Zika Virus (human)
Primary reference(s)
WHO, 2018. Zika virus. World Health Organization (WHO). Accessed 19 November 2019.
Additional scientific description
Zika virus is primarily transmitted to humans and animals through the bite of an infected mosquito from the Aedes genus, mainly A. aegypti, in tropical and subtropical regions. Aedes mosquitoes usually bite during the day, peaking during early morning and late afternoon/evening (WHO, 2018).
Zika virus is also transmitted from mother to foetus during pregnancy, through sexual contact, transfusion of blood and blood products, and organ transplantation (WHO, 2018).
Symptoms are generally mild and include fever, rash, conjunctivitis, muscle and joint pain, malaise or headache. Symptoms typically last for 2 to 7 days. Most people with Zika virus infection do not develop symptoms (WHO, 2018).
Zika virus infection during pregnancy can cause infants to be born with microcephaly and other congenital malformations and neurodevelopmental disorders, known as congenital Zika syndrome. Infection with Zika virus is also associated with other complications of pregnancy including pre-term birth and miscarriage (WHO, 2018).
An increased risk of neurological complications is associated with Zika virus infection in adults and children, including Guillain- Barré syndrome, neuropathy and myelitis (WHO, 2018).
Infection with Zika virus may be suspected based on symptoms of persons living in or visiting areas with Zika virus transmission and/or Aedes mosquito vectors (WHO, 2018).
A diagnosis of Zika virus infection can only be confirmed by laboratory tests of blood or other body fluids, such as urine or semen (WHO, 2018).
The World Health Organization (WHO) has published guidance on case classification and surveillance standards (WHO, 2016a).
Metrics and numeric limits
Not available.
Key relevant UN convention / multilateral treaty
International Health Regulations (2005), 3rd ed. (WHO, 2016b).
Examples of drivers, outcomes and risk management
Aedes mosquitoes breed in small collections of water around homes, schools, and work sites. It is important to eliminate these mosquito breeding sites (WHO, 2018).
Protection against mosquito bites during the day and early evening is a key measure to prevent Zika virus infection. Special attention should be given to prevention of mosquito bites among pregnant women, women of reproductive age, and young children (WHO, 2018).
Personal protection measures include wearing clothing (preferably light-coloured) that covers as much of the body as possible; using physical barriers such as window screens and closed doors and windows; and applying insect repellent to skin or clothing (WHO, 2018).
Young children and pregnant women should sleep under mosquito nets if sleeping during the day or early evening. Travellers and those living in affected areas should take the same basic precautions (WHO, 2018).
No vaccine is yet available for the prevention or treatment of Zika virus infection (WHO, 2018).
To date, mitigation strategies continue to rely on vector control (Achee et al., 2019).
The WHO is investigating conventional and newer tools for mosquito control (WHO, 2017).
References
WHO, 2016a. Zika virus disease case definition. World Health Organization (WHO). Accessed 20 November 2019.
WHO, 2016b. International Health Regulations (2005), 3rd ed. World Health Organization (WHO). Accessed 26 September 2020.
WHO, 2018. Zika virus. World Health Organization (WHO). Accessed 19 November 2019.
WHO, 2017. Mosquito Control: Can it Stop Zika at Source? World Health Organization (WHO)
Achee, N.L., J.P. Grieco, H. Vatandoost, G. Seixas, J. Pinto, L. Ching-Ng, A.J. Martins, W. Juntarajumnong, V. Corbel, C. Gouagna, J.P. David, J.G. Logan, J. Orsborne, E. Marois, G.J. Devine and J. Vontas, 2019. Alternative strategies for mosquito-borne arbovirus control. PLoS Neglected Tropical Diseases, 13:e0006822. doi: 10.1371/journal.pntd.0006822