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Browsing by Author "Weitzel, Thomas"

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Absence of convincing evidence of Coxiella burnetii infection in Chile: a cross-sectional serosurvey among healthy adults in four different regions
(BMJ Publishing Group, 2016) Weitzel, Thomas; Lopez, Javier; Acosta-Jamett, Gerardo; Edouard, Sophie; Parola, Philippe; Abarca, Katia
Background: Coxiella burnetii is an important zoonotic pathogen of global distribution. Still, in most parts of South America including Chile, systematic epidemiological data are lacking. The presented study aims to determine the seroprevalence of Coxiella burnetii antibodies in healthy adults of four different regions in Chile. Methods: A cross-sectional study was performed, which included healthy adults living in rural and urban areas of four cities located in different regions in northern, central, and southern Chile. In urban sectors, households were chosen by double stratified random sampling, while in rural areas convenience sampling was performed. Serum specimens were taken and screened for the presence of IgG antibodies against C. burnetii phase II antigen using a commercial ELISA kit. Positive and indeterminate results were confirmed by a reference laboratory using indirect immunofluorescence assay (IFA). Results: A total of 1112 individuals were included. Of those, 8 were positive by ELISA, but only one sample was confirmed using IFA. Statistical analysis for population freedom from disease revealed a high probability that C. burnetii was absent in our study population. Conclusion: Our work provides the first epidemiological data on human Q fever in Chile indicating either a very low endemicity or the absence of this pathogen in the studied areas.
An. gambiae gSG6-P1 evaluation as a proxy for human-vector contact in the Americas: a pilot study.
(Biomed Central Ltd., 2015) Londono, Berlin; Drame, Papa; Weitzel, Thomas; Rosas, Reinaldo; Gripping, Crystal; Cárdenas, Jenny; Alvares, Marcela; Wesson, Dawn; Poinsignon, Anne; Remoue, Franck; Colpitts, Tonya
BACKGROUND: During blood meal, the female mosquito injects saliva able to elicit an immune response in the vertebrate. This immune response has been proven to reflect the intensity of exposure to mosquito bites and risk of infection for vector transmitted pathogens such as malaria. The peptide gSG6-P1 of An. gambiae saliva has been demonstrated to be antigenic and highly specific to Anopheles as a genus. However, the applicability of gSG6-P1 to measure exposure to different Anopheles species endemic in the Americas has yet to be evaluated. The purpose of this pilot study was to test whether human participants living in American countries present antibodies able to recognize the gSG6-P1, and whether these antibodies are useful as a proxy for mosquito bite exposure and malaria risk. METHODS: We tested human serum samples from Colombia, Chile, and the United States for the presence of IgG antibodies against gSG6-P1 by ELISA. Antibody concentrations were expressed as delta optical density (ΔOD) of each sera tested in duplicates. The difference in the antibody concentrations between groups was tested using the nonparametric Mann Whitney test (independent groups) and the nonparametric Wilcoxon matched-pairs signed rank test (dependent groups). All differences were considered significant with a P < 0.05. RESULTS: We found that the concentration of gSG6-P1 antibodies was significantly correlated with malaria infection status and mosquito bite exposure history. People with clinical malaria presented significantly higher concentrations of IgG anti-gSG6-P1 antibodies than healthy controls. Additionally, a significant raise in antibody concentrations was observed in subjects returning from malaria endemic areas. CONCLUSION: Our data shows that gSG6-P1 is a suitable candidate for the evaluation of exposure to Anopheles mosquito bites, risk of malaria transmission, and effectiveness of protection measures against mosquito bites in the Americas.
