Factors associated with differences between conventional contact tracing and molecular epidemiology in study of tuberculosis transmission and analysis in the city of Barcelona, Spain

First outbreak of multi-drug resistant tuberculosis (MDR-TB) in Denmark involving six Danish-born cases

BACKGROUND

Denmark is a tuberculosis (TB) and multi-drug resistant (MDR) TB low-incidence country at 5 and 0.05 cases per 100.000 population, respectively. Until 2018, transmission of MDR-TB was nonexistent except for few pairwise related family-cases. In this study we describe the first MDR-TB outbreak in Denmark.

METHODS

Based on genotyping of all Mycobacterium tuberculosis (Mtb) culture-positive cases in Denmark spanning three decades, six molecular- and epidemiologically linked Danish-born cases were identified as the first cluster of MDR-TB in Denmark. The primary case was diagnosed posthumously in 2010 followed by five epidemiologically linked cases from 2018 through 2019.

RESULTS AND CONCLUSION

Through a combination of routine Mtb genotyping and clinical epidemiological surveillance data, we identified the first Danish MDR-TB outbreak spanning 10 years and were able to disclose the specific transmission pathways in detail guiding the outbreak investigations. The occurrence of an MDR-TB outbreak in a resource rich TB low incidence setting like Denmark, highlights the importance of a collaborative control system combining classical contact tracing; timely identification of drug resistant TB through rapid diagnostics; and a close collaboration between clinicians, classical- and molecular epidemiologists for the benefit of TB control.

Probable long-term prevalence for a predominant Mycobacterium tuberculosis clone of a Beijing genotype in Colon, Panama

Beijing genotype Mycobacterium tuberculosis strains associate with increased virulence, resistance and/or higher transmission rates. This study describes a specific Beijing strain predominantly identified in the Panamanian province of Colon with one of the highest incidences of tuberculosis in the country. Retrospective mycobacterial interspersed repetitive unit/variable number of tandem repeats analysis of 42 isolates collected between January and August 2018 allowed to identify a cluster (Beijing A) with 17 (40.5%) Beijing isolates. Subsequent prospective strain-specific PCR-based surveillance from September 2019 to March 2020 confirmed the predominance of the Beijing A strain (44.1%) in this province. Whole-genome sequencing revealed higher-than-expected diversity within the cluster, suggesting long-term prevalence of this strain and low number of cases caused by recent transmission. The Beijing A strain belongs to the Asian African 3 (Bmyc13, L2.2.5) branch of the modern Beijing sublineage, with their closest isolates corresponding to cases from Vietnam, probably introduced in Panama between 2000 and 2012.

Molecular epidemiology of M. tuberculosis in Ethiopia: A systematic review and meta-analysis

The molecular epidemiology of Mycobacterium tuberculosis (M. tuberculosis, Mtb) is poorly documented in Ethiopia. The data that exists has not yet been collected in an overview metadata form. Thus, this review summarizes available literature on the genomic diversity, geospatial distribution and transmission patterns of Mtb lineages (L) and sublineages in Ethiopia. Spoligotyping and Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR) based articles were identified from MEDLINE via PubMed and Scopus. The last date of article search was done on 12th February 2019. Articles were selected following the PRISMA flow diagram. The proportion of (sub)lineages was summarized at national level and further disaggregated by region. Clustering and recent transmission index (RTI) were determined using metan command and random effect meta-analysis model. The meta-analysis was computed using Stata 14 (Stata Corp. College Station, TX, USA). Among 4371 clinical isolates, 99.5% were Mtb and 0.5% were M. bovis. Proportionally, L4, L3, L1 and L7 made up 62.3%, 21.7%, 7.9% and 3.4% of the total isolates, respectively. Among sublineages, L4.2. ETH/SIT149, L4.10/SIT53, L3. ETH1/SIT25 and L4.6/SIT37 were the leading clustered isolates accounting for 14.4%, 9.7%, 7.2% and 5.5%, respectively. Based on MIRU-VNTR, the rate of clustering was 41% and the secondary case rate from a single source case was estimated at 29%. Clustering and recent transmission index was higher in eastern and southwestern Ethiopia compared with the northwestern part of the country. High level of genetic diversity with a high rate of clustering was noted which collectively mirrored the phenomena of micro-epidemics and super-spreading. The largest set of clustered strains deserves special attention and further characterization using whole genome sequencing (WGS) to better understand the evolution, genomic diversity and transmission dynamics of Mtb.

