Pertussis characterization in the central-west region of São Paulo state, Brazil

André Martins; Salete França Porto; Claudia Regina Delafiori; Luciano Moura Martins; Carlos Henrique Camargo; Daniela Leite

André Martins Instituto Adolfo Lutz, Centro de Laboratório Regional de Marília, Núcleo de Ciências Biomédicas, Marília, SP
Salete França Porto Instituto Adolfo Lutz, Centro de Laboratório Regional de Marília, Núcleo de Ciências Biomédicas, Marília, SP
Claudia Regina Delafiori Instituto Adolfo Lutz, Centro de Laboratório Regional de Marília, Núcleo de Ciências Biomédicas, Marília, SP
Luciano Moura Martins Instituto Adolfo Lutz, Centro de Bacteriologia, Núcleo de Doenças Entéricas e Infecções por Patógenos Especiais, SP
Carlos Henrique Camargo Instituto Adolfo Lutz, Centro de Bacteriologia, Núcleo de Doenças Entéricas e Infecções por Patógenos Especiais, SP
Daniela Leite Instituto Adolfo Lutz, Centro de Bacteriologia, Núcleo de Doenças Entéricas e Infecções por Patógenos Especiais, SP

Keywords: Bordetella pertussis, whooping cough, pulsed field gel electrophoresis, real-time PCR

Abstract

Pertussis is a highly contagious respiratory disease caused by Bordetella pertussis. This study aimed at characterizing the B. pertussis laboratory positivity and the isolated strains in municipalities of the Central-West Region of São Paulo State, Brazil from 2010 to 2014. A total of 597 nasopharyngeal swabs samples were collected from suspected patients and contacts, and analyzed by in vitro culture and Real-Time PCR (qPCR). Culture-positive B. pertussis strains were characterized by serotyping and pulsed-field gel electrophoresis. Considering culture and/ or qPCR, the positivity rate was of 19.6%. Out of 117 samples with B. pertussis, 23 were detected by both methods, 89 by qPCR only and five by culture only. Strains presenting FIM3 (40%), FIM2,3 (32%) and FIM2 (28%) serotypes were found. Five pulsotypes were detected by PFGE, 48% of which identified as BP.Xba.0039, being the predominant type in this study. Among the positive strains, 50% were isolated from < 2 months old-children and 17% were isolated from three to six months old patients. Non-vaccinated children or with incomplete vaccination schedule were at the major risk of complications and death, highlighting the importance of a continuous monitoring of this infection for the future control strategies.