Table 1.

Estimates of the key epidemiological parameters.

parasite	R0	k	density dependence, z [=exp(−λ)]	adult worm life expectancy (years)	region	reference
Ascaris		0.81	0.968	1	India	[14]
Ascaris			0.927		Nigeria	[13]
Ascaris	4–5	0.57	0.991		Iran	[17]
Ascaris		0.6–0.7			Bangladesh	[18]
Ascaris	1–3	0.46			Myanmar	[19]
Ascaris		0.59			St Lucia	[20]
Ascaris	1–2	0.44			Bangladesh	[21]
Ascaris		0.36–0.54			South Korea	[22]
Ascaris		0.54			many countries	[23]
Ascaris		—	0.992		Malaysia	[24]
Ascaris		0.2–0.5			Japan
hookworm		0.45			Papua New Guinea	[25]
hookworm					India	[26,27]
Ancylostoma		—		1
Necator	2–3	0.03–0.6		3–4
Necator		0.16–0.24			India	[7,28]
Necator		0.05–0.4			Taiwan	[15]
Necator	3–4				China	[29]
Necator	2	0.35	0.92		Zimbabwe	[30]
Trichuris	8–10	0.2–0.4			St Lucia	[20]
Trichuris	4–6				Jamaica	[31]