Intestinal parasites: clinical significance and diagnosis

Transcription

1 Intestinal parasites: clinical significance and diagnosis Tom van Gool, MD, PhD Department of Clinical Parasitology Academic Medical Center, Amsterdam, Netherlands

2 Persistentgastrointestinal illness after travel to (sub) tropics: frequently observed. intestinal parasites!

3 Protozoa E. histolytica Giardia lamblia Cryptosporidium Cyclospora Isospora D. fragilis Helminths Ascaris Hookworm Taenia Strongyloides

4 Symptomatology due to intestinal parasites most often non specific: goodlaboratory diagnosis important!

5 Important intestinal protozoan pathogens Entamoeba histolytica Giardia lamblia Cyclospora caytanensis Cryptosporidium spp. Dientamoeba fragilis Microsporidia

6 Important human helminths. Schistosoma haematobium Schistosoma mansoni Schistosoma intercalatum Schistosoma japonicum Fasciola hepatica Clonorchis sinensis Opisthorchis spp. Ascaris lumbricoides Capillaria philippinensis Enterobius vermicularis Hookworms Strongyloides srecoralis Trichuris trichiura Diphyllobothrium latum Hymenolepis diminuta Hymenolepis nana Taenia spp.

7 The old way of diagnosis for intestinal parasites: microscopy Diagnostic stages of allintestinal parasites are relative large and have a distinctive morphology. Easy to recognize under a light microscope for a well trained laboratory technician!

8 The value of microscopy: parasites observed by a well trained technician in a 10 min. search. S. stercoralis Ascaris C. cayetanensis G. lamblia S. mansoni T. trichiura hookworm E. histolytica/ dispar

9 For high sensitivity of microscopy, especially for protozoa, multiple stool samples should be examined. Three day collection kit, two tubes filled with SAF- fixative

10 Newer diagnostic methods: PCR-(molecular) based diagnosis for intestinal parasites I DNA isol. MP 96 PCR: LC 480 PCR 1 day stool sampling possible! Technical advantages: - high sensitivity - high specificity - one day stool sample sufficient (G) - easy to combine with other PCR s of i.e. virology and bacteriology - less (specialised) technicians needed - Good financial revenue for workload

11 Use of PCR - diagnosis in Dutch laboratories: in routine clinical practice only a few intestinal protozoans (3-4) are examined Giardia lamblia Cryptosporidium spp. Entamoeba histolytica (Dientamoeba fragilis) Cost test in NL ~ 80 euro No other protozoa and helminths!

12 Helminth infections worldwide highly prevalent: travel brings many in contact with the wormy world Who was in contact with the wormy world? With known or possibletravel to warm-climate countries diagnosis of intestinal helminths should be included!

13 they are indeed still imported in NL!! Diagnosed in AMC population (in ) Schistosoma haematobium Schistosoma mansoni Schistosoma intercalatum Schistosoma japonicum Fasciola hepatica Clonorchis sinensis Opisthorchis spp. Ascaris lumbricoides Capillaria philippinensis Enterobius vermicularis Mijnworm Strongyloides srecoralis Trichuris trichiura Diphyllobothrium latum Hymenolepis diminuta Hymenolepis nana Taenia spp.

14 The Dual -Feces -Test (DFT) a new, efficient, method for diagnosis of intestinal parasites One day collection kit (two tubes)!

15 Pathogenic protozoa Dual-Feces-Test (DFT) routine handling and targets + Diagnosis of 24 pathogens: protozoa and helminths (microscopy) Apathogenic protozoa Improved sensitivityfor 5 protozoal infections (PCR) Helminths Entamoeba histolytica Giardia lamblia Cryptosporidium Dientamoeba fragilis Blastocystis species* Microsporidia Cyclospora cayetanensis Isospora belli Entamoeba moshkovskii * Entamoeba chattoni* Entamoeba polecki* *pathogenicity debated PCR PCR PCR PCR PCR Endolimax nana Entamoeba coli Entamoeba dispar Entamoeba hartmanni Sarcocystis hominis Iodamoeba butschlii Chilomastix mesnili Costs test in NL ~ 120 euro Schistosoma haematobium Schistosoma mansoni Schistosoma intercalatum Schistosoma japonicum Fasciola hepatica Clonorchis sinensis Opisthorchis spp. Ascaris lumbricoides Capillaria philippinensis Enterobius vermicularis Mijnworm Strongyloides srecoralis Trichuris trichiura Diphyllobothrium latum Hymenolepis diminuta Hymenolepis nana Taenia spp.

