Mycobacterium Tuberculosis PCR Research Articles

A case of reversible isolated cognition impairment in meningoencephalitis without abnormal MRI findings

AbstractBackgroundWe report a case of meningoencephalitis with reversible isolated cognition impairment without abnormal MRI findings.MethodA 75‐year‐old man presented with confusion including bizarre behavior 2 days ago. Before visiting the hospital, his son found the patient naked and under the blanket saying it was cold. Fever didn’t occur. Mental status was alert without awareness. On neurologic examination, mutism was found. Muscle power on both upper and lower limbs was normal. Routine laboratory test showed that leukocytes count was normal but eosinophils were increased to 14.0%. Initial brain MRI including DWI and contrast enhanced image revealed no enhanced structural lesions. Initial K‐MMSE score was 4 points while the previous K‐MMSE score 3‐months‐ago was 25 points. There was no epileptic form discharge in EEG. CSF study demonstrated that WBC count was 18/L. protein was 42.6mg/dL, and glucose was 103mg/dL. CSF opening pressure was 5cmH2O. Culture study including gram stain, AFB stain, PAS stain showed no growth of aerobe, anaerobe, fungus and hyphae. Mycobacterium tuberculosis PCR and HSV PCR were negative. ADA was under 3 IU/I. Serum paraneoplastic antibodies were all negative.ResultThe patient showed only isolated cognition impairment without fever and there was no evidence of meningoencephalitis on the contrast enhanced MRI. Although the patient revealed CNS infection with unknown cause in CSF profile, it has some possibilities; 1) Aseptic meningoencephalitis with viral infection, 2) Bacterial meningoencephalitis with early stage, 3) Parasitic meningoencephalitis, 4) Autoimmune meningoencephalitis. Because of the negative findings in autoimmune antibody test, autoimmune meningoencephalitis was less likely. After treatment with acyclovir 0.6g for 7days, ceftriaxone 4g, vancomycin 2.5g and Ampicillin 8g for 10 days, confusion and mutism were improved with K‐MMSE 18 points.ConclusionMany reports have been published on meningoencephalitis accompanied by fever, altered mentality, seizure, muscle weakness and abnormal MRI findings respectively. However there have been few cases of meningoencephalitis with isolated cognition impairment and normal MRI simultaneously. If it is a change of consciousness and cognition impairment caused by meningoencephalitis, it can be reversible with proper treatment. Therefore, if only sudden onset isolated CNS symptom with normal brain MR finding, it is essential to check CSF profile.

Host factors associated with false negative results in an interferon‐γ release assay in adults with active tuberculosis

ObjectiveTo identify host factors associated with false-negative results of interferon-γ release tests in adults with active tuberculosis. MethodsThe clinical data of 943 patients with active tuberculosis diagnosed by acid-fast smear staining, Mycobacterium tuberculosis culture, Mycobacterium tuberculosis PCR and pathological examination at West China Hospital of Sichuan University were retrospectively analysed. According to the results of the interferon γ release test (IGRA), the patients were divided into the IGRA− group and IGRA+ group. Logistic regression was used to analyze the sociodemographic data and clinical characteristics of participants in the IGRA− group and IGRA+ group. ResultsAmong 943 patients with active tuberculosis, 174 (18.5 %) were IGRA negative (false negative), and 769 (81.5 %) were IGRA positive. Multivariate logistic regression analysis identified the following characteristics independently associated with IGRA negativity: age (OR: 1.02; 95 % CI: 1.01 1.03; p = 0.006), anti-tuberculosis treatment >1 month (OR: 1.68; 95 % CI: 1.12 2.52; p = 0.013), HIV infection (OR: 9.48; 95 % CI: 3.23 27.85; p = 0.000), combined with connective tissue diseases (OR: 2.78; 95 % CI: 1.30 5.94; p = 0.008) and low hemoglobin (OR: 0.99; 95 % CI: 0.98 1.00; p = 0.044) was associated with an increased false-negative probability of IGRA. ConclusionAge, anti-tuberculosis therapy >1 month, coinfection with HIV, coassociated connective tissue disease and decreased hemoglobin were identified as risk factors for false-negative results of IGRA. Our results suggest a careful interpretation of IGRA in adults with these characteristics.

