Zika virus (ZIKV) is an arthropod-borne flavivirus that was first isolated from a febrile Rhesus macaque monkey and from
Zika virus is primarily transmitted to people through the bite of an infected mosquito from the
The epidemiological data suggest that only 20% of ZIKV infections are symptomatic. The incubation period of Zika virus disease is not clear, but it is likely to be a few days. The symptoms are mild and self-limiting, involving fever, arthralgia, maculopapular rash, conjunctivitis, headache, retro-orbital pain and myalgia. These nonspecific symptoms are similar to other arbovirus infections, such as dengue and chikungunya, the diseases that share the same endemic areas and virus vectors as ZIKV (1) . Thus, the diagnosis of ZIKV infection in endemic regions based on clinical presentation alone can be wrong. The other usual differential diagnoses are measles, rubella, parvovirus and enterovirus infections, and malaria (2). However, the main concern is increasing evidence that ZIKV infection results in severe neurological complications – Guillain-Barré syndrome in infected patients, and in congenital abnormalities with microcephaly, spontaneous abortion, and intrauterine growth restriction of babies (4, 8). After a comprehensive review of evidence, there is scientific consensus that Zika virus is a cause of microcephaly and Guillain-Barré syndrome. However, many questions remain, including various spectra of birth defects caused by vertical ZIKV transmission, the degrees of risks of adverse outcomes among foetuses with regard to the ZIKV infection and the foetus gestation ages, and other possible (co)factors that might enhance ZIKV infection (5).
There is no specific antiviral treatment available for Zika virus disease. Treatment is symptomatic and supportive and can include good hydration, and the use of analgesics, antipyretics and anti-histamines for pruritic rash. Due to the similar, nonspecific symptoms and geographic distribution, patients with suspected ZIKV infections should be evaluated and managed for possible dengue or chikungunya virus infection (4). Acetylsalicylic acid (Aspirin) and other non-steroidal anti-inflammatory drugs (NSAIDs) should be avoided until dengue can be ruled out, in order to reduce the risk of haemorrhage (1). People infected with Zika should be protected from further mosquito exposure during the first week of illness, so as to decrease the risk for human-to-mosquito-to-human transmission, and thus minimize the risk of local transmission (9).
No vaccine or prophylactic treatment is currently available for Zika virus infection. Vaccine projects are at an early stage, but ZIKV vaccine is technologically feasible. However, there are still many unanswered questions about the virus, which need to be solved before a potential vaccine or specific immune prophylaxis (e.g., for pregnant women) is administered to the public (1, 4). Primary prevention is based on the protection against mosquito bites. Personal protection measures, such as applying mosquito repellents and wearing longsleeved shirts and long trousers to cover as much of the body as possible, especially during mid-morning and late afternoon hours, are necessary. Sleeping in screened or air-conditioned rooms or the use of insecticide-treated mosquito bed nets are recommended. A continuous control of mosquito population by removing their possible breeding sites should be applied around everyone’s dwellings (2).
It is recommended that pregnant women and women who are planning to become pregnant should postpone non-essential travel to areas of active ZIKV transmission. Persons with chronic illnesses or immune disorders are requested to consult their doctors before travelling to ZIKV endemic areas (10).
Sexual transmission of Zika virus through semen has been repeatedly documented in several different countries lately. Therefore, to reduce the risk of sexual transmission and potential pregnancy complications related to ZIKV infection, practicing safer sex (including the use of condoms) or abstaining from sexual activity is recommended throughout pregnancy to protect the foetus. In addition, there is also a recommendation for the people returning from ZIKV endemic areas that they should apply safer sexual practices or abstain from sex for at least 8 weeks after their return, even if no symptoms are present. Besides, if men experience Zika virus symptoms, they should practice safe sex or consider abstinence for at least 6 months. Couples that are planning pregnancy should wait at least 8 weeks before trying to conceive if no symptoms of Zika virus infection appear, or 6 months if one or both members of the couple are symptomatic (11).