16 Giardia in DFT: combined use Microscopy and PCR 45 negative 40 + PCR and MICR: - persisting DNA after (un-) successful treatment (?) - lower sensitivity microscopy versus PCR - contamination from surrounding (?) Consultation with clinician important! Initial withhold of treatment! Giardia Cp PCR value Micr. and + PCR: active Giardia infection: in general indication for therapy! 25 Microscopic threshold 20 0,0 negative 1,0 rare 2,0 few microscopic load 3,0 some 4,0 many

17 Amoebiasis due to Entamoeba histolytica an old but still most important - dangerous- cause of intestinal and liver disease

18 In older times (< ) worldwide, specific round cysts with microscopy, were all Entamoeba histolytica. New insights with i.e. PCR methods: Majorityis Entamoeba dispar: a non-pathogen! Only minority is Entamoeba histolytica: a true pathogen!

19 Globally, 500 million people may harbour E. histolytica and several tens of thousands die each year as a consequence of fulminating colitis or liver abscess (WHO 2018).

20 Growth and multiplication of E. histolytica in colon Can be asymptomatic for many years but.they are a true ticking time-bomb!!

21 at a time transformation into an invasive stage... Severe colitis: can be lethal

22 Beware: in non- endemic countries. DD E. histolytica infection and Crohn s disease! Numerous cases in world literature with presumed Crohn s disease while afterwards... amoebiasis Before diagnosis of Crohn s disease always exclude E. histolytica infection!!

23 Diagnosis Microscopy: stool with blood: motile stages), fast result ~15 min! PCR (only) highly sensitive, takes time Dual -Feces -Test: fast and high sensitivity

24 Spread of amebiasis from intestine to i.e. liver

25 Amoebic liver abcess: a potential deadly complication Potential spread to thorax!

26 For diagnosis of amoebic abscess in the liver serology is important!

27 Agglutination test (Fumouze) Fast and easy (15 min.) High sensitivity (93%) and specificity (99%) Incidentally false negative early in infection +

28 CAP- test Counter-immuno-electrophoresis Pos control Neg control Serum case with abces Pat A undiluted Pat A 1:2 diluted E. histolytica antigen Serum of patient Test becomes negative after succesfull treatment!!

29 Treatment Drainage of an amoebic liver abcess Only with large abcess: risk of bacterial contamination!

30 Treatment tissue phase: metronidazol (750 mg tid x 7-10d) luminal agents : clioquinol (3dd 250mgx 10d) diloxanide furoate (3dd 500 mg 10d) paromomycin (30 mg/kg x 7d) Always treat with a luminal agent after treatment of the tissue phase!

31 II Giardia lamblia an important cause of prolonged diarrhoea in both tropical and western countries

32 Giardia intestinalis worldwide prevalence faeco-oral transmission zoonosis highly prevalent among children located in small intestine

33 Symtomatology Giardia infection Asymptomatic carrier state: commonly occuring (80% infected) important source of infection Acute diarrhoea: often self limiting (2-4 weeks), weight loss, abdominal cramps, nausea, flatulence, steatorrhoea (in 50% of cases). Chronic diarhoea: persistence of diarrhoea, weight loss, impairment of growth and developement especially in children in developing countries Post infectious IBS

34 Diagnosis giardiasis Parasites in faeces Detection level microscopy days Microscopy has limitations: examination of one sample sensitivity (only) 70%. Need for examinations of multiple (3) sampleswith microscopy for reliable result. Alternative: PCR or Dual-Feces-Test: one sample examination is enough!

