Objective: To develop a system for the molecular diagnosis of tuberculosis by polymerase chain reaction (PCR), constructing primers based on the difference in gene organization of the intergenic region of phospholipase C (plcB-plcC region), which differentiates Mycobacterium tuberculosis from other mycobacteria. Methods: A PCR product of the expected size (432 bp) was obtained from M. tuberculosis and M. africanum only. A total of 33 mycobacterial isolates and 273 clinical samples from patients suspected of having tuberculosis were examined. These were used in the comparative study of the PCR technique versus culture. Results: For PCR versus culture, the data showed 93.8% accuracy (p < 0.0001), 93.1% sensitivity (CI: 88.7-96.0), and 96.4% specificity (CI: 96.1-99.4). The Kappa value (0.82) shows that there was a near-perfect concordance between the two tests. Conclusion: The use of the plcB-plcC region in PCR amplification was found to be an important and reliable tool for the specific diagnosis of tuberculosis in the samples analyzed.

Keywords: Polymerase chain reaction; Diagnosis; Tuberculosis; Mycobacterium tuberculosis

Objective: To compare the performance of nested polymerase chain reaction (NPCR) with that of cultures in the detection of the Mycobacterium tuberculosis complex in pulmonary and extrapulmonary specimens. Methods: We analyzed 20 and 78 pulmonary and extrapulmonary specimens, respectively, of 67 hospitalized patients suspected of having tuberculosis. An automated microbial system was used for the identification of Mycobacterium spp. cultures, and M. tuberculosis IS6110 was used as the target sequence in the NPCR. The kappa statistic was used in order to assess the level of agreement among the results. Results: Among the 67 patients, 6 and 5, respectively, were diagnosed with pulmonary and extrapulmonary tuberculosis, and the NPCR was positive in all of the cases. Among the 98 clinical specimens, smear microscopy, culture, and NPCR were positive in 6.00%, 8.16%, and 13.26%, respectively. Comparing the results of NPCR with those of cultures (the gold standard), we found that NPCR had a sensitivity and specificity of 100% and 83%, respectively, in pulmonary specimens, compared with 83% and 96%, respectively, in extrapulmonary specimens, with good concordance between the tests (kappa, 0.50 and 0.6867, respectively). Conclusions: Although NPCR proved to be a very useful tool for the detection of M. tuberculosis complex, clinical, epidemiological, and other laboratory data should also be considered in the diagnosis and treatment of pulmonary and extrapulmonary tuberculosis.

Keywords: Tuberculosis/diagnosis; Tuberculosis/microbiology; Mycobacterium tuberculosis; Polymerase chain reaction.

Background: Streptococcus pneumoniae is the most common etiologic agent of community-acquired respiratory infections. In recent years, S. pneumoniae resistance to antimicrobial agents has increased. Minimum inhibitory concentration (MIC) is routinely used to determine resistance. Polymerase chain reaction (PCR) detects the genes responsible for Streptococcus pneumoniae resistance to penicillin within approximately 8 hours. Objective: To compare the PCR and MIC methods in determining Streptococcus pneumoniae resistance to penicillin. Method: A total of 153 Streptococcus pneumoniae samples, isolated from various anatomical sites, were evaluated in order to detect mutations in the genes encoding pbp1a, pbp2a and pbp2x, which are responsible for Streptococcus pneumoniae penicillin resistance. A correlation was found between mutations and penicillin MIP, as determined by the agar diffusion method. Results: Overal Streptococcus pneumoniae resistance to penicillin was 22.8% (16.3% intermediate resistance and 6.5% high resistance). In a statistically significant finding, we observed no mutations in the penicillin-sensitive samples and only one mutation, typically in the gene encoding pbp2x, among the samples with intermediate resistance, whereas mutations in all three genes studied were observed in the high-resistance samples. Conclusion: For determining Streptococcus pneumoniae resistance to penicillin, PCR is a rapid method of detection that could well be used in clinical practice.

Keywords: Streptococcus pneumoniae. Penicillin resistance. Polymerase chain reaction/methods.