Prevention of tuberculosis in household members: estimates of children eligible for treatment

Objective

To estimate of the number of children younger than 5 years who were household contacts of people with tuberculosis and were eligible for tuberculosis preventive treatment in 2017.

Methods

To estimate the number of eligible children, we obtained national values for the number of notified cases of bacteriologically confirmed pulmonary tuberculosis in 2017, the proportion of the population younger than 5 years in 2017 and average household size from published sources. We obtained global values for the number of active tuberculosis cases per household with an index case and for the prevalence of latent tuberculosis infection among children younger than 5 years who were household contacts of a tuberculosis case through systematic reviews, meta-analysis and Poisson regression models.

Findings

The estimated number of children younger than 5 years eligible for tuberculosis preventive treatment in 2017 globally was 1.27 million (95% uncertainty interval, UI: 1.24–1.31), which corresponded to an estimated global coverage of preventive treatment in children of 23% at best. By country, the estimated number ranged from less than one in the Bahamas, Iceland, Luxembourg and Malta to 350 000 (95% UI: 320 000–380 000) in India. Regionally, the highest estimates were for the World Health Organization (WHO) South-East Asia Region (510 000; 95% UI: 450 000–580 000) and the WHO African Region (470 000; 95% UI: 440 000–490 000).

Conclusion

Tuberculosis preventive treatment in children was underutilized globally in 2017. Treatment should be scaled up to help eliminate the pool of tuberculosis infection and achieve the End TB Strategy targets.

Extensively drug-resistant tuberculosis in South Africa: genomic evidence supporting transmission in communities

Despite evidence that transmission is driving an extensively drug-resistant TB (XDR-TB) epidemic, our understanding of where and between whom transmission occurs is limited. We sought to determine whether there was genomic evidence of transmission between individuals without an epidemiologic connection.We conducted a prospective study of XDR-TB patients in KwaZulu-Natal, South Africa, during the 2011-2014 period. We collected sociodemographic and clinical data, and identified epidemiologic links based on person-to-person or hospital-based connections. We performed whole-genome sequencing (WGS) on the Mycobacterium tuberculosis isolates and determined pairwise single nucleotide polymorphism (SNP) differences.Among 404 participants, 123 (30%) had person-to-person or hospital-based links, leaving 281 (70%) epidemiologically unlinked. The median SNP difference between participants with person-to-person and hospital-based links was 10 (interquartile range (IQR) 8-24) and 16 (IQR 10-23), respectively. The median SNP difference between unlinked participants and their closest genomic link was 5 (IQR 3-9) and half of unlinked participants were within 7 SNPs of at least five participants.The majority of epidemiologically-unlinked XDR-TB patients had low pairwise SNP differences with at least one other participant, consistent with transmission. These data suggest that much of transmission may result from casual contact in community settings between individuals not known to one another.

Using genotyping to delineate tuberculosis transmission in long-term care facilities: single facility 4-year experience

Background

Residents in long-term care facilities (LTCFs) are vulnerable to tuberculosis (TB) transmission; however, to delineate possible routes of TB transmission in LTCFs is difficult. This study aimed to address the use of regular genotyping surveillance to delineate TB transmission in LTCFs.

Methods

All of Mycobacterium tuberculosis isolates in the reported 620-bed LTCF between July 2011 and August 2015 were genotyped, and we retrospectively compared epidemiological data and genotyping results.

