MeSH Myocarditis, Pericarditis, Myocardial Diseases, Chagas Disease,Trypanosomiasis, African, Larva Migrans,

Abstract

Parasitic diseases may occasionally affect the cardiovascular system, albeit rarely in childhood. In this paper, I list the main features of tropical diseases which may affect the heart.

Article

Several parasitic diseases occasionally affect the heart, causing myocarditis, cardiomyopathy and pericarditis as follows:

In the majority of instances, adults are predominantly affected, cardiac pathology being uncommon in children except in Chagas' disease.

Chagas' disease

Distribution

South and Central America

The parasite

Trypanosoma cruzi

The reservoir

Humans and arborial animals

The vector

Various species of reduviid bugs (Triatoma) 

Transmission

• Rubbing infected bug species onto skin

• Blood transfusion

• Congenital infection

Acute stage

Seen mainly in children:

• Reddish area at site of bite (chagoma)

• Unilateral painless orbital oedema (Romana's sign)

• High fever

• Tachycardia persisting through apyrexial periods

• Acute myocarditis with arrhythmias

• Pericarditis

• Heart failure

• Hepatosplenomegaly

• Lymphadenopathy

Chronic stage

Seen mainly in adult life: 

• Cardiomyopathy with right bundle branch block

• Left anterior hemiblock

• Complete heart block

• Premature ventricular beats

• Atrial fibrillation

• T wave changes

• Heart failure (left and right ventricular decompensation)

• Cardiac arrest with sudden death

• Megasyndromes of the intestines

Diagnosis

• Trypanosomes found in blood

• Serological tests (IFAT or ELISA)

• Polymerase chain reaction

Treatment

• Supportive

• Benznidazole or nifurtimox

• The elimination of the disease is being achieved in several South American countries

African trypanosomiasis

Distribution

Africa

The parasite

Trypanosoma brucei gambiense & rhodesiense 

The reservoir

Humans and wildlife

The vector

Various species of Glossina (Tsetse) flies 

Transmission

Bite by fly

Clinical features

• Local lesion at site of bite

• Fever

• Lymphadenopathy

• Myocarditis with disproportionate tachycardia

• Tachycardia persisting through apyrexial periods

• Arrhythmias

• Heart failure

• Pericardial effusion

Diagnosis

• Trypanosomes found in blood, lymph and cerebrospinal fluid

• Serological tests (IFAT)

• Direct and indirect agglutination

• Antigen detection

Treatment

• Suramin

• Pentamidine (T. gambiense only)

• Melarsoprol

• Alpha-difluoromethlyornithine (DFMO)

Trichinosis

Distribution

Worldwide

The parasite

Trichinella spiralis

The reservoir

Pigs and many wild animals

Transmission

Ingestion of raw or undercooked animal flesh - predominantly pork or wild boar

Clinical features

• Fever

• Orbital oedema

• Myalgia

• Myocarditis

• Arrhythmias

• Heart failure

Diagnosis

• Serological tests (ELISA)

• Eosinophilia

Treatment

• Mebendazole

• Corticosteroids

Visceral larva migrans

Distribution

Worldwide

The parasite

Toxocara canis & Toxocara catis 

The reservoir

Dogs and cats

Transmission

Ingestion of toxocara eggs deposited on the ground in dog faeces

Clinical features

• Fever

• Nocturnal cough and wheezing

• Myocarditis

• Unilateral loss of vision

Diagnosis

• ELISA with larval stage antigens

• Eosinophilia

• Hypergammaglobulinaemia with raised IgM and IgG levels

Treatment

• Diethylcarbamazine

• Thiabendazole

Echinococcus

Distribution

Africa, Middle East, Latin America

The parasite

Echinococcus granulosus

The reservoir

Dogs

Transmission

Ingestion of echinococcal eggs

Clinical features

• Often none and found on routine X-rays or at autopsy

• Specific features relate to affected organ: liver, lung, bone and brain

• Myocarditis

• Pericarditis

Diagnosis

• Ultrasonography

• Radiology - crescent shadow or 'water-lily' effect

• Antigen detection

Treatment

• Surgical removal

• Albendazole

• Praziquantel

Toxoplasmosis

Distribution

Worldwide

The parasite

Toxoplasma gondii

The reservoir

Cats and migratory birds

Transmission

Ingestion of oocysts and meat; congenital

Clinical features

• Fever

• Lymphadenopathy

• Retinochoroiditis

• Myocarditis

• Cardiac hypertrophy and dilatation

• Pericarditis

Diagnosis

• Biopsy and staining

• Serology e.g. dye test

• Immunohistochemistry for antigen

• Polymerase chain reaction

Treatment

• Sulphonamide and diaminopyrimidine

Amboebiasis

Distribution

Worldwide but more frequent in the tropics and subtropics

The parasite

Entamoeba histolytica & Entamoeba dispar

The reservoir

Humans

Transmission

Faeco-oral route

Clinical features

• Diarrhoea with blood and mucus

• Extra-intestinal manifestations e.g. amoebic liver abscess

• Pericardial effusion

Diagnosis

• Microscopy of fresh stools

• Antibody detection

• Sigmoidoscopy

Treatment

Schistosomiasis

Distribution

South America and the Caribbean, Middle East, Africa, Far East

The parasite

• Schistosoma haematobium (urinary schistosomiasis) 

• Schistosoma mansoni (intestinal schistosomiasis) 

• Schistosoma japonicum (intestinal schistosomiasis)

The reservoir

Humans; various animals (japonicum only)

Intermediate host

Various species of fresh water snails

Clinical features of S. haematobium

• Painless haematuria

• Dull ache in urethral or suprapubic areas

• Pulmonary hypertension

• Cor pulmonale

Clinical features of intestinal schistosomiasis

• Recurrent bloody diarrhoea

• Polyposis

• Hepatosplenic disease

• Pulmonary hypertension

• Cor pulmonale

• Spinal cord involvement

• Epilepsy with expanding intracranial mass

Diagnosis

• Eggs in urine or faeces

• Rectal biopsy

• Renography

• Ultrasonography

• Monoclonal antibody-based dipstick assay

Treatment

• Praziquantel