Trypanosoma cruzi Infection Does Not Decrease Survival or Reproduction of the Common Bed Bug, Cimex lectularius

Area of Science:

• Medical Entomology
• Parasitology
• Vector-borne Diseases

Background:

• The common bed bug, Cimex lectularius, is closely associated with humans and feeds on blood, raising concerns about its potential role in pathogen transmission.
• While not currently recognized as a vector for human pathogens, bed bugs' feeding habits warrant investigation into their vectorial capacity.

Purpose of the Study:

• To investigate the vectorial competence of Cimex lectularius for Trypanosoma cruzi, the causative agent of Chagas disease.
• To determine if Trypanosoma cruzi infection negatively affects the fitness (survival and reproduction) of Cimex lectularius, potentially explaining the lack of natural transmission.

Main Methods:

• Cimex lectularius were infected with Trypanosoma cruzi by feeding on infected mice.
• Infected and uninfected bed bugs were compared for survival rates and reproductive output (egg production).
• Juvenile and adult bed bug fitness parameters were assessed under controlled laboratory conditions.

Main Results:

• Cimex lectularius successfully acquired and transmitted Trypanosoma cruzi to naive mice in laboratory experiments.
• Trypanosoma cruzi infection showed variable effects on bed bug survival and reproduction, with no consistent negative impacts observed.
• Infected adult female bed bugs tended to exhibit increased longevity and egg production compared to controls, though with greater variability.

Conclusions:

• Decreased fitness of Trypanosoma cruzi-infected Cimex lectularius is not the reason for the absence of natural transmission in the field.
• While bed bugs can be infected with and transmit Trypanosoma cruzi experimentally, factors other than reduced fitness likely prevent natural Chagas disease transmission by these vectors.