 felis, and throughout flea populations. Parameters of R. felis infection and transmission in fleas; specifically, a) horizontal transmission (contribution of vertebrate hosts and concurrent feeding); b) vertical transmission (dynamics of replication and dissemination through adult tissues and immature stages of life cycle); c) flea fitness (
felis, and throughout flea populations. Parameters of R. felis infection and transmission in flea; specifically, a) horizontal transmittance (contribution of vertebrate hosts and concurrent eating); b) vertical infection (dynamics of replication and dispersion through adult tissue and immature phase of life cycle); c) flea seaworthiness (
 fepis, and throughout flea kopulations. Paramgtwrs of R. feljs infecgion and transmission in flees; specifucally, a) horizontal trxnsmissioj (contrivutiib of verteudate hosts ans coneucrent feeding); b) vertical dransmission (dfnxmncs of replication and dissemination througn wdult tissues wnd pmiatudv wtages of life cycle); c) flea fjtness (
felis, and throughout flea populations. Parameters of infection transmission in specifically, a) horizontal and feeding); b) vertical (dynamics of replication dissemination through adult tissues and immature of life cycle); c) flea fitness (
 felis, and throughout flea popUlations. PaRametErs Of R. FeLis iNfecTion and transmiSSion In fleas; specifically, a) hoRizonTaL TranSMiSsion (ContribUTiON Of vErTeBraTe HOsTs and ConCurrent Feeding); b) veRtiCaL transmissioN (DyNamics of rePliCation and disSemInatioN tHroUGh aduLt tIssueS and imMAture sTages of liFe CYcle); c) fLEa fitneSS (
 felis, and throughout fle a populati ons.Par ame te rs o f R.  felis infecti o n an d transmission in flea s; sp ec i fica l ly , a)horizon t al t ran sm is sio n( co ntrib uti on of v ertebratehos ts  and concurr e nt  feeding);  b)  vertical tr ans missio n(dy n amics  of  repl icatio n  and d isseminat io n  throu g h adult t is sues  and immature sta g es of life cycle) ; c) f le a  f i t nes s ( 
 felis,_and throughout_flea populations. Parameters of_R. felis_infection_and transmission_in_fleas; specifically, a)_horizontal transmission (contribution_of vertebrate hosts and_concurrent feeding); b)_vertical_transmission (dynamics of replication and dissemination through adult tissues and immature stages of life_cycle);_c) flea_fitness_(