Atovaquone/Proguanil Resistance in an Imported Malaria Case in Chile
(2021) Chenet, Stella; Oyarce, Alan; Fernández, Jorge; Tapia, Rafael; Weitzel, Thomas; Tejedo, Juan; Udhayakumar, Venkatachalam; Jercic, María Isabel; Lucchi, Naomi
In November 2018, we diagnosed a cluster of falciparum malaria cases in three Chilean travelers returning from Nigeria. Two patients were treated with sequential intravenous artesunate plus oral atovaquone/proguanil (AP) and one with oral AP. The third patient, a 23-year-old man, presented with fever on day 29 after oral AP treatment and was diagnosed with recrudescent falciparum malaria. The patient was then treated with oral mefloquine, followed by clinical recovery and resolution of parasitemia. Analysis of day 0 and follow-up blood samples, collected on days 9, 29, 34, 64, and 83, revealed that parasitemia had initially decreased but then increased on day 29. Sequencing confirmed Tyr268Cys mutation in the cytochrome b gene, associated with atovaquone resistance, in isolates collected on days 29 and 34 and P. falciparum dihydrofolate reductase mutation Asn51Ile, associated with proguanil resistance in all successfully sequenced samples. Molecular characterization of imported malaria contributes to clinical management in non-endemic countries, helps ascertain the appropriateness of antimalarial treatment policies, and contributes to the reporting of drug resistance patterns from endemic regions.
Breakthrough bacteremia due to clostridium tertium in a patient with neutropenic fever, and identification by MALDI-TOF mass spectrometry.
(Elsevier, 2013) Salvador, Francisco; Porte, Lorena; Duran, Luisa; Marcotti, Alejandra; Pérez, Jorge; Thompson, Luis; Noriega, Luis; Lois, Vivianne; Weitzel, Thomas
Clostridium tertium is rare in a human clinical specimen and its pathogenicity is often uncertain. However, the organism has been increasingly recognized as a cause of bacteremia and other infections in immunocompromised patients, especially those with hematologic malignancies. The diagnosis and treatment of C. tertium are difficult due to its growth pattern, micromorphology, and antibiotic resistance. The organism can easily be misidentified as Gram-positive aerobic rods such as Bacillus species, usually considered as a contaminant. Furthermore, it is not covered by empirical treatment with many broad-spectrum antibiotics. Here we report a case of breakthrough bacteremia due to C. tertium that occurred in a patient with acute leukemia and neutropenic fever, who was treated with an empirical regimen of ceftazidime and amikacin. The bacterium was rapidly identified by new mass spectrometry technology (MALDI-TOF MS) and the patient recovered under meropenem and vancomycin treatment, without complications.
Brotes de salmonelosis y el tamaño y rol del Estado en Chile
(Sociedad Chilena de Infectología, 2012) Fica, Alberto; Acosta-Jamett, Gerardo; Dabanch, Jeannette; Perret, Cecilia; Torres, Marisa; Lopez, Javier; Jofre, Leonor; Weitzel, Thomas; Comité de Infecciones Emergentes de la Sociedad Chilena de Infectología
During year 2011 two outbreaks of Salmonella infection captured media attention in the Metropolitan Area (MA) in Chile: one of typhoid fever associated to Salmonella serotype Typhi, and the other, of gastroenteritis related to Salmonella serotype Enteritidis, both with decreasing or stable rates in the previous years. The aim of this work is to analyze probable causes of their reemergence. Methods: Several government websites were searched looking for epidemiological data. Results: Typhoid fever rates have declined to current values of 1 case per 100.000 habitants, a decreased associated to improvements in the human development index. The typhoid outbreak was associated to a predominant clone within the MA. The only risk factor identified was consumption of raw vegetables acquired in open fairs, but without identifying a common source. Despite improvements in disease notification and molecular epidemiology capabilities, this outbreak is coincidental with a reduced number of food inspection visits in the MA, probably explained by the limited personnel available for this task. In the case of Salmonella Enteritidis, rates have increased twice since 1998 (5.3 to 10.7 per 100.000 habitants) with an important increase in the number of outbreaks linked to this agent (7 to 31 annual outbreaks) since year 2005. Persistence of this problem is probably associated to the low surveillance of poultry farms made by the Chilean state, to the absence of a cold chain during collection, distribution and selling of eggs, and to the lack of an educational program directed to the population. The recent regulation that bans home-made mayonnaise in restaurant or fast food stores is an important advance that requires further evaluation. Conclusions: The persistence and reemergence of different kind of Salmonellosis in Chile suggests chronic problems on the size and role of the Chilean state regarding food safety.
