[Polio virus detection in stool by the pathogen surveillance system of Japan. An observational study].

Objectives: To examine the applicability of data on polio virus detection in stool by the Pathogen Surveillance System of Japan (PSSJ) for the evaluation of polio virus retention status in a regional community after oral polio vaccination (OPV).

Methods: (1) Data for the city of Kobe (part of the PSSJ data): Cases of polio virus detection in stool reported to Kobe City Public Health Center from January 1, 2000 to June 30, 2010 were examined regarding time duration from vaccination to detection as well as age and gender. (2) PSSJ data: Cases of polio virus detection in stool reported to PSSJ from January 1, 2000 to December 31, 2010 were examined regarding the serological types of the virus as well as age and gender.

[Comparison of conventional tuberculin skin test and QFT-2G, a new method for diagnosis of tuberculosis infection, with the use of the contact score].

Background: QuantiFERON TB-Gold (QFT) has recently been developed as a new method for diagnosing tuberculosis (TB) infection. To evaluate the usefulness of QFT, we analyzed the relationship between QFT and the closeness of contact with a source of infection, in comparison with that of the tuberculin skin test (TST).

Methods: Male (n=322) and female (n=340) subjects (4-75 years old) who had contact with an index case received QFT and TST.

Population structure dynamics of Mycobacterium tuberculosis Beijing strains during past decades in Japan.

We used 909 strains to compare the population structures of the Mycobacterium tuberculosis Beijing family between different birth-year cohorts in Japan. The results revealed that the spread of a modern sublineage that has high transmissibility is currently increasing, while the spread of an ancient sublineage, STK, has significantly decreased in younger generations.

Hypervariable loci that enhance the discriminatory ability of newly proposed 15-loci and 24-loci variable-number tandem repeat typing method on Mycobacterium tuberculosis strains predominated by the Beijing family.

The newly proposed 15- and 24-loci mycobacterial interspersed repetitive unit (MIRU)-variable-number tandem repeat (VNTR) typing method was evaluated for its ability to differentiate 181 Mycobacterium tuberculosis Beijing family strains. Compared with the original 12-loci MIRU-VNTR typing method, the 15-loci system dramatically improved the discriminatory power for Beijing strains; however, large clusters that could be further differentiated by IS6110 restriction fragment length polymorphism (RFLP) were still obtained. The clonal stability and allelic diversity of a total of 31 VNTR loci were evaluated.