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Subject: search.filters.subject.scrub typhus

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    Hosts and vectors of scrub typhus in Chile: epidemiological study and molecular analyses of Orientia infection in rodents and rodent-associated mites
    (Springer Science and Business Media LLC, 2024-12-18)
    Constanza Martínez-Valdebenito
    ;
    Gerardo Acosta-Jamett
    ;
    Rayitray Abello
    ;
    Ju Jiang
    ;
    Allen L. Richards
    <jats:title>Abstract</jats:title><jats:p><jats:italic>Candidatus</jats:italic> Orientia chiloensis causes scrub typhus over a wide geographical range in southern Chile. The life cycle, including vectors and reservoirs of this novel rickettsial pathogen, is incompletely understood. We analyzed rodent tissue and rodent-associated mite samples collected during a field study in six localities on Chiloé Island, where human scrub typhus cases have occurred. Using molecular methods, we detected <jats:italic>Orientia</jats:italic> DNA in 24.8% of rodents, belonging to five of seven captured species. <jats:italic>Orientia</jats:italic>-infection rates showed geographical variations, but were not influenced by rodent species, sex, age, and mite infestation. Phylogenetic analysis showed that <jats:italic>Orientia</jats:italic> sequences from trombiculid mites (<jats:italic>Proschoengastia eloisae</jats:italic>) were identical to those from scrub typhus patients from the same region. The results suggest that these rodent-associated mites serve as vectors and play an important role in the ecology of scrub typhus in southern Chile. Further studies are required to determine whether <jats:italic>Orientia</jats:italic>-infected rodents can also serve as reservoir of <jats:italic>Orientia</jats:italic> in Chile.</jats:p> <jats:p><jats:bold>Graphical Abstract</jats:bold></jats:p>
      1Scopus© Citations 8
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    <i>Notes from the Field:</i> Scrub Typhus Outbreak — Los Lagos Region, Chile, January–February 2023
    (2023)
    WEITZEL, THOMAS  
    ;
    Constanza Martínez-Valdebenito
    ;
    Gerardo Acosta-Jamett
    ;
    Katia Abarca
      6Scopus© Citations 4
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      10Scopus© Citations 10
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    Scrub typhus: A new cause of acute undifferentiated febrile illness in Latin America?
    (2021)
    Carlos Ramiro Silva-Ramos
    ;
    Fernando de Castro Jacinavicius
    ;
    WEITZEL, THOMAS  
    ;
    David H. Walker
    ;
    Álvaro A. Faccini-Martínez
      16Scopus© Citations 6
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    Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. in Southern Chile
    (2023)
    María Carolina Silva de la Fuente
    ;
    Caricia Pérez
    ;
    Constanza Martínez-Valdebenito
    ;
    Pérez Ball, Ruth
    ;
    VIAL COX, MARIA CECILIA  
    <jats:sec id="sec001"> <jats:title>Background</jats:title> <jats:p>Scrub typhus is a potentially severe infection caused by bacteria of the genus <jats:italic>Orientia</jats:italic>, endemic in Asia-Pacific and recently discovered in southern Chile. The presented study aimed to determine the prevalence and species richness of rodent-associated trombiculid mites and their infection with <jats:italic>Orientia</jats:italic> spp. in different areas of two regions in southern Chile.</jats:p> </jats:sec> <jats:sec id="sec002"> <jats:title>Methodology/Principal findings</jats:title> <jats:p>During summer 2020, trombiculid mites were collected from rodents captured in three areas in southern Chile known to be endemic for scrub typhus (Cochamó and Chiloé Island in the Los Lagos Region and Tortel in the Aysén Region). A total of 132 rodents belonging to five species were captured using Sherman-like traps; 89.4% were infested with trombiculids. Mite specimens were morphologically identified and subsequently tested by <jats:italic>Orientia</jats:italic>-specific qPCR. Six mite species were identified. Among chigger-infested rodents, 33.9% carried <jats:italic>Orientia</jats:italic>-positive mites; this rate was higher in Tortel (63.8%) than in Cochamó (45.0%) and Chiloé Island (2.0%). The analysis of individual mites (n = 901) revealed that 31.2% of <jats:italic>Herpetacarus antarctica</jats:italic> samples (n = 202) were positive for <jats:italic>Orientia</jats:italic> DNA; the prevalence was 7.0% in <jats:italic>Paratrombicula neuquenensis</jats:italic> (n = 213), 6.9% in <jats:italic>Herpetacarus eloisae</jats:italic> (n = 144), 3.6% in <jats:italic>Argentinacarus expansus</jats:italic> (n = 55), and 0% in <jats:italic>Paratrombicula goffi</jats:italic> (n = 110) and <jats:italic>Quadraseta chiloensis</jats:italic> (n = 177). The southernmost site (Tortel) showed the highest rates of trombiculid infestation, trombiculid load, and <jats:italic>Orientia</jats:italic> infection in the captured rodents.