In 2014 it was occurring in Florida in the continental United States but as of 2016 there were no further locally acquired cases. The disease was first identified in 1952 in Tanzania. The term is from the Kimakonde language and means "to become contorted". Signs and symptoms
Around 85% of people infected with Chikungunya virus experience symptoms, typically beginning with a sudden high fever above 39 °C (102 °F). The fever is soon followed by severe muscle and joint pain. Pain usually affects multiple joints in the arms and legs, and is symmetric – i.e. if one elbow is affected, the other is as well. People with Chikungunya also frequently experience headache, back pain, nausea, and fatigue. Around half of those affected develop a rash, with reddening and sometimes small bumps on the palms, foot soles, torso, and face. For some, the rash remains constrained to a small part of the body; for others, the rash can be extensive, covering more than 90% of the skin. Some people experience gastrointestinal issues, with abdominal pain and vomiting. Others experience eye problems, namely sensitivity to light, conjunctivitis, and pain behind the eye. This first set of symptoms – called the "acute phase" of Chikungunya – lasts around a week, after which most symptoms resolve on their own.Many people continue to have symptoms after the "acute phase" resolves, termed the "post-acute phase" for symptoms lasting three weeks to three months, and the "chronic stage" for symptoms lasting longer than three months.
Onset
Strabismus may also be classified based on time of onset, either congenital, acquired, or secondary to another pathological process. Many infants are born with their eyes slightly misaligned, and this is typically outgrown by six to 12 months of age. Acquired and secondary strabismus develop later. The onset of accommodative esotropia, an overconvergence of the eyes due to the effort of accommodation, is mostly in early childhood. Acquired non-accommodative strabismus and secondary strabismus are developed after normal binocular vision has developed. In adults with previously normal alignment, the onset of strabismus usually results in double vision. Any disease that causes vision loss may also cause strabismus, but it can also result from any severe and/or traumatic injury to the affected eye. Sensory strabismus is strabismus due to vision loss or impairment, leading to horizontal, vertical or torsional misalignment or to a combination thereof, with the eye with poorer vision drifting slightly over time. Most often, the outcome is horizontal misalignment. Its direction depends on the persons age at which the damage occurs: people whose vision is lost or impaired at birth are more likely to develop esotropia, whereas people with acquired vision loss or impairment mostly develop exotropia. In the extreme, complete blindness in one eye generally leads to the blind eye reverting to an anatomical position of rest.Although many possible causes of strabismus are known, among them severe and/or traumatic injuries to the affected eye, in many cases no specific cause can be identified.