Pratap Sagar Tiwari

Rajeev Shah

Prakash Naag

Residents, Internal Medicine, NGMC

TREMATODE INFECTIONS

TOPICS

• Introduction

• Classification

• Life cycle

• Clinical manifestaions

• Investigations

• Management

MAJOR HUMAN TREMATODE INFECTIONS

Blood flukes Liver flukes

Schistosoma mansoni

S. Japonicum

S. Intercalatum

S. Mekongi

S. Haematobium

Clonorchis sinensis

Opisthorchis viverrini

O. Felineus

Faciola hepatica

F. gigantica

Intestinal flukes Lung flukes

Fasciolopsis buski Paragonimus westermani

LIFE CYCLE OF SCHISTOSOMAS

CLINICAL MANIFESTATIONS: SCHISTOSOMIASIS

Acute manifestations

• Cercarial dermatitis (summer’s itch):is an allergic reaction caused by the

penetration of cercariae in persons who have been exposed to cercariae in

salt water or fresh water.

• Swimmer’s itch most often occurs in S .mansoni and S. japonicum.

• Manifested as petechial hemorrhage with edema and pruritus followed by

maculopapular rashes and sometimes vesicular.

• It is self limiting

CLINICAL MANIFESTATIONS: SCHISTOSOMIASIS

Acute manifestations

• Katayama syndrome: This syndrome is caused by high worm load and egg

antigen stimuli that result from immune complex formation and leads to a

serum sickness–like illness.

• This is the most severe form and is most common in persons with S

mansoni and S japonicum infections.

• Symptoms include high fever, chills, headache, hepatosplenomegaly,

lymphadenopathy, eosinophilia, and dysentery.

CLINICAL MANIFESTATIONS: SCHISTOSOMIASIS

Chronic manifestations

• Symptoms depend on the Schistosoma species that causes the infection, the

duration and severity of the infection, and the immune response of the host

to the egg antigens.

• Terminal hematuria, dysuria, and frequent urination .

• The earliest bladder sign is pseudotubercle, but, in longstanding infection,

radiography reveals nests of calcified ova (sandy patches) surrounded by

fibrous tissue in the submucosa.

CNS SCHISTOSOMIASIS

• Headache, seizures (both generalized and focal), myeloradiculopathy with

lower limb and back pain, paresthesia, and urinary bladder dysfunction are

the noted symptoms of CNS schistosomiasis due to S japonicum infection.

• Neuroschistosomiasis is a severe manifestation of schistosomal infection.

The neurological symptoms result from the inflammatory response of the

host to the deposition of eggs in the brain and spinal cord.

• Myelopathy is the most common neurological complication of S.

mansoni infection.

SUMMARY OF MANIFESTATIONS

Organisms Symptoms

Blood flukes

S. mansoni, S. japonicum Dermatitis, abdominal pain, bloody stool, peri-portal

fibrosis, hepato-splenomegaly, ascites, CNS

Schistosoma hematobium Dermatitis, urogenital cystitis, urethritis and bladder

carcinoma

Liver flukes

C. sinensis,

O. felinus, or O. viverini

Inflammation and deformation of bile duct, hepatitis,

anemia and edema

Fasciola hepatica fever, anemia, hepatobiliary manifestations (colicky pain,

jaundice), and secondary bacterial infections are present.

SUMMARY OF MANIFESTATIONS

Intestinal flukes

Fasciolopsis buski Epigastric pain, nausea, diarrhea, edema, ascites

Lung flukes

Paragonimus

westermani

Cough (dry / rusty brown sputum), pulmonary pain,

pleurisy, tuberculosis-like features.

SCHISTOSOMIASIS

Investigation, Diagnosis and

Management

INVESTIGATION /DIAGNOSIS

• Blood:PBS

• Microscopy:stool/urine/sputum

• Serology: detecting antibodies/antigens

• Imaging

TREATMENT

PREVENTION

• Information, education and communication on safe food practices.

• Improved sanitation, aimed at decreasing contamination of freshwater

streams with human faeces.

• Control or containment of the intermediate snail hosts.

• Preventive chemotherapy ??

• Vaccination ??

TREMATODES INFECTION IN NEPAL

• Includes Fasciola spp., and Schistosoma spp. (Patz et al. 2000, Dobson et

al. 2003, Mas-Coma et al. 2009)

• The highest prevalence of infection (38.3%) was recorded among snails (I.

exustus)collected from temporary ponds in chitwan.(Devkota et al 2008)

• 1.7% infection rate of Fasciola sp. larvae in Lymnaea sp. of snail from Kavre,

Nepal (Pandey 2001)

• 3.52% rate of patent trematode infections in Chitwan and Nawal parasi

districts of Nepal (Devkota et al 2008).

Thankyou

References:• Harrison’s principles of internal medicine 18h ed

• Davidson Principles & Practice of medicine

• Uptodate 19.3

• Emedicine.com last update sept 2012

WATERCRESS /SIM RAYO

WATER CHESTNUTS/ MAKHAN

LIFE CYCLE OF SCHISTOSOMAS

LIFE CYCLE OF INTESTINAL FLUKES

LIFE CYCLE OF LUNG FLUKES :PARAGONIMUS

• Thankyou