Incidence and Transmission Dynamics of <i>Bordetella pertussis</i> Infection in Rural and Urban Communities, South Africa, 2016‒2018
Fahima Moosa, Stefano Tempia, Jackie Kleynhans, Meredith McMorrow, Jocelyn Moyes, Mignon du Plessis, Maimuna Carrim, Florette K. Treurnicht, Orienka Helferscee, Thulisa Mkhencele, Azwifarwi Mathunjwa, Neil Martinson, Kathleen Kahn, Limakatso Lebina, Floidy Wafawanaka, Cheryl Cohen, Anne von Gottberg, Nicole Wolter, for the PHIRST Group
Abstract
We conducted 3 prospective cohort studies (2016-2018), enrolling persons from 2 communities in South Africa. Nasopharyngeal swab specimens were collected twice a week from participants. Factors associated with Bordetella pertussis incidence, episode duration, and household transmission were determined by using Poisson regression, Weibull accelerated time-failure, and logistic regression hierarchical models, respectively. Among 1,684 participants, 118 episodes of infection were detected in 107 participants (incidence 0.21, 95% CI 0.17-0.25 infections/100 person-weeks). Children <5 years of age who had incomplete vaccination were more likely to have pertussis infection. Episode duration was longer for participants who had higher bacterial loads. Transmission was more likely to occur from male index case-patients and persons who had >7 days infection duration. In both communities, there was high incidence of B. pertussis infection and most cases were colonized.