Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. in Southern Chile
Journal
PLOS Neglected Tropical Diseases
ISSN
1935-2735
Date Issued
2023
Author(s)
María Carolina Silva de la Fuente
Constanza Martínez-Valdebenito
Pérez Ball, Ruth
Alexandr Stekolnikov
Katia Abarca
Gerardo Acosta-Jamett
Type
Resource Types::text::journal::journal article
URL Institutional Repository
Abstract
<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>
<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>
Cite this document
Silva De La Fuente, M. C., Pérez, C., Martínez-Valdebenito, C., Pérez, R., Vial, C., Stekolnikov, A., Abarca, K., Weitzel, T., & Acosta-Jamett, G. (2023). Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. In Southern Chile. PLOS Neglected Tropical Diseases, 17(1), e0011051. https://doi.org/10.1371/journal.pntd.0011051
Project(s)
Subjects
animals
;
chile
;
orientia
;
orientia tsutsugamushi
;
rodentia
;
scrub typhus
;
trombiculidae
;
bacterial dna
;
animal experiment
;
article
;
chile
;
data analysis
;
fauna
;
kruskal wallis test
;
methodology
;
mite infestation
;
nonhuman
;
oligoryzomys
;
orientia
;
polymerase chain reaction
;
post hoc analysis
;
prevalence
;
rat
;
rodent
;
scrub typhus
;
species richness
;
summer
;
trombiculidae
;
animal
;
chile
;
genetics
;
microbiology
;
orientia
;
orientia tsutsugamushi
;
rodent
;
scrub typhus