American Trypanosomiasis Trypanosoma cruzi: Causative agent of Chagas’ Disease. Trypanosoma rangeli: non-pathogenic species in humans.

T. cruzi

T. rangeli

Transmission Transmitted by biting insects in the order Hemiptera.

Transmission Transmitted by biting insects in the order Hemiptera. Family Reduvidae (Assassin bugs, Reduvids, or Kissing bugs).

Transmission Transmitted by biting insects in the order Hemiptera. Family Reduvidae (Assassin bugs, Reduvids, or Kissing bugs). 28 + species however most important are: Triatoma infestans Triatoma sanguisaga Panstrongylus megistus Rhodnius prolixus

Large up to 34 mm. Some species found on the ground, some in trees and some in human dwellings. Eggs, are laid and have 5 nymphal instars.

Kissing Bug Feeding on a Person

How do People Get Infected? Epimastigotes are not found in the salivary glands, but instead gather in the rectum of the kissing bugs.

How do People Get Infected? Epimastigotes are not found in the salivary glands, but instead gather in the rectum of the kissing bugs. In order to get infected epimastigotes must come in contact with mucous membranes or open wound!

Most of these bugs usually defecate at the same time as they are feeding!

Main Difference From African Trypanosomiasis Trypomastigotes do not persist long in the circulatory system and they also do not reproduce there.

Main Difference From African Trypanosomiasis Trypomastigotes do not persist long in the circulatory system and they also do not reproduce there. Instead they move into muscle cells where they become amastigotes and reproduce by binary fission.

*Epimastigotes transmitted through bug feces. Trypomastigotes found in the peripheral blood. Amastigotes reproduce in muscle cells.

In American trypanosomiasis transmission is Stercorarian or Posterior Station!

Distribution Primarily in costal areas of US and a few reports in Texas and Arizona!

Epidemiology

Dogs and Cats can serve as hosts!

Dogs and Cats can serve as hosts! Chickens serve as good blood source for bugs!

T. cruzi in North America

Sow Why don’t people get infected?

Vectors Triatoma gerstaeckeri Triatoma sanguisuga

Vectors Feeding habits of T. sanguisuga and T. gerstaeckeri differ from their Latin American counterparts.

Vectors Feeding habits of T. sanguisuga and T. gerstaeckeri differ from their Latin American counterparts. T. sanguisuga and T. gerstaeckeri are very cautious and neither will walk completely onto a host, reducing the chances of defecating on the host.

Vectors Feeding habits of T. sanguisuga and T. gerstaeckeri differ from their Latin American counterparts. T. sanguisuga and T. gerstaeckeri are very cautious and neither will walk completely onto a host, reducing the chances of defecating on the host. Both T. gerstaeckeri and T. sanguisuga generally do not defecate while feeding, reducing fecal contact with the wound even further.

So how do the reservoir hosts become infected?