Chagas Disease

Chagas Disease, also called American Trypanosomiasis, is a tropical parasitic disease which occurs in the Americas, especially in South America. The early symptoms of Chagas Disease include swelling at the site of infection.

As the disease progresses, over the course of anything up to twenty years, a range of serious chronic symptoms will appear, including heart disease and malformation of the intestines (Megaintestine). If left untreated, Chagas Disease is often eventually fatal.

Causes

Chagas Disease is caused by a flagellate protozoan, called Trypanosoma cruzi.

This parasite is a member of the same genus as the parasites that cause African Trypanosomiasis (Sleeping Sickness) and also a member of the same order as the parasites that cause Leishmaniasis. However, its clinical manifestations, geographical distribution, life cycle, and insect vectors are quite different to these other parasites.

Transmission

Chagas Disease may be transmitted to humans, or between humans, in a variety of ways:

  • Blood Transfusion: If infected people donate blood, then the recipients of the blood can become infected.
  • Contaminated Food: ingestion of food contaminated with the parasite can cause infection.
  • Fetal Transmission: Mothers can pass the infection onto their unborn children because the parasite can cross the placenta, causing prenatal death.
  • Insect Bite: specifically bites by blood-sucking assassin bugs of the subfamily Triatominae. Those insects are known by many names, depending on country, such as barbeiro, benchuca, chipo, kissing bug, and vinchuca.

Treatment

The main treatments for sufferers of Chagas Disease include the following anti-parasitic medications:

Azole, Nitroderivatives, such as benznidazole or nifurtimox.

However, these medications are usually only effective when given during the acute stage of infection. In addition, these medications are highly toxic, and they are often ineffective and unsatisfactory.
In the chronic stage of Chagas Disease, treatment involves managing the severe symptoms that the disease causes. For example:

  • Heart medications, a pacemaker, and even heart transplantation surgery to prevent chronic heart failure and heart arrhythmias.
  • Surgery for malformation of the intestines (Megaintestine).

However, Chagas Disease is not curable when it reaches the chronic stage.

Further research is constantly being conducted into other treatment options for Chagas Disease, including new drugs and medications, DNA vaccines, and so on.

Prevention and Control

The following techniques are used to attempt to prevent and control Chagas Disease, also called American Trypanosomiasis:

  • Blood and Tissue Monitoring: Better monitoring and testing or blood and organs donated to reduce the chance of transmission between humans.
  • Housing and Sanitation: improving housing and sanitary conditions, especially in the rural areas, can help reduce a persons risk of becoming infected.
  • Insect Control: involves spraying and using paints that contain insecticides (synthetic pyrethroids) to control the blood-sucking assassin bugs of the subfamily Triatominae. Those insects are known by many names, depending on country, such as barbeiro, benchuca, chipo, chupança, kissing bug, and vinchuca.
  • Personal Protection: includes a range of measures, including covering exposed skin, using mosquito nets and screens on doors and windows, and avoiding areas where the assassin bugs are common.

Further research is constantly being conducted into other prevention and control measures for this disease.

Photo: CDC/Dr. Myron G. Schultz. Trypanosoma forms in blood smear from patient with African trypanosomiasis.