Objective: To evaluate the accuracy of bacteriological methods and of polymerase chain reaction (with primers specific for IS6110 of the Mycobacterium tuberculosis complex) in testing sputum samples from indigenous (Amerindian) and non-indigenous patients. Methods: A total of 214 sputum samples (154 from indigenous patients and 60 from non-indigenous patients) were analyzed in order to determine the accuracy of smear microscopy (direct and concentrated versions) for acid-fast bacilli, culture, and polymerase chain reaction. Results: Both microscopy methods presented low sensitivity in comparison with culture and polymerase chain reaction. Specificity ranged from 91% to 100%, the concentrated acid-fast smear technique being the least specific. Nontuberculous mycobacteria were isolated three times more frequently in samples from indigenous patients than in those from non-indigenous patients. False-positive and false-negative polymerase chain reaction results were more common in the indigenous population. Conclusion: Positivity and isolation of nontuberculous mycobacteria in the acid-fast smear in conjunction with polymerase chain reaction positivity raise the following hypotheses: nontuberculous mycobacteria species with DNA regions homologous to, or even still possessing, the M. tuberculosis IS6110 exist in the Amazon; colonization of the oropharynx or of a tuberculous lesion accelerates the growth of the nontuberculous mycobacteria present in the sputum samples, making it impossible to isolate M. tuberculosis; A history of tuberculosis results in positivity for M. tuberculosis DNA. The absence of bacteriological positivity in the presence of polymerase chain reaction positivity raises questions regarding the inherent technical characteristics of the bacteriological methods or regarding patient history of tuberculosis.

Keywords: Tuberculosis, pulmonary/diagnosis; Mycobacterium tuberculosis, Polymerase chain reaction/methods; Indians, south american

Objective: The emergence of tuberculosis/HIV co-infection and the increase in the number of cases of infection with nontuberculous mycobacteria (NTM) require rapid laboratory test results in the isolation and identification of mycobacteria. The objective of this study was to evaluate the identification of mycobacteria by means of gene probes in comparison with that obtained using classical biochemical methods. Methods: Between 2002 and 2004, 178 mycobacterial cultures, all testing positive for acid-fast bacilli, were analyzed. Samples were obtained from clinical specimens of patients with respiratory symptoms or with clinical suspicion of pulmonary tuberculosis/mycobacteriosis who were treated in the greater metropolitan area of Santos. Results: The gene probe identified 137 samples (77%) as Mycobacterium tuberculosis complex and 41 (23%) as NTM. Discordant results between the methods (3%) were obtained only in the year of implementation (2002). When comparing the methods, the sensitivity, specificity, positive predictive value and negative predictive value of the gene probe method were 98%, 93%, 98% and 93%, respectively. Conclusions: Despite the cost, the identification of mycobacteria using the molecular technique is faster: maximum 3 h vs. 28-30 days for classical methods. The use of gene probes is a validated molecular technique. It is fast, easy to use and readily available on the market. It has high specificity and sensitivity, which justifies its implementation and routine use in referral laboratories, since it facilitates the diagnosis providing agile clinical interventions.

Keywords: Mycobacterium tuberculosis; Tuberculosis/diagnosis; Mycobacterium/classification; DNA probes.

Objective: To evaluate the performance of nested PCR (nPCR) in detecting the Mycobacterium tuberculosis complex in blood samples of patients suspected of having TB, in order to determine its potential for use as an auxiliary tool in the laboratory diagnosis of TB in children. Methods: Detection of the M. tuberculosis complex in blood samples using as a target the insertion sequence IS6110 of the genomic DNA of the bacillus. Blood samples of 120 patients were evaluated. All of the patients were under 15 years of age at the time of their treatment at public hospitals in the city of Recife, Brazil (between January of 2003 and August of 2005). Attending physicians at the hospitals diagnosed TB based on the criteria recommended by the American Thoracic Society. The nPCR amplified a 123-bp fragment with outer oligonucleotides (IS1/IS2) and, in the subsequent reaction, using inner oligonucleotides (IS3/IS4), generating an 81-bp amplicon. Results: Active or latent TB was found in 65 patients, TB was ruled out in 28 suspected cases, and 27 patients were TB-free (controls). The sensitivity of nPCR was 26.15% and was significantly higher for the extrapulmonary form of the disease (55.56%) than for the pulmonary form (18.18%). The specificity was 92.73%. Conclusions: Despite the difficulties in diagnosing TB in children and the low number of cases evaluated in the present study, nPCR in blood samples proved to be a rapid and specific technique, albeit one with low sensitivity. In order to establish its true usefulness in the diagnosis of paucibacillary forms, especially extrapulmonary TB, further studies need to be carried out with a larger sample of children and analyzing biological specimens other than blood.

Keywords: Tuberculosis; Diagnosis; Blood; Polymerase chain reaction.

