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We report a case of scrub typhus in a 54-year-old man who was bitten by several terrestrial leeches during a trip to Chiloé Island in southern Chile in 2006. A molecular sample, identified as related to Orientia tsutsugamushi based on the sequence of the16S rRNA gene, was obtained from a biopsy specimen of the eschar on the patient's leg. Serologic analysis showed immunoglobulin G conversion against O. tsutsugamushi whole cell antigen. This case and its associated molecular analyses suggest that an Orientia-like agent is present in the Western Hemisphere that can produce scrub typhus-like illness. The molecular analysis suggests that the infectious agent is closely related, although not identical, to members of the Orientia sp. from Asia. [ABSTRACT FROM AUTHOR]

Background: Inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been widely implemented in low- and middle-income countries. However, immunogenicity in immunocompromised patients has not been established. Herein, we aimed to evaluate immune response to CoronaVac vaccine in these patients., Methods: This prospective cohort study included 193 participants with 5 different immunocompromising conditions and 67 controls, receiving 2 doses of CoronaVac 8-12 weeks before enrollment. The study was conducted between May and August 2021, at Red de Salud UC-CHRISTUS, Santiago, Chile. Neutralizing antibody (NAb) positivity, total anti-SARS-CoV-2 immunoglobulin G antibody (TAb) concentrations, and T-cell responses were determined., Results: NAb positivity and median neutralizing activity were 83.1% and 51.2% for the control group versus 20.6% and 5.7% (both P < .001) in the solid organ transplant group, 41.5% and 19.2% (both P < .0001) in the autoimmune rheumatic diseases group, 43.3% (P < .001) and 21.4% (P<.01 or P = .001) in the cancer with solid tumors group, 45.5% and 28.7% (both P < .001) in the human immunodeficiency virus (HIV) infection group, 64.3% and 56.6% (both differences not significant) in the hematopoietic stem cell transplant group, respectively. TAb seropositivity was also lower for the solid organ transplant (20.6%; P < .0001), rheumatic diseases (61%; P < .001), and HIV groups (70.9%; P = .003), compared with the control group (92.3%). On the other hand, the number of interferon γ spot-forming T cells specific for SARS-CoV-2 tended to be lower in all immunocompromising conditions but did not differ significantly between groups., Conclusions: Diverse immunocompromising conditions markedly reduce the humoral response to CoronaVac vaccine. These findings suggest that a boosting vaccination strategy should be considered in these vulnerable patients., Clinical Trials Registration: NCT04888793., (© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: It is currently unknown which is the prevalence of latent tuberculosis infection in healthcare workers in Chile, but this group has been described as at higher risk of developing active tuberculosis than general population., Objectives: To determine the prevalence of latent tuberculosis infection in a sample of healthcare workers from at risk areas., Methodology: A cross-sectional, descriptive study, conducted in health care workers from clinical laboratories or respiratory care areas in four hospitals in Santiago. Latent tuberculosis infection detection was determined by Quantiferon® TB Gold In Tube testing (QFT)., Results: QFT resulted positive in 20 of 76 (26.3%) of the individuals tested. Test positivity reached 62.5% among the personnel that reported history of past TB contact in the community, 50% among the personnel who belonged to the national tuberculosis control program and 38% among those doing induced sputum, acid fast smear or mycobacterial cultures. The proportion of individuals with positive QFT was significantly lower in those personnel who had no such risk factors (15.7%, p = 0.03). The proportion of latent tuberculosis infection also increased in direct relation to the age of the subject., Conclusion: Latent tuberculosis infection as detected by QFT testing was highly prevalent in healthcare workers included in the present study. Further exploring the limitations and possible scenarios for this new diagnostic tool is needed, with emphasis on health personnel at higher-risk and younger individuals.