Ziekte van Pott: zeldzaam, maar niet uitgestorven

Pott’s disease: rare but not extinct In a 78-year-old woman with a history of colon diverticulitis, an incidental finding of spondylodiscitis T12-L2 was found on the CT scan to evaluate the diverticulitis. The finding was confirmed on an MRI, showing multifocal involvement of T12-L2 and the intervertebral discs with alongside an intraspinal abscess collection and a psoas abscess. Further investigations (hemocultures and cultures of the abscess) remained negative. Empirical antibiotic therapy was initiated with intravenous ceftriaxone and metronidazole for 6 weeks. The patient was discharged after the antibiotic treatment. One week later, the patient presented at the emergency department due to abnormal liver function values. Because of the multifocal lytic lesions, she received a pedicle screw fixation T11-L2 with a biopsy of L2 at the same time. The biopsy sample showed a positive PCR for Mycobacterium tuberculosis. The patient was diagnosed with tuberculous spondylitis. Multidrug anti-tubercular therapy was initiated with a 4-drug regimen (rifampicine, isoniazide, ethambutol and pyrazinamide).

Isolated Chest Wall Tuberculosis Presenting As an Abscess

Lebanon is a relatively low Tuberculosis burden country but has a high proportion of extrapulmonary tuberculosis. Tuberculosis involving the chest wall is found in around 1% of all skeletal tuberculosis cases. We present the case of an 81-year-old immunocompetent patient who presented with 3 months history of a painful lump in the anterior chest wall. PCR for MTB (mycobacterium tuberculosis) was positive and a diagnosis of the tubercular abscess of the chest wall was made mimicking a pyogenic abscess.

S3328 An Atypical Etiology of Chronic Abdominal Pain: Peritoneal Tuberculosis

Introduction: Peritoneal tuberculosis (TB) is a rare presentation of extra-pulmonary TB, comprising only 5% of extra-pulmonary TB cases. Patients oftentimes present with non-specific complaints and without typical Mycobacterium tuberculosis risk factors. Additionally, diagnostic testing lacks high sensitivity and specificity with further invasive methods frequently necessitated. We present an unusual case of peritoneal TB presenting as non-localized abdominal pain, facilitating insight into this uncommon disease. Case Description/Methods: A 53-year-old female with a past medical history of hypothyroidism presented with joint pain diagnosed as seronegative rheumatoid arthritis and subsequently began treatment with methotrexate and adalimumab for one year. Within the following year, she experienced chronic right lower quadrant (RLQ) abdominal pain, fevers, night sweats, fatigue, and ascites. Extensive work-up revealed a positive QuantiFERON gold TB test. A diagnostic laparoscopy with peritoneal biopsy successively demonstrated elevated CA-125 and large-volume ascites. Mycobacterium tuberculosis PCR and Grocott methenamine silver staining were negative. One of two acid-fast bacillus (AFB) smear and cultures yielded a positive result. Our patient was treated for peritoneal TB. She continued to have several years of chronic RLQ abdominal pain several months after RIPE treatment completion, undergoing a cholecystectomy and three adhesion lysis procedures with mild symptomatic improvement and subsequent worsening thereafter. An operative note highlighted the large amount of adhesions from the patient’s liver to her diaphragm and anterior abdominal wall, appearing similar to Fitz-Hugh-Curtis syndrome. She continues to have chronic abdominal pain and is followed closely by her treatment team. Discussion: Our patient was on immunosuppressive medications and had a history of travel to Mexico, a high TB burden country. Notably, AFB smear and culture has a poor sensitivity for peritoneal TB, oftentimes necessitating laparoscopic peritoneal biopsy for further diagnosis. Our patient was empirically treated for peritoneal TB before AFB culture yielded positive results, given her B symptoms and positive QuantiFERON test. She also had an elevated CA-125 value, which is associated with peritoneal TB and may be used in patients with a negative AFB stain. Our patient experienced recurrent adhesions, an unfortunate and persistent consequence of the inflammatory nature of peritoneal TB.

A Case of Extrapulmonary Tuberculosis

A 21 years old man immigrant from Nigeria came to our observation for swelling of the chest wall and fever. The laboratory tests showed neutrophilic leukocytosis and absence of HIV / others viruses’ infection. Chest X-ray was not conclusive. An abdomen echography showed diffuse lymphadenopathy. In the suspicion of a lymphoproliferative disease we performed a total body CT, that detected colliquated lymph nodes in the later cervical, abdominal and pelvic stations; at the left pectoral region there was an abscess collection (58x54mm) crossing the intercostal spaces until to the anterior pleura (Figure 1). Echocardiography showed mild pericardial effusion. The thoracic abscess was drained and a sample of PCR for Mycobacterium tuberculosis was positive. We started therapy with rifampicin, isoniazid, pyrazinamide, ethambutol and methyl prednisone, waiting for cultural examination The patient was discharged in good clinical status with diagnosis of disseminated lymph node tuberculosis (LNTB) fistulized to the chest wall abscess and he was referred to specialist follow-up

