The unexpected findings of pertussis by 16S rDNA sequencing in broncho-alveolar lavage fluid in an immunocompromised patient in an endemic setting
Abstract number: 1134_03_98
Dudman S., Jonassen T.Ø., Steinbakk M.
The immunization of infants has reduced the prevalence of pertussis in Norway, however in 1997 an epidemic of whooping cough started to spread in older children and adolescents throughout the country. Pertussis is a notifiable disease and in 2002 a total of 3182 cases were reported. The diagnosis of this disease can be made by the isolation of B. pertussis or detection by PCR from respiratory secretions, as well as using serological methods (ELISA) at our laboratory. This paper reports the results from the different methods used, and describes a case where pertussis was found unexpectedly.
All cases of pertussis were included from January 1st to October 31st 2004, and the positive rates were calculated according to the different laboratory methods. For the case of pertussis detected in broncho-alveolar lavage fluid, medical records were obtained.
A total number of 458 patients were diagnosed with pertussis during the observation period. In some patients, the organism could be found in two different specimens. 391 (15%) out of 2614 samples were found positive by serological methods. 74 (8%) out of 954 samples were found to be PCR positive. In 6 (5%) of the 110 cultured samples, the B. pertussis could be isolated from nasopharyngeal secretions. In one case the bacteria was isolated from a blood culture. In addition, one case was detected in broncho-alveolar lavage fluid, this patient suffered from chronic lymphatic leukaemia. He was admitted to hospital because of a fever, dyspnoea and a dry cough, and was diagnosed with interstitial pneumonia. 16S rDNA sequencing performed directly on the culture negative broncho-alveolar lavage fluid showed B. pertussis. The patient was successfully treated with Chlarithromycin.
In view of the epidemic levels of whooping cough, it is important to routinely screen for this disease even in patients not showing typical symptoms of pertussis but are suffering from coughing.
|Session name:||XXIst ISTH Congress|
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