First case of molecularly identified and genetically characterized human T-cell leukemia virus type 2 infection in a pregnant woman in non-endemic Japan.

Human T-cell leukemia virus type 2 (HTLV-2) is non-endemic in Japan unlike the related HTLV type 1. Previously, although HTLV-2-seropositivity was identified via western blotting in one male blood donor in Japan, there have been no reports of HTLV-2 provirus detection by nucleic acid testing. In this report, one Japanese pregnant woman was clinically diagnosed as being HTLV-2-infected with a line immunoassay for specific antibodies after primary testing through prenatal screening in Japan. In genomic DNA of her peripheral blood mononuclear cells, HTLV-2 proviral genome was detected by nucleic acid testing (three methods) with quantitative polymerase chain reaction. The full-genome sequence of this strain was successfully determined. The identified virus was interestingly characterized as a presumed progenitor of subtypes a and c by recombination region and phylogenetic tree analyses. In conclusion, the present infection is, to our knowledge, the first case of molecularly identified and genetically characterized HTLV-2 infection found via prenatal screening in non-endemic Japan.

A Laboratory-based Analysis of Nontuberculous Mycobacterial Lung Disease in Japan from 2012 to 2013.

RATIONALE: Since 2010, mycobacterial examination results have been used widely to survey nontuberculous mycobacteria (NTM) lung disease. OBJECTIVES: To reveal the clinical and epidemiological status of NTM lung disease in Japan. METHODS: All data on the isolation and identification of mycobacteria in 2012 and 2013 were obtained from three dominant commercial laboratories in Japan. Pulmonary NTM disease was defined on the basis of bacteriological diagnostic criteria issued by the American Thoracic Society/Infectious Diseases Society of America. The coverage population was estimated using the ratio between national tuberculosis registration data and laboratory results for each of the eight regions of Japan. MEASUREMENTS AND MAIN RESULTS: A total of 113,313 mycobacterial specimens from 4,710 institutes were collected, and specimens from 26,059 patients tested positive for NTM cultures at least once. Among patients with positive cultures, 7,167 (27.5%) satisfied the American Thoracic Society/Infectious Diseases Society of America criteria for NTM lung disease, resulting in a 2-year prevalence rate of 24.0 per 100,000. Mycobacterium avium complex (MAC) was the most commonly isolated species (93.3%), and 29.0% of the patients from whom MAC was isolated satisfied the criteria for NTM lung disease. Individuals older than 70 years of age accounted for the majority of cases, and 65.5% of cases involved females. After MAC, Mycobacterium kansasii and Mycobacterium abscessus exhibited the highest (43.6%) and second-highest (37.1%) incidence per isolation, respectively. The prevalence of M. kansasii was highest in the Kinki region (P < 0.05), and M. abscessus had the greatest prevalence in the Kyushu-Okinawa region (P < 0.005). The proportion of Mycobacterium intracellulare in MAC cases was higher in the southwestern part of Japan than in other regions. The period prevalence was highest in the southwestern part of Japan, and the standardized prevalence ratio was highest in central regions. Evaluations of clarithromycin susceptibility revealed a clear binomial distribution. CONCLUSIONS: This investigation is the first laboratory-based study in which a large number of NTM isolated from clinical samples in Japan have been assessed. Although the calculated prevalence of NTM disease might be underestimated, the approach may prove useful for monitoring relative epidemiological data for NTM lung disease.

[Relationship between time taken from collection of blood to incubation and measurement in whole-blood interferon gamma assay for diagnosis of Mycobacterium tuberculosis infection].

BACKGROUND: The introduction of second-generation QuantiFERON-TB (QFT) enables the diagnosis of Mycobacterium tuberculosis (TB) infection with high specificity and sensitivity. This in vitro diagnostic test uses 2 TB-specific proteins (ESAT-6 and CFP-10) to stimulate cells in heparinized whole blood and detects interferon-gamma (IFN-gamma) produced from blood cells. When QFT is done in laboratories outside of the hospital, several hours may be required to transport blood samples. We studied the relationship between QFT results and the time taken from collection of blood to incubation (preincubation time). METHODS: Heparinized whole blood drawn from TB suspects was immediately transported to a laboratory. We started to incubate 4 aliquots of blood with ESAT-6, CFP-10, mitogen (phytohemagglutinin), and nil control, at 1, 3, 6, 9, and 12 h after blood was drawn. After incubation, the concentration of IFN-gamma in each plasma sample was determined by ELISA, and values E and C were expressed as the concentration of IFN-gamma with ESAT-6 or CFP-10, minus the concentration of IFN-gamma in the nil control. Value E or C > or =0.35IU/mL was considered positive, > or =0.10 and<0.35IU/mL as equivocal (gray zone), and<0.10IU/mL as negative. We analyzed 8 patients with value E or C > or =0.10IU/mL at a preincubation time of 1 h. RESULTS: Value E and C decreased especially for preincubation time >6 h. As a result, the interpretation of value E changed from "positive" to "equivocal" in 2 cases and from "equivocal" to "negative" in 2 cases. Interpretation of value C also changed from "positive" to "equivocal" or "negative" in 2 cases and from "equivocal "to "negative" in 1 case. Even if the higher of value E or C were used for analysis, QFT results changed in half of patients when preincubation time was>6 h. CONCLUSION: Since QFT results in half of patients changed when preincubation time was>6 h, incubation of whole blood should start < or =6 h after blood drawing.