248.8: Mycobacterium tuberculosis Colitis and Cytomegalovirus in A Renal Transplant Recipient: An Infrequent Association

Introduction: Chronic diarrhea, infectious or inflammatory, is a frequent cause of consultation in transplant recipients. Immunosuppressants are the most common reason, but microorganisms like cytomegalovirus (CMV), clostridium difficile, campylobacter, are often reported. Tuberculosis can occur, but it has a low prevalence, described between 0.3 and 1.7%. Method: We described a 32-year woman with a history of membranoproliferative glomerulonephritis, recipient of a deceased-donor kidney transplant 12 years ago. She received basiliximab and steroids as induction therapy and maintenance with tacrolimus, mycophenolate and deflazacort. She consulted with a 7-day history of liquid diarrhea, no blood, nor mucus with abdominal pain, nausea, and fever up to 39°C. She manifested a 10kg loss of weight in a 6 month-period with no other symptoms. Upon admission, she had tachycardia, mild abdominal pain in left flank. Blood workup showed normal leukocytes and platelets, absolute lymphocyte count of 0.8x103/ L, hemoglobin 8.9g/dL, creatinine 1.51mg/dL, high C-reactive protein, and low level of albumin. Low iron, TSAT and high ferritin level. Normal folic acid and vitamin B12. Coproscopic showed blood, no leukocytes. Blood cultures, molecular panel identification of multiple gastroenterology pathogens (filmarrayTM), VIH, viral load with transcriptase-polymerase-chain-reaction (PCR) in blood for CMV were negative. Chest radiography was normal. Contrast abdominal tomography showed thickening and enhacement of the walls of the cecum, hepatic flexure, ileocecal valve and distal ileum. In ascending colon, a 4cm decreased of the lumen was seeing. Multiple round nodes smaller than 10mm after contrast were observed. Total colonoscopy showed colitis in transverse and left colon with 80% stenosis of the lumen. Biopsy documented active chronic colitis with a marked ulcerative component. No microorganisms, dysplasia or malignancy were observed. Real time-PCR was processed for CMV in colonic tissue and PCR for mycobacterium tuberculosis (MT) both reported positive. Co-infection with intestinal CMV and MT was diagnosed. She was treated with valganciclovir for 4 weeks and tetraconjugate with isoniazid(H), rifampicin(R), pyrazinamide(Z), ethambutol(E) and pyridoxine. During treatment, presented elevated transaminases and uric acid attributed to hepatotoxicity for H. It was switched to moxifloxacin with improved in hepatic profile. Moxifloxacin, R and Z were continued for 9 months. The patient had resolution of the diarrhea, recovery of weight, anemia and renal function. Conclusion: CMV is a common etiological agent in kidney transplant recipients with diarrhea, co-infection with other microorganisms, such as, MT can worsen the clinical course and without treatment can lead to death. Having a high index of suspicion is essential. A rigorous diagnostic approach is necessary and performing PCR on tissue can contribute to allow early diagnosis and timely treatment.

Population study on diagnosis, treatment and outcomes of critically ill patients with tuberculosis (2008–2018)

BackgroundTuberculosis (TB) is a preventable and curable disease, but mortality remains high among those who develop sepsis and critical illness from TB.MethodsThis was a population-based, multicentre retrospective cohort study of...

DISSEMINATED TB IN AN IMMUNOCOMPETENT PATIENT

TYPE: Case Report TOPIC: Chest Infections INTRODUCTION: Disseminated tuberculosis (TB) is a rare presentation, more common in patients with HIV, chronic liver disease or alcohol abuse and associated with high rates of treatment failure. CASE PRESENTATION: A 28 years-old male, with history of asthma, started complains of cough, sputum production and asthenia . Despite inhaled steroids, he continued to deteriorate. Skin ulcerations on the right wrist, elbow and leg appeared 4 months later. Fourteen months after the first symptoms, there was purulent drainage in the ulcers and a right knee edema which prevented the patient from walking. The patient presented to the hospital with extreme weight loss (20Kg). HIV screening was negative. CT scan with peri broncho-vascular opacities, tree-in-bud, cavitary lesions and pneumomediastinum. PCR for Mycobacterium tuberculosis was positive on sputum and knee pus. The patient started antibiotics (Clindamycin) and anti-TB drugs. A drain was placed on the right knee. Bone MRI revealed osteomyelitis in the knee, femur and cervical-dorsal spine, with need for surgical cleaning. DISCUSSION: A long evolution of symptoms was probably responsible for the exuberant presentation in this case of disseminated TB. The antibiotics and surgical strategies to treat the skin lesions were very challenging due to different microbiologic isolates and recurrence after drainage. The extension of lesions to the bone led to leg and arm movement impairment. Due to this, a multidisciplinary evaluation and decision to perform surgery were essential to prevent permanent disability. CONCLUSIONS: This case highlights the challenges in the management of thoracic complications of cavitary lesions, cutaneous ulceration and osteomyelitis due to TB. DISCLOSURE: Nothing to declare. KEYWORD: disseminated tuberculosis

