Trypanosomiasis Chagas’ disease Causes Diagnosis TREATMENT with Signs and Symptoms

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 Sicness is caused by T. brucei gambiense and T. brucei rhodesiense.
Chagas' disease 2
TrypanosomiasiChagas‘ 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.
protozoan Trypanosoma 2
TrypanosomiasiChagas‘ 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.
protozoan Trypanosoma 3
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.
protozoan Trypanosoma 1
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.
  • · Romanas 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.

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