Table 1

Parameter values for the Cotonou scenario

Parameters	Values			Symbols in equations*			Source of data
*See the appendix.
CSW, commercial sex worker; Gc, gonorrhoea.
Biological parameters
Duration of HIV infection							(19–22)
Phase 1	6 months			γ1
Phase 2	6.25 years			γ2
Phase 3	2 years			γ3
Full blown AIDS	1 year			α
HIV transmission probability per partnership in a circumcised population	in phase 1,	phase 2,	phase 3				(19–28)
Female to male
Low to low	15.00%,	3.45%,	7.50%	βnew¹_1,1,1	βnew²_1,1,1	βnew³_1,1,1
Low to high	11.50%,	2.65%,	5.00%	βnew¹_1,1,2	βnew²_1,1,2	βnew³_1,1,2
High to low	0.65%,	0.15%,	0.27%	βnew¹_1,2,1	βnew²_1,2,1	βnew³_1,2,1
High to high	0.65%,	0.15%,	0.27%	βnew¹_1,2,2	βnew²_1,2,2	βnew³_1,2,2
Male to female
Low to low	30.00%,	6.90%,	13.00%	βnew¹_2,1,1	βnew²_2,1,1	βnew³_2,1,1
Low to high	1.30%,	0.30%,	0.54%	βnew¹_2,1,2	βnew²_2,1,2	βnew³_2,1,2
High to low	23.00%,	5.30%,	10.00%	βnew¹_2,2,1	βnew²_2,2,1	βnew³_2,2,1
High to high	1.30%,	0.30%,	0.54%	βnew¹_2,2,2	βnew²_2,2,2	βnew³_2,2,2
Relative risk of HIV if not circumcised	2			RR_HIV/non-circ			(29–34)
Proportion of men circumcised	100%						(12–14)
Relative risk of HIV infection if HIV negative or partner is infected with Gc	3			RR_HIV/Gc			(35, 36)
First HIV cases (seed) in 1980	2 in low activity classes and			X¹⁰₁₁(1980)=1, X¹⁰₂₁(1980)=1			(12, 13)
	3 in high activity classes			X¹⁰₁₂(1980)=2, X¹⁰₂₂(1980)=1

STD modelled	Gonorrhoea			Gc			(14)
Duration of infection with Gc							(14–16, 37, 38)
Female low	5.7 months			1/σ₁₁
Female high (CSW)	1.3 months			1/σ₁₂
Male low	3.3 months			1/σ₂₁
Male high (frequent clients)	1.3 months			1/σ₂₂
Gc transmission probability per partnership	Female to male	Male to female					(37–41)
Low to low	0.60	0.95		ψnew₁₁₁	ψnew₂₁₁
Low to high	0.45	0.42		ψnew₁₁₂	ψnew₂₁₂
High to low	0.22	0.8		ψnew₁₂₁	ψnew₂₂₁
High to high	0.22	0.42		ψnew₁₂₂	ψnew₂₂₂

Demographic parameters
Total population size	122 605 females and 115 558 males in 1980; 205 380 and 200 003 in 1997			∑_hs,i X^hs_ki(t) for i=1,2, k=1,2, h=0,4, s=0,1			(13, 14, 42–44)
Growth rate of the population	Increases from 2.5% in 1980 to 4.3% in 1997 and eventually plateaus at 3.8% in absence of AIDS			Λ_ki (t)			(14, 16, 42–44)
Size of the CSW	1.2%			∑_sX^0s₁₂(1980)/ ∑_s,i X^0s_1i(1980), s=0,1, i=1,2			(13, 17)
Size of client population	12.0%			∑_sX^0s₂₂(1980)/ ∑_s,i X^0s_2i(1980), s=0,1, i=1,2			(13, 14, 17)
Renewal of the CSW	About 2% in 1997 but increases as more CSW get infected and progress to AIDS (details in appendix)			50% of the CSW who progress to AIDS are replaced by HIV negative with STD status according to Gc prevalence.			(14, 16, 45)
				R⁰⁰₁₂(t)=R^0s₁₂(t) =0.5•γ3•X₁₂^3s(t), s=0,1
Sexual life expectancy	45.5 years			1/μ			(14, 16, 42–44)
Sexual behaviour
Condom use at baseline	50% of CSW partnerships with men are protected by condoms			Cond_1,2,1% (1980)			(14, 16, 17)
				Cond_1,2,2% (1980)
From T1 = 1980 onward				Cond_2,1,2% (1980)
	No screening			Cond_2,2,2% (1980)
Annual rates of new partners acquisition at baseline							(12, 14, 16–17)
Low risk females	1.5			m₁₁(1980)
Low risk males	1.7			m₂₁(1980)
CSW	353			m₁₂(1980)
Clients	37			m₂₂(1980)
Mixing pattern	Very assortative						(14, 16)
	Female with male	Male with female
High with low	5.3%	4.9%		ρ₁₂₁(1980)	ρ₂₂₁(1980)
High with high	94.7%	95.1%		ρ₁₂₂(1980)	ρ₂₂₂(1980)
Low with low	86.0%	85.1%		ρ₁₁₁(1980)	ρ₂₁₁(1980)
Low with high	14.0%	14.9%		ρ₁₁₂(1980)	ρ₂₁₂(1980)