No abstract

Verocytotoxin-producing E. coli (VTEC) of serotype O157:H7 have been shown to be important agents of foodborne disease in humans worldwide. While the majority of research effort has been targeted on this serotype it is becoming more evident that other serotypes of VTEC can also be associated with human disease. An increasing number of these non-O157:H7 VTEC have been isolated from humans suffering from HUS and diarrhea. Recently a number of foodborne outbreaks in the USA, Australia, and other countries have been attributed to non-O157:H7 VTEC serotypes. Surveys of animal populations in a variety of countries have shown that the cattle reservoir contains more than 100 serotypes of VTEC, many of which are similar to those isolated from humans. The diversity and complexity of the VTEC family requires that laboratories and public health surveillance systems have the ability to detect and monitor all serotypes of VTEC.

In 1996, a population-based surveillance program for invasive adult group B streptococcal (GBS) diseases in Canada was undertaken, to define the epidemiologic and microbiologic characteristics of the disease. Nine public health units across Canada, representing 9.6% of the population, participated in the program. In total, 106 culture-positive cases of invasive adult GBS disease were reported, which represented an incidence rate 4.6 per 100,000 adults (41/100, 000 for pregnant and 4.1/100,000 for nonpregnant adults). Sixty-two (58.5%) of the 106 cases occurred in females, and, of these, 15 (14. 2%) were associated with pregnancy. Serotype V was the most common, accounting for 31% of the 90 GBS isolates typed (26.7% of nonpregnant and 4.4% of pregnant cases). This was followed by serotypes III (19%), Ia (17%), Ib (10%), II (9%), and VII (1%). Thirteen percent were nontypeable. All isolates were susceptible to penicillin, ampicillin, and vancomycin. Resistance to erythromycin and clindamycin was 6.7% and 4.4%, respectively.

Although pertussis is increasingly recognized as a cause of prolonged cough illness in adolescents and adults, its prevalence is not well established. We evaluated pertussis infection in 442 adolescents and adults > or = 12 years old (mean age, 41.3 years) who had a cough-related illness of 7--56 days' duration. For 4 patients (0.9%), results of nasopharyngeal culture or PCR were positive for Bordetella pertussis; for 10 patients (2.3%), either results of culture or PCR were positive or pertussis antibody titers increased 4-fold. Eighty-eight patients (19.9%) had either laboratory-confirmed pertussis or laboratory evidence of pertussis. These patients had significantly longer duration of cough than did patients without laboratory evidence of pertussis (56 days vs. 46 days), and more of them had vomiting with cough (45.5% vs. 28.5%, respectively). Pertussis is a common cause of prolonged cough illness in adolescents and adults and is frequently associated with other symptoms of whooping cough.

The increasing number of Streptococcus pneumoniae isolates identified as relatively or fully resistant to penicillin or fully resistant to other antimicrobials in the United States supports the need to monitor for this resistance. Thus, 5459 S. pneumoniae isolates submitted to the Centers for Disease Control in 1979-1987 by 35 hospitals in a hospital-based pneumococcal surveillance system were evaluated. The MIC to penicillin or ampicillin was greater than or equal to 0.1 micrograms/ml for 274 (5%) isolates; 1 had an MIC of 4.0 micrograms/ml to penicillin. Seventeen (0.3%) were resistant to erythromycin (MIC, greater than or equal to 8 micrograms/ml), 157 (2.9%) were resistant to tetracycline (MIC, greater than or equal to 16 micrograms/ml), and 34 (0.6%) were resistant to sulfamethoxazole/trimethoprim (MIC, greater than or equal to 76 and 4 micrograms/ml). Isolates relatively resistant to penicillin represented 1.8% of isolates in 1979, 8% in 1982, and 3.6% in 1987. Sixty-five multiply resistant isolates were identified. Pneumococci from the southwestern United States (region 4) were more likely to be relatively resistant to penicillin. Using logistic regression analysis, serotypes 14 and 19A, isolates from region 4, and isolates from middle ear fluid were associated with penicillin resistance (P less than or equal to .008, chi 2. These data confirm that antimicrobial resistance among pneumococcal isolates remained at low levels in the United States through 1987.