Shortening Isolation of Patients With Suspected Tuberculosis by Using Polymerase Chain Reaction Analysis: A Nationwide Cross-sectional Study.

BACKGROUND: Isolation of patients suspected for pulmonary tuberculosis is guided by serial sputum smears. This can result in isolation for days for patients with noncontagious tuberculosis. To determine whether a single sample negative for Mycobacterium tuberculosis complex at polymerase chain reaction (PCR) can guide isolation. METHODS: We retrospectively evaluated sputum samples analyzed for M. tuberculosis complex at the International Reference Laboratory of Mycobacteriology, Copenhagen, Denmark in 2002-2011. We selected culture-confirmed tuberculosis cases with ≥3 samples within 14 days before or after the initial culture-positive sample. We repeated the process for those with ≥2 samples within 28 days. The primary outcome was PCR-negative, smear-positive patients. RESULTS: We included 53 533 sputum samples from 20 928 individuals; 1636 had culture-confirmed tuberculosis. Of these, 856 had ≥3 sputum samples analyzed within the 28 days, and 482 had ≥1 PCR result. Nine patients (2.5% of smear-positive patients) were smear positive/PCR negative; 8 of the 9 had a smear-positive result in only 1 of 3 samples, and 5 had a low smear grade. Of 722 patients with 2 samples, 7 (1.3% of smear-positive patients) were smear positive/PCR negative. Overall, none were smear positive for the sample that produced the negative PCR result. CONCLUSIONS: Primary PCR identified >97% of serial smear-positive cases. The majority of the missed cases had low-grade smears. Nevertheless, the occurrence of smear-positive/PCR-negative cases underlines the importance of increasing the quantity and quality of samples. Moreover, it is important that samples analyzed with PCR are cultured, owing to higher-sensitivity drug susceptibility testing, differential diagnosis, and surveillance.

Effectiveness of anti-tumour necrosis factor-α therapy in Danish patients with inflammatory bowel diseases.

INTRODUCTION: The objective of this study was to evaluate the outcome of anti-tumour necrosis factor-α (anti-TNF) treatment in a large cohort of patients with inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC) in clinical practice and to establish a cohort for future studies of genetic markers associated with treatment response. METHODS: A national, clinically based cohort of previously naïve anti-TNF treated patients from 18 medical departments was established. The patients were screened for tuberculosis prior to treatment initiation. By combining the unique personal identification number of Danish citizens (the CPR number) from blood samples with data from the National Patient Registry, patients with International Classification of Diseases, Version 10 (ICD-10) codes K50-K63 were identified. Treatment efficacy reflected the maximum response within 22 weeks. RESULTS: Among 492 patients with CD and 267 patients with UC, 74%/13%/14% and 65%/12%/24% were responders, partial responders and non-responders to anti-TNF therapy, respectively. More patients with UC than with CD were non-responders (odds ratio (OR) = 1.96, 95% confidence interval (CI): 1.34-2.87, p = 0.001). Young age was associated with a beneficial response (p = 0.03), whereas smoking ≥ 10 cigarettes/day was associated with non-response among patients with CD (OR = 2.33, 95% CI: 1.13-4.81, p = 0.03). CONCLUSION: In this clinically based cohort of Danish patients with IBD treated with anti-TNF, high response rates were found. Heavy smoking was associated with non-response, whereas young age at treatment initiation was associated with a beneficial response among patients with CD. Thus, the results obtained in this cohort recruited from clinical practice were similar to those previously obtained in clinical trials. FUNDING: The work was funded by Health Research Fund of Central Denmark Region, Colitis-Crohn Foreningen and the University of Aarhus (PhD grant). TRIAL REGISTRATION: Clinicaltrials NCT02322008.

Polymorphisms in the inflammatory pathway genes TLR2, TLR4, TLR9, LY96, NFKBIA, NFKB1, TNFA, TNFRSF1A, IL6R, IL10, IL23R, PTPN22, and PPARG are associated with susceptibility of inflammatory bowel disease in a Danish cohort.