Paradoxical development of pleural-based masses in patients with pleural tuberculosis during treatment: a clinical observational study in China

BackgroundTo explored the clinical, pathological, and bacteriological characteristics of pleural-based masses occurred during anti-tuberculosis (TB) treatment in patients with pleural TB.MethodsPatients referred with newly diagnosed pleural TB were prospectively enrolled into the study. Patients were followed up throughout the treatment, and clinical data were recorded. Percutaneous biopsy and surgical tissues from pleural-based masses were examined histologically and samples sent for PCR. Cytokines in the pleural effusions and clinical factors were collected and compared between different patients.ResultsA total of 122 patients with pleural TB were enrolled, and 34.4% (42/122) displayed newly observed pleural-based mass during the treatment. Twelve cases underwent surgical resection at the 12 ± 0.5 months during the treatment course. Based on the surgical observation, 58.3% (7 /12) were located in pleura, 41.7% (5/12) were located in the lung parenchyma. Pathological observations showed that the pleural-based masses were typed as granulomatous inflammation, fibrous hyperplasia and necrosis. Mycobacterium tuberculosis PCR was positive in 57.1% of the cases (24/42). Any first-line anti-TB drug resistance gene mutations were positive in only 9.5% (4/42). Aside from 12 cases who underwent the surgical operation, 86.7% of the patients (26/30) still had a pleural-based mass at the end of 12 months treatment course. Patients with a pleural-based mass were younger, had a thicker pleural, a higher proportion of pleural adhesive, loculated pleural effusion and residual pleural effusion, and a higher level of LDH, ADA and lower glucose in pleural effusion than those without a pleural-based mass occurrence during the treatment (all Pcorr < 0.05).ConclusionsPleural-based masses were observed in about one-third of patients with pleural TB. The masses were in the lung or pleura and were divided into three pathological types.

Pneumonia surveillance with culture-independent metatranscriptomics in HIV-positive adults in Uganda: a cross-sectional study

Pneumonia is a leading cause of death worldwide and is a major health-care challenge in people living with HIV. Despite this, the causes of pneumonia in this population remain poorly understood. We aimed to assess the feasibility of metatranscriptomics for epidemiological surveillance of pneumonia in patients with HIV in Uganda. We performed a retrospective observational study in patients with HIV who were admitted to Mulago Hospital, Kampala, Uganda between Oct 1, 2009, and Dec 31, 2011. Inclusion criteria were age 18 years or older, HIV-positivity, and clinically diagnosed pneumonia. Exclusion criteria were contraindication to bronchoscopy or an existing diagnosis of tuberculosis. Bronchoalveolar lavage fluid was collected within 72 h of admission and a combination of RNA sequencing and Mycobacterium tuberculosis culture plus PCR were performed. The primary outcome was detection of an established or possible respiratory pathogen in the total study population. We consecutively enrolled 217 patients during the study period. A potential microbial cause for pneumonia was identified in 211 (97%) patients. At least one microorganism of established respiratory pathogenicity was identified in 113 (52%) patients, and a microbe of possible pathogenicity was identified in an additional 98 (45%). M tuberculosis was the most commonly identified established pathogen (35 [16%] patients; in whom bacterial or viral co-infections were identified in 13 [37%]). Streptococcus mitis, although not previously reported as a cause of pneumonia in patients with HIV, was the most commonly identified bacterial organism (37 [17%] patients). Haemophilus influenzae was the most commonly identified established bacterial pathogen (20 [9%] patients). Pneumocystis jirovecii was only identified in patients with a CD4 count of less than 200 cells per mL. We show the feasibility of using metatranscriptomics for epidemiologic surveillance of pneumonia by describing the spectrum of respiratory pathogens in adults with HIV in Uganda. Applying these methods to a contemporary cohort could enable broad assessment of changes in pneumonia aetiology following the emergence of SARS-CoV-2. US National Institutes of Health, Chan Zuckerberg Biohub.

