Recommendations of the German Central Committee against Tuberculosis (DZK) and the German Respiratory Society (DGP) for the Diagnosis and Treatment of Non-tuberculous Mycobacterioses

Non-tuberculous mycobacterioses comprise a group of diseases caused by mycobacteria which do not belong to the Mycobacterium (M.) tuberculosis-complex and are not ascribed to M. leprae. These mycobacteria are characterized by a broad variety as to environmental distribution and adaptation. Some of the species may cause specific diseases, especially in patients with underlying immunosuppressive diseases, chronic pulmonary diseases or genetic predisposition, respectively. Worldwide, a rising prevalence and significance of non-tuberculous mycobacterioses is recognized. The present recommendations summarise current aspects of epidemiology, pathogenesis, clinical aspects, diagnostics - especially microbiological methods including susceptibility testing -, and specific treatment for the most relevant species. Diagnosis and treatment of non-tuberculous mycobacterioses during childhood and in HIV-infected individuals are described in separate chapters.

[Pathogenicity of Mycobacterium kansasii]

BACKGROUND

In a recent prospective study on pulmonary infections with non-tuberculous mycobacteria (NTM) led by the WATL group, disease rates in patients with M. kansasii infection were found to be 100 %. In the present study we re-evaluated the pathogenicity of M. kansasii infections in a large lung diseases treatment center in Berlin (Lungenklinik Heckeshorn).

METHODS

All patients in whose respiratory specimen cultures M. kansasii was detected between January 2003 and June 2013 were included. The 2007 ATS diagnostic criteria were applied to differentiate disease from asymptomatic infection. The strains were further investigated by sequencing of the 16S-23S rDNA internal transcribed spacer (ITS) region.

RESULTS

We evaluated 43 consecutive cases. Complete patient data were available in 38 cases. In one patient, no culture results were obtained, in 37 patients M. kansasii was isolated and patient data could be retrieved. In 25/37 patients (68 %) clinical disease was present so that a specific treatment was initiated (underlying diseases were COPD in 8/25 (32 %), bronchiectasis in 5/25 (20 %), TB scar or scar due to prior chest surgery in 3/25 (12 %) and alcohol abuse in 4/25 (16 %)). Twelve out of 37 patients (32 %) were found to be colonized or asymptomatically infected (underlying diseases were COPD in 7/12 (58 %), bronchiectasis in 3/12 (25 %) and TB scar or scar due to prior chest surgery in 3/12 (25 %)). Sequencing results identified 30 strains as genotype I, and 2 strains as genotype II. In 22/30 cases (73 %) genotype I was considered pathogenic.

CONCLUSIONS

In our cohort, we could not confirm the high M. kansasii pathogenicity of 100 % found in a previous multi-center study; we therefore support the clinical and semiquantitative microbiologic diagnostic criteria also for infection with M. kansasii.

[Interferon-gamma release assays for hospital-based tuberculosis diagnostics in children and adolescents--a retrospective analysis]

OBJECTIVE

Interferon-gamma release assays (IGRA) are well established for diagnosing latent tuberculosis infection in adults. Evidence for their diagnostic relevance in children is still insufficient. The aim of this study was to evaluate the sensitivity and specificity of IGRA compared to the tuberculin skin test (TST) in a local population of children and adolescents presenting to our lung clinic with a specialised outpatient department.

METHODS

Records from all patients evaluated for tuberculosis at our centre between 2009 and 2011 were analysed retrospectively. Complete data sets were available for 80 children and adolescents (age 3 months to 17 years) in the following diagnostic groups: active pulmonary tuberculosis (MTB, n = 13), latent tuberculosis infection (LTBI, n = 15) and controls with tuberculosis exposure (n = 40), non-tuberculous mycobacterial disease (NTM, n = 2) or other lung diseases (n = 10).

RESULTS

All 13 patients with MTB were positive on both IGRA and TST. Among the LTBI patients, 14 /15 had a positive IGRA and 14 /15 a positive TST result. In the control group 0 /52 exceeded the IGRA cut-off, while three patients had a positive TST due to a cross reaction with BCG or NTM.

DISCUSSION

IGRA and TST results are highly correlated in paediatric patients with active or latent tuberculosis. IGRA sensitivity was comparable to that of the TST with a higher specificity as expected. The importance of IGRA in the hospital setting to guide diagnostic algorithms in an unselected population should be further evaluated in prospective studies.

Successful oral desensitization to i.v. para-aminosalicylic acid (PAS) using encapsulated PAS dry substance

INTRODUCTION

para-Aminosalicylic acid (PAS) is commonly used in the treatment of drug-resistant tuberculosis, including multidrug-resistant tuberculosis. Since its first use in the 1940s, hypersensitivity reactions frequently limit its use in clinical practice. Cases of successful desensitization against PAS using orally administered ascending doses are described in the literature.

