Tuberkulose

by Julajak Limsrivilai, Choon Kin Lee, Piyapan Prueksapanich, Kamin Harinwan, Asawin Sudcharoen, Natcha Cheewasereechon, Satimai Aniwan, Pimsiri Sripongpan, Panu Wetwittayakhlang, Ananya Pongpaibul, Anapat Sanpavat, Nonthalee Pausawasdi, Phunchai Charatcharoenwitthaya, Peter D. R. Higgins, Siew Chien Ng Background Data on external validation of models developed to distinguish Crohn’s disease (CD) from intestinal tuberculosis (ITB) are limited. This study aimed to validate and compare models using clinical, endoscopic, and/or pathology findings to differentiate CD from ITB. Methods Data from newly diagnosed ITB and CD patients were retrospectively collected from 5 centers located in Thailand or Hong Kong. The data was applied to Lee, et al., Makharia, et al., Jung, et al., and Limsrivilai, et al. model. Results Five hundred and thirty patients (383 CD, 147 ITB) with clinical and endoscopic data were included. The area under the receiver operating characteristic curve (AUROC) of Limsrivilai’s clinical-endoscopy (CE) model was 0.853, which was comparable to the value of 0.862 in Jung’s model (p = 0.52). Both models performed significantly better than Lee’s endoscopy model (AUROC: 0.713, p

Abstract Background South Africa has one of the highest tuberculosis incidence rates. Biologic disease-modifying anti-rheumatic drugs are associated with an increased risk of tuberculosis. The objective of this study was to describe the tuberculosis disease incidence rate among public sector patients receiving biologic therapies in the Western Cape Province. Methods A retrospective, descriptive analysis was undertaken using routine health data collated by the Provincial Health Data Centre from January 2007 (first use of biologic therapy in the Western Cape) to September 2018. Results We identified 609 patients treated with tumour necrosis factor-alpha (TNF-α) or non-TNF-α biologic therapies. Thirty-seven (37) patients developed tuberculosis after biologic therapy exposure, of whom the majority (78%) had an immune mediated inflammatory disease and the remainder (22%) a haematologic malignancy. The incidence rate of tuberculosis per 100,000 person-years was 2227 overall [95% confidence interval (CI): 1591, 3037]. Patients treated with TNF-α inhibitors and non-TNF-α inhibitors had estimated incidence rates of 2819 [95% CI: 1669, 4480] and 1825 [95% CI: 1131, 2797], respectively (p = 0.10). Conclusion Patients exposed to both TNF-α and non-TNF-α biologic therapies may have a higher incidence of tuberculosis disease compared to the background risk of 681 cases per 100,000 per year in the Western Cape.…

Objectives: To characterize monocyte subsets and activation in persons living with HIV (PLWH) with tuberculosis coinfection. Design: Cross-sectional study within a cohort of PLWH and HIV-uninfected participants at the Joint Clinical Research Centre in Kampala, Uganda. Methods: Participants were ≥45 years old with at least one cardiovascular risk factor. PLWH had an HIV viral load ≤1,000 copies/mL on stable antiretroviral therapy prior to cohort entry. QuantiFERON®-TB testing was performed to define latent tuberculosis infection (LTBI). Prior active TB was defined by self-report and verified by medical records. Blood was stained with monocyte subset markers (CD14, CD16), CD62p, CD69, CX3CR1, HLA-DR, and tissue factor, and examined with flow cytometry. Results: 125 participants (83 PLWH and 42 without HIV) were included. Median CD4 count was 582 cells/uL in PLWH. PLWH had a higher frequency of total monocytes (4.3% vs 3.2%; p …