Objective: To predict COVID-19 in hospitalized patients with SARS in a city in southern Brazil by using machine learning algorithms. Methods: The study sample consisted of patients = 18 years of age admitted to the emergency department with SARS and hospitalized in the Hospital Escola - Universidade Federal de Pelotas between March and December of 2020. Epidemiological, clinical, and laboratory data were processed by machine learning algorithms in order to identify patterns. Mean AUC values were calculated for each combination of model and oversampling/undersampling techniques during cross-validation. Results: Of a total of 100 hospitalized patients with SARS, 78 had information for RT-PCR testing for SARS-CoV-2 infection and were therefore included in the analysis. Most (58%) of the patients were female, and the mean age was 61.4 ± 15.8 years. Regarding the machine learning models, the random forest model had a slightly higher median performance when compared with the other models tested and was therefore adopted. The most important features to diagnose COVID-19 were leukocyte count, PaCO2, troponin levels, duration of symptoms in days, platelet count, multimorbidity, presence of band forms, urea levels, age, and D-dimer levels, with an AUC of 87%. Conclusions: Artificial intelligence techniques represent an efficient strategy to identify patients with high clinical suspicion, particularly in situations in which health care systems face intense strain, such as in the COVID-19 pandemic.

Keywords: COVID-19/diagnosis; Artificial intelligence; Machine learning.

Objective: To compare the accuracy of the amplified Mycobacterium tuberculosis direct (AMTD) test with reference methods for the laboratory diagnosis of tuberculosis in HIV-infected patients. Methods: This was a study of diagnostic accuracy comparing AMTD test results with those obtained by culture on Löwenstein-Jensen (LJ) medium and by the BACTEC Mycobacteria Growth Indicator Tube 960 (BACTEC MGIT 960) system in respiratory samples analyzed at the Bioassay and Bacteriology Laboratory of the Oswaldo Cruz Foundation Evandro Chagas Clinical Research Institute in the city of Rio de Janeiro, Brazil. Results: We analyzed respiratory samples collected from 118 patients, of whom 88 (74.4%) were male. The mean age was 36.6 ± 10.6 years. Using the AMTD test, the BACTEC MGIT 960 system, and LJ culture, we identified M. tuberculosis complex in 31.0%, 29.7%, and 27.1% of the samples, respectively. In comparison with LJ culture, the AMTD test had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.5%, 89.4%, 75.7%, and 95.0%, respectively, for LJ culture, whereas, in comparison with the BACTEC MGIT 960 system, it showed values of 88.6%, 92.4%, 83.8%, and 94.8%, respectively. Conclusions: The AMTD test showed good sensitivity and specificity in the population studied, enabling the laboratory detection of M. tuberculosis complex in paucibacillary respiratory specimens.

Keywords: Molecular diagnostic techniques; Tuberculosis; HIV; Molecular probe techniques.

Background: Knowledge of the rates of drug resistance is one of the pillars of tuberculosis control program evaluation. Data from low-resource countries are scarce and results are delayed due to the techniques employed. There is therefore an urgent need for evaluation of faster and less onerous testing methods. Objective: To compare the performance of rapid colorimetric assays for phenotyping that employ oxidationreduction indicators to determine the susceptibility profile of Mycobacterium tuberculosis with the gold-standard proportion method on Lowenstein-Jensen Medium. Method: We analyzed 166 M. tuberculosis strains of known susceptibility. Minimal inhibition concentrations for isoniazid and rifampicin were determined in microplates, using a liquid medium and Alamar Blue and tetrazolium bromide indicators. To measure agreement the Kappa value was used. Cutoff values between sensitive and resistant strains were defined as 0.2µg/mL and 1.0µg/mL for isoniazid and rifampicin, respectively. Results: There was 100% concordance between Alamar Blue and tetrazolium bromide methods in the determination of minimal inhibition concentrations. Agreement between the colorimetric method and the Lowenstein-Jensen was 95% for isoniazid and rifampicin. Using the colorimetric method, results were obtained within 7 days, in contrast to the 28 days required for the conventional method. Conclusions: Assays to determine minimal inhibition concentrations in liquid medium and employing oxidationreduction indicators proved to be rapid and inexpensive. This method has the potential to become a faster, alternative method for determining susceptibility of M. tuberculosis strains in developing countries.

Keywords: Mycobacterium tubercolis. Disease susceptibility. Isoniazid/therapeutic use. Rifampin/therapeutic use.

