The publication discusses the immunology of whooping cough (pertussis). In paragraph 3, the authors state:
"In the United States, there were 48,277 cases of pertussis in 2012, more than any year in the previous 50 years. Approximately 10% of the cases were infants and 50% were adolescents or adults [3]. Mirroring the United States, there has been a global increase in the number of cases among adolescents and adults, mainly because of poor vaccine coverage and waning immunity [2, 4, 5]."
PARAGRAPH 3
The resurgence of pertussis has been noticeable over the past several years. In the United States, there were 48277 cases of pertussis in 2012, more than any year in the previous 50 years. Approximately 10% of the cases were infants and 50% were adolescents or adults [3]. Mirroring the United States, there has been a global increase in the number of cases among adolescents and adults, mainly because of poor vaccine coverage and waning immunity [2, 4, 5]. Despite its dramatic symptoms, pertussis is still likely underdiagnosed due to poor awareness of the disease, misdiagnosis, and lack of diagnostic techniques. This is especially obvious in China, where there were only 2183 reported cases of pertussis in 2012, which is especially significant given the huge population and relatively poor healthcare system [6]. The criteria for diagnosis of pertussis issued by China's Center for Disease Control and Prevention have not been updated for more than a decade and do not include PCR. This may partially account for the low reporting rate [7]. Adolescents and adults with waning immunity and unrecognized pertussis are the most important sources of infection for children. This is why a booster tetanus toxoid, reduced diphtheria toxoid, and acelluar pertussis vaccine (Tdap) (a combination vaccine similar to diphtheria, tetanus toxoid, and acelluar pertussis vaccine [DTaP] with a lower dose of B. pertussis acellular components) is recommended for persons aged less than or equal to 11 years [8]. In this case, the mother was the most likely source of infection.