As of 2004, cholera remained both epidemic and endemic in many areas of the world.Recent major outbreaks are the 2010s Haiti cholera outbreak and the 2016–2021 Yemen cholera outbreak. In October 2016, an outbreak of cholera began in war-ravaged Yemen. WHO called it "the worst cholera outbreak in the world". In 2019, 93% of the reported 923,037 cholera cases were from Yemen (with 1911 deaths reported). Between September 2019 and September 2020, a global total of over 450,000 cases and over 900 deaths was reported; however, the accuracy of these numbers suffer from over-reporting from countries that report suspected cases (and not laboratory confirmed cases), as well as under-reporting from countries that do not report official cases (such as Bangladesh, India and Philippines).Although much is known about the mechanisms behind the spread of cholera, researchers still do not have a full understanding of what makes cholera outbreaks happen in some places and not others. Lack of treatment of human feces and lack of treatment of drinking water greatly facilitate its spread. Bodies of water have been found to serve as a reservoir of infection, and seafood shipped long distances can spread the disease. Cholera had disappeared from the Americas for most of the 20th century, but it reappeared toward the end of that century, beginning with a severe outbreak in Peru. Following the end of the 2010s Haiti cholera outbreak, there have not been any cholera cases in the Americas since February 2019.
Autoimmune optic neuropathy (AON), sometimes called autoimmune optic neuritis, may be a forme fruste of systemic lupus erythematosus (SLE) associated optic neuropathy. AON is more than the presence of any optic neuritis in a patient with an autoimmune process, as it describes a relatively specific clinical syndrome. AON is characterized by chronically progressive or recurrent vision loss associated with serological evidence of autoimmunity. Specifically, this term has been suggested for cases of optic neuritis with serological evidence of vasculitis by positive ANA, despite the lack of meeting criteria for SLE. The clinical manifestations include progressive vision loss that tends to be steroid-responsive and steroid dependent. Patients with defined SLE that go on to develop optic neuritis should be better identified as lupus optic neuritis. Signs and symptoms
AON was first described in 1982. It presents with visual loss and signs of optic nerve dysfunction, such as loss of color vision, afferent pupil defect, and sometimes abnormalities of the optic disc. The clinical features of AON can be variable and present in several unilateral or bilateral forms:

Acute anterior or retrobulbar optic neuritis sometimes associated with pain. Anterior or retrobulbar ischemic optic neuropathy not associated with pain. Chronic progressive vision loss that mimics a compressive lesion.The main features that differentiate AON from the more common typical demyelinating optic neuritis is the poor recovery of vision and the chronic or recurrent or bilateral course of AON. Furthermore, the workup for multiple sclerosis including MRI, will be negative.