Results

A total of 42 subjects were diagnosed with culture-positive pulmonary TB infection during the 4-year period. Their median age was 76.5 years, and 64.3% (27/42) of them were male. Genotyping identified 5 clustered TB infections involving 76.2% (32/42) of all TB subjects. In a multivariate logistic regression model adjusted for age, sex, chronic obstructive pulmonary disease, and body mass index, subjects with clustered TB infection were less likely to be Activities of Daily Living (ADL)-dependence (adjOR 0.073, 95% CI 0.007–0.758) when compared with subjects having individual TB infections. Prolonged surveillance is essential given that the median interval to diagnose secondary subjects was 673 days. Finally, only 63.0% (17/27) of the 27 secondary TB subjects in this study had contact history with index subject in the same ward.

Conclusions

In conclusion, possible routes of TB transmission in a complex TB outbreak at LTCFs might be delineated by routine genotyping surveillance and regular health check-up.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2526-2) contains supplementary material, which is available to authorized users.

Interventions to improve contact tracing for tuberculosis in specific groups and in wider populations: an evidence synthesis

Background

The tracing and screening of people who have had contact with an active case of tuberculosis (TB) is an important element of TB control strategies.

Objectives

This study aimed to carry out a review of evidence regarding TB contact tracing, with a particular emphasis on research that was applicable to TB contact tracing in specific population groups in the UK.

Design

An evidence synthesis of literature of any study design on TB contact tracing in developed countries was carried out.

Setting

Any setting.

Population

Individuals found to have active TB disease, and people who have come into contact with them.

Interventions

Contact-tracing investigations.

Main outcome measures

Any outcome related to TB infection, contact investigations and/or the views of staff, people with TB disease, or their contacts.

Data sources

Searches for research published 1995 onwards were undertaken in the following databases: MEDLINE via Ovid SP, EMBASE via Ovid SP, EconLit via Ovid SP, PsycINFO via Ovid SP, Social Policy and Practice via Ovid SP, Cumulative Index to Nursing and Allied Health Literature via EBSCOhost, Science and Social Science Citation Indices via Web of Science and The Cochrane Library via Wiley Online Library.

Review methods

The study comprised a review of TB contact tracing in specific population groups and a review in wider populations. A narrative synthesis was completed and a logic model was developed from the literature.

Results

There were 112 articles in the review: 23 related to specific populations and 89 related to wider populations. The literature was of limited quality, with much general description of investigations. We identified only two (uncontrolled) studies that could be considered evaluative. Although the limitations of the evidence should be recognised, the review suggested the following: the value of a location-based approach, working with local communities and the media, partnership working, using molecular epidemiological testing, ensuring adequate systems and addressing fear of stigma. The literature on investigations for specific populations has much concordance with that reporting findings from wider population groups. The recognised limitations of conventional investigation methods may, however, be exacerbated in specific populations.

Limitations

The English-language inclusion criterion may have limited the breadth of countries represented. A meta-analysis was not possible owing to the nature of the literature. Relevant studies may have been missed by our searches, which used terminology relating to contact tracing rather than to active case finding or screening.

Conclusions

The review identified a sizeable volume of literature relating to contact investigations. However, it is currently predominantly descriptive, with little evaluative work underpinning investigations in either specific or wider populations. Our findings are, therefore, based on limited evidence. Further research is required if robust conclusions are to be made.

Future work

Research should further explore the development of measures that can be used to compare the effectiveness of different contact investigations, in studies using evaluative designs.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Molecular epidemiology of tuberculosis in Havana, Cuba, 2009

OBJECTIVES

To estimate the proportion of tuberculosis cases attributable to recent transmission and the risk factors possibly associated with tuberculosis clustering.

METHODS

Population-based study combining information from epidemiological investigation of tuberculosis cases notified to the National Tuberculosis Control Program in Havana, Cuba, in 2009 with the results of genotyping of Mycobacterium tuberculosis isolates with variable number tandem repeat of mycobacterial interspersed repetitive units (MIRU-VNTR) typing.