ETIOLOGY AND CLINICAL PROFILE OF PERICARDIAL EFFUSION PATIENTS

Background Pericardial effusion is one of the most prevalent disorders . Pericardial effusion can create substantial symptoms and a lower quality of life, but its also linked to a higher risk of cardiopulmonary failure, mortality, and death. Pericardial effusion has a variety of causes that are related to the relative occurrence of certain diseases in different parts of the world. Methods:it was a retrospective study that includes data from all pericardial effusion cases diagnosed . Echocardiography was used to diagnose a total of 50 cases with pericardial effusion. Complete blood count with ESR, blood urea, serum creatinine, tuberculin skin test, chest X-ray, ECG, Thyroid profile, ANA, Rheumatoid factor, CT chest / MRI, and pericardiocentesis were all used to determine the source of the pericardial effusion. Cells, proteins, LDH, malignant cells, ADA, PCR (for Mycobacterium tuberculosis), gram staining, AFB staining, and cultures were all examined in the pericardial fluid. Iatrogenic (cardiac surgery, catheterization) and post-traumatic cases were excluded . Results: The majority of the patients were between the ages of 50 and 70. Thirty patients (60%) were men and 20 patients (40%) were women. Tuberculosis was the most prevalent cause of pericardial effusion, accounting for 28 % of cases, followed by Idiopathic 18%, Uremia 12 %, and Malignant 14 %. HIV infection was the least common cause of pericardial effusion, accounting for 2% of cases. Tachycardia was the most common clinical symptom, in 70% of patients, followed by Breathlessness (60%), and fever (56 %). Conclusions:Tachycardia, shortness of breath, fever, heaviness of chest, cough, chest pain, and other symptoms of pericardial effusion have been noted in this study. Tuberculosis, idiopathic/viral, uremic, neoplastic, CCF, hypothyroidism, post-MI, etc. are all major factors for the development of pericardial effusion.

Diagnostic value of bronchoscopy in sputum-negative pulmonary tuberculosis patients and its correlation with clinicoradiological features.

CONTEXT:Tuberculosis (TB) remains endemic in Saudi Arabia. Little local data have been reported on bronchoscopic evaluation of sputum-negative pulmonary TB patients, which poses a significant diagnostic and therapeutic challenge.AIMS:To determine the diagnostic value of bronchoscopy and bronchoalveolar lavage (BAL) and its correlation with clinical and radiological features in sputum-negative, culture-confirmed pulmonary TB patients.METHODS:We performed a retrospective analysis of patients with definite or probable pulmonary TB with overall negative (smear and/or polymerase chain reaction [PCR]) or scanty sputum that had undergone bronchoscopy with BAL over a period of 5 years. Patients’ symptoms, radiological features, lung lobe lavaged, BAL acid-fast bacilli (AFB) stain, Mycobacterium TB (MTB)-PCR, and mycobacterial cultures were analyzed. Mycobacterial cultures (either sputum or BAL) were used as a reference standard.RESULTS:Out of 154 patients, 49 (32%) were overall sputum negative and underwent a diagnostic bronchoscopy. Dry cough and fever were the most common symptoms. Uncontrolled diabetes mellitus was the most frequent comorbidity identified in 15 (31%) patients. Fifty-nine percent of the patients had diffuse lung infiltrates, with consolidation being the most common abnormality (41%), followed by cavitation (39%). Right upper lobe was the most frequent lung lobe lavaged (31%), while transbronchial lung biopsies (TBLB) were obtained in 21 (43%). BAL mycobacterial culture and MTB PCR were positive in 35 (71%) and 23 (47%) patients, respectively. Combined BAL MTB PCR and TBLB provided rapid diagnosis in 28 (57%) patients.CONCLUSIONS:An overall diagnostic yield of 90% was achieved with combined use of BAL MTB PCR, culture, and histopathology. Upper lobe lavage and presence of cavities on chest imaging had a higher diagnostic yield.

The risk of tuberculosis bacilli seeding during mediastinoscopy in mediastinal tuberculosis: Is it clinically important?

