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Background The Swiss HCVree Trial (NCT 02785666) was conducted in 2015–2017 with the goal of implementing a population-based systematic hepatitis C virus (HCV) micro-elimination program among men who have sex with men (MSM) with human immunodeficiency virus (HIV) enrolled in the Swiss HIV Cohort Study (SHCS). The trial led to a 91% and 77% decline of HCV prevalence and incidence, respectively. The long-term effect of this HCV micro-elimination program is yet to be explored. Methods All MSM enrolled in the SHCS were screened for HCV RNA using stored plasma samples obtained in 2019, termed “Swiss HCVree Post” screen. The incidence of HCV infection over time was assessed using additional information on HCV testing routinely collected in the SHCS. Characteristics of participants with replicating HCV infection were analyzed. Results The point-prevalence of “Swiss HCVree Post” (N = 4641) was 0.6%, reflecting a decline of 48% compared to the end of the Swiss HCVree Trial where the prevalence was 1.2%. Further, the incidence of HCV among MSM in the SHCS declined from 0.31/100 person-years (py) (95% confidence interval [CI] [.17, .55]) in 2017 to 0.19/100 py (95% CI [.09, .39]) in 2019. Conclusions A systematic HCV RNA-based screening among MSM with HIV conducted 2 years after the Swiss HCVree Trial revealed a sustained effect and further decline of the prevalence and incidence of replicating HCV infection. This indicates that the Swiss HCVree Trial was successful in curbing the HCV epidemic among MSM with HIV in Switzerland. Clinical Trials Registration NCT02785666.

Melanin, or products directly associated with it, regulates the maturation of the neural retina because in hypopigmented mammals the central retina fails to develop fully. To determine whether this deficit is reflected in the distribution of photoreceptors, their topography has been studied in the retinae of normally reared pigmented and albino ferrets and animals reared under reduced light conditions. In both strains, the general distribution of rods and cones was similar to that in the cat, cone density peaking in the central retina and rod density peaking in an annulus around the area centralis. The cone population was organized in the form of an orderly mosaic whose regularity was measured at a wide range of retinal eccentricities. No differences were found in cone numbers or their mosaic distribution between pigmented and albino strains, either at the area centralis or at more peripheral regions. In both cases order within the cone mosaic was independent of density or retinal eccentricity. In the albinos there was a significant deficit in the number of rods at all retinal locations when compared with rod numbers in the pigmented animals. There were no differences between normally reared and dark-reared animals in this respect either within or between the strains. Therefore, the albino gene must have a selective and specific effect on the development of this cell type in the outer retina. Ganglion cells and rods are both affected by the albino gene, while cones are not. Because cones and ganglion cells are generated during the same period and rods are generated later, the albino gene cannot be acting during a particular developmental time window. Because the cone mosaic was normal in the albinos, in spite of a large rod deficit, the factors that regulate the spacing of cones cannot depend in any significant manner upon the later generation and subsequent addition of rods to the outer retina.