Do you know why as humans we are advised to not feel full of ourselves or feel as if humans are the only creature to ever live on this earth? This is because we humans do live hand in hand with other organisms, both visible and invisible to the naked eyes. This relationship plays a great role in human’s health. You may be familiar with microorganisms such as bacteria and viruses being the most common cause for infection but if you ask a doctor, you will know that parasites also have their fair share of affecting human’s health. Parasite that will be focusing on here is Trypanosoma cruzi.
Trypanosoma cruzi is a parasite known to be causing Chagas disease. Chagas disease is also named as American trypanosomiasis. Chagas disease is common in certain parts of America such as Central and South America, not forgetting Mexico too. It is estimated that 8 million people are infected by this disease in these regions alone. Chagas disease is commonly spread by the infected triatomine bug. This triatomine bug is able to live in poor housing conditions such as mud walls and thatched roofs. It is also able to live in the wall, chicken coops, pen and warehouse. These blood sucking bugs are typically active at night while remaining in hiding during the day. Remember, only infected triatomine bugs are able to affect humans. This bug is said to be infected when it bites an infected animal or people containing the circulated parasite.
Transmission of Trypanosoma cruzi is mainly through contact with urine or stool of infected triatomine bugs. The infected triatomine bugs bite humans on the exposed skin such as face and defecates or urinates close to the bite. The stool or urine containing the parasite is able to enter the body when it is smeared into the bite or other skin breaks, commonly the eyes and mouth. Apart from this main transmission, this parasite can be transmitted with other ways such as eating food or drinking water contaminated with Trypanosoma cruzi. This specific way of consumption of contaminated food or drinks is the one that causes outbreaks or severe cases. Other modes of transmission are passing from an infected mother to her baby either in pregnancy or childbirth, blood transfusion from an infected donor and organ transplants from an infected donor. In rare cases, the parasite can be transmitted from laboratory accidents.
Chagas disease has acute and chronic phases. Acute phase can last from weeks and up to 2 months with symptoms of fever, headache, muscle pain, abdominal or chest pain, edema (swelling) around the parasite entry site, anaemia and enlargement of liver and spleen (hepatosplenomegaly). In rare occurrences, patients might experience inflammation to the heart muscle or brain (including lining around which is the meninges). In the acute phase, the number of parasites circulating in the blood is high. However, most cases show nonspecific symptoms, mild or even no symptoms at all. In the chronic phase, there are few to no parasites in blood but mainly hidden in the heart and digestive muscles. Chronic phase often does not have symptoms and this alone made people unaware of the infection. As a matter of fact, many would remain asymptomatic throughout their life. Even so, it is estimated that 20 to 30% of infected people develop heart problems, digestive issues specifically enlargement of colon or oesophagus and neurological disease. Those with immunosuppressed conditions can have severe Chaga disease as the disease is reactivated by the parasites circulating in the blood.
Treatment for Chagas disease is recommended to those diagnosed in acute phase, babies with congenital infection and those with immunosuppressed condition. It is treated with benznidazole and nifurtimox. These medications are able to eradicate infection with an 80% success rate in the acute phase. Chronic phase will need supportive treatment depending on the organ or body systems involved.
Prevention is the best way to avoid Chagas disease. While there is no vaccine or medication that can be used to protect one from the disease, there are other methods that can be used. Improving housing areas, ensuring house cleanliness and spraying insecticides can significantly curb the spread of Chagas disease. Usage of bednets can be helpful to minimise contact with the bug bites at nighttime. Practising good hygiene practices when preparing food, transporting, storing and consumption is a great way to minimise risk for the disease. Such practice also ensures humans eat clean and safe food.
It can be concluded that Trypanosoma cruzi is a parasite responsible for Chagas disease. It is mainly transmitted by the triatomine bugs. People can have no symptoms when infected by the parasite. Acute phase rarely be fatal but chronic phase may lead to life-threatening events when it is left untreated. Treatment mainly is by prescribing benznidazole or nifurtimox which are antiprotozoal agents. The World Chagas Disease was established on 14th April as it is the date where Chagas disease was first diagnosed back in 1909.