Table 1. Symbols and abbreviations used in this paper.

MWB	Mean Worm Burden
SWB	Stratified worm burden
NB	Negative binomial (distribution)
MDA	Mass drug administration
FOI	Force of infection
BRN or	Basic reproduction number in MacDonald MWB system
	critical BRN-type parameter for breakpoint in MWB system
H	Total host population
	n-th human strata in SWB system (population fraction carrying n worms)
	Demographic sources for nth strata in SWB system
	Worm increment in SWB formulation
w	Worm burden (MWB), −1st moment of SWB system
u	2nd moment of SWB system:
W	Total worm population ( = H w)
U	Total 2nd moment ( = H u)
	Source terms in the w- and u- equations
k	NB (negative binomial) aggregation parameter
	Human population turnover rate (.02−.05/year)
	Worm mortality rate ( = 1/4 years)
	Snail mortality ( = 5/year)
	Human FOI ( = mean rate of adult worm accumulation in human hosts)
	Snail FOI (transition rate “susceptible” −> “infected”)
	Mated female number for mixed strata (i males and j females)
	Mated female count for n-th strata made of n adult worms
	Total mated female count in host population
	Mating function in MacDonald (MWB) system with NB worm distribution
	Allee mating hurdle factor ()
A	Transmission rates (snail->human) per single infected snail
B	Transmission rates (human->snail) per mated female
	Relative transmission rates
	Infectious prevalence in MWB system with mean w, and NB aggregation k
	Infectious prevalence in SWB system with FOI , and host turnover
	Reduced “snail equilibrium” function for MWB (MacDonald) system
	Reduced “snail equilibrium” function for SWB system
	Drug efficacy (fraction of worms surviving a single dose)
f	Population fraction cover in MDA
E	Mean egg count in host population
	Egg production/mated female
	Equilibrium levels for MWB, SWB systems