by Shona Horter, Jay Achar, Nell Gray, Nargiza Parpieva, Zinaida Tigay, Jatinder Singh, Beverley Stringer Introduction Standard multidrug-resistant tuberculosis (MDR-TB) treatment is lengthy, toxic, and insufficiently effective. New drugs and a shorter treatment regimen (SCR) are now recommended. However, patient and health-care worker (HCW) perspectives regarding the SCR are unknown. We aimed to determine the views and experiences of patients with MDR-TB and HCW regarding the SCR in Karakalpakstan, Uzbekistan. Methods In a qualitative study, we conducted 48 in-depth interviews with 24 people with MDR-TB and 20 HCW, purposively recruited to include those with a range of treatment-taking experiences and employment positions. Data were analysed thematically using Nvivo 12, to identify emergent patterns, concepts, and categories. Principles of grounded theory were drawn upon to generate findings inductively from participants’ accounts. Results All patients viewed the SCR favourably. The SCR was seen as enabling an expedited return to work, studies, and “normality”. This reduced the burden of treatment and difficulties with treatment fatigue. The SCR appeared to improve mental health, ease difficulties with TB-related stigma, and foster improved adherence. While patients wanted shorter treatment, it was also important that treatment be tolerable and effective. However, HCW doubted the appropriateness and effectiveness of the SCR, which influenced their confidence in prescribing the regimen. Conclusion The SCR was said to benefit treatment completion and patients’ lives. HCW concerns about SCR appropriateness and effectiveness may influence who receives the regimen. These are important considerations for SCR implementation and MDR-TB treatment developments, and dissonance between patient and HCW perspectives must be addressed for successful implementation of shorter regimens in the future.…

Introduction Low-cost digital adherence technologies (DATs) such as 99DOTS have emerged as an alternative to directly observed therapy (DOT), the current standard for tuberculosis (TB) treatment supervision. However, there are limited data to support DAT scale-up. The ‘DOT to DAT’ trial aims to evaluate the effectiveness and implementation of a 99DOTS-based TB treatment supervision strategy. Methods and analysis This is a pragmatic, stepped-wedge cluster randomised trial, with hybrid type 2 effectiveness-implementation design. The trial will include all adults (estimated N=1890) treated for drug-susceptible pulmonary TB over an 8-month period at 18 TB treatment units in Uganda. Three sites per month will switch from routine care (DOT) to the intervention (99DOTS-based treatment supervision) beginning in month 2, with the order determined randomly. 99DOTS enables patients to be monitored while self-administering TB medicines. Patients receive daily automated short message service (SMS) dosing reminders and confirm dosing by calling toll-free numbers. The primary effectiveness outcome is the proportion of patients completing TB treatment. With 18 clusters randomised into six steps and an average cluster size of 15 patients per month, the study will have 89% power to detect a 10% or greater increase in treatment completion between the routine care and intervention periods. Secondary outcomes include more proximal effectiveness measures as well as quantitative and qualitative assessments of the reach, adoption and implementation of the intervention. Ethics and dissemination Ethics approval was granted by institutional review boards at Makerere University School of Public Health and the University of California San Francisco. Findings will be disseminated through peer-reviewed publications, presentations at scientific conferences and presentations to key stakeholders. Trial registration number PACTR201808609844917.…

