This post is the 2nd in a series highlighting the WHO’s list of 17 Neglected Tropical Diseases (now technically 18 as mycetoma was added to the list at the 69th World Health Assembly in May 2016). To read the previous post in this series click here.
I wrote a post about Chagas disease back in 2015 (in honor of Valentine’s Day) so I’ll try to keep this one short and sweet.
Chagas disease (also known as American trypanosomiasis) is an illness caused by the protozoan parasite Trypanosoma cruzi. Chagas disease used to be limited to mainly the Americas but has spread in recent years as globalization has allowed for increased human travel and global population movement to and from Latin America. Around 8 million people are infected worldwide, mostly in Latin America. And around 10,000 people die from complications each year.
Now on to why these “kissing bugs” aren’t as cute as their name implies. The parasite responsible for causing Chagas disease, T. cruzi, is most commonly transmitted via the triatomine bug which is also known as the “kissing bug” in some areas. This blood-sucking bug is active at night and needs to bite an exposed area of skin to feed, which usually means it bites the face of its victim. Then the bug has a blood meal and defecates next to the bite. Its feces contains the T. cruzi parasite and the parasite gets into the person’s blood when they instinctively itch the bite. If you’re interested in seeing an animated video depicting the lifecycle of T. cruzi, check this out. Vector-borne transmission accounts for almost all of the cases in the Americas. In other areas transmission occurs through fecal-oral routes, contaminated blood transfusions, or mother-to-child during pregnancy or delivery.
Chagas disease has 2 phases of infection, acute and chronic. The acute phase is generally asymptomatic. The chronic phase means patients may progress to cardiac, digestive, or neurological issues which can be life-threatening. Treatment, with one of two possible drugs, resulting in a cure is possible. Anyone in the acute phase or who is experiencing their infection reactivated due to immunosuppression can be effectively treated and cured. However, the longer the infection goes without treatment the lower the efficacy of the drugs. And since the acute phase is often asymptomatic, there are probably loads of people who could be treated and cured but don’t even know they are infected.
The best thing to do is to try to prevent getting kissed by the “kissing bug” in the first place. There’s no vaccine and the best methods of prevention consist of general vector control activities such as insecticide spraying, home improvements to prevent the triatomine bugs from getting into the house, bednets, etc.