There doesn’t seem to be a mainstream camera manufacturer specifically making left-handed cameras, but disability-focused photography groups may be your best starting point. Two resources mentioned were the Disabled Photographers’ Society and Photographers with Disabilities; communities like these can suggest equipment and adaptations that have worked for similar users.

From the answers, the most practical adaptations are:

• a remote shutter release, wired or wireless, that can be mounted or adapted for the user’s available movement
• mounting support such as a monopod with a ball head attached to the wheelchair for easier aiming and stability
• if setup help is available, a tethered camera controlled by a laptop or simple script, potentially even with speech-triggered shutter release

For cleaning/protection, simple plastic covers were suggested for control devices.

So the best answer is less about a special camera brand and more about adapting a camera with accessible triggering and support hardware, while also consulting disability-photography organizations for proven setups.