Mediastinoscopy is the gold standard for diagnosis in the absence of parenchymal lesions in mediastinal tuberculosis lymphadenitis. During mediastinoscopy biopsy, tuberculous bacillus seeding into the mediastinum is a rare complication. This study aimed to test the safety of mediastinoscopy in terms of Mycobacterium tuberculosis seeding in the mediastinum by microbiologically evaluating mediastinal lavage samples taken before and after biopsy. Classical cervical mediastinoscopy was performed all of patients and who were reported as granulomatous inflammatory events results of histopathological examinations and who underwent mediastinal lavage before and after biopsy, were included in the study. All the lavage fluids were tested for AFB and subjected to Mycobacterium tuberculosis PCR DNA testing and standard tuberculosis culture. The patients were divided into two groups, Group 1: Necrotizing granulomatous inflammation, Group 2: non-necrotizing granulomatous inflammation. The microbiological tests of the patients in Group 1 were negative before biopsy. However, in two patients of Group 1, the results of cultures of lavage fluids that taken from after biopsy were positive for tuberculosis. In all patients in Group 2, all microbiological tests of the lavage fluids were negative (Power of the decision: 99.8%, with 5% error). All of patients in group 1, Antituberculosis treatment was initiated and continued for 6 months. There weren’t seen any serius complications due to treatment and recurrence during the follow-up period. Mediastinoscopy can be used safely, with low morbidity and mortality rates and a high success rate for the diagnosis of mediastinal tuberculosis.

193. Impact of COVID-19 Pandemic on Pulmonary Tuberculosis Evaluations and Diagnosis at a Large Safety Net Hospital in Los Angeles, California

BackgroundThere is significant global concern that the COVID-19 pandemic may negatively impact tuberculosis (TB) control. This is a descriptive analysis of TB evaluations and diagnosis during 2019 (pre COVID-19 period) and 2020 (COVID-19 period) at the largest safety net hospital in Los Angeles County (LAC+USC Medical Center). MethodsThe medical records of patients diagnosed with pulmonary TB from January 1, 2019 to December 31, 2020 were identified through laboratory and electronic medical records. We included all patients with ≥ 1 sputum positive result for Mycobacterium tuberculosis (MTB) culture and reviewed their Xpert MTB/RIF MTB PCR. ResultsTable 1 shows summary of results. During the COVID-19 period, the number of patients evaluated for pulmonary TB decreased by 64% compared to the previous year (Figure 1). The proportion of patients with culture-confirmed TB disease however, was nearly identical (P=0.913) (Table 1). Sputum acid-fast bacilli (AFB) smear positivity increased 52% to 64% during COVID-19 (P=0.324) and disease severity as measured by chest radiograph, was significantly higher during the COVID-19 period (P = 0.031) (Figure 2). Trend of sputum AFB smear and culture samples collected from January 1, 2019 to December 31, 2020. Summary of results of patients diagnosed with pulmonary TB from January 1, 2019 to December 31, 2020 at LAC+USC Medical Center. Results of two-sample test for proportions of 2019 vs 2020 for cavitary lesions, extent of disease, and sputum positive AFB smear microscopy.ConclusionThese preliminary results suggest that when compared to the previous year, the number of pulmonary TB evaluations decreased by 64% during the COVID period. Whereas the proportion of patients diagnosed with TB disease was similar, TB patients during the COVID-19 period had more advanced disease at diagnosis, as measured by sputum smear AFB microscopy and disease severity on chest radiograph (P=0.031). These data suggest potentially consequential interruptions and delays in pulmonary TB diagnosis during the COVID-19 period. Disclosures Susan Bulter-Wu, PhD , Cepheid (Consultant)

Increased Detection of Mycobacterium tuberculosis Disease Using a Tissue-Based Laboratory-Developed Polymerase Chain Reaction Assay Compared to Standard Diagnostics.

Standard diagnostics for Mycobacterium tuberculosis (MTB) including acid-fast bacilli (AFB) smear and culture, and Xpert™ MTB/RIF real-time Polymerase Chain Reaction (RT-PCR; Xpert) have variable sensitivity and/or long turnaround times. We describe the clinical performance of a laboratory-developed tissue-based MTB PCR compared with AFB culture and Xpert using a composite reference standard (CRS). Over an 8-year period, MTB PCR was performed on pulmonary, pleural, or lymph node specimens for 36 patients. Of these, 11 met criteria for confirmed/probable MTB using CRS. MTB PCR was positive in 100% (11/11), AFB cultures were positive in 73% (8/11), and Xpert in 0% (0/4). MTB PCR was negative in 25 cases of "No MTB" (100% specific). The MTB PCR assay resulted faster than positive AFB culture (mean time 4.3 versus 21.2 days). Tissue-based MTB PCR was associated with increased and rapid detection of MTB, improving clinical sensitivity in strongly suspected MTB cases.

