Author: Vargas Rodriguez, Juan Sebastian
Public health has been a great challenge in many parts of the world, and underdeveloped nations present the greatest challenges in addressing the health problems in the field of public health. In recent years there have been outbreaks of reemerging diseases transmitted by vectors, such as the mosquito, Zika virus disease belonging to this group.
Zika virus, which was discovered incidentally in Uganda in 1947 in the course of monitoring mosquitoes and primates, had remained a dark virus confined to a narrow equatorial belt that traversed Africa and Asia. Arboreal mosquitoes such as Aedes africanus and rarely caused infections known as “spillage” in humans, even in highly enzootic areas.
The challenges given by Zika virus began from its transmission, constituting an evolution of this virus in this aspect. The arboreal Aedes aegypti then adapted to deposit its eggs in domestic containers containing water and to feed on humans, which led to the adaptation of arboreal viruses to infect humans.
Although transmission is caused mainly by mosquitos of Aedes species, two instances of sexual transmission of Zika virus have been reported, both involving symptomatic males. No sexual transmission of Zika virus from infected women to their partners and from infected people without symptoms has been reported.
A high load of replicative Zika virus and Zika virus RNA was detected in semen samples, but Zika virus remained undetectable by real-time reverse transcription PCR in blood samples collected at the same time. These results suggest that viral replication may have occurred in the genital tract, but it is unclear when this replication began and how long it lasted. In a recent study on sexually transmitted routes involving experiments on mice, viral replication occurs in the brain and spleen along with viral load in vaginal washings 10 days after infection. The study presented a transgenital transmission accompanied by a variation in the levels of hormones of the female reproductive tract with a prolonged prevalence of viral replication.
Another study noted that transmission goes beyond that by vectors or the parenteral route. Viable Zika virus particles were isolated from saliva and urine collected from two acutely infected people, and therefore they were recognized as vectors for transmission.
In addition to the evolutionary challenge in its transmission, Zika virus has brought with it greater controls and vigilance with regard to pregnant women. A series of reports suggesting an increase in the number of babies born with microcephaly in areas affected by Zika virus began to emerge, and Zika virus RNA was identified in the amniotic fluid of two women whose fetuses had microcephaly according to findings from ultrasonography performed before birth.