RESULTS

Of 186 cases, 61 were genotyped: 33 patterns and five clusters with 19, 7, 3, 2 and 2 cases were found. The proportion of cases due to recent transmission was 45% (95% confidence interval 33-58%). Routine contact investigation failed to identify a substantial number of epidemiological links. A history of living in a closed setting was strongly associated with clustering.

CONCLUSIONS

The proportion of cases due to recent transmission in Havana in 2009 is high. The existing control measures in closed settings should be strengthened. A study on a larger number of cases and for a longer time period should be carried out to obtain more precise estimates. Further studies on the utility and cost-effectiveness of the addition of molecular epidemiology techniques to support the progress towards tuberculosis elimination in Cuba, a low-incidence resource-limited setting, are also needed.

Whole genome sequencing based characterization of extensively drug-resistant Mycobacterium tuberculosis isolates from Pakistan

Improved molecular diagnostic methods for detection drug resistance in Mycobacterium tuberculosis (MTB) strains are required. Resistance to first- and second- line anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs) in particular genes. However, these SNPs can vary between MTB lineages therefore local data is required to describe different strain populations. We used whole genome sequencing (WGS) to characterize 37 extensively drug-resistant (XDR) MTB isolates from Pakistan and investigated 40 genes associated with drug resistance. Rifampicin resistance was attributable to SNPs in the rpoB hot-spot region. Isoniazid resistance was most commonly associated with the katG codon 315 (92%) mutation followed by inhA S94A (8%) however, one strain did not have SNPs in katG, inhA or oxyR-ahpC. All strains were pyrazimamide resistant but only 43% had pncA SNPs. Ethambutol resistant strains predominantly had embB codon 306 (62%) mutations, but additional SNPs at embB codons 406, 378 and 328 were also present. Fluoroquinolone resistance was associated with gyrA 91-94 codons in 81% of strains; four strains had only gyrB mutations, while others did not have SNPs in either gyrA or gyrB. Streptomycin resistant strains had mutations in ribosomal RNA genes; rpsL codon 43 (42%); rrs 500 region (16%), and gidB (34%) while six strains did not have mutations in any of these genes. Amikacin/kanamycin/capreomycin resistance was associated with SNPs in rrs at nt1401 (78%) and nt1484 (3%), except in seven (19%) strains. We estimate that if only the common hot-spot region targets of current commercial assays were used, the concordance between phenotypic and genotypic testing for these XDR strains would vary between rifampicin (100%), isoniazid (92%), flouroquinolones (81%), aminoglycoside (78%) and ethambutol (62%); while pncA sequencing would provide genotypic resistance in less than half the isolates. This work highlights the importance of expanded targets for drug resistance detection in MTB isolates.

Identification and Characterization of Mycobacterium Tuberculosis Isolates from Cattle Owners in North Western and North Eastern Parts of Rural Ethiopia

Tuberculosis (TB) is a major global public health problem resulting in a considerable morbidity and mortality worldwide. Ethiopia ranks 8^th among the 22 high TB burden countries. Establishing an appropriate and improved intervention strategy to prevent and control tuberculosis requires the presence of evidence based data on the genetic diversity of its causative agent. The current research work, therefore, was to differentiate strains of Mycobacterium tuberculosis isolated from pulmonary tuberculosis patients who own cattle in North Eastern and North Western parts of Ethiopia using molecular techniques. Sputum samples were collected from Acid Fast Bacilli (AFB) positive pulmonary tuberculosis patients and cultured on Lowenstein-Jensen (LJ) medium containing glycerol and sodium pyruvate. Deoxyribonucleic acid (DNA) was extracted from each positive culture, spoligotyping and single nucleotide polymorphisms were performed to further differentiate strains of M. tuberculosis, after deletion typing PCR confirmed that all the isolates were Mycobacterium tuberculosis. The mean age of study participants was 35.7 years (18-63 years) + 13.24. The majority (55.7%) were from North Gondar zone. Spoligotyping revealed that (47/50) 94% had interpretable patterns and 3 lineages namely; East-Africa-Indian (57.4%), Euro-American-African (EAA lineage-Lineage 4) 38.3% and Ethiopian (lineage-7) 2/50 (4.3%). Lineage 7 was registered in North Wollo zone only. In this study 8 clusters (with cluster size ranging from 2-8), 8 unique and 10 new patters were recorded. Spoligotype International Types (SIT) (21, 25, 26, 35, 53, 109, 149 and 289), were found as clusters and of these SIT 25 (7) and SIT 289 (8) were the predominant ones. Our study proved that 3 Mycobacterium tuberculosis lineages, namely; the ancient, intermediate between the modern lineages as well as modern were identified. Besides, considerable clustering was seen, which indicates the presence of current TB transmission in the study areas.