35 Current therapy metronidazole: 500mg 3dd, 7 days main alternatives: tinidazol: 2 gram / day once (USA no.1)!! albendazol: > 1 year: 400 mg. 1dd, 5 dgn

36 A frequent, under recognised, problem: Regular treatment not effective to eradicate Giardia infection: nitroimidazole - resistant Giardiasis (Refractory Giardiasis, RG). E.R. Carter, *, L.E. Nabarro1, L. Hedley2, P.L. Chiodini The HospitalforTropicalDiseases, UK, Pharmacy, University College London Hospitals NHS Foundation Trust, London, UK

37 How to deal with a patient with persistent Giardia infection after standard treatment? Councelling for possible re-infections from environment : partners (MSM), children, pets, and water sources. Examination for IgA deficiency, HIV, coeliac disease When When negative: negative: possible possible true true nitroimidazle therapy resistance resistant Giardia of Giardia isolates. Not possible to examine in clinical practice isolates. Difficult to examine in routine clinical practice! start pragmatic approach guided by experience for other treatment regimen (i.e. Carter 2017)

38 Suggested treatment regimens in RG: 1: tinidazol (1d, 2 gr), albendazol (400 mg 2dd, 5d), tinidazol (1d, 2gr) 2: mepacrine (100mg 3dd, 3-7d) ++ Carter et al : aldendazol (2dd 400mg, 14 d.(?)) also with microscopy!!

39 III Cyclospora cayetanensis the overlooked parasite Soave. Patients in Haiti and Mexico with diarrhea. Structures 8-10 µm, defined wall, granular material inside: coccidian body/fungal spore. Big Crypto.

40 Cyclospora cayetanensis Intracellular location small intestine Intestinal coccidian from distinct protozoan genus Humans only natural host.

41 Diagnosis: relative easy with microscopy! 8-10 um with several globlets inside. when properly trained technicians cannot miss it!!

42 The importance of microscopy also in NL! A group of persons with severe symptomatology i.e. severe abdominal pain and loss of weight (8 kg in two weeks) Standard: PCR for E. histolytica, Giardia and Cryptosporidium: Result (2x): No parasites found. All patients persisted, for two weeks, to be most ill!!! Additional routine microscopy (10 min search) : result: many cysts of Cyclospora

43 Transmission: contaminated food (i.e.produce), water.. Prevalence: many countries - Latin America Guatamala Peru Mexico -India -SE Asia -Also USA. USA 2018: multiple outbreaks > 2000 cases (no int. travel) Contaminated raspberries from Guatamala

44 Symptomatology associated with Cyclospora infection patients often feel very ill! predominant symptom: watery diarrhea often in relapsing, cyclical pattern important associated symptoms: heartburn-like symptoms, abdominal cramps fatigue anorexia, weight loss (up to 10 kg!) and vomiting infection may last for weeks (but is self-limiting)

45 Effective treatment available!! In case of severe complaints: Co-trimoxazole (trimethoprim - sulfamethoxazole (160/800 mg) 2x dd for 7-10 days Fast effect after start of treatment!

46 Intestinal protozoa observed with Triple Feces Test (TFT) in routine practice (n: 462 patients) AMC Giardia intestinalis 24 (5,2) Entamoeba histolytica/dispar 18 (3,9) Dientamoeba fragilis 45 (9,7) Blastocystis 124 (26,8) Combined: positive in about 30% of patients!! Entamoeba coli 65 (14,0) Entamoeba hartmanni 23 (5,0) Endolimax nana 47 (10,2) Chilomastix mesnili 10 (2,2) Iodamoeba butschlii 12 (2,6)

47 Dientamoeba fragilis a parasite of importance for children and (some) adults!

48 Clinical significance Studies form USA and Canada 1977: symptomatic disease in part (15 25%) of infected cases (75-85% no symptoms!)

49 Dientamoeba fragilis NTVG 2004 Important to consider in children with persistent intestinal complaints! 43 children with abdominal complaints and no other cause treatment clioquinol or metronidazol (27C, 6 M/T) In 33 / 43 children after therapy eradication of parasites. In 27 out of 33 (82%) symptoms were considerably less or were completely disappeared. From 10 children without clearance of parasites after treatment, in 2 (20%) complaints were less or disappeared

50 Effects on symptomatology in children with DF after parasitological effective treatment (paromomycin) : Vandenberg et al.