BACKGROUND: The inflammatory bowel diseases (IBD), Crohn's disease (CD) and ulcerative colitis (UC), result from the combined effects of susceptibility genes and environmental factors. Polymorphisms in genes regulating inflammation may explain part of the genetic heritage. METHODS: Using a candidate gene approach, 39 mainly functional single nucleotide polymorphisms (SNPs) in 26 genes regulating inflammation were assessed in a clinical homogeneous group of severely diseased patients consisting of 624 patients with CD, 411 patients with UC and 795 controls. The results were analysed using logistic regression. RESULTS: Sixteen polymorphisms in 13 genes involved in regulation of inflammation were associated with risk of CD and/or UC (p ≤ 0.05). The polymorphisms TLR2 (rs1816702), NFKB1 (rs28362491), TNFRSF1A (rs4149570), IL6R (rs4537545), IL23R (rs11209026) and PTPN22 (rs2476601) were associated with risk of CD and the polymorphisms TLR2 (rs1816702), TLR4 (rs1554973 and rs12377632), TLR9 (rs352139), LY96 (rs11465996), NFKBIA (rs696), TNFA (rs1800629), TNFRSF1A (rs4149570), IL10 (rs3024505), IL23R (rs11209026), PTPN22 (rs2476601) and PPARG (rs1801282) were associated with risk of UC. When including all patients (IBD) the polymorphisms TLR2 (rs4696480 and rs1816702), TLR4 (rs1554973 and rs12377632), TLR9 (rs187084), TNFRSF1A (rs4149570), IL6R (rs4537545), IL10 (rs3024505), IL23R (rs11209026) and PTPN22 (rs2476601) were associated with risk. After Bonferroni correction for multiple testing, both the homozygous and the heterozygous variant genotypes of IL23R G>A(rs11209026) (OR(CD,adj): 0.38, 95% CI: 0.21-0.67, p = 0.03; OR(IBD,adj) 0.43, 95% CI: 0.28-0.67, p = 0.007) and PTPN22 1858 G>A(rs2476601) (OR(CD,unadj) 0.54, 95% CI: 0.41-0.72, p = 7*10-4; OR(IBD,unadj): 0.61, 95% CI: 0.48-0.77, p = 0.001) were associated with reduced risk of CD. CONCLUSION: The biological effects of the studied polymorphisms suggest that genetically determined high inflammatory response was associated with increased risk of CD. The many SNPs found in TLRs suggest that the host microbial composition or environmental factors in the gut are involved in risk of IBD in genetically susceptible individuals.

Non-tuberculous mycobacteria and the performance of interferon gamma release assays in Denmark.

BACKGROUND: The QuantiFERON-TB-Gold Test (QFT) is more specific than the Mantoux skin-test to discriminate between Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterial (NTM) infections. Here we study the performance of the QFT in patients with NTM disease. METHODS: From 2005 to 2011, nationwide patient data on positive NTM cultures (n = 925) were combined with nationwide data on QFT results (n = 16,133), both retrieved from the International Reference Laboratory of Mycobacteriology, Denmark. A total of 112 patients with NTM infections had a QFT performed, 53 patients had definite NTM disease, 10 had possible disease and 49 had NTM colonization. RESULTS: QFT was positive in 8% (4/53) of patients with definite disease, 40% (4/10) with possible disease and 31% (15/49) with colonization. Positivity rate was lowest among patients with definite disease infected with NTM without the RD1 region 4% (2/50). None of the 15 children with MAC lymphadenitis had a positive QFT. CONCLUSION: This study is one of the largest assessing IGRAs in patients with NTM disease in a TB low-incidence setting. Our study showed that the QFT holds potential to discriminate between NTM and MTB infections. We found no positive IGRA test results among children with NTM not sharing the RD1-region of MTB resulting in a 100% specificity and we suggest that a QFT in a child presenting with cervical lymphadenitis may be helpful in distinguishing NTM from TB lymphadenitis.

Inventory study of non-tuberculous mycobacteria in the European Union.

BACKGROUND: Since non-tuberculous mycobacteria (NTM) disease is not notifiable in most European Union (EU) and European Economic Area (EEA) countries, the epidemiological situation of the >150 NTM species is largely unknown. We aimed to collect data on the frequency of NTM detection and NTM species types in EU/EEA countries. METHODS: Officially nominated national tuberculosis reference laboratories of all EU/EEA countries were asked to provide information on: laboratory routines for detection and identification of NTM, including drug sensitivity testing (DST) methods; data on the number and type of NTM species identified; coverage and completeness of the provided data on NTM; type and number of human specimens tested for NTM; and number of specimens tested for Mycobacterium tuberculosis complex and NTM. This information was summarized and the main results are described. RESULTS: In total, 99 different NTM species were identified with M. avium, M. gordonae, M. xenopi , M. intracellulare, and M. fortuitum identified most frequently. Seven percent of the NTM species could not be identified. NTM was cultured from between 0.4-2.0% of the specimens (data from four countries). The laboratories use culturing methods optimised for M. tuberculosis complex. Identification is mainly carried out by a commercial line probe assay supplemented with sequencing. Most laboratories carried out DST for rapid growers and only at the explicit clinical request for slow growers. CONCLUSION: It is likely that the prevalence of NTM is underestimated because diagnostic procedures are not optimized specifically for NTM and isolates may not be referred to the national reference laboratory for identification. Due to the diagnostic challenges and the need to establish the clinical relevance of NTM, we recommend that countries should concentrate detection and identification in only few laboratories.

