Schistosomes and other flukes

Rahajeng N. Tunjungputri, MD, MSc

Department of Parasitology Faculty of Medicine Diponegoro University - 2012

Case

A 22-year-old student from Sulawesi presented at the hospital with acute haematemesis

Physical examination revealed marked hepatosplenomegaly

Oesophageal and gastric varices were identified at upper gastrointestinal endoscopy portal hypertension

Trematodes

Schistosomes

S. mansoni

S. japonicum

S. hematobium

Liver flukes

Clonorchis sinensis

Opistorchis sp.

Fasciola hepatica

Intestinal flukes

Fasciolopsis buski, Metagonimus yokogawai, Heterophyes heterophyes

Human schistosomiasis/ bilharziasis

Human schistosomiasis: epidemiology

200 million persons infected with schistosomes in 74 countries

120 million persons have symptoms, 20 million have severe disease, and 100,000 die each year

Higher infection rate and infection burden in children

amount of water exposure, partial acquired immunity, age, and genetic susceptibility

Water resource development projects and population movements have spread the disease to non-endemic areas

Global distribution

Schistosomiasis in Indonesia

1975: highest prevalence 72%

Domestic and wild animals maintain transmission cycle: eg deer, cow, buffalo, rats

2001: increased prevalence due to Poso unrest population movement

Snail habitat

Schistosomes morphology

Male

9,5 mm x 19,5 mm

Canalis gynecophorus

Female : 16 mm x 26 mm

Thin-shaped

S. mansoni

Habitat

Mesenteric and portal veins

V. mesenterica inferior

S. mansoni

S. mansoni male adult: tegument

S. japonicum

Habitat Mesenteric and portal veins V. mesenterica superior

S. haematobium

Habitat

V. vesicalis

Video

Life cycle

Cercariae penetration

Intensity of infection

Severity of disease

In snails: sporocyst I sporocyst II cercaria

Transmission

Clinical manifestation

Period Affected organ Manifestation

Immediate Skin Dermatitis: A maculopapular eruption at the site of penetration In migrants or tourists: skin reactions (hours), a rash (up to one week later)

Acute Schistosomiasis Katayama fever

Systemic Gastrointestinal Lungs Liver, spleen

A history of contact with contaminated water 2-6 weeks before (in travellers) Mediated by the immune complex Majority of cases begin with the deposition of an egg into host tissues Fever, headache, generalized myalgias, right-upper-quadrant pain, and bloody diarrhea, respiratory symptoms Tender hepatomegaly, splenomegaly, aseptic meningitis. Not all patients shed eggs, but all have eosinophilia and most have positive serologic tests

Chronic shistosomiasis

Especially in people with longstanding infection in poor areas Gastrointestinal and Liver Disease Genitourinary Disease Neurologic and Other Manifestations

Pathogenesis

Egg production commences four to six weeks after infection and continues for the life of the worm — usually three to five years.

Eggs in blood vessels

Tissue Pass the mucosa

Shed in feces (S.m, S.j) and

urine (S.h)

Gastrointestinal and liver disease

Intestinal disease: Eggs in the gut wall inflammation, hyperplasia, ulceration, microabscess formation, and polyposis

Light infections: fatigue, intermittent abdominal pain, and diarrhea

Heavy infections: anemia, intestinal polyps

Liver disease

presinusoidal inflammation, periportal fibrosis & collagen deposits, progressive obstruction of blood flow, portal hypertension, hepatomegaly

Early chronic: granuloma infiltration around eggs in small venulae

In 5-10%: periportal fibrosis in years after infection

Adult in mesenteric

veins

Eggs in venulae/ tissue

Inflammation

Portal hypertension, variceal bleeding

Hepatomegaly Varices Variceal bleeding Splenomegaly

Genitourinary Disease

Dysuria and hematuria (early and late disease)

Late manifestations:

proteinuria (often in the nephrotic range)

calcifications in the bladder

obstruction of the ureter

renal colic

hydronephrosis

renal failure

associated risk of bladder cancer

Secondary bacterial infection is frequent

Genital disease in 1/3 women: vulval and perineal hypertrophic, ulcerative, fistulous, or wart-like

Schistosomal dermatitis

http://img.medscape.com/pi/emed/ckb/pediatrics_general/996090-999469-98.jpg

Schistosomal dermatitis

http://upload.wikimedia.org/wikipedia/commons/5/5a/Cercarial_dermatitis_lower_legs.jpg

GU disease

27-year-old man with hematuria and left-sided loin pain who had S. haematobium eggs in his urine

Liver disease

ultrasonogram showing gross hepatic fibrosis (arrows) in a 45-year-old man with severe hepatic schistosomiasis

Diagnosis: Schistosomiasis

Eggs in stool

Multiple samples

Others:

PCR

Serology - ELISA

Schistosomiasis control

Indonesia

2 times /year: Human stool survey, Snails survey, Reservoir host survey

Control activity

MDA Selective drug administration using praziquantel

Snail control: Chemical molluscicide in limited area

Environment: drying / flooding of snails habitats, cleaning of irrigation channels (drainage)

Education

Vaccination of reservoir host research

Host population control satellite tracking

Other liver flukes

Clonorchis sinensis

flattened

10-25 mm long by 3-5 mm wide

ovary

two branches testes

habitat: bile ducts

Opistorchis spp.

Testes: 2, lobular shape

Eggs often indistinguishable from C. sinensis

Habitat: bile ducts

Opisthorchiasis and Clonorchiasis

2-3 weeks after exposure

Fever, abdominal pain, hepatomegaly, urticaria, and eosinophilia

Chronic infection

inflammation and thickening of bile duct walls and localized obstruction in about 10% of persons with heavy chronic infections

right upper quadrant discomfort, anorexia, and weight loss

Heavy infection

Gall stones, recurring cholangitis with bacterial sepsis, cholecystitis, liver abscess, and occasionally pancreatitis

Infection:

ingesting the metacercariae in raw or inadequately cooked fish

Fasciola hepatica

large and broadly-flat

up to 30 mm x 15 mm

The anterior end is cone-shaped

Habitat: bile duct

ingesting uncooked aquatic vegetation

Clinical syndromes of F. hepatica infection

• In 6-12 weeks after infection: Marked eosinophilia, abdominal pain, intermittent high fever, weight loss, urticaria

• Tender hepatomegaly, jaundice, anemia

Acute/ Migratory phase

• eosinophilia

• inflammation and intermittent obstruction of bile ducts, cholecystitis, ascending cholangitis

Chronic phase

Diagnosis: other liver flukes

Finding eggs in stool

Multiple samples

Treatment

Schistosomiasis: Praziquantel repeated dose after 4-6 weeks in Katayama fever

Niridazol for schistosomiasis due to toxicity

Case: Examination of stool specimens

Serology

Enzyme immunoassay high levels of serum antibodies to S. mansoni were subsequently detected

Therapy

Endoscopy sclerotherapy

Pharmacotherapy

Reference

Mandell GL, Bennet JE, Dolin R. Principles and practice of infectious diseases. 2010 Ed. 7 pp. 3595-3605.

Ross AG, Bartley PB, Sleigh AC, Olds GR, Li Y, Williams GM, McManus DP. Schistosomiasis. N Engl J Med. 2002 Apr 18;346(16):1212-20.

Gryseels B, Polman K, Clerinx J, Kestens L. Human schistosomiasis. Lancet. 2006 Sep 23;368(9541):1106-18.