Campylobacter spp. Prevalence in Santiago, Chile: A Study Based on Molecular Detection in Clinical Stool Samples from 2014 to 2019
(2023) Porte, Lorena; Pérez, Caricia; Barbé, Mario; Varela, Carmen; Vollrath, Valeska; Legarraga, Paulette; Weitzel, Thomas
Campylobacter spp. is an emerging cause of infectious diarrhea worldwide. In South American countries such as Chile, its prevalence is underestimated due to inadequate detection methods. Gastrointestinal multiplex PCR panels (GMP) permit rapid and sensitive detection of bacterial pathogens and provide important epidemiological information. This study aimed to analyze Campylobacter epidemiology using the results of molecular methods and to compare molecular detection results to those of culture methods. We performed a retrospective, descriptive analysis of Campylobacter spp. detected in clinical stool samples between 2014-2019 by GMP and culture. Within 16,582 specimens examined by GMP, Campylobacter was the most prevalent enteropathogenic bacteria (8.5%), followed by Salmonella spp. (3.9%), Shigella spp./enteroinvasive Escherichia coli (EIEC) (1.9%), and Yersinia enterocolitica (0.8%). The highest Campylobacter prevalence occurred in 2014/2015. Campylobacteriosis affected more males (57.2%) and adults from 19-65 years (47.9%) and showed a bimodal seasonality with summer and winter peaks. In 11,251 routine stool cultures, Campylobacter spp. was detected in 4.6%, mostly C. jejuni (89.6%). Among 4533 samples tested by GMP and culture in parallel, GMP showed a superior sensitivity (99.1% versus 50%, respectively). The study suggests that Campylobacter spp. is the most frequent bacterial enteropathogen in Chile.
Canine seroprevalence to Orientia species in southern Chile: A cross-sectional survey on the Chiloé Island
(2018) Weitzel, Thomas; Jiang, Ju; Acosta-Jamett, Gerardo; Martínez-Valdebenito, Constanza; López, Javier; Richards, Allen L.; Abarca, Katia
Background Scrub typhus is a potentially life-threatening vector-borne infection caused by Orientia species. It occurs mainly in the Asian-Pacific region, where it causes significant morbidity and mortality. Recently, an endemic focus of scrub typhus has been described in South America, on Chiloé Island in southern Chile. Dogs have been used as sentinel hosts to determine the presence and spatial distribution of various vector-borne infections. Their suitability to gain insight into human exposure to Orientia tsutsugamushi has been suggested in studies from Asia. Methodology In January 2016, we conducted a cross-sectional study, which included the two main cities on Chiloé Island. Canine blood samples were obtained in households, chosen by double stratified random sampling in urban and by convenience in rural locations. Specimens were tested by ELISA for IgG antibodies against whole-cell antigen preparations from three strains of O. tsutsugamushi. Data were further analyzed for factors associated with seropositivity including spatial clustering. Results Serum samples from 202 dogs (104 urban, 98 rural) were tested for IgG against O. tsutsugamushi, of which 43 (21.3%) were positive. Seroprevalence rates were higher in rural than in urban settings (p<0.01) and in older compared to younger dogs (p<0.01). Spatial analysis by LISA indicated the presence of four localities of highly grouped cases. Conclusions The detected seroprevalence supports the endemicity of scrub typhus in southern Chile and suggests a wide exposure of household dogs to the infected, yet unknown vector(s). The spatial data will be used for future research identifying further human cases as well as the local vector(s)/reservoirs for scrub typhus in southern Chile. The study reinforces that dogs are useful sentinels for Orientia spp. in regions of uncertain endemicity and distribution.