A review of paediatric tuberculosis in Denmark: 10-year trend, 2000-2009.

Paediatric tuberculosis (TB) is a key indicator for recent transmission and presents a reservoir for the disease. We describe trends in epidemiology, microbiological characteristics and treatment outcome in Denmark between 2000 and 2009. Data were retrieved from the national TB surveillance system and the International Reference Laboratory of Mycobacteriology. In total, 323 TB cases were reported in children aged <15 years, accounting for 7.6% of all notified cases in Denmark. The overall incidence rate of childhood TB declined from 4.1 per 100,000 to 1.9 per 100,000 in the study period. Immigrant children comprised 79.6% of all cases, with the highest incidence rate of 94.1 per 100,000 children in 2001. In contrast to immigrant children, the majority of Danish children were aged <5 years and had a known exposure to TB. Pulmonary TB was the commonest presentation. Only half of the cases were culture confirmed. We observed an overall decreasing trend in the child to adult notification ratio, but a slight increase in the ratio when calculated specifically for ethnic Danes. Childhood TB needs continuous attention with a special focus on risk groups. Emphasis on improving early TB case detection, contact tracing and further implementation of preventive treatment is necessary.

Rifampin heteroresistance in Mycobacterium tuberculosis cultures as detected by phenotypic and genotypic drug susceptibility test methods.

Tuberculosis patients may harbor both drug-susceptible and -resistant bacteria, i.e., heteroresistance. We used mixtures of rifampin-resistant and -susceptible Mycobacterium tuberculosis strains to simulate heteroresistance in patient samples. Molecular tests can be used for earlier discovery of multidrug resistance (MDR), but the sensitivity to detect heteroresistance is unknown. Conventional phenotypic drug susceptibility testing was the most sensitive, whereas two line probe assays and sequencing were unable to detect the clinically important 1% resistant bacteria.

Can molecular methods detect 1% isoniazid resistance in Mycobacterium tuberculosis?

Patients may harbor both drug-susceptible and -resistant bacteria, representing heteroresistance. We studied mixtures of isoniazid-resistant and -susceptible Mycobacterium tuberculosis strains. Conventional drug susceptibility testing was the most sensitive method of detection, whereas the line probe assay and sequencing were not able to detect the clinically relevant 1% proportion of resistant bacteria.

Chronic respiratory disease, inhaled corticosteroids and risk of non-tuberculous mycobacteriosis.

BACKGROUND: Chronic respiratory disease and inhaled corticosteroid (ICS) therapy for chronic obstructive pulmonary disease (COPD) increase the risk of pneumonia. Few data are available on the association of these risk factors with non-tuberculous mycobacterial (NTM) pulmonary disease. METHODS: This study examined chronic respiratory diseases and ICS use as risk factors in a population-based case-control study encompassing all adults in Denmark with microbiologically confirmed NTM pulmonary disease between 1997 and 2008. The study included 10 matched population controls per case. Conditional logistic regression was used to compute adjusted ORs for NTM pulmonary disease with regard to chronic respiratory disease history. RESULTS: Overall, chronic respiratory disease was associated with a 16.5-fold (95% CI 12.2 to 22.2) increased risk of NTM pulmonary disease. The adjusted OR for NTM disease was 15.7 (95% CI 11.4 to 21.5) for COPD, 7.8 (95% CI 5.2 to 11.6) for asthma, 9.8 (95% CI 2.03 to 52.8) for pneumoconiosis, 187.5 (95% CI 24.8 to 1417.4) for bronchiectasis, and 178.3 (95% CI 55.4 to 574.3) for tuberculosis history. ORs were 29.1 (95% CI 13.3 to 63.8) for patients with COPD on current ICS therapy and 7.6 (95% CI 3.4 to 16.8) for patients with COPD who had never received ICS therapy. Among patients with COPD, ORs increased according to ICS dose, from 28.1 for low-dose intake to 47.5 for high-dose intake (more than 800 µg/day). The OR was higher for fluticasone than for budesonide. CONCLUSION: Chronic respiratory disease, particularly COPD treated with ICS therapy, is a strong risk factor for NTM pulmonary disease.

