Endemic Scrub Typhus-like Illness, Chile

Balcells, María Elvira; Rabagliati, Ricardo; García, Patricia; Poggi, Helena; Oddo, David; Concha, M; Abarca, Katia; Jiang, Ju; Kelly, Daryl J.; Richards, Allen L.; Fuerst, Paul A.

doi:10.3201/eid1709.100960

Cited by 119 publications

(134 citation statements)

References 15 publications

(20 reference statements)

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“…However two recent reports indicate that scrub typhus occurs outside this region, one case occurred in a patient visiting UAE and Chile (Izzard, et al 2010, Balcells, et al 2011. Moreover, there have been reports suggesting that scrub typhus occurs in Africa (Ghorbani, et al 1997,Osuga, et al 1991 with the most recent report from Kenya (Thiga, et al 2015).…”

Section: Discussionmentioning

confidence: 99%

“…detected in scrub typhus patients from UAE (Orientia chuto) and Chile (Orientia sp. ), is unknown (Izzard, et al 2010, Balcells, et al 2011. Clinical signs of the infection in humans include fever, headaches, maculopapular rash, eschar, lymphadenopathy and neurological signs, cough and interstitial pneumonia in some cases (Parola and Raoult 2006).…”

Section: Discussionmentioning

confidence: 99%

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Molecular Detection of Zoonotic Rickettsiae andAnaplasmaspp. in Domestic Dogs and Their Ectoparasites in Bushbuckridge, South Africa

Kolo

Sibeko-Matjila

Maina

et al. 2016

Vector-Borne and Zoonotic Diseases

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Members of the order Rickettsiales are small, obligate intracellular bacteria that are vector-borne and can cause mild to fatal diseases in humans worldwide. There is little information on the zoonotic rickettsial pathogens that may be harboured by dogs from rural localities in South Africa. To characterize rickettsial pathogens infecting dogs we screened 141 blood samples, 103 ticks and 43 fleas collected from domestic dogs in Bushbuckridge Municipality, Mpumalanga Province of South Africa between October 2011 and May 2012 using the reverse line blot (RLB) and Rickettsia genus and species-specific qPCR assays. Results from RLB showed that 49% of blood samples and 30% of tick pools were positive for the genus-specific probes for Ehrlichia/Anaplasma; 16% of the blood samples were positive for Ehrlichia canis. Haemoparasite DNA could not be detected in 36% of blood samples and 30% of tick pools screened. Seven (70%) of tick pools and both flea pools were positive for Rickettsia spp; three (30%) of tick pools were positive for R. africae and both flea pools phagocytophilum, and an Orientia tsutsugamushi-like sequence were identified from blood samples.The detection of emerging zoonotic agents from domestic dogs and their ectoparasites in a rural community in South Africa highlights the potential risk of human infection that may occur with these pathogens.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Molecular Detection of Zoonotic Rickettsiae andAnaplasmaspp. in Domestic Dogs and Their Ectoparasites in Bushbuckridge, South Africa

Kolo

Sibeko-Matjila

Maina

et al. 2016

Vector-Borne and Zoonotic Diseases

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“…HeLa cells were infected with O. tsutsugamushi, and the inoculum was removed at 1 h. At 2,4,8,12,24,48, and 72 h postinfection, total RNA was isolated using the RNeasy minikit (Qiagen, Germantown, MD). Genomic DNA was removed by treatment with amplification-grade DNase (Invitrogen).…”

Section: Cultivation Of Uninfected and O Tsutsugamushi-infected Hostmentioning

confidence: 99%

Orientia tsutsugamushi Modulates Endoplasmic Reticulum-Associated Degradation To Benefit Its Growth

et al. 2018

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Orientia tsutsugamushi, an obligate intracellular bacterium that is auxotrophic for the aromatic amino acids and histidine, causes scrub typhus, a potentially deadly infection that threatens 1 billion people. O. tsutsugamushi growth is minimal during the first 24 to 48 h of infection but its growth becomes logarithmic thereafter. How the pathogen modulates cellular functions to support its growth is poorly understood. The unfolded protein response (UPR) is a cytoprotective pathway that relieves endoplasmic reticulum (ER) stress by promoting ER-associated degradation (ERAD) of misfolded proteins. Here, we show that O. tsutsugamushi invokes the UPR in the first 48 h and benefits from ER stress in an amino acid-dependent manner. O. tsutsugamushi also impedes ERAD during this time period. By 72 h, ER stress is alleviated and ERAD proceeds unhindered. Sustained inhibition of ERAD using RNA interference results in an O. tsutsugamushi growth defect at 72 h that can be rescued by amino acid supplementation. Thus, O. tsutsugamushi temporally stalls ERAD until ERAD-derived amino acids are needed to support its growth. The O. tsutsugamushi effector Ank4 is linked to this phenomenon. Ank4 interacts with Bat3, a eukaryotic chaperone that is essential for ERAD, and is transiently expressed by O. tsutsugamushi during the infection period when it inhibits ERAD. Ectopically expressed Ank4 blocks ERAD to phenocopy O. tsutsugamushi infection. Our data reveal a novel mechanism by which an obligate intracellular bacterial pathogen modulates ERAD to satisfy its nutritional virulence requirements.