ACTIVE TB AFTER THE USE OF TOCILIZUMAB FOR COVID-19 INFECTION

TOPIC: Chest Infections TYPE: Fellow Case Reports INTRODUCTION: Tocilizumab is a humanized anti-IL-6 receptor antibody and inhibits the binding of IL-6 to its receptors, associated with Th17 and Th22 cell differentiation which is critical for anti-mycobacterial activity. It is commonly used in patients with active rheumatoid arthritis. During the COVID-19 pandemic, tocilizumab has been widely used in severe COVID-19 infection with elevated markers of systemic inflammation. We report a case of active tuberculosis after the use of tocilizumab for COVID-19 pneumonia. CASE PRESENTATION: An 80-year-old Asian female with hypertension, coronary artery disease presented to the emergency department(ED) due to a one-day duration of fever, cough, and altered mental status. About three months prior to presentation, she had COVID-19 pneumonia requiring prolong hospitalization which was complicated by acute respiratory distress syndrome. She received tocilizumab, remdesivir, steroids and hydroxychloroquine for COVID-19 infection. Following the hospital stay, she was discharged to a long-term acute care facility, and then went home. She is originally from China and moved to the United States 50 years ago. In the ED she was febrile (100.4°F) and hypoxemic, subsequently placed on 4L of nasal cannula. The laboratory data was remarkable for leukocytosis and lactic acidosis. The chest radiograph showed bilateral reticular nodular patchy opacities. The patient was admitted and empiric antibiotics were started for possible pneumonia. Despite this treatment, her respiratory status deteriorated and she was intubated on day 4, with CT chest (figure1) revealing innumerable bilateral micronodules with centrilobular distribution and tree-in-bud opacities. There were also 2 large cavitary lesions in the right upper lobe. The sputum specimen was sent, which returned positive for Acid-Fast Bacillus. In addition, Mycobacterium tuberculosis PCR on sputum was positive. Therefore, the first-line anti-tuberculosis agents including rifampin, isoniazid, pyrazinamide, and ethambutol were started. The Mycobacterium tuberculosis Complex was isolated on sputum 3 weeks later. DISCUSSION: The data from clinical trials indicate that the use of tocilizumab is associated with a very low or absent risk of tuberculosis reactivation. However, this case highlights the judicious use of tocilizumab in patients who are at high risk of exposure or reactivation such as immigrants from endemic regions, IV drug users and health care workers, etc. In our case, the patient had other factors including severe COVID-18 infection, use of steroids, prolonged hospital stay, and malnutrition which might compromise the immune system, and predispose to active tuberculosis. CONCLUSIONS: We suggest that tests be performed to rule out latent tuberculosis in selected patients prior to tocilizumab use and monitor all patients for active tuberculosis during treatment. REFERENCE #1: Scriba TJ, Kalsdorf B, Abrahams DA, Isaacs F, Hofmeister J, Black G, et al. Distinct, specific IL-17- and IL-22-producing CD4+ T cell subsets contribute to the human anti-mycobacterial immune response. J Immunol. 2008;180(3):1962-70. REFERENCE #2: Cantini F, Nannini C, Niccoli L, Petrone L, Ippolito G, Goletti D. Risk of Tuberculosis Reactivation in Patients with Rheumatoid Arthritis, Ankylosing Spondylitis, and Psoriatic Arthritis Receiving Non-Anti-TNF-Targeted Biologics. Mediators Inflamm. 2017;2017:8909834. REFERENCE #3: Koike T, Harigai M, Inokuma S, Ishiguro N, Ryu J, Takeuchi T, et al. Postmarketing surveillance of tocilizumab for rheumatoid arthritis in Japan: interim analysis of 3881 patients. Ann Rheum Dis. 2011;70(12):2148-51. DISCLOSURES: No relevant relationships by Goutham Dronavalli, source=Web Response No relevant relationships by Sungryong Noh, source=Web Response

Tuberculosis peritoneal, un diagnóstico diferencial para ascitis en cirrosis

Se presenta el caso de un paciente con antecedente de consumo crónico de alcohol, que consultó por dolor abdominal inespecífico, fiebre intermitente no cuantificada y pérdida de peso, con posterior aumento del perímetro abdominal. Se encontró ascitis y hallazgos en imágenes que sugerían cirrosis. El estudio del líquido ascítico fue no hipertensivo con predominio de linfocitos y niveles de adenosina-desaminasa (ADA) elevados. La ecografía y tomografía de abdomen mostraron el engrosamiento del peritoneo y la biopsia peritoneal por laparoscopia fue compatible con enfermedad granulomatosa, con reacción en cadena de la polimerasa (PCR) positiva para Mycobacterium tuberculosis en un paciente sin otras causas de inmunosupresión. Este caso muestra la necesidad de mantener una alta sospecha clínica de TB en patologías abdominales con clínica inespecífica, aun en pacientes sin inmunocompromiso claro.

