagnosis,prevalence and/or clinical outcomes of strongyloidiasis in Ethiopia.The prevalence of 5.stercoralis ranged from 0.2 to 11.1%in adults,0.3%to 20.7%in children,1.5%to 17.3%in HIV positive adults and 5%in HIV positive children.The identified studies primarily used microscopy based techniques that potentially underestimated the prevalence four fold compared with serology and PCR.Strongyloidiasis in children presents a particularly significant issue in Ethiopia as children often presented with anemia,which is associated with impaired mental and cognitive development.The most significant risk factor for strongyloidiasis was HIV status and although other risk factors were identified for helminth infections,none were statistically significant for 5.stercoralis specifically.Several studies detected 5.stercoralis in dogs and non-biting cyclorrhaphan flies.However,future research is needed to explore the role of these reservoirs in disease transmission.Conclusions:This review demonstrated that strongyloidiasis is an overlooked and neglected disease in Ethiopia.There is a need for a systematic approach using a combination of molecular and serology based diagnostic methods to ascertain the true incidence and burden of strongyloidiasis in Ethiopia.Further research is also needed to break the cycle of transmission by identifying environmental reservoirs,risk factors and exploring the potential for zoonotic transfer.

Control programs for strongyloidiasis in areas of high endemicity: an economic analysis of different approaches

Background:Implementation of control programmes for Strongyloides stercoralis infection is among the targets of the World Health Organization Roadmap to 2030.Aim ofthis work was to evaluate the possible impact in terms of economic resources and health status of two different strategies of preventive chemotherapy(PC)compared to the current situation(strategy A,no PC):administration of ivermectin to school-age children(SAC)and adults(strategy B)versus ivermectin to SAC only(strategy C).Methods:The study was conducted at the IRCCS Sacro Cuore Don Calabria hospital,Negrar di Valpolicella,Verona,Italy,at the University of Florence,Italy,and at the WHO,Geneva,Switzerland,from May 2020 to April 2021.Data for the model were extracted from literature.A mathematical model was developed in Microsoft Excel to assess the impact of strategies B and C in a standard population of 1 million subjects living in a strongyloidiasis endemic area.In a case base seenario,15%prevalence of strongyloidiasis was considered;the 3 strategies were then evaluated at different thresholds of prevalenee,ranging from 5 to 20%.The results were reported as number of infected subjects,deaths,costs,and Incremental-Effectiveness Ratio(ICER).A 1-year and a 10-year horizons were considered.Results:In the case base seenario,cases of infections would reduce dramatically in the first year of implementation of PC with both strategy B and C:from 172500 cases to 77040 following strategy B and 146700 following strategy C.The additional cost per recovered person was United States Dollar(USD)2.83 and USD 1.13 in strategy B and C,respectively,compared to no treatment in the first year.For both strategies,there was a downtrend in costs per recovered person with increasing prevalenee.The number of adverted deaths was larger for strategy B than C,but cost to advert one death was lower for strategy C than B.Conclusions:This analysis permits to estimate the impact of two PC strategies for the control of strongyloidiasis in terms of costs and adverted infections/deaths.This could represent a basis on which each endemic country can evaluate which strategy can be implemented,based on available funds and national health priorities.

Prevalence of chronic infections and susceptibility to measles and varicellazoster virus in Latin American immigrants

Background:Large numbers of Latin American immigrants recently arrived in Western Europe.Curative and preventive programmes need to take account of their risk of suffering and transmitting imported chronic infections and of their susceptibility to cosmopolitan infections.We aimed to assess the prevalence and co-occurrence of imported chronic infections among Latin American immigrants,and their susceptibility to highly prevalent cosmopolitan infections.Methods:Adult participants were recruited in the community and in a primary health centre in Geneva in 2008.Serological tests were performed on stored sera for HIV,HBV,syphilis,Strongyloides stercoralis,Trypanosoma cruzi,varicella and measles.We considered only chronic active infections in the analysis.Results and discussion:The 1012 participants,aged 37.2(SD 11.3)years,were mostly female(82.5%)and Bolivians(48%).Overall,209(20.7%)had at least one and 27(2.7%)two or more chronic infections.T.cruzi(12.8%)and S.stercoralis(8.4%)were the most prevalent chronic active infections compared to syphilis(0.4%),HBV(0.4%)and HIV(1.4%).Concomitant infections affected 28.2 and 18.5%of T.cruzi and S.stercoralis infected cases.Bolivian origin(aOR:13.6;95%CI:3.2–57.9)was associated with risk of multiple infections.Susceptibilities for VZV and measles were 0.7 and 1.4%,respectively.Latin American immigrants are at risk of complications and possible reactivation of chronic parasitic infections but have overall low risks of chronic viral and syphilitic active infections.Conclusions:Systematic screening for chronic active parasitic infections is therefore necessary especially among Bolivians.The high protection rate against measles and VZV doesn’t require specific preventive interventions.

Hepatobiliary strongyloidiasis presenting as an ampullary lesion on esophagogastroduodenoscopy/endoscopic ultrasound

Strongyloidiasis is an intestinal infection caused by the parasitic nematodes of the Strongyloides species,most commonly Strongyloides stercoralis.We report a case of a 66-year-old immigrant male from Haiti who presented with complaints of diarrhea and an unintentional 80-lb weight loss over the past 5 years.Stool examination was positive for strongyloidiasis.Following albendazole therapy,esophagogastroduodenoscopy(EGD)showed a unique ampullary lesion.Histopathology of the ampullary lesion showed reactive epithelium with Strongyloides larva.In addition,endoscopic ultrasound(EUS)detected a large pancreatic cyst.Both these findings were absent on EGD 5 years previously,prior to the onset of his symptoms.This paper documents a rare case of an ampullary lesion and pancreatic cyst secondary to hepatobiliary strongyloidiasis in a non-Human Immunodeficiency Virus(HIV)patient.We review the epidemiology,life cycle,clinical presentation and treatment of strongyloidiasis.