Tuberculosis Recurrences

Viedma, Darío García de; Marı́n, Mercedes; Hernangómez, Susana; Díaz, Marisol; Serrano, Manuel Nistal Martín; Alcalá, Luís; Bouza, Emilio

doi:10.1001/archinte.162.16.1873

Cited by 59 publications

(9 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even in this moderate-incidence setting, for 14 (33%) of these 43 patients, the recurrence isolates were unrelated to the original isolates, and thus, these patients were in fact reinfected. Poor treatment adherence and HIV status were not associated with either relapses or reinfections (481).…”

Section: Applications Of Strain Typing To M Tuberculosis Complex Isomentioning

confidence: 87%

“…Here, IS6110-RFLP typing showed that 24 (77%) of 31 recurrences after successful treatment were attributable to reinfection, whereas only 4 (11%) of 37 recurrences after treatment default were reinfections (476). García de Viedma et al performed a similar analysis, investigating recurrent TB among 43 patients in Madrid, Spain, most of whom had been poorly adherent to TB therapy (481). Even in this moderate-incidence setting, for 14 (33%) of these 43 patients, the recurrence isolates were unrelated to the original isolates, and thus, these patients were in fact reinfected.…”

Section: Applications Of Strain Typing To M Tuberculosis Complex Isomentioning

confidence: 99%

See 1 more Smart Citation

Methodological and Clinical Aspects of the Molecular Epidemiology of Mycobacterium tuberculosis and Other Mycobacteria

et al. 2016

View full text Add to dashboard Cite

SUMMARYMolecular typing has revolutionized epidemiological studies of infectious diseases, including those of a mycobacterial etiology. With the advent of fingerprinting techniques, many traditional concepts regarding transmission, infectivity, or pathogenicity of mycobacterial bacilli have been revisited, and their conventional interpretations have been challenged. Since the mid-1990s, when the first typing methods were introduced, a plethora of other modalities have been proposed. So-called molecular epidemiology has become an essential subdiscipline of modern mycobacteriology. It serves as a resource for understanding the key issues in the epidemiology of tuberculosis and other mycobacterial diseases. Among these issues are disclosing sources of infection, quantifying recent transmission, identifying transmission links, discerning reinfection from relapse, tracking the geographic distribution and clonal expansion of specific strains, and exploring the genetic mechanisms underlying specific phenotypic traits, including virulence, organ tropism, transmissibility, or drug resistance. Since genotyping continues to unravel the biology of mycobacteria, it offers enormous promise in the fight against and prevention of the diseases caused by these pathogens. In this review, molecular typing methods forMycobacterium tuberculosisand nontuberculous mycobacteria elaborated over the last 2 decades are summarized. The relevance of these methods to the epidemiological investigation, diagnosis, evolution, and control of mycobacterial diseases is discussed.

show abstract

Section: Applications Of Strain Typing To M Tuberculosis Complex Isomentioning

confidence: 87%

Section: Applications Of Strain Typing To M Tuberculosis Complex Isomentioning

confidence: 99%

Methodological and Clinical Aspects of the Molecular Epidemiology of Mycobacterium tuberculosis and Other Mycobacteria

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Evidence suggests that in countries with a low TB burden, TB recurrence is usually caused by relapse [30], whereas in countries with a high TB burden the principle cause is reinfection [31], especially when high levels of HIV infection co-exist [20]. In countries with a medium TB burden (like Uzbekistan), relapse and reinfection are both thought to play a role [32], with their relative contribution depending on the prevalence of epidemiological risk factors and the microbiological features of circulating M . tuberculosis strains.…”

Section: Discussionmentioning

confidence: 99%

Recurrent tuberculosis and associated factors: A five - year countrywide study in Uzbekistan

