Zika Virus: Essay On Emergence, Transmission, And Impact On Human Lives.

Introduction from Outside sources

Zika Virus is an infection caused by the Aedes mosquitoes which are known to be active during the day. The name Zika was derived from the Zika forest in Uganda as research suggests that it was first discovered there around 1947.  The disease causes some symptoms including dengue and yellow fever and other types of mild sicknesses which are hard to notice. The virus statistically started in Africa, and around 2007 began to spread all around the world (Musso, 2014). The main way in which the virus spreads is through the Aedes mosquitoes, but can also be passed sexually or at birth. If a man visits a region and gets the virus, it is possible for them to give it to their sexual partner who did not visit the area. Blood semen is therefore put into consideration when studying the transmission of the virus from one individual to the other.  The virus can also be passed from mother to child through the process of birth, and this might lead to brain defects on the baby. Research also shows that an individual can contract the disease through body fluids like tears and sweat of the infected person (Musso, 2014). There are no known cures for the virus although Paracetamol and other medication can help with the symptoms. Zika virus is a dangerous and fast spreading disease that cannot be prevented by vaccinations.                                                                                                                            

The ZIKV has in the recent days emerged to be one of the leading causes of brain anomalies for new born babies due to the increased affected expectant mothers. The most common transmission of maternal fetal transmission is via the placenta. The placenta is an organ that connects the mother to her fetus and therefore in the cases of ZIKV; it is easier to pass it from mother to child at birth. Human cytomegalovirus (HCMV) is also another member of the viral family that affects body tissues and interferes with maternal processes (Weisblum, 2017). However when compared to Zika virus, the former induces cell activation while the latter upregulate placental molecular functions. An experiment conducted earlier indicate that ZIKV transmission in fetal maternal usually takes the Placenta as its main route. It also revealed some distinct patterns of cell and tissue response to the Virus and some of the ways to reduce this impact on maternal processes. The placenta is also at a high risk of damage due to the emergence of complications like placental calcifications, fetal loss and intrauterine growth restriction (IUGR).In the studies, an experiment puts ZIKV in immune tissues with the use of 3D tissue cultures to examine the extent of transmission and destruction (Weisblum, 2017).

The main objective of this study is to learn more on ZIKV by looking at its emergence, transmission, and impact on human lives. Tissue cultures will enable the researcher to gain more information on the growth and differentiation of body organs. The study focuses more on the maternal fetal transmission of the virus through the placenta. It is important to note that maternal fetal transmission cannot be quickly stopped as the delivery process must involve the cutting of the placenta. Other objectives include a comparison of other similar but different diseases like HCMV and their impacts on the placenta as well as the rest of the body tissues.  

Introduction from Article

Material and Methods

Cells and viruses.

Cells collected from the American Culture were used for ZIKV propagation. Cells were infected with a particular type of ZIKV PRVABC59 from an infected patient. At two days post-infection (dpi),  were collected, to get rid of cellular debris with freezing done at 80°C. The Virus titers had to be determined by standard plaque assay like the use of human foreskin. All cell lines were also tested for mycoplasma contamination (Weisblum, 2017)

The study involved the development of Decidual and chorionic villus organ cultures. They were all obtained from women who were undergoing first-trimester pregnancy terminations. They were then were kept on ice until sectioning, and later washed with a chemical known as phosphate buffered saline (PBS) (Weisblum, 2017).  They were cut into thin slices followed by decidual incubation. The infected tissues were nicely placed on plates then inoculated with the virus (5 _ 104 PFU/well) for 12 h, for optimized viral adsorption. Following viral adsorption, the cultures were washed extensively and further incubated for the duration of the experiment, with medium replacement every 2 to 3 days

ZIKV-infected tissues sectioned, formaldehyde fixed and sectioned. The sections were then placed citrate buffer (0.01.M) and heated at 110°C in a pressure cooker for 5 min. Cooling followed to room temperatures, and the cells were then incubated with monoclonal antibodies obtained from mice.   Sections were then washed and incubated with horseradish peroxidase (HRP)-conjugated goat antimouse or anti-rabbit secondary antibodies (Biocare Medical). The sections were rewashed, and the antigens were detected by the HRP substrate 3-amino-9 ethyl carbazole (AEC; Sigma), followed by counterstaining with hematoxylin (Weisblum, 2017).

The collected data were analyzed by two-tailed t tests that simply compared the values of the two groups. The P values were stated to be-0.05 to ensure that approximation can be made efficiently.  Statistical analysis of the transcriptome data was then put into figures.

The study was approved by the Hadassah Medical Center Institutional Review Board (0138-08 HMO) and performed according to the Declaration of Helsinki, Good Clinical Practice guidelines, and the Human-Experimentation Guidelines of the Israeli Ministry of Health. All participants signed written informed consent.

Through the use of proper and dependable methods of collecting and evaluating data, the study came up with results that indicate the truths about ZIKV. Just like any other types of diseases, experts have to test the virus on living laboratory tissues and ensure that any outcome is taken into consideration. The following were the results obtained from scientific experimental procedures:

ZIKV infects and spreads through early- and mid-gestation decidual tissues.