[Continued problems with tuberculosis among Danes and Greenlanders in Denmark and the need for reinforced control--a systematic review]. / Fortsat tuberkuloseproblemer blandt danskere og grønlændere i Danmark og behov for styrket kontrol.

Active transmission of Mycobacterium tuberculosis (Mt) continues at surprisingly high rates in Denmark. The transmission is particularly observed in specific high risk segments of the population with social problems such as homelessness, alcohol, and/or drug abuse. The patients are infected with the "Danish Cluster 2" Mt outbreak strain, and the transmission is attributed to delayed diagnosis. This situation demands increased focus on early tuberculosis diagnosis, control of transmission, and improved actions calls for prioritising the prevention and control of tuberculosis politically and economically.

Migrant tuberculosis: the extent of transmission in a low burden country.

BACKGROUND: Human migration caused by political unrest, wars and poverty is a major topic in international health. Infectious diseases like tuberculosis follow their host, with potential impact on both the migrants and the population in the recipient countries. In this study, we evaluate Mycobacterium tuberculosis transmission between the national population and migrants in Denmark. METHODS: Register study based on IS6110-RFLP results from nationwide genotyping of tuberculosis cases during 1992 through 2004. Cases with 100% identical genotypes were defined as clustered and part of a transmission chain. Origin of clusters involving both Danes and migrants was defined as Danish/migrant/uncertain. Subsequently, the proportion of cases likely infected by the "opposite" ethnic group was estimated. RESULTS: 4,631 cases were included, representing 99% of culture confirmed cases during 1992 through 2004. Migrants contributed 61.6% of cases. Up to 7.9% (95% CI 7.0-8.9) of migrants were infected by Danes. The corresponding figure was 5.8% (95% CI 4.8-7.0) for Danes. Thus, transmission from Danes to migrants occurred up to 2.5 (95% CI 1.8-3.5) times more frequent than vice versa (OR = 1). A dominant strain, Cluster-2, was almost exclusively found in Danes, particular younger-middle-aged males. CONCLUSIONS: Transmission between Danes and migrants is limited, and risk of being infected by the "opposite" ethnic group is highest for migrants. TB-control efforts should focus on continues micro-epidemics, e.g. with Cluster-2 in Danes, prevention of reactivation TB in high-risk migrants, and outbreaks in socially marginalized migrants, such as Somalis and Greenlanders. Fears that TB in migrants poses a threat for resident Danes seem exaggerated and unjustified. We believe this to be true for other low incidence countries as well.

Characteristics of non-clustered tuberculosis in a low burden country.

Molecular genotyping studies often focus on clustered tuberculosis and recent transmission. Less attention has been paid to non-clustered tuberculosis. However, non-clustered cases also contribute significantly to the tuberculosis burden, especially in low-incidence countries. The objective of this study is to characterize non-clustered tuberculosis cases in Denmark and point out potential implications for tuberculosis control. The study is based on nationwide IS6110-RFLP genotyping of tuberculosis cases from 1992 through 2004, corresponding to 98% of culture verified cases. Of 3988 cases, 45% were non-clustered. Both Danes and immigrants had a peak incidence of non-clustered tuberculosis at older ages, 80-89 years (4.3 cases/10(5) population/year) and 60-69 years (28.8 cases/10(5) population/year), respectively. In addition, immigrants had a peak at 20-29 years (43.2 cases/10(5) inhabitants/year). In Danes, the incidence of non-clustered tuberculosis decreased during the study period and was predominantly found in elderly persons, presumably reactivating infection acquired during 1910-40, when tuberculosis incidence was high. In immigrants, the incidence was high at all ages, presumably reflecting reactivation of imported infections. In the future, the number of non-clustered tuberculosis cases will decrease, as older Danes die, and as time since primary infection increases for immigrants residing in Denmark. TB control should include focus on non-clustered cases.

Demographic and clinical characteristics in relation to patient and health system delays in a tuberculosis low-incidence country.