Catheter-associated bloodstream infection caused by Leifsonia aquatica in a haemodialysis patient: a case report
(Microbiology Society, 2012) Porte, Lorena; Soto, Andres; Andrighetti, Daniela; Dabanch, Jeannette; Braun, Stephanie; Saldivia, Alejandra; Flores, Juan Carlos; Wozniak, Aniela; Garcia, Patricia; Weitzel, Thomas
Leifsonia aquatica is an aquatic coryneform rod that is capable of forming biofilms in environmental water sources. It has rarely been associated with human infections and its pathogenicity and clinical significance are uncertain. We describe a case of catheter-related bloodstream infection in a haemodialysis patient. The isolate grew on conventional media as a yellow-pigmented colony, but identification required molecular methods. Although the strain displayed reduced sensitivity to vancomycin, the clinical outcome was favourable after catheter removal and intravenous treatment with this antibiotic. Our report gives further evidence of the capability of this aquatic bacterium to cause human infection.
Chigger Mites (Acariformes: Trombiculidae) of Chiloé Island, Chile, With Descriptions of Two New Species and New Data on the Genus Herpetacarus
(2020) Silva, María Carolina; Stekolnikov, Alexandr A.; Weitzel, Thomas; Beltrami, Esperanza; Martínez-Valdebenito, Constanza; Abarca, Katia; Acosta-Jamett, Gerardo
Three species of chigger mites are recorded in our collections from four species of cricetid rodents on Chiloé Island (southern Chile, Los Lagos Region), an area endemic to scrub typhus (Orientia sp.). Two species are described as new—Herpetacarus (Abonnencia) eloisae sp. nov. and Quadraseta chiloensis sp. nov. One species, Paratrombicula goffi Stekolnikov and González-Acuña 2012, is for the first time recorded on a mammal host (one species of cricetid rodent), and its distribution is extended to the Los Lagos Region of Chile. The genus Proschoengastia Vercammen-Grandjean, 1967 is synonymized with the subgenus Herpetacarus (Abonnencia) Vercammen-Grandjean, 1960, and four new combinations are established: Herpetacarus (Abonnencia) herniosa (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) insolita (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) macrochaeta (Brennan and Jones, 1961), comb. nov., and Herpetacarus (Abonnencia) antarctica (Stekolnikov and Gonzalez-Acuña, 2015), comb. nov.
Chikungunya, enfermedad emergente en América Latina. Descripción de los primeros casos en Chile
(2018) Perret, Cecilia; Vizcaya, Cecilia; Weitzel, Thomas; Rosas, Reinaldo; Dabanch, Jeannette; Martínez, Constanza
Background: Chikungunya (CHIK) was introduced in The Americas in 2013, spreading rapidly. In 2014, the first imported case was diagnosed in Chile. Aim: To identify patients with clinical suspicion of CHIK and describe their clinical and laboratory characteristics. Patients and Methods: Patients with suspected CHIK were enrolled. All were confirmed by PCR, IgM or IgG CHIK. A structured survey was applied, which included demographic questions, travel characteristics, clinical manifestations, and laboratory results. Results: 21 patients were enrolled and CHIK was confirmed in 16, who were further analyzed; 12 were female (75%), average age 39 years (27-52). The Caribbean and South Americawere the most frequent sites of exposure. In 63%, the initial symptom was arthralgia. Most frequent symptoms were myalgias, malaise (both 100%), fever, and polyarthralgia (both 94%). The median duration of arthralgias was 90 days (3-262); in 53% arthralgias lasted ≥ 3 months. Main joints involved were ankles, hands, and wrists; 87% reported invalidating pain. Arthritis lasted longer in men than in women (p < 0.001). 38% of patients presented lymphopenia and one patient mild thrombocytopenia. Two patients required hospitalization, one with severe headaches, the other with acute pyelonephritis. Conclusions: Chikungunya should be suspected in returning travelers presenting with fever and severe polyarthralgia. Travelers to endemic areas should apply prevention measures to avoid mosquito bites.
Cluster of imported vivax malaria in travelers returning from Peru.
(International Society of Travel Medicine., 2015) Weitzel, Thomas; Labarca, Jaime; Cortés, Claudia; Rosas, Reinaldo; Balcells, Elvira; Perret, Cecilia
We report a cluster of imported vivax malaria in three of five Chilean travelers returning from Peru in March 2015. The cluster highlights the high risk of malaria in the Loreto region in northern Peru, which includes popular destinations for international nature and adventure tourism. According to local surveillance data, Plasmodium vivax is predominating, but Plasmodium falciparum is also present, and the incidence of both species has increased during recent years. Travelers visiting this region should be counseled about the prevention of malaria and the options for chemoprophylaxis.
