An antigenic diversification threshold for falciparum malaria transmission at high endemicity
The analytical expression shows that , measured in units of , increases faster than exponential as the average number of available hosts decreases. The dashed line represents the time to fixation of a neutral gene, which means that under small , once established, the gene can be maintained in the population for much longer than the typical epidemiological timescale (or for much longer than the simulation period of 200 years in our model). The average lifespan Tnew obtained from the computational model will always be considerably smaller than the theoretical expectation derived under the assumption that other factors remain constant, in particular the average number of hosts that are susceptible to the invading gene. The general trend of increased persistence with lower will hold however for the full numerical system and for finite time windows.