Correlation between tuberculin skin test and IGRAs with risk factors for the spread of infection in close contacts with sputum smear positive in pulmonary tuberculosis

Background

The aim of the study was to assess the correlation between the tuberculin skin test (TST) and in vitro interferon-gamma released assays (IGRAs) with risk factors for the spread of infection in smear positive pulmonary tuberculosis (TB) contacts.

Methods

We recruited prospective contacts with smear positive pulmonary TB cases. We looked at human immunodeficiency virus (HIV) infection and other conditions of immunosuppression, presence of BCG vaccination and the degree of exposure to the index case. Patients underwent the TST, chest radiography, sputum analysis when necessary, and IGRA assays (QFN-G-IT and T-SPOT.TB). Presence of cough, diagnostic delay (days between first symptoms and TB diagnostic), contact conditions: room size (square meters) and index of overcrowding (square meters per person) were investigated in the index case.

Results

156 contacts (119 adults, 37 children) of 66 TB patients were enrolled, 2.4 (1-14) contacts per TB case. The positivity of the TST did not correlate with the risk factors studied: presence of cough (p = 0.929); delayed diagnosis (p = 0.244); room size (p = 0.462); overcrowding (p = 0.800). Both QFN-G-IT and T-SPOT.TB, showed significant association with cough (p = 0.001, and p = 0.007) and room size (p = 0.020, and p = 0.023), respectively.

Conclusions

Both IGRA associated better than TST with certain host-related risk factors involved in the transmission of disease, such as the presence of cough.

Tuberculosis recurrence after completion treatment in a European city: reinfection or relapse?

BACKGROUND

Tuberculosis (TB) recurrence can be due to reinfection or relapse. The contribution of each to TB incidence and the factors associated with recurrence are not well known. Effectiveness of TB control programs is assessed in part by recurrence rates. The aim of this study was to establish the recurrence rate of TB in Barcelona, the associated risk factors and the role of reinfection.

METHODS

A population-based retrospective longitudinal study was performed in Barcelona, Spain. TB patients with positive culture results who completed treatment between Jan 1(st), 2003 and Dec 31(st), 2006 were followed-up until December 31st, 2009 by the TB Control Program. The incidence rate of recurrence was calculated per person-year of follow-up (py). Kaplan-Meier and Cox regression methods were used for the survival analysis by calculating the hazard ratio (HR) with 95% confidence intervals (CI).

RESULTS

Of the 1,823 TB cases identified, 971 fulfilled the inclusion criteria and 13 (1.3%) had recurrent TB. The recurrence rate was 341 cases per 100,000 py, 13 times higher than the TB incidence of the general population. Likelihood of TB recurrence at the 1st, 3rd and 5th year of follow-up was 0.1%, 1.4% and 1.6%, respectively. Factors associated with recurrence were HIV infection (HR: 4.7, CI: 1.4-15.7), living in the inner city district (HR: 3.9, CI: 1.3-11.8) and history of TB treatment (HR: 5.2, CI: 1.7-16.2). Genotyping results of recurrent cases were available for 6 patients (3 reinfections and 3 relapses).

