Reported cases of whooping cause are on the rise in industrialized countries. Mooi et al (2009) have attributed this to a combination of many factors:
According to He (2016), the type of vaccine used has also shown to have an effect on the resurgence of whooping cough. The most commonly used vaccines for whooping cough in industrialized countries are acellular vaccines (ACVs). Whole cell vaccines (WCVs) are more commonly used in developing countries. As the whooping cough virus mutates, these vaccines are becoming less effective, but the virus mutations are dependent on which type of vaccine (ACV vs WCV) were used. Hamborsky, Kroger, and Wolfe (2015) state that in recent years, the cases of whooping cough in fully vaccinated adolescents and adults is on the rise, indicating that a large part of the increase in whooping cough may be due to pathogen adaptation.B. pertussis attaches to the cilia in the epithelia cells of the lung.
Once there, it secretes a toxin which causes the cilia to become immobilized. It also causes inflammation which leads to the buildup of mucus and phlegm. This buildup of mucus in the tracheobronchial tree is what causes the characteristic coughing associated with B. pertussis (Hamborsky, Kroger, & Wolfe, 2015).One study cited by the CDC found that infant deaths represented 83% of deaths due to whooping cough. The infant mortality rate is so high because infants are more likely to develop secondary complications than others who contract whooping cough.
These complications include secondary bacterial pneumonia, seizures, encephalopathy, pneumothorax, hernias, and more (Hamborsky, Kroger, & Wolfe, 2015).According to the Center for Disease Control (CDC), herd immunity is not a reliable source of immunity against whooping cough for a few different reasons. First, pertussis is very contagious. Second, the effectiveness of the vaccine decreases over time. Once vaccinated does not mean forever invincible. Finally, ACVs may not be reliable at preventing colonization of B. pertussis, meaning it could still be spread even if the symptoms are mild or nonexistent (National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, 2017).
Hamborsky, J., Kroger, A., & Wolfe, C. (2015). Epidemiology and Prevention of Vaccine-Preventable Diseases (13 ed.). Washington D.C.: Public Health Foundation. Retrieved November 6, 2018, from https://www.cdc.gov/vaccines/pubs/pinkbook/pert.htmlHe, Q. (2016, August). Evolution of Bordetella Pertussis. The Pediatric Infectious Disease Journal, 35(8), 915-917. doi:10.1097/INF.0000000000001218Mooi, F. R., van Loo, I. H., van Gent, M., He, Q., Bart, M. J., Heuvelman, K. J., de Greeff, S. C., Diavatopoulos, D., Teunis, P., Nagelkerke, N., … Mertsola, J. (2009). Bordetella pertussis strains with increase toxin production associated with pertussis resurgence. Emerging infectious diseases, 15(8), 1206-13.National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases. (2017, August 7). Pertussis Frequently Asked Questions. Retrieved November 6, 2018, from Center for Disease Control and Prevention: https://www.cdc.gov/pertussis/about/faqs.htm