Typically, four out of five individuals infected with the Zika virus will never develop symptoms, and when symptoms occur, they will be rather mild and include one or more of the following:
- Mild fever
- Joint pain (arthralgia)
- Red rash with small bumps (maculopapular rash)
- Red, irritated eyes (conjunctivitis)
- Muscle pain
- Headache
- Vomiting
With mild symptoms, Zika infection usually last for several days to a week. Individuals typically do not require hospitalization and very rarely do individual die from the infection. Because symptoms are usually mild or non-existing, many people may not realize they have been infected.
On the other hand, more severe symptoms or conditions can occur in the following situations:
- Microcephaly and other birth defects during pregnancy: More information on this condition will be presented later in this course.
- Increased incidence of Guillain-Barre syndrome (GBS): GBS is a rare, but serious autoimmune disorder that affects the central nervous system.