CONCLUSION

The rate of TB recurrence in Barcelona is low and most episodes occur within the first three years. Patients at higher risk of recurrence are co-infected with HIV, living in neighborhoods with high TB incidence or with a history of TB treatment. When available, genotyping results help determine whether the recurrence is due to reinfection or relapse.

Contact investigation for tuberculosis: a systematic review and meta-analysis

Investigation of contacts of patients with tuberculosis (TB) is a priority for TB control in high-income countries, and is increasingly being considered in resource-limited settings. This review was commissioned for a World Health Organization Expert Panel to develop global contact investigation guidelines. We performed a systematic review and meta-analysis of all studies reporting the prevalence of TB and latent TB infection, and the annual incidence of TB among contacts of patients with TB. After screening 9,555 titles, we included 203 published studies. In 95 studies from low- and middle-income settings, the prevalence of active TB in all contacts was 3.1% (95% CI 2.2-4.4%, I(2)=99.4%), microbiologically proven TB was 1.2% (95% CI 0.9-1.8%, I(2)=95.9%), and latent TB infection was 51.5% (95% CI 47.1-55.8%, I(2)=98.9%). The prevalence of TB among household contacts was 3.1% (95% CI 2.1-4.5%, I(2)=98.8%) and among contacts of patients with multidrug-resistant or extensively drug-resistant TB was 3.4% (95% CI 0.8-12.6%, I(2)=95.7%). Incidence was greatest in the first year after exposure. In 108 studies from high-income settings, the prevalence of TB among contacts was 1.4% (95% CI 1.1-1.8%, I(2)=98.7%), and the prevalence of latent infection was 28.1% (95% CI 24.2-32.4%, I(2)=99.5%). There was substantial heterogeneity among published studies. Contacts of TB patients are a high-risk group for developing TB, particularly within the first year. Children <5 yrs of age and people living with HIV are particularly at risk. Policy recommendations must consider evidence of the cost-effectiveness of various contact tracing strategies, and also incorporate complementary strategies to enhance case finding.

Pediatric tuberculosis in Stockholm: a mirror to the world

BACKGROUND

Increasing international migration has changed the epidemiology of tuberculosis (TB) in Europe. Little is published on clinical manifestations and epidemiology in children in this new era.

METHODS

Clinical and laboratory data on all children with TB in Stockholm between 2000 and 2009 were entered into a database and retrospectively completed with information from case records. Population data, including parents' country of birth, were obtained from Statistics Sweden.

RESULTS

TB was diagnosed in 147 children <18 years of age (78 confirmed, 12 probable, 57 possible). Fifty-six children (38%) presented clinically, and 91 were identified by screening procedures. Ninety children (61%) were born in high-endemic countries and 38 in Sweden to parents from such countries. The incidence was 451/100,000 person years among children born in Somalia, 44 among those born in other high-endemic countries, and 13 among Swedish-born children with parents from high-endemic countries. All but 1 of the 19 Swedish-born children with Swedish parents belonged to a single outbreak. Median age was 12 years. Severe, adult-type TB was predominantly observed in adolescents, whereas young children presented mild, primary disease that was diagnosed at the time of screening. The 78 positive cultures were traced back to 67 strains. Resistance to any first-line drug was present in 25% of the strains, of which 4 were multidrug resistant.

CONCLUSIONS

Active TB in Stockholm is common in children born in high-endemic countries, especially Somalia. The most severe cases are seen in adolescents. The high prevalence of antimicrobial resistance is a cause for concern.

[Influence of immigration on tuberculosis transmission patterns in Castellón, Spain (2004-2007)]

BACKGROUND

This study aimed to identify tuberculosis transmission patterns in Castellón in a period of major demographic changes.

METHODS

A prospective study of patients with positive culture in the province of Castellon over a 4-year period (2004-2007) was carried out. Cases were described by year and nationality and were compared with those reported to the Department of Public Health. We studied the population with available molecular patterns, identified through restriction fragment length polymorphism (RFLP) and analyzed the variables from patient clusters, based on data collected in surveys of the Department of Health and the Laboratory Management Program.