51 Many other reports, worldwide, which suggest pathogenicity of D. fragilis.. Simon et al. (1967) Spencer et al. (1979) Keystone et al. (1983) Dardick (1983) Millet et al. (1983) Oxner et al. (1987) Preiss et al. (1991) Butler (1996) Cuffari et al. (1998) Girginkardesler et al. (2003) Bosman et al. (2004) Vandenberg et al. (2006, 2007). Kurt et al. (2008) Stark et al. (2010) van Hellemond et al. (2012) Longstanding worldwide evidence / observations that D. fragilis infections can elicit symptomatology in humans. Pathogenesis is unknown As with Giardia, there are also many asymptomatic carriers with DF!!

52 In The Netherlands. After introduction of PCR for diagnosis of D. fragilis no difference in prevalence in between symptomatic and asymptomatic individulas D. fragilis is not (never) a cause of disease Diagnosis is also no longer indicated

53 Fifty years English literature: D. fragilis can, in a selected group of persons, be a cause of symptomatology But only in this country (NL), after introduction of PCR for diagnosis, D. fragilis End is declared to be an apathogen!!?

54 PCR diagnosis for Dientamoeba fragilis : a pitfall for interpretation of pathogenicity and4. clinical care!! Clinical practice after microscopic positive result: treatment for D. fragilis offered to patients were no other causes for complaints are found. In these cases often good response! No. positves with microscopy: Patients with symptomatology due to D.fragilis = small group of total No. positives with PCR: strong increase Additional no. positives: often low DNA loads! In practice: with PCR too many positivesto treat all! Loss of old selection criterion for indication of treatment, and.observations of good effect of treatment

55 Persistent DNA from D.fragilis present in bowl after usage by patient with D. fragilis amc.uva.nl

56 Current treatment options for Dientamoeba fragilis Eff % Eff % Eff %

57 Clioquinol usage in The Netherlands: with restricted use, it is safe. (also in common use in Amsterdam UMC) Use of clioquinol is safe in dosage of 3 dd 250 mg (adults) and mg/kg/day divided in three doses (children), for 7-10 days. Neurotoxicity (SMON) described in Japan, especially after usage of high dosages in short period of time, or prolonged usage (months-years). Side effects possible related to deficiency of Vit B12 in post war Japan. Outside Japan complications only seldom observed: only some cases described in over 500 million doses provided (!), before side effects in Japan were noticed. No evidence of accumulation in the body after treatment in recent studies*: Clioquinol not detectable in plasma 3 days after 7-14 days of treatment with a dosage of 750 mg/day. Intracellular concentrations of clioquinol in Peripheral Blood Mononuclear cells very low after treatment with 800 mg/day for 8 days. Clinical no side effects < 2400 mg /day for 8 days. *(potential use as anticancer agent: studies in 2003, 2007, 2012)

58 Practical aspects use of clioquinol Can be obtained from every pharmacy in NL Suspension 100 mg/ml according to FNA Preferable produced by De Magistrale Bereider (preparation of a proper suspension is difficult) Do shake bottle thoroughly in advance: most important, otherwise only water will be used Important to calculate appropriate volume and instruct mother with handling of syringe Costs: relative cheap: 43 euro per bottle(= 100 ml of 100 mg/ml, ) Dosage: 15 mg/kg/day (max 750 mg), divided over 3 doses, for 10 days.

59 Blastocystisspp. infection an intriguing new field of interest!

60 Intestinal protozoan parasites observed in routine clinical practice Entamoeba histolytica Giardia lamblia Dientamoeba fragilis Cryptosporidium spp. Isospora belli Cyclospora cayetanensis Microsporidia spp Blastocystis hominis Entamoeba dispar Entamoeba coli Entamoeba hartmannii Iodamoeba butschlii Endolimax nana Chilomastix mesnili pathogens Most common protozoan parasite (25%)! non- pathogens

61 Blastocystis spp: many answers to be answered! Taxonomic status Mode of transmission. Clinical significance. Best diagnostic procedure. Effective therapy..

