Zika Virus
Zika Virus
•Single stranded RNA virusGenus Flavivirus, family Flaviviridae.
▪ Closely related to dengue, yellow fever,
Japanese encephalitis, and West Nile viruses
• Primarily transmitted through the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus).
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ZIQUIK
ZIQUIK
Zika is spread mostly by the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). These mosquitoes bite during the day and night.
Our product basically will suggest a method for early detection of the zika virus so that early prevention methods can be taken.
Ziquik is a product which will use the method of immunochromatogragy (ICT) to detect zika virus early in the blood of the infected person.
Product ZIQUIK
This product is based on the principle of ICT which states that the colloidal gold test strip is used to detect specific antigen–antibody reaction.
A monoclonal antibody will be combined with gold nanoparticles by electrostatic adsorption to form the gold-labelled monoclonal antibodies(mAb). These Monoclonal antibodies will be used against the zika virus antigens (NS1, NS2A, NS2B, NS3, NS4A, 2K, NS4B, and NS5) [1].
The liquid sample used is blood sample which will be taken from a lancet (as it is easy to use and minimum pain is felt), blood is used because the antigen appears in the blood within 5 days of infection but antibody appears in four weeks [2].
Product ZIQUIK
Monoclonal antibodies are immobilized on the chromatographic paper and is labelled with colloidal gold and infiltrated into sample pad. An imunochromatographic unit is completed by attaching the sample pad at the end of the membrane.
Liquid sample (blood) is dropped on the sample pad The antigen in the sample forms an immunocomplex with the monoclonal antibody labelled with colloidal gold. The complex moves along with the liquid sample and makes contact with the antibody immobilized on the membrane. It then forms an immunocomplex with the immobilized antibody, resulting in a red-purple coloured line.
Appearance of red-purple line on the membrane indicates the presence of Zika antigen in the sample. Liquid of the sample migrates through the membrane very fast, and the presence of antigen can be detected within as less as 15 minutes.
Product ZIQUIK
It is instrument-free rapid point-of-care tests for diagnosis and surveillance of arbovirus diseases, since these infections typically occur in resource-poor settings where infrastructures, expensive equipment and trained personnel are not available.
In case of pregnancy ICT can be done in foetus after birth using CSF sample and if the test is negative then the foetus has less chances of getting the zika virus [3].
Drugs
Drugs are in the clinical trial stage of development. The drug aims to restrict the transmission of transfer of zika virus through placenta to the foetus. Synthetic peptide 72 is derived from the stem region of ZIKV envelope protein, which disrupts the integrity of ZIKV viral membrane and has been proven to inhibit vertical transmission in mice [4]
Practical Applications
Zika virus is known to cause Microcephaly in the foetus via vertical transmission from infected mother to the child. The Zika virus crosses the placental barrier and affects the child. Guillain Barre syndrome is also noted.
Once the women have been screened, confirmatory tests like nuclear antigen testing can be done. Drugs once developed can be administered at the earliest.
Epidemiology
•Zika virus was first identified in Uganda in 1947.
•Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.
•Large outbreaks in French Polynesia and Brazil in 2013 and 2015 respectively were reported.
Modes of transmission
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Modes of transmission
Bite from an infected mosquito
- Maternal-fetal
• Intrauterine
• Perinatal
Sexual transmission from infected male partners
- Laboratory exposure
Theoretical: blood transfusion, organ and tissue transplant, fertility treatment, and breast feeding
Incubation period
Incubation period and viremia
Incubation and viremia
•Incubation period for Zika virus disease
is 3-14 days.
•Zika viremia ranges from a few days to 1
week.
•Virus remains in semen and urine longer than in blood.
Signs and �Symptoms
Signs and Symptoms
•The symptoms are similar to other arbovirus infectionssuch as dengue, and include:
fever, skin rashes, conjunctivitis, muscle and joint pain,malaise, and headache.
•These symptoms are usually mild and last for 2-7 days.
•Only one out of four infected people develops symptoms of the disease.
Diagnostic tests
•Real time reverse transcriptase-polymerase chain reaction (rRT-PCR) for viral RNA in clinical specimens collected < 7 days (serum) or < 14 days (urine) after illness onset.
•Serology for IgM and neutralizing antibodies in serum collected up to 12 weeks after illness onset.
•Plaque reduction neutralization test (PRNT) for
presence of virus-specific neutralizing
antibodies in paired serum samples..
• Immunohistochemical (IHC) staining for viral antigens or RT-PCR on fixed tissues.
Diagnostic tests
Prevention
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For preventing/ controlling mosquito breeding
•Cover all water tanks and containers with tight lids.
•Dispose & destroy all unused containers, junk materials, tyres, coconut shells etc.
•Empty, scrub & dry desert coolers every week before refilling.
•Use larvivorous fish in ornamental tanks at houses and hotels
For Personal Protection
•Use bed-net at home and hospital during Dengue/ Zika Virus fever to prevent
mosquito bite so as to interrupt transmission.
•To avoid mosquito bite during day time wear full sleeved clothing and apply
mosquito repellent.
For managing fever: Use paracetamol for fever.
Zika in pregnancy
Zika in pregnancy
•Zika virus can pass from a pregnant woman to her fetus during pregnancy or around the time of
birth.
•Zika infection in pregnancy is a cause of microcephaly and other severe brain defects. Other problems include
– Eye defects, hearing loss,impaired growth, and fetal loss.
Zika in infants
Zika in infants
Doctors have found problems among fetuses and infants infected with Zika virus before birth, Show
– Microcephaly
– Miscarriage
– Stillbirth
– Absent or poorly developed brain
structures
– Defects of the eye
– Hearing defecits
– Impaired growth
Sexual transmission
Sexual transmission
References
Thank You!