Trypanosomiasis Chagas‘ disease Causes Diagnosis TREATMENT with Signs and Symptoms

African trypanosomiasis — African sleeping sickness, caused by Trypanosoma gambiense, and American trypanosomiasis —A disease caused by Trypanosoma cruzi and transmitted by the biting reduviid bug.

• The protozoan Trypanosoma is the cause of Chagas’ disease and sleeping sickness.
• American trypanosomiasis or Chagas‘ disease is caused by T. cruzi.
• Human African Trypanosomiasis or Sleeping Sick­ness is caused by T. brucei gambiense and T. brucei rhodesiense.

Trypanosomiasis Chagas‘ disease Causes Diagnosis

CHAGAS’ DISEASE Trypanosomiasis

• Occurs in Americans. It caused by T. cruzi. A mild illness with fever occurs and subsides.
• Later in life, cardiac and gastrointestinal lesions de­velop and can even result in death.
• The typical feature of Chagas’ disease is that the acute illness subsides spontaneously and then may recur after an indefinite period.

Trypanosomiasis Chagas‘ disease Causative insect reduviid bugs fly

Life cycle Trypanosomiasis

• Insects called reduviid bugs become infected by suck­ing blood from a human.
• The parasite multiplies, and is discharged with the feces of the insect, which can then contaminate skin, mucus membrane, and con­junctiva of a person.
• The parasite then enters through a break in the skin, mucus membrane and again mul­tiplies.

Trypanosomiasis Chagas’ disease life cycle

Pathology of Trypanosomiasis

• A chagoma is formed at the site of entry of the para­site. There is inflammation at the site.
• The organism disseminates via blood vessels and lym­phatics and multiplies to form pseudocysts.
• The heart is affected, with destruction of heart valves and involvement of conduction system.
• The GIT is involved and there may be megacolon, involvement of the oesophagus and other parts of GIT.

Trypanosomiasis Chagas’ disease Pathology

Clinical features of  Trypanosomiasis

• · At first there is acute Chagas’ disease which sub­sides and many years later chronic Chagas’ dis­ease appears.
• After one week of invasion by parasites, acute Chagas’ disease develops.
• · At the site of entry, there is erythema, swelling (Chagoma), and local lymphadenopathy.
• · Romana‘s sign is classic finding of Chagas’ dis­ease – there is unilateral painless edema around the eyes and is seen in conjunctival trypanoso­miasis.
• There is malaise, fever, anorexia, edema over face and limbs. Rashes may also appear.
• · Generalized lymphadenopathy, hepatomegaly may occur.
• · Involvement of heart – Myocarditis, heart fail­ure, conduction defects are seen.
• · In chronic Chagas’ disease there is dilated car­diomyopathy, arrhythmias like ventricular ectopics, thromboembolism, RBBB(right bundle branch block), AV block(atiroventricular heart block) heart failure.
• · Embolization from a mural thrombus in the heart, may occur.
• · Neurologic involvement – meningoencephalitis may occur.
• · GIT involvement – Dysphagia, odynophagia, chest pain, regurgitation, aspiration due to se­vere oesophageal dysfunction and aspiration pneumonitis, can occur.
• · There is weight loss, cachexia(wasting)
• · Death may occur due to septicemia, pulmonary infection, arrhythmias.

Diagnosis of Trypanosomiasis

• · Fresh blood or buffy coat may show motile para­sites in thin and thick smears. Acridine orange or Giemsa stain can be used.
• · PCR or hemoculture can be performed to diag­nose Chagas’ disease.
• · Chronic Chagas’ disease is diagnosed by detec­tion of specific antibodies for T cruzi.
• · Radiolabelled T cruzi antigens and electrophore­sis are also used for diagnosis.

Trypanosomiasis Treatment

• Two drugs are available to treat Chagas’ disease. Nifurtimox and Benznidazole.
• They are very toxic and can cause nausea, vom­iting, restlessness, seizures, polyneuritis.
• Dose of Nifurtimox is 10 mg/kg in 4 divided doses for 120 days.
• Cardiac transplantation is the only treatment for end-stage cardiomyopathy.