Patterns of Antibiotic Nonsusceptibility Among Invasive Group A Streptococcus Infections-United States, 2006-2017.

BACKGROUND: Treatment of severe group A Streptococcus (GAS) infections requires timely and appropriate antibiotic therapy. We describe the epidemiology of antimicrobial-resistant invasive GAS (iGAS) infections in the United States (US). METHODS: We analyzed population-based iGAS surveillance data at 10 US sites from 2006 through 2017. Cases were defined as infection with GAS isolated from normally sterile sites or wounds in patients with necrotizing fasciitis or streptococcal toxic shock syndrome. GAS isolates were emm typed. Antimicrobial susceptibility was determined using broth microdilution or whole genome sequencing. We compared characteristics among patients infected with erythromycin-nonsusceptible (EryNS) and clindamycin-nonsusceptible (CliNS) strains to those with susceptible infections. We analyzed proportions of EryNS and CliNS among isolates by site, year, risk factors, and emm type. RESULTS: Overall, 17 179 iGAS cases were reported; 14.5% were EryNS. Among isolates tested for both inducible and constitutive CliNS (2011-2017), 14.6% were CliNS. Most (99.8%) CliNS isolates were EryNS. Resistance was highest in 2017 (EryNS: 22.8%; CliNS: 22.0%). All isolates were susceptible to ß-lactams. EryNS and CliNS infections were most frequent among persons aged 18-34 years and in persons residing in long-term care facilities, experiencing homelessness, incarcerated, or who injected drugs. Patterns varied by site. Patients with nonsusceptible infections were significantly less likely to die. The emm types with >30% EryNS or CliNS included types 77, 58, 11, 83, and 92. CONCLUSIONS: Increasing prevalence of EryNS and CliNS iGAS infections in the US is predominantly due to expansion of several emm types. Clinicians should consider local resistance patterns when treating iGAS infections.

Strategies for surveillance of pediatric hemolytic uremic syndrome: Foodborne Diseases Active Surveillance Network (FoodNet), 2000-2007.

BACKGROUND: Postdiarrheal hemolytic uremic syndrome (HUS) is the most common cause of acute kidney failure among US children. The Foodborne Diseases Active Surveillance Network (FoodNet) conducts population-based surveillance of pediatric HUS to measure the incidence of disease and to validate surveillance trends in associated Shiga toxin-producing Escherichia coli (STEC) O157 infection. METHODS: We report the incidence of pediatric HUS, which is defined as HUS in children <18 years. We compare the results from provider-based surveillance and hospital discharge data review and examine the impact of different case definitions on the findings of the surveillance system. RESULTS: During 2000-2007, 627 pediatric HUS cases were reported. Fifty-two percent of cases were classified as confirmed (diarrhea, anemia, microangiopathic changes, low platelet count, and acute renal impairment). The average annual crude incidence rate for all reported cases of pediatric HUS was 0.78 per 100,000 children <18 years. Regardless of the case definition used, the year-to-year pattern of incidence appeared similar. More cases were captured by provider-based surveillance (76%) than by hospital discharge data review (68%); only 49% were identified by both methods. CONCLUSIONS: The overall incidence of pediatric HUS was affected by key characteristics of the surveillance system, including the method of ascertainment and the case definitions. However, year-to-year patterns were similar for all methods examined, suggesting that several approaches to HUS surveillance can be used to track trends.