Infection Rates of Triatoma protracta (Uhler) with Trypanosoma cruzi in Southern California and Molecular Identification of Trypanosomes

Hwang, Wei Song; Zhang, Guanyang; Maslov, Dmitri; Weirauch, Christiane

doi:10.4269/ajtmh.2010.10-0167

Cited by 18 publications

(17 citation statements)

References 14 publications

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“…The phylogenetic analysis of the miniexon gene of the NOLA T. cruzi sequences showed a strong cluster association with reference sequences of DTU TcII corresponding to Tul18 and AFcl17, with a significant bootstrap value of 92% obtained with ML. A previous phylogenetic analysis of the 24Sα subunit gene found T. cruzi isolates from Triatoma protracta in California that were grouped in a clade with some TcII and TcVI reference strains, but the different DTUs were not resolved [ 34 ]. Our analysis showed a strong and well defined association with the TcII in small rodents, indicating a higher genetic diversity of T. cruzi in the US.…”

Section: Discussionmentioning

confidence: 99%

Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana

Herrera

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et al. 2015

Parasites & Vectors

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BackgroundChagas disease is an anthropozoonosis caused by the protozoan parasite Trypanosoma cruzi that represents a major public health problem in Latin America. Although the United States is defined as non-endemic for Chagas disease due to the rarity of human cases, the presence of T. cruzi has now been amply demonstrated as enzootic in different regions of the south of the country from Georgia to California. In southeastern Louisiana, a high T. cruzi infection rate has been demonstrated in Triatoma sanguisuga, the local vector in this area. However, little is known about the role of small mammals in the wild and peridomestic transmission cycles.MethodsThis study focused on the molecular identification and genotyping of T. cruzi in both small rodents and T. sanguisuga from a rural area of New Orleans, Louisiana. DNA extractions were prepared from rodent heart, liver, spleen and skeletal muscle tissues and from cultures established from vector feces. T. cruzi infection was determined by standard PCR using primers specific for the minicircle variable region of the kinetoplastid DNA (kDNA) and the highly repetitive genomic satellite DNA (satDNA). Genotyping of discrete typing units (DTUs) was performed by amplification of mini-exon and 18S and 24Sα rRNA genes and subsequent sequence analysis.ResultsThe DTUs TcI, TcIV and, for the first time, TcII, were identified in tissues of mice and rats naturally infected with T. cruzi captured in an area of New Orleans, close to the house where the first human case of Chagas disease was reported in Louisiana. The T. cruzi infection rate in 59 captured rodents was 76%. The frequencies of the detected DTUs in such mammals were TcI 82%, TcII 22% and TcIV 9%; 13% of all infections contained more than one DTU.ConclusionsOur results indicate a probable presence of a considerably greater diversity in T. cruzi DTUs circulating in the southeastern United States than previously reported. Understanding T. cruzi transmission dynamics in sylvatic and peridomestic cycles in mammals and insect vectors will be crucial to estimating the risk of local, vector-borne transmission of T. cruzi to humans in the United States.

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Section: Discussionmentioning

confidence: 99%

Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana

Herrera

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et al. 2015

Parasites & Vectors

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“…However, data on genetic diversity in southwestern regions (e.g. California, Arizona, and New Mexico) are very limited [ 25 ].…”

Section: Introductionmentioning

confidence: 99%

Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA

et al. 2016

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BackgroundTrypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US) may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections.Methodology/Principle FindingsWe conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles) and northern (Vallecito) California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs), revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes) were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans.Conclusions/SignificanceTriatoma protracta populations in California are frequently infected with T. cruzi. Our data extend the northern limits of the range of TcI and identify a novel genetic exchange event between TcI and TcIV. High similarity between sequences from California and specific Latin American strains indicates US strains may be equally capable of causing human disease. Additional genetic characterization of Californian and other US T. cruzi strains is recommended.

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“…Dogs housed in proximity to two U.S. human autochthonous cases tested positive for T. cruzi antibodies, providing some evidence of a potential role for dogs in human risk in the United States (Navin et al 1985, Herwaldt et al 2000). Recent studies of T. cruzi infection in triatomine specimens collected in and around houses in the United States report prevalence rates of 19% ( n = 139) in California (Hwang et al 2010), 42% ( n = 164) in Arizona (Reisenman et al 2010), 53% ( n = 137) in Texas (Kjos et al 2009), and 56% ( n = 18) in Louisiana (Dorn et al 2007), indicating continued presence of infected vectors in peridomestic and domestic domains across a wide geographic area. The interactions of hosts, parasite, and vectors in the United States in the peridomestic and domestic domains, where triatomine species are not habitually domiciliated, are not yet well understood.…”

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confidence: 99%

Identification of Bloodmeal Sources andTrypanosoma cruziInfection in Triatomine Bugs (Hemiptera: Reduviidae) From Residential Settings in Texas, the United States

et al. 2013

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The host–vector–parasite interactions in Chagas disease peridomestic transmission cycles in the United States are not yet well understood. Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) infection prevalence and bloodmeal sources were determined for adult and immature triatomine (Hemiptera: Reduviidae) specimens collected from residential settings in central Texas. Sequenced cytochrome b DNA segments obtained from triatomine digestive tract identified nine vertebrate hosts and one invertebrate host in four triatomine species (Triatoma gerstaeckeri, Triatoma indictiva, Triatoma protracta, and Triatoma sanguisuga). The broad range of wild and domestic host species detected in triatomine specimens collected from residential sites indicates high host diversity and potential movement between the sylvatic and peridomestic settings. Domestic dogs appear to be key in the maintenance of the peridomestic transmission cycle as both a blood host for the triatomine vectors and a potential reservoir for the parasite. The high rate of T. cruzi infection among triatomine specimens that were collected from inside houses, outside houses, and dog kennels (69, 81, and 82%, respectively) suggests a current risk for Chagas disease vector-borne transmission for humans and domestic animals in residential settings in Texas because of overlap with the sylvatic cycle.

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Infection Rates of Triatoma protracta (Uhler) with Trypanosoma cruzi in Southern California and Molecular Identification of Trypanosomes

Cited by 18 publications

References 14 publications

Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana

Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana

Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA

Identification of Bloodmeal Sources andTrypanosoma cruziInfection in Triatomine Bugs (Hemiptera: Reduviidae) From Residential Settings in Texas, the United States

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