Development and evaluation of a multiplex loop-mediated isothermal amplification (LAMP) assay for differentiation of Mycobacterium tuberculosis and non-tuberculosis mycobacterium in clinical samples.

IntroductionThe rapid and accurate diagnosis of tuberculosis (TB) is important to reduce morbidity and mortality rates and risk of transmission. Therefore, molecular detection methods such as a real-time PCR–based assay for Mycobacterium tuberculosis (MTB) have been commonly used for diagnosis of TB. Loop-mediated isothermal amplification (LAMP) assay was believed to be a simple, quick, and cost-effective isothermal nucleic acid amplification diagnostic test for infectious diseases. In this study, we designed an in-house multiplex LAMP assay for the differential detection of MTB and non-tuberculosis mycobacterium (NTM), and evaluated the assay using clinical samples.Material and methodsFor the multiplex LAMP assay, two sets of specific primers were designed: the first one was specific for IS6110 genes of MTB, and the second one was universal for rpoB genes of mycobacterium species including NTM. MTB was confirmed with a positive reaction with both primer sets, and NTM was identified with a positive reaction by only the second primer set without a MTB-specific reaction. Total 333 clinical samples were analyzed to evaluate the multiplex LAMP assay. Clinical samples were composed of 195 positive samples (72 MTB and 123NTM) and 138 negative samples. All samples were confirmed positivity or negativity by real-time PCR for MTB and NTM. Analytical sensitivity and specificity were evaluated for the multiplex LAMP assay in comparison with acid fast bacilli staining and the culture method.ResultsOf 123 NTM samples, 121 were identified as NTM and 72/72 MTB were identified as MTB by the multiplex LAMP assay. False negative reactions were seen only in two NTM positive samples with co-infection of Candida spp. All 138 negative samples were identified as negative for MTB and NTM. Analytical sensitivity of the multiplex LAMP assay was 100% (72/72) for MTB, and 98.4% (121/123) for NTM. And the specificity of assay was 100% (138/138) for all.ConclusionsOur newly designed multiplex LAMP assay for MTB and NTM showed relatively good sensitivity in comparison with previously published data to detect isolated MTB. This multiplex LAMP assay is expected to become a useful tool for detecting and differentiating MTB from NTM rapidly at an acceptable sensitivity.

Evaluation of Truenat MTB/RIF Test in Comparison with Microscopy and Culture for Diagnosis of Extrapulmonary Tuberculosis in a Tertiary Care Centre

Introduction: Worldwide, Extrapulmonary Tuberculosis (EPTB) accounts for 15-20% of all cases of TB. The diagnosis of EPTB is a big challenge, as the number of Mycobacterium tuberculosis(MTB) bacilli in the tissues and other organs is often very low. Truenat MTB/RIF (rifampicin) is a novel method, which is battery operated, point-of-care and chip-based Real Time Polymerase Chain Reaction (RT-PCR) micro device. Aim: To evaluate Truenat as a screening test in the diagnosis of EPTB in comparison with microscopy and culture. Materials and Methods: A prospective cross-sectional study was carried out over a year in which samples from suspected cases of EPTB fitting in the inclusion criteria were subjected to Ziehl-Neelsen (ZN) staining for smear microscopy, culture on Lowenstein Jensen (LJ) medium and PCR for MTB by Truenat. Comparisons were made between the tests and the data was presented using summary statistics with 95% Confidence Interval (CI). Results: A total of 248 samples were received from suspected cases of EPTB. Out of the different samples tested, 9 (3.6%) were positive with Truenat MTB. The predominant type of EPTB observed in the study was lymph node Tuberculosis (TB) (66.6%) followed by intestinal, pleural and skeletal TB. Out of the 106 samples tested for culture, four were culture positive for MTB and out of 178 samples tested for microscopy, three were positive for acid fast bacilli. Sensitivity, specificity, Negative Predictive Value (NPV), Positive Predictive Value (PPV), observed agreement of Truenat with culture and microscopy were 100%, 95.1%, 100%, 44.4%, 95.3% and 100%, 96.6%, 100%, 33.3%, 96.6%, respectively. Conclusion: Truenat MTB test is a cost-effective rapid molecular test with good sensitivity and specificity for the diagnosis of EPTB in low resource settings.