CASE REPORT

A 25-year-old patient with severe pulmonary multidrug-resistant tuberculosis developed drug fever with rash, acral cyanosis, and shivering immediately after the intravenous application of PAS. Hard gelatine capsules containing PAS dry substance were prepared in order to desensitize this patient. Encapsulated PAS was applied orally in rising doses starting with 10 mg/day and doubling the dose every 2 days until the half-maximal dose of 5,120 mg was reached. Desensitization covers a period of 21 days. Subsequent intravenous application of PAS at the full dose was well tolerated. In a 12-month follow-up period, no more allergic reactions appeared.

CONCLUSIONS

PAS dry substance encapsulated in hard gelatine capsules and administered orally in rising concentrations may be useful to archive a successful desensitization for subsequent intravenous applications.

A prediction model for bacterial etiology in acute exacerbations of COPD

OBJECTIVES

Bacteria play a leading role in acute exacerbations of chronic obstructive pulmonary disease (COPD), but we lack predictors of bacterial etiology. We developed a prediction model for infection with gram-negative enteric bacteria (GNEB) and Pseudomonas aeruginosa.

METHODS

Clinical presentation, sputum characteristics, microbial sputum patterns, lung function and previous and concomitant medication were prospectively recorded in patients with moderate to severe exacerbation of COPD. Risk factors for a specific bacterial etiology were calculated and a prediction model developed.

RESULTS

A total of 193 patients with acute exacerbation were included. In 121 (62.6%) of them a microbial etiology could be identified, most frequently Haemophilus influenzae (32 strains), Streptococcus pneumoniae (22 strains) and P. aeruginosa (12 strains). Multivariate analysis identified severe airflow obstruction and use of systemic steroids as predictors for exacerbation due to gram-negative enteric bacilli and P. aeruginosa. A prediction model including FEV1 < 35% of predicted value, systemic steroid use and prior antibiotic therapy within preceeding 3 months had a negative predictive of 89%, being a helpful tool in excluding patients at risk of exacerbation due to gram-negative enteric bacilli and P. aeruginosa when all criteria are absent.

CONCLUSION

A simple prediction model based on three factors may identify COPD patients at low risk for exacerbations with gram-negative enteric bacilli and P. aeruginosa. Bacterial Etiology in COPD Exacerbations.

Interferon- Release Assays Improve the Diagnosis of Tuberculosis and Nontuberculous Mycobacterial Disease in Children in a Country with a Low Incidence of Tuberculosis

BACKGROUND

Diagnosis of childhood tuberculosis (TB) is challenging. The widely used tuberculin skin test (TST) may produce -positive results because of cross-reactivity with nontuberculous mycobacteria or bacille Calmette-Guerin vaccination, resulting in unnecessary treatment. Two recently developed interferon- gamma release assays (IGRAs) show good diagnostic accuracy for active TB in adults; pediatric data are limited, particularly in areas with a low incidence of TB. We assessed the diagnostic accuracy of IGRAs for TB in children in an area with a low incidence of TB.

METHODS

In a hospital-based study, the diagnostic accuracy of the TST and 2 IGRAs (T SPOT-TB [T-SPOT; Oxford Immunotec] and QuantiFERON-TB Gold In-Tube [QFT-IT; Cellestis]) were assessed in a cohort of 73 children (median age, 39 months); 28 children with bacteriologically confirmed TB were compared with children without TB (23 with bacteriologically confirmed nontuberculous mycobacterial lymphadenitis and 22 with other nonmycobacterial respiratory tract infections).

RESULTS

The specificity for TB of QFT-IT was 100% (95% confidence interval [CI], 91%-100%), and the specificity of T-SPOT was 98% (95% CI, 87%-100%), both of which were considerably higher than the specificity of TST (58%; 95% CI, 42%-73%). The specificity of the TST was 10.5% (95% CI, 1%-33%) in children with nontuberculous mycobacterial lymphadenitis and was 100% (95% CI, 83%-100%) in children with other nonmycobacterial respiratory tract infections. The sensitivity of both QFT-IT and T-SPOT was 93% (95% CI, 77%-99%), and the sensitivity of the TST was 100% (95% CI, 88%-100%). Agreement between the IGRAs was 95.6% ( kappa =0.91); 6.8% of the IGRAs showed indeterminate results.

CONCLUSIONS

Both IGRAs showed high diagnostic value in bacteriologically confirmed childhood TB. Their advantage in this study, when performed in addition to the TST, was the ability to distinguish -positive TST results caused by nontuberculous mycobacterial disease, thereby reducing overdiagnosis of TB and guiding clinical management.