Comparative evaluation of four rapid SARS-CoV-2 antigen detection tests using universal transport medium
(2021) Weitzel, Thomas; Legarraga, Paulette; Iruretagoyena, Mirentxu; Pizarro, Gabriel; Vollrath, Valeska; Araos, Rafael; Munita, José; Porte, Lorena
Correspondence
Complete Genome Sequences of 17 Clinical Campylobacter jejuni Strains from Chile
(2020) Bravo, V.; Porte, Lorena; Weitzel, Thomas; Varela, Carmen; Blondel, C. J.; Gonzalez-Escalona, N.
Campylobacter jejuni is the leading cause of bacterial foodborne disease worldwide. Here, we report the complete annotated genomes and plasmid sequences of 17 Campylobacter jejuni strains isolated from patients with gastroenteritis in Santiago, Chile.
Covid-19 in South America: clinical and epidemiological characteristics among 381 patients during the early phase of the pandemic in Santiago, Chile
(2020) Vial, Macarena; Peters, Anne; Pérez, Inia; Spencer-Sandino, María; Barbé, Mario; Porte, Lorena; Weitzel, Thomas; Aylwin, Mabel; Vial, Pablo; Araos, Rafael; Munita, José
Background: Understanding the characteristics of the Covid-19 pandemic in different geographical regions, ethnic and socioeconomic settings are of emerging importance. This study presents the demographic and clinical features of SARS-CoV-2 infected patients in a large private healthcare center in Santiago, Chile, during the first month of the pandemic. Methods: We analyzed the demographics, laboratory and clinical characteristics including severity and outcome of all patients diagnosed with Covid-19 during the first month of the pandemic. SARS-2-CoV infection was confirmed by RT-PCR in nosopharyngeal samples. The primary outcome was a composite of ICU admission or all-cause, in-hospital mortality. Clinical and laboratory parameters of hospitalized patients were analyzed regarding their association with the primary outcome. Results: From March 3 to April 4, 2020, 3679 individuals were tested for SARS-CoV-2 in our hospital. Of those, 381 had Covid-19 and were included into this analysis. Most patients (99.2%) were Chileans, 12% returning from recent travel. The median age was 39 years (IQR 31–49) and 52% were female. A total of 88 patients (23.1%) were hospitalized; 18 (3.7%) required ICU and/or died. The overall mortality was 0.7%. Increased body mass index (BMI) and elevated C-reactive protein (CRP) were independently associated with ICU care or death. Conclusion: During the first weeks of the pandemic in Chile, most Covid-19 patients were young, with low rates of hospitalization, ICU requirement, and fatality. BMI and CRP on admission were predictors for severity. Our data provide important information on the clinical course and outcome of Covid-19 in a Latin American setting.
Cryptococcus bacillisporus (VGIII) Meningoencephalitis Acquired in Santa Cruz, Bolivia
(2021) Thompson, Luis; Porte, Lorena; Díaz, Violeta; Díaz, María; Solar, Sebastián; Valenzuela, Pablo; Norley, Nicole; Pires, Yumai; Carreño, Fernando; Valenzuela, Sergio; Shabani, Rukmane; Rickerts, Volker; Weitzel, Thomas
We describe a case of chronic meningoencephalitis with hydrocephalus caused by Cryptococcus bacillisporus (VGIII) in an immunocompetent patient from Santa Cruz, Bolivia. This first report of a member of the Cryptococcus gattii species complex from Bolivia suggests that C. bacillisporus (VGIII) is present in this tropical region of the country and complements our epidemiological and clinical knowledge of this group of emerging fungal pathogens in South America.
