Hemolytic uremic syndrome in pediatric intensive care units in são paulo, Brazil

Abstract

The hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli (STEC) is one of the most frequent causes of pediatric acute renal failure. The aim of this study was to report the clinic and microbiologic features associated with 13 post-diarrheal HUS cases identified in pediatric intensive care units in the city of São Paulo, Brazil, from January 2001 to August 2005. Epidemiologic, clinic, and laboratorial information, along with fecal and serum samples, were collected for identifying the genetic sequences of Stx and for studying antibodies directed against LPS O26, O111 and O157. STEC was isolated from three patients, and serotypes O26:H11, O157:H7 and O165:H- were identified. In nine patients, high levels of IgM against LPS O111 (n=2) and O157 (n=7) were detected. Dialysis was required in 76.9% of the patients; arterial hypertension was present in 61.5%, neurological complications were observed in 30.7%, and only one patient died. During a 5-year follow-up period, one patient developed chronic kidney disease. The combined use of microbiologic and serologic techniques provided evidence of STEC infection in 92.3% of the HUS cases studied, and the importance of O157 STEC as agents of HUS in São Paulo has not been previously highlighted.

Keywords: E. coli O157; Hemolytic Uremic Syndrome; Shiga toxin; children.; dialysis; diarrhea; pediatric intensive care unit.

Fig. (1)

Detection of IgM and IgG antibodies against LPS O26 in the serum from patients with HUS and controls by ELISA. Serum samples were diluted 1:500 in PBS-Tween, and absorbance values (Abs) were measured at 492 nm.

Fig. (2)

Detection of. IgM and IgG antibodies against LPS O111 in the serum from patients with HUS and controls by ELISA. Serum samples were diluted 1:500 in PBS-Tween, and absorbance values (Abs) were measured at 492 nm.

Fig. (3)

Detection of IgM and IgG antibodies against LPS O157 in the serum from patients with HUS and controls by ELISA. Serum samples were diluted 1:500 in PBS-Tween, and absorbance values (Abs) were measured at 492 nm.

Fig. (4)

Representative reaction of patients sera with O111 and O157 LPS by immunoblotting. a, serum of patient positive for LPS O111 ( case 1 ); b, serum of patient positive for LPS O157 (case 8). Lanes: 1, LPS O26; 2, LPS O111; 3, LPS O157.