An experiment conducted revealed that the rate at which ZIKV spreads on certain tissues differ depending on the nature of the body cells involved. Decidual body tissues were infected with ZIKV and put under observation for a while to study its spreading. The study monitored kinetics involved with viral infection by examining the accumulation of viral RNA contained in the infected tissues (Weisblum, 2017). It came to pass that the viral cells rapidly increased in number showing that the ZIKV was taking effect. The 2-log increase was taken over seven days post infection which in return suggests a viral replication in the body cells. The same study was used to provide more information on parallel and vertical infections of the virus. Parallel infected tissues were also discovered to be exposed to HCMV. Cells infected with HCMV

Aim of the study (hypothesis)

were detected at two dpi, and the disease progressed at 3 to 7 dpi. ZIKV, on the other hand, spread in a cell-free pattern from the indications of significant amounts of free virus.

The study established the kinds of birth abnormalities as linked to the pregnancy outcomes that were connected to ZIKV. Figures show that the virus starts to build up at 19 to 21 weeks of pregnancy and at this point, it is challenging to stop the transfer of ZIKV from the mother to the fetus. The experiment takes three tissues from different donors with the difference in blood health. The cells recorded a specialty in ZIKV as gestation did not alter any case of HCMV. The figures, therefore, portray maternal fetal to be the most suitable site for ZIKV transmission. It is during early gestation that most of the transmissions take place as it provides a conducive environment for the transfer of most fluids from the mother to the fetus through the placenta which is also the passage of ZIKV (Weisblum, 2017). A further study of the exposed tissues indicates that there were an increased ZIKV positive cells that were distributed in the whole section. This is a sign that the virus got more viral and spread all over the victim’s body. To finalize this particular experiment, tissues infected over an hour and then extensively washed tested negative for ZIKV E antigen staining, which was an indication that the observed staining at two dpi will more likely reflect viral replication (Weisblum, 2017). The infected tissue sections reacted with secondary antibodies only were negative by immune histochemical staining.

The experiment was now taken to another stage of studying the innate responses of the tissues to the virus. Later on, there was a comparison of tissue responses impact between ZIKV and HCMV which was meant to show the consequences of both viruses on similar fabrics. Performing a genome-wide analysis of the affected tissues revealed that decidual ones were affected by both viruses in a parallel manner. In the 2di tissues, ZIKV spread at a viral speed as compared to those infected with HCMV, but in the latter, they weaken after 24 to 48hrs of exposure (Musso, 2014).

The study revealed both ZIKV and HCMV  dysregulated the decidual tissue’s gene of expression. Despite the faster rate of spread observed for ZIKV, it finally gave less response to the decidual tissues as compared to HCMV (Weisblum, 2017). These statistics can be reflected by reduced number of differential genes due to ZIKV infection in comparison of the effect of

HCMV.  Another observation is that HCMV altered the immune cell, cell trafficking paths, and proliferation but ZIKV did not affect any of these.

The study further examined the effect of ZIKV and HCMV on villus tissues, and rather different results were obtained. Divergent cytokines were observed from the experiment in that ZIKV induced the type I and III IFNs while HCMV affects other cytokines (Weisblum, 2017).

The difference between the responses of ZIKV and HCMV became more evident in villous tissues as compared to the decidual ones.  Some of the ZIKV responses noted in villous  tissues include apoptosis, necrosis molecular functions, and cell death,

The study examines the development and spread of ZIKV in the human body by identifying the organ cultures involved. The decidual and villus tissues are a significant part of the experiment as the study had to compare the impact of several viruses on them. ZIKV and HCMV affect the maternal fetal process which in return can adversely affect the newborn’s health. The placenta is known to be the most suitable way of transferring Zika virus from the mother to their unborn child, and not much can be done to control those forces. Placenta tissues react differently in parallel transmissions of diseases since they all have different components. The routes of vertical transmission, however, vary concerning the kind of gestational stage at the moment. In the experiments conducted, it is clear that the virus mostly affects individuals in the later stages. It was discovered that the innate response to both viruses results to different cytokines. A precise observation made from the experiment in that ZIKV induced the type I and III IFNs while HCMV affects other cytokines.

Conclusion

Taking a look at the methods, results, and observations taken from the article, ZIKV is a chronic disease that goes far beyond HIV. The methods of infection and transmission worry scientists and medical professionals as there are little things that can be done to prevent them. Unlike other viruses that can be maintained, ZIKV poses a threat to all the people around the infected victims. It can be transmitted through sexual relations, mother-unborn child, body fluids and other ways. When compared to other diseases like HCMV, Zika might have a less impact, but at the end of the day, it is a threat to human existence. I would, therefore, recommend from a medical point of view that ZIKV patients should be secluded from the rest of the population and treated in a controlled and caution method to avoid spreading.

References

Weisblum, Y., Oiknine-Djian, E., Vorontsov, O. M., Haimov-Kochman, R., Zakay-Rones, Z., Meir, K., ... & Bronstein, M. (2017). Zika virus infects early-and midgestation human maternal decidual tissues, inducing distinct innate tissue responses in the maternal-fetal interface. Journal of virology, 91(4), e01905-16.

Musso, D., Nhan, T., Robin, E., Roche, C., Bierlaire, D., Zisou, K., ... & Broult, J. (2014). Potential for Zika virus transmission through blood transfusion demonstrated during an outbreak in French Polynesia, November 2013 to February 2014. Euro Surveill, 19(14), 20761.