Pneumocystis jiroveci-Pneumonie bei immunsupprimierten Patienten ohne AIDS-Erkrankung - eine Fallserie

BACKGROUND AND OBJECTIVE

Patients with pneumonia resistant to treatment are a common problem in chest hospitals. Pneumocystis jiroveci (Pc) should always be considered as an opportunistic pathogen in case of potential, especially T cell-related immunodeficiency, even if AIDS is not obvious. We report on cases of Pneumocystis jiroveci pneumonia (PcP) (n = 1921) without associated AIDS in a chest hospital.

PATIENTS AND METHODS

We assessed 1921 inpatients presenting with pneumonia during January 1 (st) 1996 and September 30 (th) 2005 in our hospital. Identification of the cases with PcP was based on discharge diagnosis as well as on our microbiological database (detection of Pc by immunofluorescence-test (IFT) and/or PCR).

RESULTS

The diagnosis of PcP was made in 14 patients (11 males, 3 females) without associated AIDS. All patients were treated with immunosuppressive medication before admission. CD4 cell-counts were substantially decreased (CD4 cells < 200/microl) in 11 patients. To establish the diagnosis of PcP a Pc-PCR (using broncho-alveolar lavage (BAL) as the best material) was necessary in 8 patients, since the Pc-IFT proved positive only in 6 patients. Severe hypoxemia had to be managed by noninvasive ventilation in 3 patients, while another 4 patients had to be ventilated invasively. The mortality rate was 2 out of 14 patients.

CONCLUSIONS

PcP is an important disease in the differential diagnosis of pneumonia and at the same time constitutes a severe pulmonary complication in immunodeficient patients. If immunodeficiency is suspected, a CD4 cell-count as well as bronchoscopy with BAL should be performed to diagnose PcP. As expected, Pc-PCR was superior to Pc-IFT and should therefore be used on a routine basis for diagnosing PcP.

Characteristics and outcome of patients with active pulmonary tuberculosis requiring intensive care

Severe tuberculosis (TB) requiring intensive care unit (ICU) care is rare but commonly known to be of markedly bad prognosis. The present study aimed to describe this condition and to determine the mortality rate and risk factors associated with mortality. Patients with confirmed TB admitted to ICU between 1990 and 2001 were retrospectively identified and enrolled. Clinical, radiological and bacteriological data at admission and during hospital stay were recorded. A multivariate analysis was performed to identify the predictive factors for mortality. A total of 58 TB patients (12 females, mean age 48 yrs) admitted to ICU were included. Mean Acute Physiology and Chronic Health Evaluation (APACHE) II score at admission was 13.1+/-5.6 and 22 of 58 (37.9%) patients required mechanical ventilation. The in-hospital mortality was 15 of 58 (25.9%); 13 (22.4%) patients died in the ICU. The mean survival of patients who died was 53.6 days (range 1-229), with 50% of the patients dying within the first 32 days. The factors independently associated with mortality were: acute renal failure, need for mechanical ventilation, chronic pancreatitis, sepsis, acute respiratory distress syndrome, and nosocomial pneumonia. These data indicate a high mortality of patients with tuberculosis requiring intensive care unit care and identifies new independently associated risk factors.

Interferon-γ-Tests in der Tuberkulose-Diagnostik - Aktueller Stand

Up to now the diagnosis of latent tuberculosis infection (LTBI) was based solely on the tuberculin skin test. However, this method offers neither 100 % sensitivity nor -- and this is in particular due to its cross-reactivity with BCG and environmental mycobacteria -- a 100 % specificity. The demand in Germany for a more reliable in vitro test is currently enhanced by the change from the multipuncture test to the intradermal (Mendel-Mantoux) test and by the uncertainty resulting from the ceased production of the tuberculin previously used in Germany. The manufacturers of immunologic test methods such as the QuantiFERON-TB Gold In-Tube (ELISA assay) and the T SPOT-TB Test (ELISPOT assay), which are based on the Interferon-gamma (IFN-gamma) production of sensitized T lymphocytes, offer their products as possible alternatives. This article explains the function of the IFN-gamma tests and gives an overview of the most recent data, possible indications and the open scientific questions to be investigated by future clinical studies. Although the new test methods have the potential to eventually prevail as an additional helpful diagnostic tool, the authors consider a complete replacement of the tuberculin skin test as premature. The IFN-gamma tests may, however, prove already now to be a useful additional diagnostic method.

Monotherapy of nosocomial pneumonia

Nosocomial pneumonia remains a common problem and is the leading cause of death among patients with nosocomial infection. However, the initial empiric therapy of nosocomial pneumonia is directed at the leading organisms common to all patients, and for many patients monotherapy is adequate for at least 48 hours, at which time the microbiological results of appropriate diagnostic procedures should be known and the treatment can be focused. The currently available antimicrobial agents such as third- and fourth-generation cephalosporins, piperacillin plus tazobactam, carbapenems, and some fluoroquinolones are highly active and bactericidal. They should be used in consideration of current pharmacodynamic knowledge, which will lead to convincing clinical results. Combination of antibiotics is necessary only in specific situations or for the amelioration of special pathogens, such as Pseudomonas aeruginosa, Acinetobacter spp., and against mixed aerobic and anaerobic infections.

