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Frontiers in Genetics 2020Mixed strain infection (MSI) refers to the concurrent infection of a susceptible host with multiple strains of a single pathogenic species. Known to occur in humans and...
Mixed strain infection (MSI) refers to the concurrent infection of a susceptible host with multiple strains of a single pathogenic species. Known to occur in humans and animals, MSIs deserve special consideration when studying transmission dynamics, evolution, and treatment of mycobacterial diseases, notably tuberculosis in humans and paratuberculosis (or Johne's disease) in ruminants. Therefore, a systematic review was conducted to examine how MSIs are defined in the literature, how widespread the phenomenon is across the host species spectrum, and to document common methods used to detect such infections. Our search strategy identified 121 articles reporting MSIs in both humans and animals, the majority (78.5%) of which involved members of the complex, while only a few (21.5%) examined non-tuberculous mycobacteria (NTM). In addition, MSIs exist across various host species, but most reports focused on humans due to the extensive amount of work done on tuberculosis. We reviewed the strain typing methods that allowed for MSI detection and found a few that were commonly employed but were associated with specific challenges. Our review notes the need for standardization, as some highly discriminatory methods are not adapted to distinguish between microevolution of one strain and concurrent infection with multiple strains. Further research is also warranted to examine the prevalence of NTM MSIs in both humans and animals. In addition, it is envisioned that the accurate identification and a better understanding of the distribution of MSIs in the future will lead to important information on the epidemiology and pathophysiology of mycobacterial diseases.
PubMed: 33408740
DOI: 10.3389/fgene.2020.600692 -
Journal of the Formosan Medical... Jun 2020Nontuberculous mycobacteria (NTM) are critical emerging global infectious pathogens. Though NTM can be mere colonizers when isolated from human specimens, NTM are also...
Nontuberculous mycobacteria (NTM) are critical emerging global infectious pathogens. Though NTM can be mere colonizers when isolated from human specimens, NTM are also responsible for diverse human infections. NTM-lung disease (NTM-LD) is the most common human disease entity. The present review aims to provide general insight into NTM-LD epidemiology in Taiwan. In reviewing NTM epidemiology in Taiwan, we discovered three distinguishing features. First, NTM disease incidence has increased in Taiwan over the past decade. Second, the distribution of NTM varies geographically in Taiwan. Mycobacterium avium-intracellulare complex (MAC) is the dominant species in northern Taiwan, whereas Mycobacterium abscessus complex and MAC may be equally dominant in southern Taiwan. Third, researchers in Taiwan have published valuable research investigating NTM among special patient populations, including patients in intensive care units, with ventilator dependency, with pulmonary tuberculosis, and who are infected with specific NTM species. The largest obstacle to clarifying NTM epidemiology in Taiwan may be the lack of routine NTM species identification in laboratories. Increased awareness of NTM diseases and acknowledgment that NTM species identification is crucial and guides clinical management are essential steps for facilitating the identification of NTM species in laboratories.
Topics: Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium abscessus; Mycobacterium avium Complex; Nontuberculous Mycobacteria; Taiwan
PubMed: 32482605
DOI: 10.1016/j.jfma.2020.05.019 -
FEMS Microbiology Reviews Jan 2022Understanding the interactions of ecosystems, humans and pathogens is important for disease risk estimation. This is particularly true for neglected and newly emerging...
Understanding the interactions of ecosystems, humans and pathogens is important for disease risk estimation. This is particularly true for neglected and newly emerging diseases where modes and efficiencies of transmission leading to epidemics are not well understood. Using a model for other emerging diseases, the neglected tropical skin disease Buruli ulcer (BU), we systematically review the literature on transmission of the etiologic agent, Mycobacterium ulcerans (MU), within a One Health/EcoHealth framework and against Hill's nine criteria and Koch's postulates for making strong inference in disease systems. Using this strong inference approach, we advocate a null hypothesis for MU transmission and other understudied disease systems. The null should be tested against alternative vector or host roles in pathogen transmission to better inform disease management. We propose a re-evaluation of what is necessary to identify and confirm hosts, reservoirs and vectors associated with environmental pathogen replication, dispersal and transmission; critically review alternative environmental sources of MU that may be important for transmission, including invertebrate and vertebrate species, plants and biofilms on aquatic substrates; and conclude with placing BU within the context of other neglected and emerging infectious diseases with intricate ecological relationships that lead to disease in humans, wildlife and domestic animals.
Topics: Animals; Buruli Ulcer; Ecosystem; Humans; Mycobacterium ulcerans; Plants
PubMed: 34468735
DOI: 10.1093/femsre/fuab045 -
ERJ Open Research Oct 2022Immune checkpoint inhibitors (ICIs) are drugs growingly employed in the treatment of cancers, but there are still uncertainties about their possible role in the risk of...
Immune checkpoint inhibitors (ICIs) are drugs growingly employed in the treatment of cancers, but there are still uncertainties about their possible role in the risk of developing nontuberculous mycobacteria (NTM) infections. To understand this, we performed a systematic review of the literature including studies published between 20 June 2012 and 20 June 2022 which described the occurrence of NTM infections among patients treated with ICIs. Overall, we included seven studies describing nine patients with NTM infection occurring during ICIs therapy. NTM infections occurring during ICIs therapy are mainly caused by germs belonging to the , involve primarily the lungs, on average 1 year after the start of treatment, and are not associated with immunosuppressive treatments.
