Excess of physical exertion may precipitate facial and eye muscle spasm. It can be due to muscle fatigue. Side effects of certain medicines can produce facial twitching. Drinking excess of coffee, or any other caffeinated drinks can cause involuntary twitching of muscles, facial muscles are one of them.
Blood and organ donors are screened in many endemic areas and, since 2006, in the US to prevent transfusion- and organ transplantârelated Chagas disease. Key Points Chagas disease is caused by Trypanosoma cruzi, which is transmitted by Triatominae (reduviid, kissing, or assassin) bugs. Infection is endemic in South and Central America and Mexico; an estimated 8 million people worldwide, including an estimated 300,000 people in the US (primarily immigrants), are infected.
Trypanosomes are also found in the Americas in the form of Trypanosoma cruzi, which causes American human trypanosomiasis, or Chagas' disease. This disease is found in humans in two forms: as an amastigote in the cells, and as a trymastigote in the blood. The vectors for Trypanosoma cruzi include members of the order Hemiptera, such as assassin flies, which ingest the amastigote or trymastigote and carry them to animals or humans.