Zika Virus: Symptoms, Treatment, Vaccination | What You Need to Know
Introduction
Zika virus (ZIKV) is a mosquito-borne virus in the Flaviviridae family and the Flavivirus genus, which also includes dengue, yellow fever, Japanese encephalitis, and West Nile viruses. The Zika virus was discovered in Uganda in 1947 in the body of a caged rhesus monkey in the Zika Forest. It was isolated from Aedes africanus mosquitoes collected from the same woodland the following year. Human Zika virus infection was initially documented in 1952 in Nigeria, and since then, occasional cases and outbreaks have been detected throughout Africa and Asia.
However, Zika virus disease has emerged as a global public health threat since 2007, with large-scale outbreaks in Africa, the Americas, Asia, and the Pacific. The greatest outbreak occurred in Brazil in 2015, with over 1.5 million cases documented and a link between Zika virus infection and microcephaly (an abnormally tiny head) established. The outbreak extended to other nations in the Americas and beyond, prompting the World Health Organisation (WHO) to declare a Public Health Emergency of International Concern (PHEIC) in February 2016. After the causal link between the Zika virus and congenital malformations was established, the PHEIC was lifted in November 2016.
Transmission of the Zika virus remains low in numerous countries, although it has typically dropped since 2017. To date, 89 nations and territories have reported evidence of mosquito-borne Zika virus infection; nevertheless, global surveillance remains limited. Sexual contact, blood transfusion, laboratory exposure, and intrauterine and perinatal transmission are all other mechanisms of transmission. Unprotected intercourse, travel to countries with epidemics, and residing in Aedes mosquito-infested areas are all risk factors for Zika virus infection.
Most people who contract the Zika virus have mild or asymptomatic infections; those who do develop symptoms often experience a rash, fever, conjunctivitis, muscle and joint pain, malaise, and headache that lasts 2–7 days. In some circumstances, however, Zika virus infection can result in serious neurological and congenital problems. Infection with the Zika virus during pregnancy can result in microcephaly and other congenital abnormalities, as well as preterm birth and miscarriage. In adults and children, Zika virus infection is linked to Guillain-Barré syndrome, neuropathy, and myelitis.
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Symptoms
The majority of people infected with the Zika virus do not experience symptoms; those who do get minor symptoms that last 2–7 days. Among the symptoms are:
- Skin irritation
- Conjunctivitis, sometimes known as "red eyes,"
- Fever
- Joint discomfort
- Muscle ache
- Headache
- Back of the eye pain
- Vomiting
Treatment
There is currently no antiviral medication available for the Zika virus infection. Only supportive care is available because the infection is self-limiting. This could include:- To reduce fever and joint pain, take acetaminophen or ibuprofen.
- Fluids and rest are needed to avoid dehydration.
- To limit the risk of bleeding, avoid aspirin and other nonsteroidal anti-inflammatory medicines (NSAIDs) until dengue is ruled out.
Vaccination
As of April 2019, no vaccinations against the Zika virus have been authorised for clinical use. Several vaccines, however, are currently in clinical trials. These are some examples:- DNA vaccines that introduce genetic material encoding Zika virus proteins into cells in order to elicit an immune response
- Inactivated vaccines that induce an immunological response by using killed Zika virus particles
- To produce an immune response, live attenuated vaccines use weakened Zika virus strains that can replicate but not cause disease.
- Purified Zika virus proteins or fragments are used in subunit vaccines to elicit an immunological response.
- The development of safe and effective Zika virus vaccines is a global priority, particularly for pregnant women and women of childbearing age who are at high risk of Zika virus sequelae.
Vaccines that are inactivated and use killed Zika virus particles to trigger an immune response This method is comparable to that employed for vaccinations against Japanese encephalitis and tick-borne encephalitis. In phase I studies, one inactivated vaccine candidate produced by Bharat Biotech demonstrated safety and immunogenicity.
To produce an immune response, live attenuated vaccines use weakened Zika virus strains that can replicate but not cause disease. This approach is comparable to that employed for yellow fever and dengue vaccines. In animal models, one live attenuated vaccine candidate produced by Instituto Butantan demonstrated protection.Purified Zika virus proteins or fragments are used in subunit vaccines to elicit an immunological response. This approach is comparable to that used for hepatitis B and human papillomavirus vaccines. In phase I studies, one subunit vaccine candidate produced by Themis Bioscience demonstrated safety and immunogenicity.
mRNA vaccines that self-amplify and transport messenger RNA encoding Zika virus proteins into cells to elicit an immune response.This is a unique platform technology that enables vaccine candidate manufacturing and scalability. In animal models, one self-amplifying mRNA vaccine candidate produced by Imperial College London demonstrated protection.
The development of safe and effective Zika virus vaccines is a global priority, particularly for pregnant women and women of childbearing age who are at high risk of Zika virus sequelae.
Epidemiology
Since the 1950s, the Zika virus has caused sporadic human infections in Africa and Asia. However, outbreaks of Zika virus disease have been documented in Africa, the Americas, Asia, and the Pacific since 2007. The greatest outbreak occurred in Brazil in 2015, with over 1.5 million documented cases and a relationship established between Zika virus infection and microcephaly. The outbreak extended to other nations in the Americas and beyond, prompting the World Health Organisation (WHO) to declare a Public Health Emergency of International Concern (PHEIC) in February 2016. After the causal link between the Zika virus and congenital malformations was established, the PHEIC was lifted in November 2016.Transmission of the Zika virus remains low in numerous countries, although it has typically dropped since 2017. To date, 89 nations and territories have reported evidence of mosquito-borne Zika virus infection; nevertheless, global surveillance remains limited. Sexual contact, blood transfusion, laboratory exposure, and intrauterine and perinatal transmission are all other mechanisms of transmission. Unprotected intercourse, travel to countries with outbreaks, and residing in Aedes mosquito-infested areas are all risk factors for Zika virus infection.
