Comparison of nasopharyngeal aspirates with swabs for culture of Bordetella pertussis

Abstract

Nasopharyngeal samples were collected from 117 children by aspiration from one nostril and by swab from the other one and cultured for Bordetella pertussis. Among 33 culture-positive specimens, there were 30 positive aspirates and 26 positive swab specimens. Aspirates are easily divided and saved for investigations with other assays which may further improve diagnostic sensitivity. As the aspiration technique was also preferred by nurses and parents, it was recommended and chosen for a planned pertussis vaccine efficacy trial to take place in Sweden from 1992 to 1995. * Corresponding author. aspiration technique was slightly modified and no clinical data were collected.

Nested PCR optimized for detection of Bordetella pertussis in clinical nasopharyngeal samples

“…Samples for culture were obtained from our patients earlier in the course of disease during the 1992 to 1993 period (data not shown), which may be one explanation of why only 8% were culture negative and nested PCR positive during this period whereas 14% from the previous period were culture negative and nested PCR positive. Another factor could be that culture of nasopharyngeal aspirate is more efficient than culture of swab, as documented by Hallander et al (7).…”

“…To date this has mainly depended on culture and serology. Culture has, however, a low sensitivity (5) and serology is not helpful in the acute phase of the disease, and the culture result for samples from, for example, vaccinated children can be difficult to interpret (7). Antigen detection by immunofluorescence and enzyme-linked immunosorbent assay techniques as well as tests for adenylate cyclase activity (2) have therefore been tried as diagnostic tests.…”

Laboratory diagnosis of pertussis: state of the art in 1997

“…Collection of specimens. Nasopharyngeal aspirates (NPAs) of nasopharyngeal secretions have been shown to be better specimens than secretions obtained on nasopharyngeal swabs (NPSs) (9,34,36). This is not surprising since more material is obtained in NPAs, which, in addition, allows PCR to be conducted in parallel.…”

Diagnosis of pertussis using nasopharyngeal IgA and polymerase chain reaction in specimens from outpatients in Australia

“…NPA collection using soft catheters was well tolerated in our experience, including in very young children (specimens were obtained from 97 children below the age of 2 years, and 15 below 1 month). This experience has also been confi rmed by controlled clinical trial, with NPA being shown to be better tolerated than nasopharyngeal swab collection [30]. The relative performance of NPA testing in our communities needs to be formally compared to more commonly requested methods such as respiratory swabs and blood serology.…”