Development of a New Genus-Specific Quantitative Real-Time PCR Assay for the Diagnosis of Scrub Typhus in South America
(2022) Jiang, Ju; Martínez, Constanza; Weitzel, Thomas; Farris, Christina; Acosta, Gerardo; Abarca, Katia; Richards, Allen
Scrub typhus is a potentially severe rickettsiosis, caused by Orientia tsutsugamushi in the Asia-Pacific region. Recently, however, two distinct pathogens, “Candidatus Orientia chuto” and “Candidatus Orientia chiloensis”, have been discovered in the Middle East and South America, respectively. Since the novel pathogens differ significantly from O. tsutsugamushi, many established diagnostic methods are unreliable. This work describes the development and validation of a new quantitative real-time PCR (qPCR) assay (Orien16S) for the detection of all known Orientia species. Based on a 94 bp sequence of the 16S rRNA gene (rrs), Orien16S recognized DNA samples from O. tsutsugamushi (n = 41), Ca. O. chiloensis (n = 5), and Ca. O. chuto (n = 1), but was negative for DNA preparations from closely related rickettsiae and other members of the order Rickettsiales (n = 22) as well as unrelated bacterial species (n = 11). After its implementation in Chile, the assay was verified, correctly identifying all tested eschar and buffy coat samples (n = 28) of clinical suspected cases. Furthermore, Orien16S detected Orientia DNA in trombiculid mites collected in endemic regions in southern Chile. The presented novel qPCR assay provides a useful tool for detecting Orientia and diagnosing scrub typhus from all geographical regions.
Diagnosis and therapy of cutaneous and mucocutaneous Leishmaniasis in Germany
(2011) Boecken, Gerhard; Sunderkoetter, Cord; Bogdan, Christian; Weitzel, Thomas; Fischer, Marcellus; Mueller, Andreas; Loebermann, Micha; Anders, Gerlind; von Stebut, Esther; Schunk, Mirjam
The incidence of cutaneous and mucocutaneous Leishmaniasis (CL/MCL) is in- creasing globally, also in Germany, although the cases are imported and still low in number. The current evidence for the different therapies has many limitations due to lack of sufficient studies on the different Leishmania species with differing virulence. So far there is no international gold standard for the optimal management. The aim of the German joint working group on Leishmaniasis, formed by the so- cieties of Tropical Medicine (DTG), Chemotherapy (PEG) and Dermatology (DDG), was to establish a guideline for the diagnosis and treatment of CL and MCL in Germany, based on evidence (Medline search yielded 400 articles) and, where lacking, on consensus of the experts. As the clinical features do not necessarily reflect the involved Leishmania species and, as different parasite species and even geographically distinct strains of the same species may require different treatments or varying dosages or durations of therapy, the guidelines suggest for Germany to identify the underlying parasite prior to treatment. Because of relevant differences in pro- gnosis and ensuing therapy species should be identified in i) New World CL/MCL (NWCL/ MCL) to distinguish between L. mexicana-complex and subge- nus Viannia, ii) in suspected infections with L. mexicana-complex to distinguish from L. amazonensis, and iii) in Old World CL (OWCL) to distinguish between L. infantum and L. major, L. tropica, or L. aethiopica. A state-of-the-art diagnostic algorithm is presented. For recommendations on localized and systemic drug treatment and physical procedures, data from the accessible literature were adjusted according to the involved parasite species and a clinical differentiation into uncomplicated or complex lesions. Systemic therapy was strictly recommended for i) complex lesions (e. g. > 3 infected lesions, infections in functionally or cosmetically critical areas such as face or hands, presence of lymphangitis), ii) lesions refractory to therapy, iii) NWCL by the subgenus Viannia or by L. amazonensis, iv) in MCL and v) in recalcitrant, or disseminating or diffuse cutaneous courses. In e. g. infection with L. major it encompasses miltefosine, fluconazole and ketoconazole, while anti- mony or allopurinol were here considered second choice. Local therapy was considered appropriate for i) uncomplicated lesions of OWCL, ii) L. mexicana-complex and iii) pregnant women. In e. g. infection with L. major it encompasses perilesional antimony, combined with cryotherapy, paromomycin 15 %/in methylbenzethoniumchlorid 12 % and thermotherapy. The group also stated that there is an urgent need for improving the design and the way of publishing of clinical trials in leishmaniasis.
