Diagnosis of pertussis in vaccinated children of Khairpur, Sindh, Pakistan by Cough Plate Method

Abstract

Objectives: Pertussis or whooping cough is a communicable infection of upper respiratory tract that mainly affects children. Reports regarding resurgence of pertussis in vaccinated children mainly motivated us to document pertussis in the children. The aim of the study was to explore pertussis in vaccinated children using an alternative method for pertussis diagnosis. Materials and methods: A total of 700 clinical samples were collected during study period (2006-2009), from suspected whooping cough cases of Diphtheria-tetanus- whole cell pertussis (DTwP) vaccinated children both male and female aged from 6 months to 84 months The classical ‘Cough Plate Method’ instead of Nasopharyngeal Swab was used for sampling to find out its potential in diagnosis of pertussis. Results: Present study reports the presence of pertussis in vaccinated children using Cough Plate Method. The method successfully isolated Bordetella pertussis from suspected patients of pertussis. A total of 28 culture confirmed cases were detected among 700 samples tested. (Total Isolation rate: 4%).The peak incidence age under risk was 48 months. However, pertussis was detected in children aged as young as 6 and 12 months. Conclusion: The ‘Cough plate’ method used for isolation proved successful and simple instead of nasopharyngeal swabs that is difficult to perform and children may be reluctant to this sampling method when tried. J Microbiol Infect Dis 2011;1 (2) : 68-72