This study aimed to assess drug resistance in Mycobacterium tuberculosis strains isolated from sputum samples. To that end, sputum samples were collected from 263 patients suspected of having tuberculosis. All subjects lived in the Complexo de Manguinhos, which is located in the city of Rio de Janeiro, Brazil. Cultures testing positive between October of 2000 and December of 2002 were tested to determine strain susceptibility to isoniazid, rifampicin, streptomycin, ethionamide, and ethambutol. Of the 75 patients diagnosed with tuberculosis, resistance to at least one of the drugs was found in 16 (21.4%). Of those 16 patients, 8 (50%) were new cases, and 8 (50%) had previously been treated. Multidrug-resistant tuberculosis was identified in 8 (10.6%) of the 75 patients, being associated with previous treatment in 6 (8%). The incidence of multidrug-resistant tuberculosis might have been underestimated, since M. tuberculosis was not isolated from all of the samples testing positive for acid-fast bacilli. However, at least, our findings shed some light on the problem.

Keywords: Tuberculosis; Drug resistance; Drug resistance, multiple.

Objective: To determine the prevalence of alternative diagnoses based on chest CT angiography (CTA) in patients with suspected pulmonary thromboembolism (PTE) who tested negative for PTE, as well as whether those alternative diagnoses had been considered prior to the CTA. Methods: This was a cross-sectional, retrospective study involving 191 adult patients undergoing CTA for suspected PTE between September of 2009 and May of 2012. Chest X-rays and CTAs were reviewed to determine whether the findings suggested an alternative diagnosis in the cases not diagnosed as PTE. Data on symptoms, risk factors, comorbidities, length of hospital stay, and mortality were collected. Results: On the basis of the CTA findings, PTE was diagnosed in 47 cases (24.6%). Among the 144 patients not diagnosed with PTE via CTA, the findings were abnormal in 120 (83.3%). Such findings were consistent with an alternative diagnosis that explained the symptoms in 75 patients (39.3%). Among those 75 cases, there were only 39 (20.4%) in which the same alterations had not been previously detected on chest X-rays. The most common alternative diagnosis, made solely on the basis of the CTA findings, was pneumonia (identified in 20 cases). Symptoms, risk factors, comorbidities, and the in-hospital mortality rate did not differ significantly between the patients with and without PTE. However, the median hospital stay was significantly longer in the patients with PTE than in those without (18.0 and 9.5 days, respectively; p = 0.001). Conclusions: Our results indicate that chest CTA is useful in cases of suspected PTE, because it can confirm the diagnosis and reveal findings consistent with an alternative diagnosis in a significant number of patients.

Keywords: Pulmonary embolism/diagnosis; Pulmonary embolism/epidemiology; Angiography.

Background: Various primers are being tested for the detection of Mycobacterium tuberculosis DNA. The accuracy of the polymerase chain reaction (PCR) depends on the target sequence used and whether the test will be performed in culture or in clinical specimens. Objectives: To identify DNA sequences, specifically those commonly reported as targets for diagnosis of tuberculosis (TB), in clinical samples of M. tuberculosis strains. Method: Eighty-one clinical samples from suspected TB patients were initially processed and submitted to bacilloscopy (smear) and culture, and PCR was performed with specific primers for the following targets: IS 6110, 65 kDa, 38 kDa and MPB64. Results: Smear and culture results were negative in 24 samples, as was the PCR. The 19 samples testing smear positive, as well as the isolated strains, were 100% positive on PCR, with the exception of the 89.4% result from PCR with MPB64 primers. In the 38 smear negative and culture positive samples, PCR results were inconsistent. The primers specific for amplifying the 123 bp IS 6110 fragment gave the highest positivity (92.1%), diagnostic agreement (0.9143), co-positivity (94.7%) and co-negativity (100%). Conclusion: The IS 6110, 38 kDa, MPB64 and 65 kDa sequences were found in the genome of all M. tuberculosis strains isolated in patients from the state of Amazonas. The protocol for processing the clinical samples prior to PCR analysis and the specific primers used to amplify the 123bp IS 6110 fragment showed a greater efficiency in diagnosing pulmonary (paucibacillary) tuberculosis in comparison to published data.

Keywords: Primers/PCR. Diagnosis/Tuberculosis. Mycobacterium tuberculosis.