Abstract Background Tuberculosis (TB) though primarily affects the lungs it may also affect the other parts of the body and referred as extra pulmonary (EPTB). This study is focused on understanding the genetic diversity and molecular epidemiology of Mycobacterium tuberculosis (M.tb) among tuberculous lymphadenitis (TBL), a form of EPTB patients identified in Chennai, Tamil Nadu. Methods The genetic diversity was identified by performing spoligotyping on the M.tb clinical isolates that were recovered from lymph node samples. A total of 71 M.tb isolates were recovered from extra pulmonary lymph node samples and subjected to Drug susceptibility testing and spoligotyping was carried out. In addition, immunological characterization from blood of same individuals from whom M.tb was isolated was carried out between the two major lineages groups East African Indian 3 (EAI3) and non-EAI3 strains by ELISA. The results of spoligotyping patterns were compared with the world Spoligotyping Database of Institute Pasteur de Guadeloupe (SpolDB4). Results We found 41 spoligotype patterns and their associated lineages. Out of 41 spoligotype pattern, only 22 patterns are available in the spoldB4 database with Spoligotype international Type (SIT) number and remaining patterns were orphan strains without SIT number. The most predominant spoligotype lineage that was found in lymph node sample in this region of India was EAI (36), followed by central Asian strain (CAS) (6), T1 (5), Beijing (3), Latin American & Mediterranean (LAM) (2), U (1), X2 (1) and orphan (22). In addition to EAI, CAS and Beijing, our study identified the presence of orphan and unique spoligotyping patterns in Chennai region. We observed six drug resistant isolates. Out of six drug resistant isolates, four were resistant to isoniazid drug and associated with EAI family. Moreover, we observed increased levels of type 2 and type 17 cytokine profiles between EAI3 and non-EAI family, infected individuals. Conclusions The study confirms that EAI lineage to be the most predominant lineages in EPTB patients with lymphadenitis and were found to have increased type 1 and type 17 proinflammatory cytokine profiles.…

C. A. Haley et al.

Abstract Background Following infection with Mycobacterium tuberculosis (M.tb), individuals may rapidly develop tuberculosis (TB) disease or enter a “latent” infection state with a low risk of progression to disease. Mathematical models use a variety of structures and parameterisations to represent this process. The effect of these different assumptions on the predicted impact of TB interventions has not been assessed. Methods We explored how the assumptions made about progression from infection to disease affect the predicted impact of TB preventive therapy. We compared the predictions using three commonly used model structures, and parameters derived from two different data sources. Results The predicted impact of preventive therapy depended on both the model structure and parameterisation. At a baseline annual TB incidence of 500/100,000, there was a greater than 2.5-fold difference in the predicted reduction in incidence due to preventive therapy (ranging from 6 to 16%), and the number needed to treat to avert one TB case varied between 67 and 157. The relative importance of structure and parameters depended on baseline TB incidence and assumptions about the efficacy of preventive therapy, with the choice of structure becoming more important at higher incidence. Conclusions The assumptions use to represent progression to disease in models are likely to influence the predicted impact of preventive therapy and other TB interventions. Modelling estimates of TB preventive therapy should consider routinely incorporating structural uncertainty, particularly in higher burden settings. Not doing so may lead to inaccurate and over confident conclusions, and sub-optimal evidence for decision making.…

Shorter, more potent regimens are needed for tuberculosis. The nitroimidazole pretomanid was recently approved for extensively drug-resistant tuberculosis in combination with bedaquiline and linezolid. Pretomanid may also have benefit as a treatment-shortening agent for drug-sensitive tuberculosis. It is unclear how and if it can be used together with rifamycins, key sterilizing first-line drugs.In this analysis, data were pooled from two studies: the Assessing Pretomanid for Tuberculosis (APT) trial, in which patients with drug-sensitive pulmonary TB received pretomanid, isoniazid, pyrazinamide, plus either rifampin or rifabutin versus standard of care under fed conditions and the AIDS Clinical Trials Group (ACTG) 5306 trial, a phase I study in healthy volunteers receiving pretomanid alone or in combination with rifampin under fasting conditions.In our population pharmacokinetic (PK) model, participants taking rifampin had 44.4 and 59.3% reduction in pretomanid AUC compared to rifabutin or pretomanid alone (due to 80 or 146% faster clearance) in APT and A5306, respectively. Median Cmax in the rifampin and rifabutin arms were 2.14 and 3.35 mg/liter, while median AUC0-24h were 30.1 and 59.5 mg·h/liter, respectively. Though pretomanid exposure in APT was significantly reduced with rifampin, AUC0-24 values were similar to those associated with effective treatment in registrational trials, likely because APT participants were fed with dosing, enhancing pretomanid relative bioavailability and exposures. Pretomanid concentrations with rifabutin were high, but in range with prior observations. While pretomanid exposures with rifampin are unlikely to impair efficacy, our data suggest that pretomanid should be taken with food if prescribed with rifampin.…