Background: Genotyping of Mycobacterium tuberculosis complex (cMtb) allows us to know geographically predominant lineages. Some lineages spread more rapidly and are associated with multidrug resistance, particularly Beijing, which has been reported in Latin America (Peru). There is little information about this topic in Chile and there are no reports of the presence of the Beijing genotype., Aim: To determine the most prevalent lineages in the Metropolitan Region of Chile with emphasis on the search for Beijing in two health centers., Methods: Two complementary molecular methods were used: spoligotyping, based on the variations of the direct repeat regions in the genome of cMtb and MIRU-VNTR, based in the variable number of tandem repeats of mycobacterial interspersed repetitive units, and subsequent analysis in international databases. A designed lineage was assigned to 37 of the 43 strains studied (86%); 6 isolates could not be assigned to any genotype. LAM and T genotype were the most frequent (39.5 and 32.5%, respectively) followed by Haarlem (7.0%), Beijing (4.7%) and X (2.3%)., Conclusion: We describe for the first time the presence of the Beijing genotype in Chile. cMtb molecular surveillance should be implemented in our country in order to know the dynamics of its transmission.

Setting: Santiago, Chile, has a mean annual tuberculosis (TB) rate of 13 per 100 000 population; however, TB incidence in human immunodeficiency virus (HIV) infected individuals is at least 20 times higher., Objective: To assess the accuracy of rapid molecular testing for pulmonary TB (PTB) detection in routine care in HIV-infected patients., Design: Cross-sectional study, conducted prospectively in five hospitals between March 2010 and June 2011. HIV-positive subjects with suspected PTB provided sputum or mouth wash samples that were directly processed for acid-fast smear, mycobacterial cultures and Xpert® MTB/RIF. Positive test results were reported on the same day., Results: We enrolled 166 subjects into the study; 50.6% provided two sputum samples, 33.1% only one sputum sample and 16.3% a mouth wash sample. The prevalence of TB was 8.1% (13/160). Diagnostic sensitivity increased from 66.7% (95%CI 39.1-86.2) for acid-fast smear to 91.7% (95%CI 64.6-98.5) for Xpert MTB/RIF, with comparable specificity at 98.6% (146/148, 95%CI 95.2-99.6) and 99.3% (147/148, 95%CI 96.3-99.9). Xpert MTB/RIF allowed early detection of rifampicin resistance in 16.6% of cases, with rapid adjustment to multidrug-resistant treatment., Conclusion: Xpert MTB/RIF provided earlier TB diagnosis in 25% more cases than acid-fast smear alone. Its implementation should be considered for TB diagnosis in HIV-positive patients even outside TB-endemic areas.

Background: The incidence and epidemiological profile of tuberculosis (TB) has changed significantly in the recent years in Chile., Aim: To evaluate the clinical and epidemiological characteristics of TB cases diagnosed in the last decade at a university hospital in Santiago., Material and Methods: The Mycobacterium tuberculosis culture registry of the microbiology laboratory was reviewed. Medical records of patients with a positive culture registered between 2000 and 2010 were retrieved and analyzed., Results: Two hundred forty positive Mycobacterium tuberculosis cultures were identified and the medical records of 158 of these patients were accessed for analysis. The median age was 53 years (range: 3 to 89), 55.1% were female and nearly 42% had extra-pulmonary TB. Among known risk factors, 32.9% of patients were older than 65 years, 4.4% were health care workers and 3.9% immigrants. Twenty eight percent (41/145) had some type of immunosuppression at diagnosis: 11.7% HIV infection and 16.6% were using immunosuppressive drugs. In this group, a previous tuberculin skin test was done in only 5 cases (12.2%). Adverse events related to TB treatment were reported in 21.3% of cases (17/80). No cases of fulminant hepatitis or death from this cause were identified. Four of 92 patients that had a complete follow up during treatment, died. Two of these patients were receiving steroids., Conclusions: Almost one third of TB cases occurred among immunosuppressed patients and 42% were extra-pulmonary forms. The prevention of TB reactivation in this group should be strengthened.