BACKGROUND: Delays in the diagnosis and treatment of tuberculosis (TB) are commonly encountered. METHODS: A study was undertaken among pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) patients in a Danish university hospital to describe demographic and clinical characteristics in relation to delay. RESULTS: Of the 313 patients enrolled, 213 (68%) were diagnosed with PTB and 100 (32%) with EPTB only. Logistic regression analysis of EPTB showed an association with female sex and non-Danish ethnicity. Mean total delay from onset of symptoms until initiation of TB treatment was 123 (95% confidence interval (CI) 106-138) days. Mean patient delay was significantly longer than mean health system delay: 90 (95% CI 74-105) vs 33 (95% CI 23-44) days (p < 0.0001). Delay was independent of ethnicity and significantly shorter for PTB patients compared to EPTB patients. Fever was found to be strongly predictive of a short patient delay (<1 month), whereas weight loss was associated with a long patient delay (> 3 months). In contrast, weight loss was associated with a short health system delay (<1 week). Elevated inflammatory markers were also associated with a short delay in the diagnosis of TB. CONCLUSIONS: This study confirmed a typical delay of months in duration in the diagnosis and treatment of TB in the low endemic country of Denmark. Increased TB awareness is needed, in particular in communities with immigrants originating from high-endemic areas.

Characterization of the long-term immune response to vaccination against Mycobacterium avium subsp. paratuberculosis in Danish dairy cows.

Vaccination of cattle against Mycobacterium avium subsp. paratuberculosis (MAP) provides partial protection by delayed shedding of MAP and reduced numbers of clinically affected animals. The duration of vaccine induced immune response is not known. The primary objective of this study was therefore to characterize the long-term effect of whole-cell based vaccination against MAP on the immune response. A secondary objective was to evaluate whether immunodiagnosis of MAP and Mycobacterium bovis infections is affected by MAP vaccination. Two studies were performed: (1) A retrospective longitudinal study including 895 vaccinated and 2526 non-vaccinated dairy cows in 9 Danish dairy herds aiming at characterizing the long-term antibody-response to vaccination; and (2) a cross-sectional study of responses in the IFN-γ assay carried out in 140 vaccinated animals in two herds to evaluate the effect of vaccination on the cell-mediated immune response and to evaluate a possible interference with the diagnosis of M. bovis infections. The results showed that 37% of samples from vaccinated animals and 5% of samples from non-vaccinated animals, respectively, were test positive in the milk antibody ELISA. The prevalence of antibody responses of the vaccinated animals was relatively constant from 2 to 6 years of age, but decreased in older animals. Among the 140 vaccinated animals 88% tested positive with the IFN-γ test to johnin PPD and 50% responded to PPDb with IFN-γ production above a similar cut-off. Although Denmark is free of M. bovis, two of the vaccinated animals responded with higher IFN-γ levels when cultured with PPDb compared to PPDa. In conclusion, immunization with whole-cell MAP vaccines elicits both humoral and cell-mediated immune reactions, which may interfere with surveillance and diagnosis of both MAP and M. bovis infections using currently available tests.

Risk factors for Mycobacterium tuberculosis infection among children in Greenland.

OBJECTIVE: To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection. METHODS: Between 2005 and 2007, 1797 Greenlandic schoolchildren in five different areas were tested for MTI with an interferon gamma release assay (IGRA) and a tuberculin skin test (TST). Parents or guardians were surveyed using a standardized self-administered questionnaire to obtain data on crowding in the household, parents' educational level and the child's health status. Demographic data for each child--i.e. parents' place of birth, number of siblings, distance between siblings (next younger and next older), birth order and mother's age when the child was born--were also extracted from a public registry. Logistic regression was used to check for associations between these variables and MTI, and all results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). Children were considered to have MTI if they tested positive on both the IGRA assay and the TST. FINDINGS: The overall prevalence of MTI was 8.5% (152/1797). MTI was diagnosed in 26.7% of the children with a known TB contact, as opposed to 6.4% of the children without such contact. Overall, the MTI rate was higher among Inuit children (OR: 4.22; 95% CI: 1.55-11.5) and among children born less than one year after the birth of the next older sibling (OR: 2.48; 95% CI: 1.33-4.63). Self-reported TB contact modified the profile to include household crowding and low mother's education. Children who had an older MTI-positive sibling were much more likely to test positive for MTI themselves (OR: 14.2; 95% CI: 5.75-35.0) than children without an infected older sibling. CONCLUSION: Ethnicity, sibling relations, number of household residents and maternal level of education are factors associated with the risk of TB infection among children in Greenland. The strong household clustering of MTI suggests that family sources of exposure are important.

Diabetes, glycemic control, and risk of tuberculosis: a population-based case-control study.