62 Formerly assumed in humans only one species: Blastocystis hominis But.. there were many more subgroups of Blastocystis! also common in animals! terminology was confusing: clusters, clades now at least 14 species identified of which 4 species commonly are observed in humans

63 Prevalence and subtyping of Blastocystisspp. in samples routinely examined for intestinal parasites at Dept. Parasitology, AMC, Amsterdam (n = 442) 30,0% Overall prevalence in population: 24% prevalence 25,0% 20,0% 15,0% ST4; 2.7% ST3; 9.7% Microscopy only ST7 ST6 10,0% ST2; 5.2% 5,0% ST1; 5.2% 0,0%

64 Different species in other studies using PCR on faeces 100% Other ST ST4 80% 31 60% ST3 40% 20% 0% country No Blasto infections prevalence (%) Netherlands Belgium Denmark 197 nd 12 8 Turkey 87 nd 6 28 Australia ST2 ST1

65 Treatment options infection with Blastocystis spp. it seems rather staightforward 80-90% eradication 95% eradication 86% eradication 77% eradication Review: Current therapy of Blastocystis spp. (Stensvold, JCG 2010)

66 However.treatment failure not uncommon: diagnostic problems, resistance, other subtypes? 40-60% effective? 20-40% effective???? Coyle et al (CID 2012): Metronidazole is considered first line treatment, but the success of eradicating Blastocystis with this drug has been reported to be anywhere from 0% to 100% Review: Current therapy of Blastocystis spp. (Stensvold, JCG 2010)

67 Different Blastocystis species: Different fenotype on agar plates! ST1: slimy colonies of variable size

68 ST4: smaller, separate, colonies!

69 End

70 Microsporidia from an incidental to highly prevalent human pathogens.

71 1985: a strange microorganism observed in a patient with AIDS Small parasite, belongs to the microsporidia but an unknown species: Enterocytozoon bieneusi

72 Microsporidia: old group of protozoan parasites, well known from diseases in animals. Specific spore stages and invasion mechanism E.i. Schottelius MI 2000

73 Diagnosis Electron microscopy i.e. small intestinal biopsies Microscopy on stool: fast and easy Molecular diagnosis (PCR): detection, species differentiation

74 chronic diarrhea cholangiopathy rhinosinusitis Treatment difficult: fumagilin

75 Another strange parasite observed in AIDS in epithelial cells of small intestine. Encephalitozoon spp.!!

76 Spores of Encephalitozoon in urine in AIDS (Uvitex 2B)

77 Pathology due to Encephalitozoon infections in AIDS: involvement of multiple organs encephalitis diarrhea hepatitis nephritis keratoconjunctivitis

78 Treatment of Encephalitozoon species Albendazole 400 mg twice a day for 4 weeks Rapid disappearance of spores from body fluids Prolonged treatment necessary to prevent relapses

79 Microsporidiosis in immunosuppression other than AIDS Solid organ tranplantation (kidney, heart-long and liver) Bone marrow transplant recipiënts. E. bienusi: prolonged diarrhea Encephalitozoon spp.: multipe organ involvement

80 Antibodies to microsporidia frequently present in general Dutch and French population (7%)!

81 How do people come in contact with microsporidia? Humans: E. bieneusi,e. intestinalis, E. hellem, E. cuniculi, Vittaforma corneae,, Nosema ocularum, Brachiola spp., Trachipleisthophora spp., Pleistophora spp and Microsporidum spp. Animals: Enterocytozoon bieneusi i.e.: cats, chickens, dogs, goats, pigs, cattle, rats +++ Encephalitozoon intestinalisi.e.: donkeys, dogs, pigs, cows, goats, gorillas Encephalitozoon cuniculi: i.e.: rabbits, rodents, foxes, goats, horses, birds Encephalitozoon hellem i.e.: birds Water: E. bieneusi, E. intestinalis,, Nosema, Pleistophora spp, Vittaforma cornea + Food: Pleistophora spp. +/- Insects: Brachiola algera, Nosema cornea +/-

82 Microsporidia are (indeed) close by studies among Dutch pigeons Sequence confirmed human microsporidia species in 36/331 (11%) pigeon feces samples!