Background: Clinical practice guidelines (CPG) are widely used as tools for improving quality of health care. Guidelines developed elsewhere, can be adapted using a valid and systematic process., Aim: To describe the methodology used in the process of adaptation of a guideline for the management of adults with community-acquired pneumonia (CAP) in a private health care organization., Material and Methods: We used the ADAPTE framework involving three main phases. At the set-up phase a guideline adaptation group integrated by medical specialists from different disciplines, a methodologist and a nurse coordinator was formed. At the adaptation phase, the specific clinical questions to be addressed by the guidelines were identified., Results: Twenty five guidelines were initially retrieved. After their assessment, the number was reduced to only three. Recommendations from these guidelines were 'mapped' and focused searches were carried out where 'evidence gaps' were identified. An initial draft was written and revised by the adaptation group. At the finalization phase, the external review of the guideline was carried out and a process for the regular review and update of the adapted guideline was defined., Conclusions: We developed a guideline for the management of adults with CAP, adapted to the local context of our health care system, using guidelines developed elsewhere. This guideline creation method can be an efficient means of saving professional resources.

Background: Some infections share common modes of transmission with HIV and have the potential to change the course of the latter., Aim: To assess the prevalence of hepatitis B virus (HBV) hepatitis C virus (HCV), Treponema palladium and Toxoplasmosis gondii co-infections in HIV-1 infected patients followed at a university hospital., Material and Methods: Clinical records of HIV-positive individuals were reviewed. The analysis included: demographical data, hepatitis B surface antigen (HBsAg), IgM and IgG anti-HBc, antibodies, anti-HCV antibodies, RPR or VDRL test and IgG anti Tgondii antibodies., Results: Three hundred ninety five patients (aged 16 to 89 years, 359 males) were included in the review. Seventy nine percent had been tested for HBV status with HBsAg, and the global HIV-HBV co-infection prevalence was 6.1%. A subgroup of 190 individuals were tested for HBV infection with HBsAg and IgM/IgG anti-HBc markers. Of these, 46% fulfilled co-infection criteria: eight with acute hepatitis B, 11 with chronic hepatitis B and 69 with inactive HBV infection. The frequency of HIV-HBV co-infection was 48% and 22% among men and women respectively (NS). HCV-HN co-infection was detected in 3%, syphilis-HIV co-infection in 21% and T gondii-HIV co-infection in 26%., Conclusions: In this cohort, HIV infection is accompanied by a high prevalence of other co-infections, particularly HBV among men.

Background: Tuberculosis (TB) in Chile is reaching the elimination phase; however, in HIV positive individuals the incidence of TB in still very high., Aim: To describe the association between TB and HIV in different geographical regions in Chile, and to determine the association between TB and HIV/AIDS mortality., Patients and Methods: A retrospective study that included individuals from the main HIV clinics from four regions with different TB prevalence in the general population (per 100,000): Arica (>30), Concepcion/Arauco (25-29), Valparaiso/San Antonio (20-24) and Metropolitana Sur-Oriente (SSMSO) (<20), attended between January 1998 and September 2004., Results: Nine hundred and twelve HIV positive individuals were included. Global prevalence of TB was 6.2% [95% confidence intervals (Cl) 5.2-7.2%]. TB was more common in older subjects (p =0.039) and those with lower CD4 counts (p <0.001) and higher HIV viral load (p =0.033). In 66% of cases, the disease had a pulmonary localization. TB was the recorded cause of death in 7.4% of subjects. Only 29% of patients had a tuberculin skin test performed at the moment of HIV diagnosis. The prevalence of TB in HIV positive patients, followed the trend of TB prevalence in the general population: Concepcion/Arauco (11.9%), Valparaiso/San Antonio (7.1%) and SSMSO (3.9%). However HIV positive subjects from Arica showed an unexpectedly low TB prevalence (5.5%)., Conclusions: TB in HIV/AIDS patients included in this study is over 300 times more prevalent than in the general population. TB prevalence in HIV positive subjects follows regional TB prevalence, excepting Arica. Effectiveness and feasibility of latent TB diagnostic strategies and treatment in HIV positive individuals should be reviewed.