Gadoev¹,

Harries

et al. 2017

PLoS ONE

View full text Add to dashboard Cite

BackgroundIn Uzbekistan, despite stable and relatively high tuberculosis treatment success rates, relatively high rates of recurrent tuberculosis have recently been reported. Recurrent tuberculosis is when a patient who was treated for pulmonary tuberculosis and cured, later develops the disease again. This requires closer analysis to identify possible causes and recommend interventions to improve the situation. Using countrywide data, this study aimed to analyse trends in recurrent tuberculosis cases and describe their associations with socio-demographic and clinical factors.MethodCountrywide retrospective cohort study comparing recurrent tuberculosis patients with all new tuberculosis patients registered within the NTP between January 2006 and December 2010 using routinely collected data. Determinants studied were baseline characteristics and treatment outcomes.ResultsOf 107,380 registered patients during the period January 2006 and December 2010, 9358 (8.7%) were recurrent cases. Between 2006 and 2008, the number of recurrent cases per annum increased from 1530 to 2081, then fell slightly thereafter from 2081 to 1888 cases. The proportion of all notified cases during this period increased from 6.5% to 9.9%. Factors associated with recurrent tuberculosis included age (35–55 years old), having smear positive pulmonary tuberculosis, residing in certain areas of Uzbekistan, having particular co-morbidities (including chronic obstructive pulmonary disease and HIV), and being unemployed, a pensioner or disabled. Recurrent tuberculosis patients also had a higher likelihood of having an unfavourable treatment outcomeConclusionDespite signs of declining national tuberculosis notifications between 2006 and 2010, the relative proportion of recurrent cases appears to have increased. These findings, together with the identification of possible risk factors associated with recurrent tuberculosis, highlight various areas where Uzbekistan needs to focus its tuberculosis control efforts, particularly in light of the country’s rapidly emerging multi drug resistant tuberculosis epidemic.

show abstract

“…Since the risk of reinfection (a pre-requisite for a mixed strain infection) is a function of the local prevalence of infectious source cases, mixed infection will be most common in settings with a high disease burden. However, reinfection has also been shown to play an important role in disease dynamics in moderate- [17–18] and low-incidence communities [19]; this may reflect the increased importance of local clustering of disease among household and close social contacts in these lower incidence settings [20]. Heterogeneity in the frequency of detection of mixed strain infections between existing studies may also reflect differences in study participant selection, methods of specimen collection and storage [21], and in approaches for laboratory identification of multiple strains [22].…”

Section: Introductionmentioning

confidence: 99%

Models to understand the population-level impact of mixed strain M. tuberculosis infections

Sergeev

Colijn

Cohen

2011

Journal of Theoretical Biology

View full text Add to dashboard Cite

Over the past decade, numerous studies have identified tuberculosis patients in whom more than one distinct strain of M. tuberculosis is present. While it has been shown that these mixed strain infections can reduce the probability of treatment success for individuals simultaneously harboring both drug-sensitive and drug-resistant strains, it is not yet known if and how this phenomenon impacts the long-term dynamics for tuberculosis within communities. Strain-specific differences in immunogenicity and associations with drug resistance suggest that a better understanding of how strains compete within hosts will be necessary to project the effects of mixed strain infections on the future burden of drug-sensitive and drug-resistant tuberculosis. In this paper, we develop a modeling framework that allows us to investigate mechanisms of strain competition within hosts and to assess the long-term effects of such competition on the ecology of strains in a population. These models permit us to systematically evaluate the importance of unknown parameters and to suggest priority areas for future experimental research. Despite the current scarcity of data to inform the values of several model parameters, we are able to draw important qualitative conclusions from this work. We find that mixed strain infections may promote the coexistence of drug-sensitive and drug-resistant strains in two ways. First, mixed strain infections allow a strain with a lower basic reproductive number to persist in a population where it would otherwise be outcompeted if has competitive advantages within a co-infected host. Second, some individuals progressing to phenotypically drug-sensitive tuberculosis from a state of mixed drug-sensitive and drug-resistant infection may retain small subpopulations of drug-resistant bacteria that can flourish once the host is treated with antibiotics. We propose that these types of mixed infections, by increasing the ability of low fitness drug-resistant strains to persist, may provide opportunities for compensatory mutations to accumulate and for relatively fit, highly drug-resistant strains of M. tuberculosis to emerge.

show abstract

Tuberculosis Recurrences

Abstract: Reinfection plays an important role in recurrent TB in a population without the clinical/epidemiological circumstances that are usually assumed to favor it. Reinfection should, thus, be considered as a cause of TB recurrences in a wider context than before.

Cited by 59 publications

References 31 publications

Methodological and Clinical Aspects of the Molecular Epidemiology of Mycobacterium tuberculosis and Other Mycobacteria

Methodological and Clinical Aspects of the Molecular Epidemiology of Mycobacterium tuberculosis and Other Mycobacteria

Recurrent tuberculosis and associated factors: A five - year countrywide study in Uzbekistan

Models to understand the population-level impact of mixed strain M. tuberculosis infections

Contact Info

Product

Resources

About