Abstract Background Tuberculosis (TB) and Acquired Immune Deficiency Syndrome (AIDS) are leading causes of death globally. However, little is known about the long-term mortality risk and the timeline of death in those co-infected with human immunodeficiency virus (HIV) and Mycobacterium tuberculosis (MTB). This study sought to understand the long-term mortality risk, factors, and the timeline of death in those with HIV-Mycobacterium tuberculosis (MTB) coinfection, particularly in those with insufficient TB treatment. Methods TB-cause specific deaths were classified using a modified ‘Coding of Cause of Death in HIV’ protocol. A longitudinal cross-registration-system checking approach was used to confirm HIV/MTB co-infection between two observational cohorts. Mortality from the end of TB treatment (6 months) to post-treatment year (PTY) 5 (60 months) was investigated by different TB treatment outcomes. General linear models were used to estimate the mean mortality at each time-point and change between time-points. Cox’s proportional hazard regressions measured the mortality hazard risk (HR) at each time-point. The Mantel-Haenszel stratification was used to identify mortality risk factors. Mortality density was calculated by person year of follow-up. Results At the end point, mortality among patients with HIV/MTB coinfection was 34.7%. From the end of TB treatment to PTY5, mortality and loss of person years among individuals with TB treatment failure, missing, and adverse events (TBFMA) were significantly higher than those who had TB cure (TBC) and TB complete regimen (TBCR). Compared to individuals with TBC and with TBCR, individuals with TBFMA tended to die earlier and their mortality was significantly higher (HRTBFMA-TBC = 3.0, 95% confidence interval: 2.5–3.6, HRTBFMA-TBCR = 2.9, 95% CI: 2.5–3.4, P 

Tuberculosis (TB) is caused by Mycobacterium tuberculosis complex (MTBC), which typically affects the lungs (pulmonary TB, PTB), but can also affect virtually any other site (extrapulmonary TB, EPTB) (Kruijshaar et al., 2009; Solovic et al., 2013). EPTB represented 15% of the 7.0 million incident cases notified globally during 2018, ranging from 8% to 24% (WHO, 2019). Recent limited epidemiological studies indicate that the proportion of EPTB is steadily increasing all over the world including China.

P. C. Hopewell et al.

Tuberculosis (TB) remains a major public health threat, as the leading infectious cause of morbidity and mortality throughout the world (World Health Organization, 2019). According to the World Health Organization (WHO), there were an estimated 10 million incident cases of TB and 1.5 million deaths worldwide, with the African region displaying the highest annual risk of infection, aggravated by high HIV co-infection rates and the emergence of drug-resistant TB (World Health Organization, 2019). TB disease, caused by the Mycobacterium tuberculosis complex (MTBc) has been present in the human population since the beginning of recorded history (Guttierez et al., 2005) and coevolved with ancient hominids (Gagneux, 2012; Comas et al., 2013).

Introduction Vitamin D status may be an important determinant of multidrug-resistant tuberculosis (MDR-TB) infection, progression to disease and treatment outcomes. Novel and potentially cost-effective therapies such as vitamin D supplementation are needed to stem the tide of TB and MDR-TB globally, particularly in India, a country that accounts for the largest fraction of the world’s TB incidence and MDR-TB incidence, and where vitamin D deficiency is endemic. While vitamin D has shown some promise in the treatment of MDR-TB, its role in the context of MDR-TB infection and progression to disease is largely unknown. Methods and analysis Through a case–control study in Mumbai, India, we aim to examine associations between vitamin D status and active MDR-TB and to investigate vitamin D status and TB infection among controls. Cases are adult outpatient pulmonary patients with MDR-TB recruited from two public TB clinics. Controls are recruited from the cases’ household contacts and from non-respiratory departments of the facilities where cases were recruited. Cases and controls are assessed for serum 25-hydroxyvitamin D concentration, nutrient intake, diet quality, anthropometry and other relevant clinical and sociodemographic parameters. Controls undergo additional clinical assessments to rule out active TB and laboratory assessments to determine presence of TB infection. Statistical analysis investigates associations between vitamin D status and active MDR-TB and between vitamin D status and TB infection among controls, accounting for potential confounding effects of diet, anthropometry and other covariates. Ethics and dissemination This study has been approved by Harvard T.H. Chan School of Public Health Institutional Review Board; Foundation for Medical Research Institutional Research Ethics Committee and Health Ministry’s Screening Committee of the Indian Council for Medical Research. Permission was granted by the Municipal Corporation of Greater Mumbai, India, a collaborating partner on this research. Outcomes will be disseminated through publication and scientific presentation. Trial registration number NCT04342598.…