Draft Whole-Genome Sequences of 51 Campylobacter jejuni and 12 Campylobacter coli Clinical Isolates from Chile
(2020) Bravo, Verónica; Varela, Carmen; Porte, Lorena; Weitzel, Thomas; Kastanis, George J.; Balkey, María; Blondel, Carlos J.; Gonzalez-Escalona, Narjol
Campylobacter species are the leading cause of gastroenteritis worldwide and an emerging threat in developing countries. Here, we report the draft whole-genome sequences of 51 Campylobacter jejuni and 12 Campylobacter coli strains isolated from patients with gastroenteritis in Santiago, Chile.
Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. in Southern Chile
(2023) Silva, María; Pérez, Caricia; Martínez, Constanza; Pérez, Ruth; Vial Cox, María Cecilia; Stekolnikov, Alexandr; Abarca, Katia; Thomas Weitzel; Weitzel, Thomas; Acosta, Gerardo
Background: Scrub typhus is a potentially severe infection caused by bacteria of the genus Orientia, 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 Orientia spp. in different areas of two regions in southern Chile. Methodology/principal findings: 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 Orientia-specific qPCR. Six mite species were identified. Among chigger-infested rodents, 33.9% carried Orientia-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 Herpetacarus antarctica samples (n = 202) were positive for Orientia DNA; the prevalence was 7.0% in Paratrombicula neuquenensis (n = 213), 6.9% in Herpetacarus eloisae (n = 144), 3.6% in Argentinacarus expansus (n = 55), and 0% in Paratrombicula goffi (n = 110) and Quadraseta chiloensis (n = 177). The southernmost site (Tortel) showed the highest rates of trombiculid infestation, trombiculid load, and Orientia infection in the captured rodents. Conclusions/significance: Our study provides new insights into the trombiculid fauna and prevalence of Orientia in mites collected from wild rodents in southern Chile. Orientia DNA was detected in four of the six mite species. Rates of infestation, mite loads, and Orientia 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.
Empfehlungen zur Malariaprophylaxe
(2020) Rothe, Camilla; Rosenbusch, Deike; Alberer, Martín; Bühler, Silja; Burchard, Gerd; Erkens, Kai; Feldt, Torsten; Grobusch, Martín; Köhler, Carsten; Kapaun, Annette; Löbermann, Micha; Meischner, Karin; Metzger, Wolfram; Müller, Andreas; Dieter, Hans; Ramharter, Michael; Rieke, Burkhard; Schlaich, Clara; Schönfeld, Christian; Schulze, Marco; Siedenburg, Jörg; Steiner, Florian; Veit, Olivia; Weitzel, Thomas; Boecken, Gerhard
Die Deutsche Gesellschaft für Tropenmedizin, Reisemedi- zin und Globale Gesundheit e.V. (DTG) erarbeitet jährlich Empfehlungen zu Reiseimpfungen und zur Malariapro- phylaxe. Autoren sind die Mitglieder des Ständigen Aus- schuss Reisemedizin (StAR) der DTG. Dieser setzt sich aus Expertinnen und Experten der großen Tropeninstitute und tropenmedizinischen Abteilungen, des Auswärtigen Amts, der Bundeswehr, der Gesellschaft für Internationale Zu- sammenarbeit (GIZ), der Arbeitsmedizin, der Flugmedizin und maritimen Medizin sowie des niedergelassenen Be- reichs zusammen. Im StAR ist damit ein großer Teil der reisemedizinischen Expertise in Deutschland vertreten. Der StAR arbeitet zudem eng mit dem schweizerischen, Expertenkomitee für Reisemedizin (EKRM) zusammen. Ziel ist eine Harmonisierung der Malariaempfehlungen im deutschsprachigen Raum. Nicht nur zur Prophylaxe, sondern auch zur Therapie der Malaria wurde von der DTG im Februar 2021 eine neue Leitlinie erarbeitet und publiziert. Das Dokument gibteinen verständlichen Überblick über Diagnostik und The-rapie der Malaria und ist online verfügbar. Die im Folgenden zur besseren Lesbarkeit gewählte männ- liche Form bezieht sich immer zugleich auf weibliche, männliche und diverse Personen. 2020

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