Der Tuberkulose-Schnelltest von DiaVita - keine Alternative zum Tuberkulinhauttest

New methods for diagnosing active tuberculosis (TB) and/or latent tuberculosis infection have been offered increasingly during recent years, also in Germany. The Tuberculosis Rapid Assay ('Tuberkulose Schnelltest [TB-ST]') from DiaVita is a serologic test method aiming to detect, within a few minutes, tuberculosis-specific antibodies in whole blood or serum of tuberculosis patients. Due to a lack of data, it is, however, hardly possible to assess this test on a scientific basis. With a relatively high specificity (according to DiaVita over 95 %) but inadequate sensitivity (approximately 60 - 80 %), particularly in paucibacillary types of TB, we consider this method of limited value for routine testing. If active TB is strongly suspected, a positive test result may corroborate the tentative diagnosis, whereas a negative test result is not helpful for differential diagnosis considering the great number of false-negative test results to be expected. The greatest value of the test seems to be in bacteriologically confirmed TB, in which however there may be no need for additional diagnostics. The test has not been evaluated, and in our opinion is probably unsuitable for detecting latent TB infection. Data is also lacking for a number of patient groups in urgent need of a reliable alternative to the tuberculin skin test (e. g., immunocompromised patients, children). It is not clear whether this method will find a place in routine TB diagnostics. We therefore cannot recommend this test as a routine diagnostic tool for TB at present.

Influence of ionizing radiation on nucleus 24 cochlear implants

HYPOTHESIS

To evaluate the influence of conventional or hyperfractionated radiotherapy on Nucleus CI24M or CI24R(CS) implant systems.

BACKGROUND

As a consequence of more than 70,000 cochlear implant recipients worldwide, the potential need for radiotherapy is an issue requiring consideration by both implantees and implantation centers. Conditions requiring radiotherapy of the head may include head, neck, or brain tumors.

METHODS

The study examines the effect of ionizing radiation on cochlear implant function. The implanted devices examined were the Nucleus CI24M and Nucleus CI24R(CS). In a modeled study, two implants of each type were treated with fraction schemes most frequently used in clinical routine (e.g., conventional fractionation [total dose, 120 Gy] and hyperfractionation [total dose, 116 Gy]). Parameters quantified were the implant output amplitude changes at high and low current level (current levels 255 and 100, respectively), the charge balance of the biphasic pulse, and the accuracy of the impedance telemetry function.

RESULTS

Within the clinically relevant dose range (< 80 Gy), implant function in all four devices was normal. Failure occurred in one Nucleus CI24R(CS) device treated with hyperfractionation. A dramatic drop in the output amplitude at 106 Gy was observed, and the impedance measurement failed at a total dose of 111 Gy.

CONCLUSION

The results suggest that conventional or hyperfractionated radiotherapy can be applied safely at Nucleus CI24M or CI24R(CS) implant systems in a patient-like setting. Therefore, the authors propose that the results of the study can be applicable in clinical practice.

Ampicillin + sulbactam vs. clindamycin ± cephalosporin for the treatment of aspiration pneumonia and primary lung abscess

Aspiration pneumonia, necrotising pneumonia and primary lung abscess are complications arising from the aspiration of infectious material from the oral cavity or stomach. There is limited information on optimal antibacterial therapeutic regimens. Patients with pulmonary infection following aspiration (n = 95) were included in a prospective, open, randomised, comparative multicentre trial to compare the safety, clinical and bacteriological efficacy of ampicillin + sulbactam vs. clindamycin +/- cephalosporin. Treated patients (n = 70) received sequential antibiotic therapy with either ampicillin + sulbactam (n = 37) or clindamycin (n = 33), with or without a second- or third-generation cephalosporin, administered until the complete resolution of clinical and radiological abnormalities. Definite or presumptive pathogens were isolated from 58 patients. Mean duration of therapy was 22.7 days for ampicillin + sulbactam and 24.1 days for clindamycin. In patients treated with ampicillin + sulbactam, the clinical response was 73.0% at the end of therapy and 67.5% 7-14 days after therapy. For clindamycin, the rates were 66.7% and 63.5%, respectively. Bacteriological response was similar in both treatment arms. Nine patients died (12.9%), with a Simplified Acute Physiology Score of > 30 points being the only significant predictive factor for therapeutic failure. Ampicillin + sulbactam and clindamycin +/- cephalosporin were both well-tolerated and proved equally effective in the treatment of aspiration pneumonia and lung abscess.