Методы исследования
Исследования, которые показаны в первую очередь
culture of a nasopharyngeal aspirate or swab from the posterior nasopharynx
.
Collect cultures from the nasopharynx within 2 weeks of cough onset.[10][29] Definitive test for diagnosis, with a specificity of 100%. Sensitivity is 30% to 60% if the specimen is obtained <2 weeks after symptoms start but is greatly reduced after 3 weeks of illness.[30] Sensitivity is also reduced if specimens are obtained from patients who have partial immunity to pertussis or who have received antimicrobials that are effective against pertussis, and if specimens are not collected and transported appropriately. Positive cultures are more specific than other diagnostic tests and, if positive, may permit strain identification and confirmation of antimicrobial susceptibilities. Specimens require special collection and processing.
Результат
may be positive for Bordetella pertussis
nucleic acid amplification test (NAAT) of nasopharyngeal aspirate or posterior nasopharyngeal swab
.
NAAT, including polymerase chain reaction (PCR), can be obtained within 4 weeks of cough onset.[10][29] NAAT testing has increased sensitivity compared with culture (94%) and is recommended as adjunct to culture. Sensitivity is reduced if specimens are obtained from patients who have partial immunity to pertussis or who have received antimicrobials that are effective against pertussis, or if specimens are not collected and transported appropriately. False positives may result from Bordetella pertussis DNA contamination of the environment, including from B pertussis vaccines administered in clinics. Nasopharyngeal specimens for PCR testing should be collected using a polyethylene terephthalate swab or nasopharyngeal wash or aspirate. Calcium alginate swabs can be inhibitory to PCR and should not be used.
Результат
positive or negative
serology
Исследования, проведение которых нужно рассмотреть
chest radiograph
.
Typically demonstrates nonspecific and mild peribronchial thickening, infiltrates, or atelectasis. Lobar infiltrates suggest secondary bacterial infections. May demonstrate complications such as pneumonia, pneumothorax, or rib fracture.
Результат
normal or peribronchial thickening, infiltrates, atelectasis
oral fluid testing
.
Detection of anti-pertussis toxin immunoglobulin G (IgG) in oral fluid is available in the UK for confirmation of pertussis in children ages >2 years and adolescents.[26] Recent immunization may result in a false positive test; testing is recommended only in patients who have not received a pertussis-containing vaccine in the preceding year.
Результат
positive or negative
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