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“…5 As part of a broader study examining exposure to vector-borne and zoonotic pathogens in a high-risk environment in Djibouti, human samples were analyzed for evidence of exposure to and infection with rickettsiae and orientiae, and tick samples were examined for infection with rickettsiae.…”

mentioning

confidence: 99%

Evidence of Rickettsia and Orientia Infections Among Abattoir Workers in Djibouti

Horton

Jiang

Maina

et al. 2016

The American Journal of Tropical Medicine and Hygiene

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Abstract. Of 49 workers at a Djiboutian abattoir, eight (16%, 95% confidence interval [CI]: 9-29) were seropositive against spotted fever group rickettsiae (SFGR), two (4%, 95% CI: 1-14) against typhus group rickettsiae, and three (6%, 95% CI: 2-17) against orientiae. One worker (9%, 95% CI: 2-38) seroconverted against orientiae during the study period. This is the first evidence of orientiae exposure in the Horn of Africa. SFGR were also identified by polymerase chain reaction in 32 of 189 (11%, 95% CI: 8-15) tick pools from 26 of 72 (36%) cattle. Twenty-five (8%, 95% CI: 6-12) tick pools were positive for Rickettsia africae, the causative agent of African tick-bite fever. Health-care providers in Djibouti should be aware of the possibility of rickettsiae infections among patients, although further research is needed to determine the impact of these infections in the country.Rickettsiae, obligate intracellular Gram-negative bacteria primarily transmitted to vertebrate hosts by arthropod vectors, are divided into four groups, two of which were examined in this study: spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR).1 The closely related Orientia spp. causes scrub typhus, a disease similar to rickettsioses. 2Although rickettsiae are found globally, orientiae are mainly endemic in the Asia-Australia-Pacific region, with limited evidence of infections in Africa, 3 the Middle East, 4 and South America. 5 As part of a broader study examining exposure to vector-borne and zoonotic pathogens in a high-risk environment in Djibouti, human samples were analyzed for evidence of exposure to and infection with rickettsiae and orientiae, and tick samples were examined for infection with rickettsiae.Before study initiation, the research protocol was reviewed by the institutional review boards (IRBs) and Institutional Animal Care and Use Committees at U. IRB protocol no. 911) and the U.S. Centers for Disease Control and Prevention (IRB protocol no. 5901), and by the Ministry of Health (MOH) and the Ministry of Agriculture, Livestock and the Sea in Djibouti. Samples were then collected at the Abattoir Frigorifique de Djibouti.In September 2010, participating abattoir workers completed baseline questionnaires and provided blood samples. Every 4 weeks, for a total of 20 weeks, an additional blood sample and questionnaire were collected from workers who self-reported a recent history of acute febrile illness (AFI); no subsequent samples were collected from workers who did not report recent AFI. Serum was stored at −20°C at MOH, transferred to NAMRU-3 in Cairo, Egypt, on dry ice, and stored at −40°C. Aliquots of 49 baseline and 11 follow-up samples were sent to the Naval Medical Research Center (NMRC) in Silver Spring, Maryland, on dry ice. Serum samples were screened for IgG antibodies against whole-cell antigens of SFGR, TGR, and orientiae by enzyme-linked immunosorbent assays (ELISAs), as described previously. 6,7 An ELISA titer procedure was performed on all screenpositive samples. Western blot assays us...

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Endemic Scrub Typhus-like Illness, Chile

Abstract: TOC Summary: Rickettsiae closely related to the scrub typhus agent are present in the Western Hemisphere.

Cited by 119 publications

References 15 publications

Molecular Detection of Zoonotic Rickettsiae andAnaplasmaspp. in Domestic Dogs and Their Ectoparasites in Bushbuckridge, South Africa

Molecular Detection of Zoonotic Rickettsiae andAnaplasmaspp. in Domestic Dogs and Their Ectoparasites in Bushbuckridge, South Africa

Orientia tsutsugamushi Modulates Endoplasmic Reticulum-Associated Degradation To Benefit Its Growth

Evidence of Rickettsia and Orientia Infections Among Abattoir Workers in Djibouti

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