Abstract Background The discovery of antibiotics in the mid-twentieth century marked a major transition in tuberculosis (TB) treatment and control. There are few studies describing the duration of TB disease and its treatment from the pre-chemotherapy era and little data on how these treatments changed in response to the development of effective antibiotics. The goal of this research is to understand how inpatient treatment for high incidence populations, the First Nations peoples of Saskatchewan, Canada, changed in response to increasing availability of antibiotics effective against TB. We expected that as treatment regimens transitioned from convalescence-only to triple antibiotic therapy, the length of inpatient treatment would shorten. Methods Analyses were performed on records of sanatoria admissions and discharges occurring between 1933 and 1959 in Saskatchewan, Canada. Year of antibiotic discovery was taken as a proxy for treatment regimen: no chemotherapy (pre-1944), mono-therapy (Streptomycin, 1944–1946), dual-therapy (Streptomycin and PAS, 1946–1952), and triple-therapy (Streptomycin, PAS, and INH 1952-). A pooled linear regression of log-transformed length of first admission as predicted by year of admission was modeled to assess the relationship between admission length and year of admission, corrected for clinical and demographic variables. Results First admission length increased 19% in the triple-therapy era as compared to the pre-chemotherapy era, from 316 days (10.4 months) to 377 days (12.4 months). After the discovery of INH (1952), we find statistically significant increases in the proportion of successfully completed therapies (0.55 versus 0.60, p = 0.035), but also in patients who left hospital against medical advice (0.19 versus 0.29, p 

Tropical Medicine & International Health, Accepted Article.

Abstract. Lung ultrasound (LUS) is highly portable and has excellent diagnostic accuracy for pneumonia compared with conventional radiography, but the literature on its use in pulmonary tuberculosis (PTB) is limited. This study characterized LUS lesions in patients with PTB and compared them with chest X-ray (CXR) findings. Adult patients in Lima, Peru, with PTB were recruited within 1 week of starting antituberculosis treatment. Comprehensive LUS was performed in all patients at enrollment and assessed for consolidation, small subpleural consolidation (SPC, hypothesized to be a marker of CXR consolidation), cavity, pleural effusion, pathologic B-lines, and miliary pattern. Patient CXRs were digitized and interpreted by a board-certified radiologist. Fifty-one patients were included in the final analysis. Lung ultrasound detected either consolidation or SPC in 96.1% of participants. No significant difference was found between the LUS detection of a composite of consolidation or SPC, and CXR detection of consolidation (96.1% versus 98%, P > 0.99). The proportion of patients with cavity detected by LUS was significantly lower than that detected by CXR (5.9% versus 51%, P < 0.001). Overall, LUS detection of consolidation or SPC may be a sensitive marker for diagnosis of PTB. Lung ultrasound demonstrated poor ability to detect radiographically identified cavity, although previous studies suggest SPC could add specificity for the diagnosis of PTB. Based on its portability and evidence base for diagnosing other pulmonary diseases, LUS may have a role in screening and diagnosis of PTB in areas without ready access to CXR. Further studies should evaluate its diagnostic accuracy in patients with and without PTB.…

