The Zika virus is the causative agent of an acute viral disease, which causes clinical manifestations very similar to those of dengue and chikungunya.
The infection in humans is mainly transmitted by the bite of mosquitoes of the genus Aedes (A. aegypti and A. albopictus), although direct contagion through blood products or sexually is possible.
The virus has also been found in the placenta and amniotic fluid of pregnant women, so a maternal-fetal infection can occur; this mode of transmission can have teratogenic effects on the embryo, especially if the infection is contracted in the first trimester of gestation (it is believed that the viral agent can cause cases of microcephaly and other fetal malformations).
The Zika virus is present in tropical and subtropical regions of the Americas, Africa, South Asia and the Western Pacific.After an infected mosquito bite, symptoms of Zika virus fever tend to occur after an incubation period of 3-12 days.
The infection causes flu-like symptoms, such as low-grade fever, asthenia, conjunctivitis, headache, myalgia, and joint pain (especially in the hands and feet). In addition, a maculo-papular rash may occur, often starting on the face and then spreading to the rest of the body. Zika virus fever generally has a benign course and usually resolves spontaneously within 2-7 days.
It should be noted that one in four people does not develop symptoms.
At present, the complications of the disease are poorly understood. However, during the recent Zika outbreaks, there was an unusual increase in Guillain-Barré syndrome (a neurological complication due to an immune response that mistakenly attacks a part of the nervous system);
this potential association is still under study. Further investigation is also needed to clarify the link between infection in pregnant women and the increase in babies born with microcephaly.Microcephaly Zika Virus
Zika virus fever is diagnosed on the basis of symptoms, recent medical history (such as mosquito bites or travel to an endemic area) and on laboratory tests that demonstrate infection (serological tests and RT-PCR).
Currently, there are no specific antiviral drugs or vaccines available to treat and prevent Zika virus fever. Treatment is therefore aimed at controlling symptoms and involves rest, fluid intake and the use of analgesics and antipyretics. Most patients recover completely without neurological complications.