Zika Virus: Transmission & Impact

This assignment delves into the intricacies of Zika virus, focusing on its modes of transmission and profound impact on human health. It examines the virus's spread through vectors and sexual contact, highlighting its ability to cross the placenta and cause severe birth defects, particularly microcephaly. The assignment also sheds light on the global public health implications of Zika outbreaks and the ongoing research efforts aimed at developing effective prevention and treatment strategies.

Running head: COMMUNICABLE DISEASE
Communicable disease
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Zika virus
Zika virus is a type of mosquito Borne flavivirus. Zika virus is transmitted by the
aedes mosquitoes. This virus is related to Dengue yellow fever and encephalitis. This virus
was first identified at Uganda in 1947 in the monkey's which causes the yellow fever. It was
later identified in 1952 in the humans of United Republic of Tanzania and Uganda it has also
been recorded in Asia Africa and America. Generally the zika virus causes very mild
symptoms such as mild fever, rash, conjunctivitis, joint pain, muscle pain or headache
(Shankar, 2016). These symptoms generally stay for 2-7 days. The incubation period of the
Zika virus is not known clearly but is it is assumed to be some few days of the incubation.
Role of zika virus
Structure of the zika virus
ZIKV is a type of virus in the family of Flaviviridae of class Flavivirus, which
additionally incorporates the main pathogen human Japanese encephalitis virus (JEV) and the
Dengue virus (DENV). The genome of flavivirus is a RNA of 11 kilo bytes long which
contains a 5′ top structure however does not have a polyA tail. The RNA code for a long open
chain which is converted into a protein was prepared by virus and has proteases into three
basic and seven non-structural proteins (Lei et al., 2016). Non-structural protein 5 (NS5) is
fundamental for the flaviviral RNA genome replication (Gourinat et al., 2015). The N-
terminal bit of NS5 contains a methyl-transferase (MT), trailed by a short linker that
associates with the RNA-subordinate RNA polymerase (RdRp). The MT includes the 5′ RNA
top structure to encourage interpretation of the polyprotein and to diminish elicitation of the
host inborn invulnerable reaction. The RdRp starts RNA amalgamation by an all over again
component wherein a solitary nucleotide triphosphate fills in as a preliminary for nucleotide
polymerization (Petersen et al., 2015).

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Critical review
According to Chiramel and Best (2017), recent studies have suggested a role for
autophagy in Zika infection (ZIKV) replication by showing the aggregation of autophagic
vesicles after the ZIKV disease in both in vitro and in vivo models. In human fetal neural
immature microorganisms, ZIKV restrains Akt-mTOR motioning to actuate autophagy,
increment infection replication and block neurogenesis. In any case, autophagy additionally
can possibly constrain ZIKV replication, with partitioned thinks about exhibiting antiviral
parts for autophagy at the maternal-placental-fetal interface, and all the more particularly, at
the endoplasmic reticulum where infection replication is set up in a tainted cell. Strangely,
ZIKV (and related flaviviruses) has advanced particular components to overcome autophagy
at the ER, hence exhibiting vital parts for these autophagic pathways in infection replication
and host reaction (Lei et al., 2016).
According to Tsunoda et al. (2016), ZIKV have direct neuro-tropism and neuro-
virulence but does not have neuro-invasiveness. Intrauterine ZIKV disease (viral pathology)
has been connected to an expanded frequency of microencephaly, following ZIKV
contamination is likely insusceptible interceded. Clinically, in ZIKV disease, antibodies
against different flaviviruses, for example, DENV, have been identified; these are the
antibodies that can cross-respond with ZIKV balance. In principle, such non-killing
antibodies are created to the detriment of diminished generation of killing antibodies
(Tsunoda et al., 2016). While the non-killing antibodies can likewise upgrade viral replication
in Fc receptor (FcR)- bearing cells by means of immunizer subordinate improvement (ADE).
Here, we propose three potential parts of the neutralizer interceded pathogenesis of ZIKV
contamination:

