The following key points currently relate to the Zika virus:
- Since 2015, the Zika virus has spread rapidly in Latin America and the Caribbean. As of late 2016, the virus was present in more than 50 countries. In the past, cases of Zika virus infection have been identified in Florida and Texas. However, since 2019, there have been no confirmed Zika virus disease cases reported from United States territories.
- As of the end of 2022, no countries were experiencing active Zika outbreaks. However, some countries are still considered at risk for the Zika virus.
- Zika virus is primarily transmitted by the Aedes mosquito. However, the virus can also be transmitted from mother to child during pregnancy and can also be spread via sexual activity, blood transfusion, and lab exposure.
- Typically, most individuals with a Zika virus infection never develop symptoms, and when symptoms occur, they are usually rather mild.
- More serious health problems especially related to the central nervous system, can occur with in-utero Zika virus infections (congenital Zika virus infection). The most common health abnormality occurring during pregnancy is microcephaly in infants born to Zika virus-infected mothers. It is important to stress that not all women who have Zika virus infection during pregnancy will have a fetus with microcephaly.
- The diagnosis of a Zika virus infection is based on a patient’s clinical features, places and dates of travel, and activities. Clinical symptoms, if present, typically begin two to seven days after being bitten by an infected mosquito or after contacting the Zika virus from other transmission sources. Since clinical symptoms and features may be absent, minimal, or mimic other types of viral infections, a definitive diagnosis is usually made by laboratory testing of serum or urine for viral nucleic acid or virus-specific immunoglobulin M (IgM) and neutralizing antibodies.
- Currently, there are three types of laboratory tests for the identification of the Zika virus:
- Nucleic acid testing, most commonly, Real-time reverse transcription-polymerase chain reaction (rRT-PCR) for measuring Zika virus RNA in serum and urine
- Zika IgM antibody capture enzyme-linked immunosorbent assay (Zika MAC-ELISA) for the detection of Zika virus IgM antibodies in serum
- Plaque reduction neutralization test (PRNT) to confirm the presence of Zika virus-specific antibodies
