Asymptomatic Infection and Transmission of Pertussis in Households: A Systematic Review

Abstract

We conducted a systematic review to describe the frequency of mild, atypical, and asymptomatic infection among household contacts of pertussis cases and to explore the published literature for evidence of asymptomatic transmission. We included studies that obtained and tested laboratory specimens from household contacts regardless of symptom presentation and reported the proportion of cases with typical, mild/atypical, or asymptomatic infection. After screening 6789 articles, we included 26 studies. Fourteen studies reported household contacts with mild/atypical pertussis. These comprised up to 46.2% of all contacts tested. Twenty-four studies reported asymptomatic contacts with laboratory-confirmed pertussis, comprising up to 55.6% of those tested. Seven studies presented evidence consistent with asymptomatic pertussis transmission between household contacts. Our results demonstrate a high prevalence of subclinical infection in household contacts of pertussis cases, which may play a substantial role in the ongoing transmission of disease. Our review reveals a gap in our understanding of pertussis transmission.

Asymptomatic Bordetella pertussis infections in a longitudinal cohort of young African infants and their mothers

“…A key finding of our investigation is the common occurrence of asymptomatic (and/or minimally symptomatic) pertussis infections in adults. This issue has long been a subject of debate and speculation but has remained unresolved due to the lack of longitudinal data sets that would allow one to distinguish asymptomatic from pre-symptomatic infections ( Althouse and Scarpino, 2015 ; Wiley et al, 2013 ; Craig et al, 2020 ; Tan et al, 2005 ; de Graaf et al, 2020 ; Rubin and Glazer, 2016 ). A partial exception are a pair of sero-conversion studies in household contacts of index symptomatic pertussis infections in children.…”

Modeling Immune Evasion and Vaccine Limitations by Targeted Nasopharyngeal Bordetella pertussis Inoculation in Mice

“…Furthermore, infections remained localized to the upper respiratory tract and rarely progressed to the lungs, agreeing with the notion that pertussis is primarily an upper respiratory tract infection. Of note, multiple contact tracing studies identify asymptomatic carriage as the likely source of human infections (42). In addition, the strong inflammatory responses and high antibody titers observed in pneumonic infection models are not routinely observed in most surveys of human infections (43)(44)(45).…”

Vaccine-Induced Cellular Immunity against Bordetella pertussis: Harnessing Lessons from Animal and Human Studies to Improve Design and Testing of Novel Pertussis Vaccines

“…There is indirect evidence of asymptomatic transmission of Bp from aP-vaccinated to naïve individuals [ 20 , 113 , 114 , 115 ]. To date, however, little is known on human vaccine-induced mucosal immune responses, the contribution of respiratory TRMs, particularly of Th1 and Th17 phenotype, to protection against infection/disease and how this may vary between vaccine types [ 42 , 116 ].…”