83 Blatocystis infection: most common intestinal protozoan in humans Parasite Diagnostic yield (%) Giardia intestinalis 24 (5,2) Entamoeba histolytica/dispar 18 (3,9) Dientamoeba fragilis 45 (9,7) Blastocystis spp. 124 (26,8) Entamoeba coli 65 (14,0) Entamoeba hartmanni 23 (5,0) Endolimax nana 47 (10,2) Chilomastix mesnili 10 (2,2) Iodamoeba butschlii 12 (2,6) Most common protozoan parasite! (no. examined 462 patients)

84 Culture of Blastocystis spp. in liquid media Growth with intestinal bacteria: difficult to estimate effectiveness of antibiotics!

85 Axenic cultures (without bacteria) of Blastocystis spp. needed for reliabe drug testing Culture of Blastocystis spp on agarplates Originally described by Tan, Exp. Par IMDM- HS, Iscove s Modified Dulbecco s Medium with 10% horse serum

86 Disc diffusion testing of antibiotics with Blastocystis spp. Subtype 1 with Ciprofloxacin en Furazolidone Growth control: growth Ciprofloxacin Growth: resistant Furozolidone: Inhibition: sensitive

87 IV Strongyloides stercoralis The endless persisting worm commonly encountered in visitors returning from the tropics Continious replication in intestine, migration to lungs, swallowing, to intestine replication.and so on

88 Because of internal autoinfectionpotentially life-long persistenceonce infected! In 47 out of 145 (33%) ex-prisoners of war Strongyloides persisted for 45 yearafter leaving the tropics! Birma railroad: a monstrous project of the Japanese in WOII

89 Prevalence Present in most tropical and subtropical countries Especially also South America (Surinam!) and South East Asia (Indonesia). Also in rural areas Spain, Italia, Poland, Romania Occasionally in Turkey

90 Symptomatology (immunocompetent host) Acute phase: Chronic phase: itching on spot of penetration, moderate to severe diarrhea larva currens upper abdominal pain malabsorption, diarrhea eosinophilia In general not too severe

91 The major complication of infection with Strongyloides stercoralis infection hyperinfection syndrome Immunosuppressionresults in massive proliferation of Strongyloides stercoralis! Without prompt treatment: lethal condition!

92 Involvement of intestine, lungs and other organs. Intestine Lungs and sputum

93 Patients at risk for hyperinfection syndrome: - administration of corticosteroids (even 6-17 days courses) - hematopoietic stem cell transplantation - organ transplantation - cytotoxic drugs - Human T-lymphotropic virus type I (HTLV-I) infection

94 Prevention of hyperinfection syndrome Anyone at risk: serodiagnosis with specific IgG In case of a positive serological result: treatment with ivermetine 0,2 mg/kg body weight daily, 2 days

95 Serodiagnosis of Strongyloides infection: most effective!! ELISA: high sensitivity and specificity!

96 New test in routine use: Dual-Feces-Test (DFT) 1 day collecting set Unfixed Stool (A) SAF-fixed stool (B) Confirmation and determination of protozoa PCR (5 targets) culture (yeasts) + Microscopy (25 targets)

97 Op empirisch gronden werken met geneesmiddelen en combinaties daarvan die in vivo bewezen effectiviteit hebben tegen Giardia. Meest gebruikt: Metronidazol Tinidazol Albendazol Paromomycine Combinaties: oa tinidazol met albendazol Nitazoxanide Meparicine

98 Carter et al 2017 Beleid behandeling refractaire giardiasis 1: 1d tinidazol, 5d albendazol, 1d tinidazol We have chosen this regimen on the basis of the small trial performed by Cacopardo et al. which demonstrated the superior efficacy of nitroimidazole albendazole combination therapy over albendazole alone. Furthermore, in our own experience, 60% of patients with refractory disease are cured with this combination. 2: 3dd 100mg 3-5 (7) d Mepacrine 3: Aldendazol 2dd 400mg 14 d.(?) -> Controle diagnostiek direct (tot 1 week) na einde behandeling!