</jats:p> </jats:sec> <jats:sec id="sec003"> <jats:title>Conclusions/Significance</jats:title> <jats:p>Our study provides new insights into the trombiculid fauna and prevalence of <jats:italic>Orientia</jats:italic> in mites collected from wild rodents in southern Chile. <jats:italic>Orientia</jats:italic> DNA was detected in four of the six mite species. Rates of infestation, mite loads, and <jats:italic>Orientia</jats:italic> prevalences differed geographically and were highest in the Aysén Region. Our data improve our knowledge on possible vectors of scrub typhus and their distribution in Chile.</jats:p> </jats:sec>
      1Scopus© Citations 9  2
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    Marginalized mites: Neglected vectors of neglected diseases
    (2020)
    WEITZEL, THOMAS  
    ;
    Benjamin L. Makepeace
    ;
    Ivo Elliott
    ;
    Kittipong Chaisiri
    ;
    Allen L. Richards
      1Scopus© Citations 15  2
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    Rickettsial infections: A blind spot in our view of neglected tropical diseases
    (2021)
    Jeanne Salje
    ;
    WEITZEL, THOMAS  
    ;
    Paul N. Newton
    ;
    George M. Varghese
    ;
    Nicholas Day
    <jats:p>Rickettsial diseases are a group of vector-borne bacterial infections that cause acute febrile illness with potentially severe or fatal complications. These vector-borne diseases are prevalent in tropical and subtropical regions worldwide and disproportionately affect poorer communities but are scientifically underrecognized. Despite this, they are not included in the World Health Organization’s list of neglected tropical diseases nor were they mentioned in Peter Hotez’s recent reflections on “What constitutes a neglected tropical disease?” in <jats:italic>PLOS Neglected Tropical Diseases</jats:italic> [1]. Here we present the case that rickettsial infections, as an overlooked cause of morbidity, mortality, and economic losses in marginalized populations, should be recognized as neglected tropical diseases. We describe how this oversight is the result of a number of factors and how it negatively impacts patient outcomes. We then propose measures to address the neglect of rickettsial infections in both scientific research and public health interventions.</jats:p>
    Scopus© Citations 44  1
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    Identification of trombiculid mites (Acari: Trombiculidae) on rodents from Chiloé Island and molecular evidence of infection with Orientia species
    (2020)
    Gerardo Acosta-Jamett
    ;
    Constanza Martínez-Valdebenito
    ;
    Esperanza Beltrami
    ;
    María Carolina Silva-de La Fuente
    ;
    Ju Jiang
      23  1Scopus© Citations 42
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    Molecular Description of a Novel <i>Orientia</i> Species Causing Scrub Typhus in Chile
    (2020)
    Katia Abarca
    ;
    Constanza Martínez-Valdebenito
    ;
    Jenniffer Angulo
    ;
    Ju Jiang
    ;
    Christina M. Farris
      1Scopus© Citations 78  1
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    Novel Vector of Scrub Typhus in Sub-Antarctic Chile: Evidence From Human Exposure
    (2021)
    WEITZEL, THOMAS  
    ;
    María Carolina Silva-de la Fuente
    ;
    Constanza Martínez-Valdebenito
    ;
    Alexandr A Stekolnikov
    ;
    Caricia Pérez
    <jats:title>Abstract</jats:title> <jats:p>The exposure of a research team to chigger mites in southern Chile allowed the first identification of a trombiculid species as vector and reservoir of scrub typhus outside the tsutsugamushi triangle, providing unique insights into the ecology and transmission of this recently discovered rickettsial infection in South America.</jats:p>
    Scopus© Citations 22  5