Identification and characterization of Shigella boydii 20 serovar nov., a new and emerging Shigella serotype.

Analysis of 163 putative Shigella isolates from Canada and the USA showed biochemical reactions consistent with Shigella species, although none of the isolates reacted with antiserum raised against any of the well-established or provisional Shigella serotypes. All these isolates, provisionally designated serotype SH108, were positive for the ipaH gene and the invasion-associated locus. All fermented mannitol, were serologically indistinguishable from each other and showed no reaction in antisera prepared against Escherichia coli serotypes O1 to O181. PCR-RFLP analysis of the genes involved in O-antigen synthesis revealed a common pattern among these isolates that was distinct from recognized Shigella serotypes and E. coli. Between 1999 and 2003, isolates from across Canada were submitted to the National Laboratory for Enteric Pathogens for antibiotic susceptibility testing, phage typing and PFGE. These assays revealed heterogeneity among the members of this serotype. Antimicrobial susceptibility testing with seven antibiotics identified six profiles, with 90 % (45/50) of the isolates resistant to four or more antibiotics and 72 % (36/50) resistant to five or more. All isolates were typable using a panel of 16 phages, with 11 different phage types (PTs) represented. The most common PTs found were PT 3 (64 %), PT 6 (10 %) and PT 16 (6 %). Analysis of XbaI-restricted genomic DNA revealed 16 highly related patterns that were not readily distinguishable from those obtained for some other Shigella serotypes. The World Health Organization Collaborating Center for Shigella has added serotype SH108 to the Shigella scheme as S. boydii serotype 20 (serovar nov.). Strain SH108 (isolate 99-4528) is the reference strain for this serotype.

Increased mammography use and its impact on earlier breast cancer detection in Vermont, 1975-1999.

BACKGROUND: A trend toward earlier breast carcinoma detection in the United States has been attributed to screening mammography, although direct evidence linking this trend to the increased use of mammography in a general population is lacking. This study examined the effects of mammography on tumor size and axillary lymph node metastasis in Vermont over 25 years. METHODS: Pathology and mammography data from 3499 Vermont women who were diagnosed with invasive breast carcinoma during 1975-1984, 1989-1990, and 1995-1999 were compared. Logistic regression analysis was used to estimate the effects of age, mammography use, and period on the odds of a tumor < or = 2 cm and the odds of negative lymph nodes. RESULTS: The proportion of breast tumors that were detected by screening mammography increased from 2% during 1974-1984 to 36% during 1995-1999 (P < 0.001), and these tumors were more likely to measure < or = 2 cm than tumors that were detected by other methods. Among women age > 50 years, the odds ratio (OR) was 4.5, with a 95% confidence interval (95% CI) of 3.5-6.4. The effect was smaller in younger women (OR, 1.8; 95% CI, 1.1-3.0). Mammographic detection increased the odds of negative lymph nodes by a similar amount in both age groups, although women age > 50 years were more likely to have negative lymph nodes than younger women (OR, 1.3; 95% CI, 1.1-1.6). Tumor size and lymph node metastasis also were related to the number of mammograms and to the mammographic interval. CONCLUSIONS: Most of the trend toward earlier detection in Vermont was due to mammography. Mammography had a lesser effect on tumor size among younger women, which may be related to less frequent screening, although its effect on lymph node metastasis was not age dependent. Women age < 50 years were more likely to have positive lymph nodes, independent of the method of detection or the frequency of mammography.

American Cancer Society guidelines for breast cancer screening: update 2003.

In 2003, the American Cancer Society updated its guidelines for early detection of breast cancer based on recommendations from a formal review of evidence and a recent workshop. The new screening recommendations address screening mammography, physical examination, screening older women and women with comorbid conditions, screening women at high risk, and new screening technologies.

Evaluation of a community breast screening promotion program.

BACKGROUND: This study reports results of a controlled evaluation of a comprehensive community breast screening promotion program. This program promoted increased use of mammography, clinical breast examination, and breast self-examination through community organization, physician training, and public education. METHODS: The program was conducted in one of three matched Florida study areas, with before and after assessment of breast screening behaviors, beliefs, and perceptions of women ages 40 and older. Baseline measures in 1990 were obtained by combining telephone and household survey data; follow-up measures using similar combined data were conducted with 4,096 women in 1997. RESULTS: . There was no evidence that the breast screening promotion program achieved higher levels of screening among women ages 40 and older in the program area. Mammography use and supportive beliefs and perceptions of mammography increased in all three study areas between 1990 and 1997. CONCLUSIONS: Among factors that may have reduced the differential impact of the program were public attention to breast cancer screening in the late 1980s throughout the U.S., effects of managed care, and limited penetration of a key program component. While the program was well received and served the community, its impact was overwhelmed by temporal trends observed in this study.