Anaphylactic Reactions Due to Triatoma protracta (Hemiptera, Reduviidae, Triatominae) and Invasion into a Home in Northern California, USA

Abstract

Background: Triatoma protracta is a triatomine found naturally throughout many regions of California and has been shown to invade human dwellings and bite residents. A man living in Mendocino County, California, reported developing anaphylactic reactions due to the bite of an “unusual bug”, which he had found in his home for several years. Methods: We conducted environmental, entomological, and clinical investigations to examine the risk for kissing bug invasion, presence of Trypanosoma cruzi, and concerns for Chagas disease at this human dwelling with triatomine invasion. Results: Home assessment revealed several risk factors for triatomine invasion, which includes pack rat infestation, above-ground wooden plank floor without a concrete foundation, canine living in the home, and lack of residual insecticide use. Triatomines were all identified as Triatoma protracta. Midgut molecular analysis of the collected triatomines revealed the detection of T. cruzi discrete typing unit I among one of the kissing bugs. Blood meal PCR-based analysis showed these triatomines had bitten humans, canine and unidentified snake species. The patient was tested for chronic Chagas disease utilizing rapid diagnostic testing and laboratory serological testing, and all were negative. Conclusions: Triatoma protracta is known to invade human dwellings in the western portions of the United States. This is the first report of T. cruzi-infected triatomines invading homes in Mendocino County, California. Triatoma protracta is a known vector responsible for autochthonous Chagas disease within the United States, and their bites can also trigger serious systemic allergic reactions, such as anaphylaxis.

Trypanosoma cruzi infection in mammals in Florida: New insight into the transmission of T. cruzi in the southeastern United States

“…A sample was considered T. cruzi infected when the Ct value was ≤38 ( Beatty et al, 2021 ; Torhorst et al, 2022 ). Any sample that amplified between the Ct values of 38–40 was labeled as suspect positive, and these samples were rescreened.…”

“…Any sample that amplified between the Ct values of 38–40 was labeled as suspect positive, and these samples were rescreened. If amplification occurred at the second attempt, these samples were then considered T. cruzi infected ( Beatty et al, 2021 ; Torhorst et al, 2022 ). Samples that did not amplify the exogenous control were rescreened at a template DNA dilution series of 1:5 and 1:10 to eliminate amplification inhibition within the sample.…”

“…The samples which screened positive for T. cruzi were then subject to DTU determination via a multi-stepped, multiplexed qPCR ( Beatty et al, 2021 ; Cura et al, 2015 ; Torhorst et al, 2022 ). Each DTU determination assay was performed using an ABI 7500 FAST Real Time PCR machine (Thermo Fisher Scientific, Waltham, MA).…”

Identification of the parasite, Trypanosoma cruzi, in multiple tissues of epidemiological significance in the Virginia opossum (Didelphis virginiana): Implications for environmental and vertical transmission routes

“…A sample was classified as T . cruzi positive when the Ct value was ≤ 38 [ 42 ]. Any sample that amplified between the Ct values of 38 to 40 was labeled as suspect positive, and these samples were rescreened [ 42 ].…”

“…A sample was classified as T. cruzi positive when the Ct value was � 38 [42]. Any sample that amplified between the Ct values of 38 to 40 was labeled as suspect positive, and these samples were rescreened [42]. For those samples where the exogenous amplification control did not amplify, they were rescreened at a template DNA dilution series of 1:5 and 1:10 to reduce amplification inhibition within the sample.…”