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1) cross-receptive antibodies that perceive ZIKV and neural antigens cause GBS;
2) ZIKV-counter acting agent complex is transported transplacentally through
neonatal FcR (FcRn), bringing about fetal disease; and
3) ZIKV-immune response complex is taken up at nerve endings and transported to
neurons in the focal sensory system (CNS), from here the infection can enter the CNS
without intersecting the barrier of blood and brain.
Panchaud et al. (2016) stated that the current accessible proof backings the presence
of a causal connection between pre-birth Zika infection disease and microcephaly and
different genuine cerebrum peculiarities. Microcephaly can be caused by a few components,
and its clinical course and anticipation are hard to foresee. Different pathogens with
demonstrated teratogenicity have been recognized some time before the current ZIKV plague.
In spite of the developing number of cases with maternal indications of contamination and
additionally nearness of ZIKV in tissues of influenced babies or embryos, it is as of now hard
to evaluate the extent of increment of microcephaly pervasiveness in Brazil, and also the part
of different factors in the advancement of inborn neurological conditions (Tang et al., 2016).
In the interim, wellbeing offices and therapeutic associations have issued wary rules
prompting medicinal services specialists and hopeful couples making a trip to, coming back
from, or living in influenced regions. Undifferentiated from dengue infection (DENV)
plagues, ZIKV can possibly wind up noticeably endemic in all nations swarmed by Aedes
mosquitoes, while new changes could affect viral replication in people, prompting expanded
harmfulness and subsequently elevated odds of viral transmission to extra credulous
mosquito vectors. Studies are critically expected to answer the inquiries encompassing ZIKV
and its part in inherent neurological conditions (Zhang et al., 2017).

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According to Musso (2014), the sporadic human diseases were accounted for in
Africa and Asia. In 2007, the main expansive archived ZIKV episode was accounted for from
Yap State, Federated States of Micronesia. No further transmission was distinguished in the
Pacific until October 2013, when French Polynesia (FP) revealed the primary cases; an
ensuing hazardous episode brought about an expected 28 000 cases looking for restorative
care. Phylogenetic examinations exhibited that the FP strain was firmly identified with
Cambodia 2010 and Yap State 2007 strains, authenticating past discoveries of the
development of the ZIKV Asian ancestry. Amid the FP episode, most clinical cases gave
gentle malady described by poor quality fever, maculopapular rash, arthralgia, and
conjunctivitis. No extreme sickness coming about because of ZIKV contamination had been
accounted for preceding the FP episode, yet past clinical portrayal depended on a set number
of affirmed cases. The current fleeting and spatial relationship between the FP ZIKV episode
and the exceptionally strange GBS bunch is extremely suspicious, however does not affirm
ZIKV as the antigenic jolt inclining to this immune system sickness. Following the FP
episode in late 2013, there were resulting flare-ups in New Caledonia, the Cook Islands, and
Easter Island. As a result of the regularly gentle clinical indications, constrained ZIKV
analytic limit, and covering clinical highlights of ZIKV, dengue, and chikungunya, which are
likewise flowing in the Pacific, we trust that continuous and undetected ZIKV transmission in
other Pacific island nations, and possibly past, is profoundly plausible. The perception that
serious clinical intricacies may happen features the need to reinforce reconnaissance for this
developing infection, and, in case of a ZIKV episode, set up thorough clinical observing to
distinguish GBS or other bizarre clinical indications.
Freire et al. (2014) had studied the molecular evolution of zika virus by investigating
37 Zika virus isolates that were collected from Senegal and six different countries. Samples
collected that are utilized as a part of this examination. Monkey and human strains were

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acquired separately in 1979 and 1991 in Senegal amid routine observation. None of the
information was specifically derived from human or creature tests but instead from cell
culture supernatant. Along these lines every one of the specimens was mysterious and just
reference numbers were utilized amid the investigation that began this examination. Viral
contamination was affirmed following seven days of engendering by a roundabout immuno-
fluorescence measure utilizing particular hyper-invulnerable mouse ascitic liquid, as
portrayed already. Cultures supernatants were gathered for RNA isolation. Then the RNA
was extracted by gel electrophoresis and was eluted by AVE buffer and then stored at -80°C
for further use. Then cDNA was synthesized and PCR was done for the amplification of the
viral RNA. For the amplification cDNA is mixed with the buffer, primers, dNTPs, MgCl2 and
Taq polymerase. After the amplification the phylogenetic analysis is done it was found that
some of the countries from West Africa show the emergence of the Zika virus during the 20 th
century.
In the year 2015, Musso et al., proved the sexual transmission of the Zika virus by the
help of a man who had the symptoms of the Zika infection such as low fever, asthenia and
arthralgia. They collected the blood and the semen samples ans tested for teh confirmation of
hematospermia. They extracted RNA from 200μL of blood and 500μL of semen, and then
were eluted by a 50μL of the elution buffer. From this 5μL of RNA was extracted for doing
the amplification. The samples were then tested by doing RT-PCR using the primers specific
of the Zika virus. The results shows that there are positive signs of Zika virus in semen but
there are no virus in the blood. Thus it can be proved that the Zika can be transmitted
sexually.
Cauchemez et al. (2016) studied the emergence of the Zika virus in America has
increased rate of microencephaly with the birth of the babies. They reflectively analysed the
information from a Zika virus epidemic in French Polynesia, which was the biggest archived

