Do Bites of Kissing Bugs Cause Unexplained Allergies? Results from a Survey in Triatomine-Exposed and Unexposed Areas in Southern California

BACKGROUND: The bite of Triatominae can cause cutaneous allergic reactions and even anaphylaxis. Since the early 1980s, no population-based surveys have been done in Southern California, and none was ever carried out in inland Los Angeles or Riverside Counties. OBJECTIVES: To measure the frequency of insect sightings, bites and allergic reactions in a suburban area of eastern Los Angeles County and along with rural and urban sites in Riverside County. METHODS: A door-to-door survey was done in triatomine exposed and unexposed areas. Logistic regression modeling was used for the analysis, and study participants were asked to collect insects. RESULTS: Out of the 221 study participants in the exposed areas, 46 (20%) knew about the presence of Triatominae in their neighborhood. Fifteen (7%) persons reported triatomine sightings in their house during the month preceding the interview. Also, 15 (7%) participants reported ever being bitten by a triatomine. Ten (5%) participants collected either a Triatoma protracta Uhler and/or Paratriatoma hirsuta Barber in and around their house. Twenty-nine (13%) persons in the rural Riverside County reported symptoms compatible with allergy to triatomine bites. This was 4 times higher than in the urban control area where only 4 (3%) of 115 persons reported these symptoms. The association between living in a triatomine-exposed area and self-reported symptoms suggestive of allergies increased slightly when adjusted for the participant’s sex and the age of their house (adjusted odds ratio: 5.1, 95% confidence interval: 1.2 to 22.0). Reporting these symptoms was associated with seeing Triatominae in the neighborhood and having been bitten. CONCLUSION: Allergies to triatomine bites could be a significant problem in inland Southern California. Further investigations, a diagnostic test and better information of persons living in triatomine-exposed areas are needed.