RESULTS

According to data from the Department of Public Health, the overall rate of tuberculosis per 100,000 inhabitants in the province of Castellón was 15.7 in 2004, 19.9 in 2005, 18.2 in 2006 and 17.5 in 2007. In our laboratory, strains were identified from 301 patients, representing 77% (301/390) of reported cases and 94% (301/321) of reported cases with a positive culture. The percentage of tuberculosis among foreigners increased with age, exceeding 50% in 2007. Molecular studies were available in 95% of patients (286); 58% were Spanish and 42% were foreigners, of whom 54% were Romanians. The cluster percentage was 40%, with 30% of mixed clusters. According to conventional contact studies, 85% of patients in clusters had been considered isolated cases.

CONCLUSIONS

The increased rate of tuberculosis in Castellón was mainly due to the increasing number of cases among foreigners, mostly Romanians. The availability of molecular studies in all patients with a positive culture allowed us to analyze how and where tuberculosis is transmitted in our province. Forty percent of the patients were grouped into clusters; of these, mixed clusters accounted for one third, indicating the high integration of immigrants in our area.

Multiple introductions of multidrug-resistant tuberculosis into households, Lima, Peru

Two cases of multidrug-resistant tuberculosis (MDR TB) in a household are assumed to reflect within-household transmission. However, in high-incidence areas of MDR TB, secondary cases may arise through exposure to MDR TB in the community. To estimate the frequency of multiple introductions of MDR TB into households, we used spoligotyping and 24-loci mycobacterial interspersed repetitive unit- variable number tandem repeats to classify isolates from 101 households in Lima, Peru, in which >1 MDR TB patient received treatment during 1996-2004. We found different MDR TB strains in >10% of households. Alternate approaches for classifying matching strains produced estimates of multiple introductions in <38% of households. At least 4% of MDR TB patients were reinfected by a second strain of MDR Mycobacterium tuberculosis. These findings suggest that community exposure to MDR TB in Lima occurs frequently. Rapid drug sensitivity testing of strains from household contacts of known MDR TB patients is needed to identify optimal treatment regimens.

[Respiratory disease registries in Spain: fundamentals and organization]

This present paper describes the general characteristics, objectives and organizational aspects of the respiratory disease registries in Spain with the aim to report their activities and increase their diffusion. The document compiles information on the following registries: the Spanish Registry of Patients with Alpha-1 Antitrypsin Deficiency, Spanish Registry of Bronchiectasis, International Registry of Thromboembolic Disease, Spanish Registry of Occupational Diseases, Spanish Registry of Pulmonary Artery Hypertension, Registry of Pleural Mesothelioma, Spanish Registry of Tuberculosis and Spanish Multi-center Study of Neuroendocrine Pulmonary Tumors. Our paper provides information on each of the registries cited. Each registry has compiled specific clinical information providing data in real situations, and completes the results obtained from clinical assays. Said information has been published both in national as well as international publications and has lead to the creation of various guidelines. Therefore, the activities of the professionals involved in the registries have spread the knowledge about the diseases studied, promoting the exchange of information among workgroups.

[Diagnosis of tuberculosis in pediatrics. Consensus document of the Spanish Society of Pediatric Infectology (SEIP) and the Spanish Society of Pediatric Pneumology (SENP)]

Tuberculosis is one of the most important health problems worldwide. There are an increased number of cases, including children, due to different reasons in developed countries. The most likely determining cause is immigration coming from high endemic areas. Measures to optimize early and appropriate diagnosis of the different forms of tuberculosis in children are a real priority. Two Societies of the Spanish Pediatric Association (Spanish Society of Pediatric Infectology and Spanish Society of Pediatric Pneumology) have agreed this Consensus Document in order to homogenize diagnostic criteria in pediatric patients.