PubMed: 36451841
DOI: 10.1183/23120541.00364-2022 -
International Journal of Environmental... Mar 2020Construction activities are a known risk contributing to the growth and spread of waterborne pathogens in building water systems. The purpose of the study is to...
Construction activities are a known risk contributing to the growth and spread of waterborne pathogens in building water systems. The purpose of the study is to integrate evidence for categorizing construction activity risk factors contributing to waterborne disease in community and healthcare settings, establish severity of such risk factors and identify knowledge gaps. Using a systematic review, the inclusion criteria were: 1) studies with disease cases suspected to be associated with construction activities and waterborne pathogens, and 2) active construction work described in a community or healthcare setting. Each construction activity risk factor was correlated across all studies with the number of disease cases and deaths to establish risk severity. The eligibility review and quantitative synthesis yielded 31 studies for inclusion (community, n = 7 and healthcare, n = 24). From 1965 to 2016, a total of 894 disease cases inclusive of 112 deaths were associated with nine construction activity risk factors and waterborne pathogens. The present study findings support the need for building owners, water management teams and public health professionals to address construction activity risk factors and the analysis of current knowledge deficiencies within the scope of an ongoing water management program. The impact of construction activities on waterborne disease is preventable and should no longer be considered incidental nor accidental.
Topics: Disease Outbreaks; Facility Design and Construction; Humans; Water Microbiology; Water Pollutants; Water Supply; Waterborne Diseases
PubMed: 32214051
DOI: 10.3390/ijerph17062168 -
Open Forum Infectious Diseases May 2021Health care administrative database research frequently uses standard medical codes to identify diagnoses or procedures. The aim of this review was to establish the...
BACKGROUND
Health care administrative database research frequently uses standard medical codes to identify diagnoses or procedures. The aim of this review was to establish the diagnostic accuracy of codes used in administrative data research to identify nontuberculous mycobacterial (NTM) disease, including lung disease (NTMLD).
METHODS
We searched Ovid Medline, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from inception to April 2019. We included studies assessing the diagnostic accuracy of (ICD-9-CM) diagnosis codes to identify NTM disease and NTMLD. Studies were independently assessed by 2 researchers, and the Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess bias and quality.
RESULTS
We identified 5549 unique citations. Of the 96 full-text articles reviewed, 7 eligible studies of moderate quality (3730 participants) were included in our review. The diagnostic accuracy of ICD-9-CM diagnosis codes to identify NTM disease varied widely across studies, with positive predictive values ranging from 38.2% to 100% and sensitivity ranging from 21% to 93%. For NTMLD, 4 studies reported diagnostic accuracy, with positive predictive values ranging from 57% to 64.6% and sensitivity ranging from 21% to 26.9%.
CONCLUSIONS
Diagnostic accuracy measures of codes used in health care administrative data to identify patients with NTM varied across studies. Overall the positive predictive value of ICD-9-CM diagnosis codes alone is good, but the sensitivity is low; this method is likely to underestimate case numbers, reflecting the current limitations of coding systems to capture NTM diagnoses.
PubMed: 34041304
DOI: 10.1093/ofid/ofab035 -
International Journal of... 2023Mycobacterium nebraskense is a rare, slow growing nontuberculous mycobacterium species with limited documented cases. This systematic review aims to comprehensively...
BACKGROUND
Mycobacterium nebraskense is a rare, slow growing nontuberculous mycobacterium species with limited documented cases. This systematic review aims to comprehensively analyze the clinical characteristics, presentation, and management of M. nebraskense infections by analyzing the available literature, including a newly reported case that we present in this article.
METHODS
A comprehensive search was conducted using PubMed and Google Scholar to identify relevant cases up to October 2023. Only seven reported cases were found, highlighting the scarcity of information on this pathogen.
RESULTS
Our analysis revealed several key findings. First, gender disparities were observed, with females being more susceptible to M. nebraskense infections. Additionally, a significant portion of patients presented with asymptomatic infections. Most affected individuals were over the age of 60, emphasizing potential age-related susceptibility. Comorbidity profiles varied widely among cases, and patients with preexisting lung comorbidities were at an increased risk of infection. The decision to treat or observe depended on clinical presentation, with even immunosuppressed individuals not always requiring treatment. Regarding treatment, we proposed an empirical approach with amikacin, clarithromycin, or rifabutin, considering the reported resistance to doxycycline and minocycline. Combination therapy was commonly employed to minimize resistance development, consistent with mycobacterial infection management.
CONCLUSION
This study underscores the need for further research to validate these findings and enhance our understanding of M. nebraskense infections. As limited data are available, this review aims to provide valuable insights into a rare and emerging pathogen to guide clinical practice and future research endeavors.
Topics: Female; Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium; Nontuberculous Mycobacteria; Clarithromycin; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 38149541
DOI: 10.4103/ijmy.ijmy_167_23