Pertussis (whooping cough) is an acute respiratory disease caused by the bacterium Bordetella pertussis1. It causes violent coughing spells, which makes a person difficult to breathe. It becomes paroxysmal between 1-2 weeks and often followed by a characteristic whooping noise. B. pertussis is an aerobic, gram-negative aerobic coccobacillus1. It transmits from person to person via airborne droplets containing the bacteria during sneezing or coughing2.
B. pertussis produces a number of virulence factors that interact with host cells and alter their functions. Filamentous hemagglutinin, pertactin and agglutinogen serve as adhesion molecules help to anchor B. pertussis to the ciliated respiratory epithelial cells3. While tracheal cytotoxin releases nitric oxide which paralyze the cilia, stopping them from beating. This hinders the ability to mechanically remove mucus and debris. Mucus starts building up which triggers a violent cough reflex to clear the airway. Besides, pertussis toxin (PT) is a protein exotoxin secreted…show more content… Nasopharyngeal (NP) swab specimens should be obtained during the first 2 weeks of illness when the viable bacteria are still present. Sensitivity reduces and risk of false negative results increases at the later course of illness7. Bacteria DNA can also be detected by polymerase chain reaction (PCR). PCR has fast turnaround time and high sensitivity. However, PCR tests vary in specificity. Thus, culture confirmation of pertussis should be obtained for diagnosis. PCR should be tested from NP specimens taken at 0-3 weeks following cough onset, but it may give accurate results for up to 4 weeks6, 7. Serologic testing is useful for diagnosis in the later stage of disease. It can be performed from 2-12 weeks following cough onset. Antibody levels are at their highest between 2-8 weeks following cough onset, which is the ideal time for specimen collection6,