Table 7.

Sensitivity testing of N. gonorrhoeae isolates to azithromycin.

Study (year)	Country	Year(s)	Sample size	MIC range (µg/ml)	Percent of strains susceptible	Additional details	Ref.
High-risk populations
CDC (2011)	USA	2009	55	NR	90.9%	9.1% resistant (95% CI: 4.0 to 19.6%); of 5 resistant (all from MSM), 3 had MIC = 8 µg/ml and two had MIC = 16ug/ml	[69]
Starnino et al. (2009)	Italy	2007–2008	219	1.0–256.0	90.0%	72.7% (95% CI: 51.6–86.8%) of resistant isolates from MSM	[176]
Donegan et al. (2004)	Bali	2004	147	0.013–0.512	100%	Study in FSWs; prevalence of NG estimated to be 35-60%	[177]
Morris et al. (2009)	USA	2000–2002	79	0.03–0.5	100%	Increased MIC values seen in MSM subject isolates	[178]
Leven et al. (2003)	Indonesia	1996	267	0.032–0.5	100%	Study in FSWs; prevalence of NG estimated to be 18–44%	[179]
CDC (2000)	USA	1999	12	1.0–4.0	NR	Median MIC was 2.0 µg/ml. 6 of 12 samples were from men who had sex with a CSW; 2 of 12 were from HIV positive men	[180]
Mixed-risk populations
Bruck et al. (2012)	UK	2005–2006	147	NR	99.3%	Mixed male heterosexual, MSM and female heterosexual isolates	[181]
Dan et al. (2010)	Israel	2002–2007	406	0.023–8.0	91.8%	Mixed male heterosexual, MSM and female heterosexual; resistance to azithromycin did not appear to rise over 5 year period	[182]
McLean et al. (2004)	USA	1999–2001	1,248	≤4	97.4%	Mixed high- and low-risk population. Median MIC was 2.0ug.mL	[183]
Arreaza et al. (2003)	Spain	1992–2001	63	0.03–4.0	96.8%	58.7% of strains had reduced susceptibility (0.25–1.0 µg/ml). 50% of resistant isolates were from FSW	[184]

BV: Bacterial vaginosis; CSW: Commercial sex worker (gender not specified); FSWs: Female sex workers; GI: Gastrointestinal; MIC: Minimum inhibitory concentration; MSM: Men who have sex with men; NG: Neisseria gonorrhoeae; NR: Not reported; PROM: Preterm premature rupture of the membranes; SD: Standard deviation; TOC: Test of cure.