Objective: To compare 28-day mortality rates and clinical outcomes in ICU patients with ventilator-associated pneumonia according to the diagnostic strategy used. Methods: This was a prospective randomized clinical trial. Of the 73 patients included in the study, 36 and 37 were randomized to undergo BAL or endotracheal aspiration (EA), respectively. Antibiotic therapy was based on guidelines and was adjusted according to the results of quantitative cultures. Results: The 28-day mortality rate was similar in the BAL and EA groups (25.0% and 37.8%, respectively; p = 0.353). There were no differences between the groups regarding the duration of mechanical ventilation, antibiotic therapy, secondary complications, VAP recurrence, or length of ICU and hospital stay. Initial antibiotic therapy was deemed appropriate in 28 (77.8%) and 30 (83.3%) of the patients in the BAL and EA groups, respectively (p = 0.551). The 28-day mortality rate was not associated with the appropriateness of initial therapy in the BAL and EA groups (appropriate therapy: 35.7% vs. 43.3%; p = 0.553; and inappropriate therapy: 62.5% vs. 50.0%; p = 1.000). Previous use of antibiotics did not affect the culture yield in the EA or BAL group (p = 0.130 and p = 0.484, respectively). Conclusions: In the context of this study, the management of VAP patients, based on the results of quantitative endotracheal aspirate cultures, led to similar clinical outcomes to those obtained with the results of quantitative BAL fluid cultures. (Brazilian Registry of Clinical Trials - ReBEC; identification number RBR-86DCDX [http://www.ensaiosclinicos.gov.br])

Keywords: Bronchoalveolar lavage fluid/diagnosis; Respiratory aspiration; Pneumonia, ventilator-associated.

Objective: To evaluate the rapid diagnosis of multidrug-resistant tuberculosis, by using a commercial line probe assay for rifampicin and isoniazid detection (LPA-plus), in the routine workflow of a tuberculosis reference laboratory. Methods: The LPA-plus was prospectively evaluated on 341 isolates concurrently submitted to the automated liquid drug susceptibility testing system. Results: Among 303 phenotypically valid results, none was genotypically rifampicin false-susceptible (13/13; 100% sensitivity). Two rifampicin-susceptible isolates harboured rpoB mutations (288/290; 99.3% specificity) which, however, were non-resistance-conferring mutations. LPA-plus missed three isoniazid-resistant isolates (23/26; 88.5% sensitivity) and detected all isoniazid-susceptible isolates (277/277; 100% specificity). Among the 38 (11%) invalid phenotypic results, LPA-plus identified 31 rifampicin- and isoniazid-susceptible isolates, one isoniazid-resistant and six as non-Mycobacterium tuberculosis complex. Conclusions: LPA-plus showed excellent agreement (≥91%) and accuracy (≥99%). Implementing LPA-plus in our setting can speed up the diagnosis of multidrug-resistant tuberculosis, yield a significantly higher number of valid results than phenotypic drug susceptibility testing and provide further information on the drug-resistance level.

Keywords: Tuberculosis, multidrug-resistant; Molecular diagnostic techniques; Microbial sensitivity tests; Mycobacterium tuberculosis.

Objetivo: Descrever as taxas de cura, falência e abandono do tratamento da tuberculose com o esquema básico preconizado pelo Ministério da Saúde (tratamento com rifampicina, isoniazida, pirazinamida e etambutol por dois meses seguido de isoniazida e rifampicina por quatro meses) utilizando comprimidos em dose fixa combinada em regime autoadministrado e descrever os eventos adversos e seus possíveis impactos nos desfechos do tratamento. Métodos: Estudo descritivo utilizando dados coletados prospectivamente dos prontuários médicos de pacientes com tuberculose (idade ≥ 18 anos) tratados com o esquema básico em duas unidades básicas de saúde da região metropolitana de Goiânia, GO. Resultados: A amostra foi composta por 40 pacientes com tuberculose. A taxa de cura foi de 67,5%, a taxa de abandono foi de 17,5%, e não ocorreram casos de falência. Nessa amostra, 19 pacientes (47%) relataram reações adversas aos medicamentos. Essas foram leves e moderadas, respectivamente, em 87% e 13% dos casos. Em nenhum caso houve necessidade de mudança do esquema ou suspensão do tratamento. Conclusões: A taxa de cura do esquema básico com o uso de comprimidos em dose fixa combinada sob regime autoadministrado foi semelhante às taxas históricas do esquema anterior. A taxa de abandono, na amostra estudada, foi muito acima da taxa preconizada como adequada (até 5%).

Keywords: Tuberculose; Resultado de tratamento; Combinação de medicamentos.

