Decreasing prevalence of transmitted drug resistance among ART-naive HIV-1-infected patients in Iceland, 1996–2012

Figures & data

Table 1. Characteristics of the HIV-1 infected individuals included in the study.

	All
Characteristic	n ^a	%
Total	106
Sex
Male	64	60
Female	42	40
Risk factor^b
MSM	29	27
HET	45	42
IDU	26	25
MTCT	1	1
Unknown	5	5
Country of birth
Iceland	65	61
Non-Iceland	41	39
Country of infection^c
Iceland	39	37
Non-Iceland	51	48
Unknown	16	15

^a n: number; ^bRisk factor: Self-reported risk factor for HIV-1 acquisition (MSM: men who have sex with men; HET: heterosexual; IDU: injection drug use; MTCT: mother to child transmission; ^cCountry of infection: self-reported country of infection.

Table 2. Distribution of the study subjects compared to the total population of patients who were diagnosed during the same time interval.

	Study subjects		Total population		Coverage
Characteristic	n ^a	%	n	%	%
Total	106		209		51
Sex
Male	64	60	134	64	48
Female	42	40	75	36	56
Risk Factor^b
MSM	29	27	48	23	60
HET	45	42	81	39	56
IDU	26	25	45	22	58
Others/unknown	6	6	35	17	17

^a n: number; ^bRisk factor: self-reported risk factor for HIV-1 acquisition (MSM: men who have sex with men; HET: heterosexual; IDU: injection drug use; Others: mother to child transmission, blood transfusion.

Table 3. Characteristics of ART-naive patients with and without TDR.

	TDR^a		Non-TDR		p-value
	n ^b	%	n	%	TDR vs. non-TDR
Patients no.	9		97
Sex
Male	5	56	59	61	1.00
Female	4	44	38	39
Risk factor
MSM ^c	3	33	26	27	MSM vs. HET: 1.00
HET ^d	5	56	40	41	HET vs. IDU: 0.40
IDU ^e	1	11	25	26	MSM vs. IDU: 0.61
MTCT ^f	0	0	1	1
Unknown	0	0	5	5
Country of birth
Iceland	8	89	57	59	0.15
Non-Iceland	1	11	40	41
Reported country of Infection
Iceland	6	50	37	34	0.16
Non-Iceland	2	17	59	54
Unknown	4	33	14	13
Subtype
B	8	89	55	57	0.08
Non-B	1	11	42	43

^aTDR: transmitted drug resistance; ^b n: number; ^cMSM: men who have sex with men; ^dHET: heterosexual; ^eIDU: injection drug use; ^fMTCT: mother-to-child-transmission.

Figure 1. Time-resolved maximum clade credibility tree of 63 subtype B Icelandic sequences. The tree was constructed using TreeAnnotator v1.8.0 included in BEAST software package. Branches with posterior probability value of 1.0 are marked with an asterisk. Terminal branches marked with a black circle at the tip represent sequences harbouring at least one transmitted drug resistance (TDR) mutation. The grey shaded area represents the monophyletic cluster with TDR mutation (T215C/D).

Figure 2. Temporal trend of transmitted drug resistance (TDR) over the study period. The horizontal axis represents the study period divided into four quarters, each of which represents 4.25 years. The vertical axis represents proportion of TDR in each quarter. The p-value indicates the result of trend analysis conducted using linear-by-linear test for association.