Splitting this JIRA off from SAK-38381, to split out the issue with high contrast mode from the aria screen reader issue.

This is for the High Contrast Mode view. 

[New] - 3/18/2018

[Issue]

Left navigation links lack the status of the active or current link. Screen reader announces name with the role of the link only and there is no indication of which link is activated.Additionally, when high contrast mode on or when there is no color on the page or when CSS disabled, assistive technologies users not able to differentiate

[User Impact]

Screen reader users not able to identify that which link is activated. However, there is an alternative solution to this is available that page title is there but still screen reader users and low vision users do not have the same experience as visual users have it.

[Expected behavior]

Developers need to make sure that they provide state of the link which is activated currently so that screen reader users know about the state of the link. Additionally, developers /designers need to make sure that they provide a proper style guide for an activated page which can be differentiated in high contrast mode too.Developers can set "aria-current" properties which help screen readers users to identify active link.

[Reference link]

https://www.w3.org/TR/wai-aria-1.1/#aria-current