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flare-up before that in the Americas. They utilized serological and observation information to
gauge the likelihood of contamination with Zika infection for every seven day stretch of the
plague and looked restorative records to recognize all instances of microencephaly from
September, 2013, to July, 2015. Simple models were utilized to evaluate times of hazard in
pregnancy when Zika infection may expand the danger of microencephaly and gauge the
related hazard. From the study it was found that the Zika virus epidemic was started in
October, 2013, and finished in April, 2014, and 66% (95% CI 62– 70) of the overall public
were contaminated. Of the eight microencephaly cases recognized amid the 23-month think
about period, seven (88%) happened in the 4-month time span March 1 to July 10, 2014. The
planning of these cases was best clarified by a time of hazard in the main trimester of
pregnancy. In this model, the standard pervasiveness of microencephaly was two cases (95%
CI 0– 8) per 10 000 neonates, and the danger of microencephaly connected with Zika
infection disease was 95 cases (34– 191) per 10 000 ladies tainted in the primary trimester.
We couldn't preclude an expanded danger of microencephaly from contamination in different
trimesters; however models that avoided the principal trimester were not supported by the
information.
Gourinat et al. (2015) described the presence of Zika virus in the urine samples. They
have collected some urine samples from 6 peoples who are suffering from the Zika virus
infection. To detect the ZIKV in the urine samples firstly RNA was extracted from 200 μL of
urine, then they use the sets of specific primers for ZIKV. A standard curve was obtained
with the serial dilutions of a Zika virus stock of known concentrations. All the urine samples
were also being tested for the dengue and chikungunya virus infections by using RT-PCR and
it showed negative results. Then the urine samples that were taken from the patients showed a
positive result for ZIKV. Some urine samples were also taken from 6 healthy persons that
were also assessed and it showed the negative results.

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Conclusion
In general, since there are no particular medicines for Zika infection disease, and in
addition for other developing arbo-viruses of general wellbeing significance, the viable
control of mosquito vectors with eco-accommodating instruments is of pivotal significance.
Natural control programs against mosquito youthful instars depend on the arrival of savage
amphibian life forms, and this system is as often as possible not reasonable in the greater part
of urban conditions misused by hatchlings of some Aedes species, accordingly additionally
look into is required (Benelli, 2016). Be that as it may, the utilize of organic control operators
of mosquito youthful instars in nearness of ultra-low amounts of plant-integrated metal and
carbon nanoparticles, may prompt the effective decrease of vector populaces, since the sub-
deadly dosages of these nano-formulations are lethal towards the Culicidae, yet not to their
regular adversaries. Other than the utilization of manufactured and plant-borne anti-agents to
dodge Culicidae nibbles, and also the exemplary pesticide-based control programs focusing
on mosquito youthful instars, facilitate viable alternatives will incorporate radiation,
transgenic and symbiont-based control approaches (Fauci & Morens, 2016). Likewise, the
utilization of organic control specialists of mosquito eggs, hatchlings and pupae, in nearness
of ultra-low amounts of bioreduced nanoparticles, which help their predation rates, appears to
be encouraging.
Further researches are to be done to get the correct idea of the use of chemical compound and
decision elements in mosquito vectors is required. Additionally behavioral examinations
dismembering the relative significance of visual (with uncommon reference to swarming
historic points), vibrational, olfactory and material signals are seen during swarming and
mating. This is of essential significance to permit the compelling uses of swarming control
(the "lure and kill" approach), pheromone traps and sound traps.

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