Abstract. Identifying children with, or at substantial risk of, Mycobacterium tuberculosis infection (TBI) and providing TB preventive therapy (TPT) represent an important, yet challenging, strategy in curbing the global burden of childhood TB. Risk assessment scoring tools, which quantify risks associated with unique factors characterizing an individual, could act as a surrogate measure of TBI risk and guide effective and efficient TPT delivery. We assessed important risk factors of childhood TBI and created risk assessment tools through secondary analysis of data from a large, community-based childhood TB prevalence study in the island province of Bohol in the Philippines, a low–HIV- and high–TB-burden, post-disaster setting. We identified four factors that were statistically associated with acquiring TBI—being 5 years or older, having a known TB contact, having a known TB contact who was either the mother or another primary caregiver, and living in a high–TB-burden municipality. We created 2-item, 4-item, and 9-item scores intended to identify child TBI in this low-resource, low–HIV-, and high–TB-burden setting. In addition to the design, evaluation, and impact analysis of these generalizable and valuable risk assessment tools, our study findings emphasize the necessity of targeting both household and community-associated transmissions of childhood TBI to achieve the global goal to end TB.…

Immigration from areas of high incidence is thought to have fueled the resurgence of tuberculosis (TB) in areas of low incidence. To reduce the risk of disease in low-incidence areas, the main countermeasure has been the screening of immigrants on arrival. This measure is based on the assumption of a prompt decline in the incidence of TB in immigrants during their first few years of residence in a country with low overall incidence. We have documented that this assumption is not true for 619 Somali immigrants reported in Denmark as having TB. The annual incidence of TB declined only gradually during the first 7 years of residence, from an initial 2,000 per 100,000 to 700 per 100,000. The decline was described by an exponential function with a half-time of 5.7 (95% confidence interval 4.0 to 9.7) years. This finding seriously challenges the adequacy of the customary practice of screening solely on arrival.

As countries approach the elimination phase of tuberculosis, specific problems and challenges emerge, due to the steadily declining incidence in the native population, the gradually increasing importance of the importation of latent tuberculosis infection and tuberculosis from other countries and the emergence of groups at particularly high risk of tuberculosis. Therefore, a Working Group of the World Health Organization (WHO), the International Union Against Tuberculosis and Lung Disease (IUATLD) and the Royal Netherlands Tuberculosis Association (KNCV) have developed a new framework for low incidence countries based on concepts and definitions consistent with those of previous recommendations from WHO/IUATLD Working Groups. In low-incidence countries, a broader spectrum of interventions is available and feasible, including: 1) a general approach to tuberculosis which ensures rapid detection and treatment of all the cases and prevention of unnecessary deaths; 2) an overall control strategy aimed at reducing the incidence of tuberculosis infection (risk-group management and prevention of transmission of infection in institutional settings) and 3) a tuberculosis elimination strategy aimed at reducing the prevalence of tuberculosis infection (outbreak management and provision of preventive therapy for specified groups and individuals). Government and private sector commitment towards elimination, effective case detection among symptomatic individuals together with active case finding in special groups, standard treatment of disease and infection, access to tuberculosis diagnostic and treatment services, prevention (e.g. through screening and bacille Calmette-Guéria immunization in specified groups), surveillance and treatment outcome monitoring are prerequisites to implementing the policy package recommended in this new framework document.

Infliximab is a humanized antibody against tumor necrosis factor alpha (TNF-alpha) that is used in the treatment of Crohn's disease and rheumatoid arthritis. Approximately 147,000 patients throughout the world have received infliximab. Excess TNF-alpha in association with tuberculosis may cause weight loss and night sweats, yet in animal models it has a protective role in the host response to tuberculosis. There is no direct evidence of a protective role of TNF-alpha in patients with tuberculosis.