Objective: To assess the diagnostic performance of the Xpert MTB/RIF assay, a rapid molecular test for tuberculosis, comparing it with that of AFB staining and culture, in BAL fluid (BALF) samples from patients with clinically suspected pulmonary tuberculosis (PTB) who are sputum smear-negative or produce sputum samples of insufficient quantity. Methods: This was a retrospective study of 140 cases of suspected PTB in patients who were smear-negative or produced insufficient sputum samples and were evaluated at a tertiary teaching hospital in the city of Rio de Janeiro, Brazil. All of the patients underwent fiberoptic bronchoscopy with BAL. The BALF specimens were evaluated by AFB staining, mycobacterial culture, and the Xpert MTB/RIF assay. Results: Among the 140 patients, results for all three microbiological examinations were available for 73 (52.1%), of whom 22 tested positive on culture, 17 tested positive on AFB staining, and 20 tested positive on the Xpert MTB/RIF assay. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for AFB staining were 68.1%, 96.1%, 88.2%, 87.5%, and 87.6%, respectively, compared with 81.8%, 96.1%, 90.0%, 92.4%, and 91.8%, respectively, for the Xpert MTB/RIF assay. The agreement between AFB staining and culture was 82.3% (kappa = 0.46; p < 0.0001), whereas that between the Xpert MTB/RIF assay and culture was 91.8% (kappa = 0.8; p < 0.0001). Conclusions: In BALF samples, the Xpert MTB/RIF assay performs better than do traditional methods, providing a reliable alternative to sputum analysis in suspected cases of PTB. However, the rate of discordant results merits careful consideration.

Keywords: Tuberculosis; Molecular diagnostic techniques; Bronchoscopy; Bronchoalveolar lavage fluid; Mycobacterium tuberculosis.

Objective: To evaluate paranasal sinuses in patients with stable or acute asthma in order to determine the prevalence of acute bacterial rhinosinusitis. Methods: A cross-sectional study including 30 patients with acute asthma (73% females) treated in the emergency room and 30 patients with stable asthma (80% females) regularly monitored as outpatients. All patients completed a questionnaire on respiratory signs and symptoms and were submitted to ear, nose and throat (ENT) examination, as well as to X-ray and computed tomography (CT) imaging of the sinuses. Results: Based on the clinical diagnosis, the prevalence of acute bacterial rhinosinusitis was 40% in the patients with acute asthma and 3% in those with stable asthma. The ENT examination findings and the imaging findings in isolation were not useful to confirm the diagnosis. Conclusions: In themselves, ENT examination findings, X-ray findings and CT findings were not useful for the diagnosis of acute bacterial rhinosinusitis. Our results provide further evidence that a clinical diagnosis of bacterial rhinosinusitis should be made with caution.

Keywords: Asthma; Sinusitis; Radiography; Tomography, X-ray computed; Endoscopy.

Objective: To compare the effects of a home-based pulmonary rehabilitation (PR) program with and without telecoaching on health-related outcomes in COVID-19 survivors. Methods: A total of 42 COVID-19 patients who completed medical treatment were randomly divided into two groups: the study (telecoaching) group (n = 21) and the control (no telecoaching) group (n = 21). Both groups participated in an 8-week home-based PR program including education, breathing exercises, strength training, and regular walking. The study group received phone calls from a physiotherapist once a week. Both groups of patients were assessed before and after the program by means of the following: pulmonary function tests; the modified Medical Research Council dyspnea scale; the six-minute walk test; extremity muscle strength measurement; the Saint George's Respiratory Questionnaire (to assess disease-related quality of life); the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36, to assess overall quality of life); and the Hospital Anxiety and Depression Scale. Results: In both groups, there were significant improvements in the following: FVC; the six-minute walk distance; right and left deltoid muscle strength; Saint George's Respiratory Questionnaire activity domain, impact domain, and total scores; and SF-36 social functioning, role-physical, role-emotional, and bodily pain domain scores (p < 0.05). Decreases in daily-life dyspnea, exertional dyspnea, and exertional fatigue were significant in the study group (p < 0.05), and the improvement in SF-36 social functioning domain scores was greater in the study group (p < 0.05). Conclusions: A home-based PR program with telecoaching increases social functioning and decreases daily-life dyspnea, exertional dyspnea, and exertional fatigue in COVID-19 survivors in comparison with a home-based PR program without telecoaching.

Keywords: COVID-19; Exercise; Telerehabilitation; Dyspnea; Fatigue.