An antigenic diversification threshold for falciparum malaria transmission at high endemicity

We present here the concept of a threshold in local pathogen diversification that defines a sharp transition in transmission intensity below which new antigen-encoding genes generated by either recombination or migration cannot establish. Transmission still occurs below this threshold, but diversity of these genes can neither accumulate nor recover from interventions that further reduce it. An analytical expectation for this threshold is derived and compared to numerical results from a stochastic individual-based model of malaria transmission that incorporates the major antigen-encoding multigene family known asvar. This threshold corresponds to an “innovation” number we callRdiv; it is different from, and complementary to, the one defined by the classic basic reproductive number of infectious diseases,R0, which does not easily apply under large and dynamic strain diversity. This new threshold concept can be exploited for effective malaria control and applied more broadly to other pathogens with large multilocus antigenic diversity.

Source: PLoS Computational Biology - February 19, 2021 Category: Biology Authors: Qixin He Source Type: research