Does immigration from a high-prevalence area contribute to an increased risk of tuberculosis in a low-incidence country? The tuberculosis incidence in Somalia is among the highest ever registered. Due to civil war and starvation, nearly half of all Somalis have been forced from their homes, causing significant migration to low-incidence countries. In Denmark, two-thirds of all tuberculosis patients are immigrants, half from Somalia. To determine the magnitude of Mycobacterium tuberculosis transmission between Somalis and Danes, we analyzed DNA fingerprint patterns of isolates collected in Denmark from 1992 to 1999, comprising >97% of all culture-positive patients (n = 3,320). Of these, 763 were Somalian immigrants, 55.2% of whom shared identical DNA fingerprint patterns; 74.9% of these were most likely infected before their arrival in Denmark, 23.3% were most likely infected in Denmark by other Somalis, and 1.8% were most likely infected by Danes. In the same period, only 0.9% of all Danish tuberculosis patients were most likely infected by Somalis. The Somalian immigrants in Denmark could be distributed into 35 different clusters with possible active transmission, of which 18 were retrieved among Somalis in the Netherlands. This indicated the existence of some internationally predominant Somalian strains causing clustering less likely to represent recent transmission. In conclusion, M. tuberculosis transmission among Somalis in Denmark is limited, and transmission between Somalis and Danes is nearly nonexistent. The higher transmission rates between nationalities found in the Netherlands do not apply to the situation in Denmark and not necessarily elsewhere, since many different factors may influence the magnitude of active transmission.

The whole-genome fingerprinting technique, fluorescent amplified-fragment length polymorphism (FAFLP) analysis, was applied to Mycobacterium tuberculosis. Sixty-five clinical isolates were analyzed to determine the value of FAFLP as a stand-alone genotyping technique and to compare it with the well-established IS6110 typing system. The genome sequence of M. tuberculosis strain H37Rv (S. T. Cole et al., Nature 393:537-544, 1998) was used to model computer-generated informative primer combination(s), and the precision and reproducibility of FAFLP were evaluated by comparing the results of in vitro and computer-generated experiments. Multiplex FAFLP was used to increase resolving power in a predictable and systematic fashion. FAFLP analysis was broadly congruent with IS6110 typing for those strains with multiple IS6110 copies. It was also able to resolve an epidemiologically unlinked group of strains with only one copy of IS6110; up to 10% of clinical isolates may fall into this category. For certain epidemiological investigations, it was concluded that a combination of FAFLP and IS6110 typing would give higher resolution than would either alone. FAFLP data were digital, precise, reproducible, and suitable for rapid electronic dissemination, manipulation, interlaboratory comparison, and storage in national or international epidemiological databases. Because FAFLP samples and analyzes base substitution across the genome as a whole, FAFLP could generate new information about the microevolution of the M. tuberculosis complex.

To estimate the risk and prevalence of Mycobacterium tuberculosis (MTB) infection and tuberculosis (TB) incidence, prevalence, and mortality, including disease attributable to human immunodeficiency virus (HIV), for 212 countries in 1997.

The present study is based on notified cases of tuberculosis (TB) in the National tbc. register 1972-1996. A decline in Tb incidence was seen from 1972 and until the mid-1980's. Subsequently the trend has reversed due to an increasing number of TB cases in foreigners. In 1996, 60% of all cases of TB in Denmark were found in foreigners reflecting the rising number of refugees and their families arriving in Denmark from highly endemic areas, mainly Somalia. Among native Danes the TB incidence fell from 14 per 100,000 in 1972 to 4 per 100,000 in the 1980's and stabilized at this very low level. The unchanged incidence in Danes covers a falling incidence in the older and a rising incidence in the younger and middle-aged adult population, mainly in the capital. Approximately half of the cases occur in high-risk groups. The TB-epidemic is close to elimination in the indigenous Danish population, but the disease is maintained at a low level probably due to increased patient and doctor delay and resulting microepidemics primarily in high-risk populations.