OBJECTIVE: To examine the association between diabetes, glycemic control, and risk of tuberculosis (TB). RESEARCH DESIGN AND METHODS: We conducted a population-based case-control study in Northern Denmark. Cases of active TB were all individuals with a first-time principal hospital diagnosis of TB between 1980 and 2008. Each case subject was matched with up to five population control subjects with similar age, sex, place and length of residence in Denmark, and country of emigration. We computed odds ratios (ORs) for a first-time TB diagnosis among people with and without diabetes using regression to control for other comorbidities, alcoholism, immunosuppressive medications, and socioeconomic markers. RESULTS: We identified 2,950 patients, including 156 diabetic individuals (5.3%), with active TB, and 14,274 population control subjects, of which 539 had diabetes (3.8%). The adjusted OR for active TB among subjects with diabetes was 1.18 (95% CI 0.96-1.45) compared with nondiabetic individuals. We found a similar risk increase from diabetes in the 843 (29%) TB case subjects who were immigrants; adjusted OR = 1.23 (95% CI 0.78-1.93). In a subset with laboratory data, diabetic individuals with an HbA(1c) <7.0, 7-7.9, and ≥8.0% had ORs of 0.91 (0.51-1.63), 1.05 (0.41-2.66), and 1.19 (CI 0.61-2.30), respectively, compared with individuals without diabetes. CONCLUSIONS: In the low TB-burden country of Denmark, the TB risk increase associated with diabetes is substantially lower than previously suggested. We found no evidence for any association between TB and dysglycemia.

Effect of sex, age, and race on the clinical presentation of tuberculosis: a 15-year population-based study.

Extrapulmonary tuberculosis (EPTB) is an important health problem that may cause serious morbidity and diagnostic challenges. We conducted a case-control study involving 5,684, approximately 99% of bacteriologically confirmed TB patients (including 1,925 EPTB cases) diagnosed in Denmark and Greenland during 1992-2007 to gain insight to the role of host factors in EPTB pathogenesis. Among patients from Somalia and Asia, persons 25-44 and 45-64 years of age were more likely to have EPTB than persons 15-24 years of age. In contrast, among persons from Greenland, the two oldest age groups were significantly less likely to have EPTB than the youngest age group. For all the age groups, the odds for having EPTB was significantly higher among patients from Somalia and Asia and significantly lower among the patients from Greenland than among patients from Denmark. Furthermore, the occurrence of specific types of EPTB significantly varied among different age groups or origins.

The continuing search for Mycobacterium tuberculosis involvement in sarcoidosis: a study on archival biopsy specimens.

INTRODUCTION: Increasing evidence indicates that mycobacteria may be involved in the aetiology and pathophysiology of sarcoidosis. OBJECTIVES: To investigate the association between Mycobacterium tuberculosis complex infection and sarcoidosis. METHODS: Mediastinal lymph node biopsy specimens (formalin-fixed, paraffin-embedded) from 52 Danish patients with sarcoidosis, 50 patients with mediastinal lymphadenopathy of other non-mycobacterial causes (negative controls) and 12 patients with histologically and/or culture-verified mycobacteriosis (positive controls) were included in the study. Biopsy samples were analysed for the presence of Mycobacterium tuberculosis complex by strand displacement assay and a subset of specimens were examined for bacterial rRNA by fluorescent in situ hybridisation using an eubacterial probe with general bacterial specificity (EUB338). RESULTS: One patient with sarcoidosis displayed a positive M. tuberculosis complex test. All negative controls were negative in the test and 5/12 patients with mycobacteriosis were positive in the test. We detected M. tuberculosis complex DNA in 10-year-old biopsy samples. Thirty-six samples were tested with the eubacterial probe; of these, 67% were positive with no difference between patients and controls. CONCLUSION: Our results do not support the hypothesis that M. tuberculosis complex infection is involved in the pathogenesis of sarcoidosis. However, we stress the importance of excluding mycobacteriosis in the diagnostic workup of sarcoidosis patients.

[Strengthening of laboratories is a new component in the global strategy for tuberculosis control]. / Styrkelse af laboratorier er et nyt element i den globale tuberkulosekontrolstrategi.

Although old techniques remain important, new techniques offer new possibilities. Mutations conferring resistance to rifampin and isoniazid can be detected in primary specimens from infectious pulmonary cases. Infections can be detected with interferon-gamma release assays, and chains of transmission can be detected by mycobacteria interspersed repetitive units. Centralized diagnostics makes it possible to apply results of routine analyses in national and international surveillance.