Dissemination ofMycobacterium tuberculosisacross the San Francisco Bay Area

Abstract

The propensity of Mycobacterium tuberculosis genotypes to spread across geographic boundaries was investigated by comparing the IS6110 and polymorphic GC-rich sequence patterns of M. The modern age of transportation has brought unprecedented rated countries and spread of multidrug-resistant organisms between distant domestic sites have been demonstrated, spread movement of large numbers of people across geographic boundaries, heightening concerns about the global disseminaof M. tuberculosis between geographically proximate regions has not been systematically examined [3, 5]. tion of infectious pathogens. This increasing mobility of human populations has resulted in instances of widespread disseminaAdvances in M. tuberculosis genotyping techniques have made it possible to determine the genetic relatedness of individtion of a number of pathogens, including serogroup A Neisseria meningitidis, Vibrio cholerae O1, and Mycobacterium tubercuual isolates and to study the geographic spread of specific genotypes [3 -5, 8 -11]. In this report, we describe a study in losis [1 -5].The dissemination of M. tuberculosis is of particular concern which IS6110 genotyping was used to investigate the occurrence of tuberculosis caused by the same genotype of M. tubergiven its airborne mode of transmission, the virulence of the organism, and the significant morbidity and costs associated culosis in geographically distinct but proximate areas, San Francisco and the East Bay. These areas are separated by San with tuberculosis. Furthermore, disparities in the prevalence of tuberculosis infection and disease, the frequency of drug Francisco Bay, but an estimated 371,403 individual trips are made daily across the bay by either bridge or rail [12,13]. resistance, and the effectiveness of tuberculosis control practices between different communities may favor the dissemination of M. tuberculosis from higher to lower prevalence areas [6,7]. The propensity of M. tuberculosis to spread between Materials and Methods communities, therefore, has important public health implica- losis registries. Isolates were genotyped using standard IS6110-The study protocol was reviewed and approved by the UCSF Committee based methods; the San Francisco and the East Bay isolates were on Human Research prior to initiation of the study.Grant support: NIH (AI-34238) and CDC (U52-CCU 900454).

Epidemiology of Tuberculosis in Hamburg, Germany: Long-Term Population-Based Analysis Applying Classical and Molecular Epidemiological Techniques

“…Multivariate analyses indicated that alcohol abuse was the strongest risk factor associated with recent transmission in Hamburg. This is somewhat surprising, since in several international reports published so far (1,4,10), alcohol abuse has not been identified as an independent predictor for recent transmission. Further independent risk factors for being in an IS6110 cluster are a history of contact tracing and unemployment, whereas being male, being homeless, testing positive for sputum smear, living as a drug addict, or suffering from AIDS was not significantly associated with clustering in multivariate analysis.…”

Avoiding the effect of BCG vaccination in detectingMycobacterium tuberculosisinfection with a blood test

“…In addition, other important key components of TB control are the improvement of case finding among persons presenting with symptoms of TB, especially in HIV-infected individuals, by providing better access to quality-assured TB sputum microscopy as well as the Directly Observed Therapy Short-Course strategy in TB treatment. The latter achieves higher cure rates by an uninterrupted supply of antituberculotic drugs in a standardised short-course chemotherapy under direct observation [2].By applying classical epidemiological and molecular strain-typing techniques, population-based studies have recently revealed a high frequency of transmission of MTB, even in countries with a low TB incidence [3][4][5][6][7]. The tuberculin skin test (TST) introduced by Mantoux has been widely used as a screening test to identify individuals with LTBI.…”

“…By applying classical epidemiological and molecular strain-typing techniques, population-based studies have recently revealed a high frequency of transmission of MTB, even in countries with a low TB incidence [3][4][5][6][7]. The tuberculin skin test (TST) introduced by Mantoux has been widely used as a screening test to identify individuals with LTBI.…”

Pulmonary Tuberculosis and Mycobacterium Tuberculosis: Modern Molecular Epidemiology and Perspectives

“…Of the 24 genes, 19 were monomorphic and the last five appeared slightly polymorphic (only six polymorphic nucleotide sites on all five genes). On the contrary, the transposable elements show high levels of genetic polymorphism, and they are widely used for studying the genetic variability in the MTB species [17,95,173] (see below for more details). Nevertheless, the only way to detect the real genetic diversity of an organism is the whole sequencing of several genomes from different clinical isolates.…”