zika virus overview

Actually, Zika virus comes into our sight in 2015. Between April and November, 2015, 18 of the 27 Brazilian states reported ZIKV autochthonous cases. After Zika virus emerged in Brazil, a 20-fold annual increase of microcephaly cases was observed.

In 2015, there has been 1248 new suspected cases, a prevalence of 99•7 per 100 000 livebirths. The Brazilian Ministry of Health confirmed the relation between ZIKV and microcephaly, and WHO issued an epidemiological alert about the association of ZIKV infection with congenital malformations and neurological syndromes.

So, what is Zika virus? Here are answers.
Family: Flaviviridae
Lineages: Asian and African
Vector: Aedes aegypti mosquitoe
Rwservior/Host: non-human primate, mosquitoe, human
Antigens: Capsid protein, M, E, pr, NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5
Disease & disease may cause: Zika fever, microcephaly in infant when pregnant women being infected, GBS (Guillain-Barrésyndrome)

Zika virus is a kind of arbovirus. It belongs to Flaviviridae family, genus Flavivirus. Dengue virus, Yellow fever virus and West Nile virus are also members of this family. Zika virus was first isolated from a rhesus monkey in the Zika forest in Uganda in 1947.

Zika virus is a single stranded RNA virus with two major lineages: Asian and African. Upon phylogenetic analysis of the viral genome, it was found that Zika virus probably emerged around 1920 at Uganda and upon two migration stages to West Africa has started the two African lineages. From Uganda, Zika virus must have migrated to Asia in the 1940s and emerged as the Asian lineage, with outbreaks reported in Indonesia and a major epidemic in Micronesia. The Asian lineage was also responsible for the native transmitted cases of the virus that recently occurred in Brazil.

The key Zika virus vector is thought to be the daytime biting (indoors and outdoors), urban dwelling Aedesaegypti mosquito. Evidence to support this comes from detection of the virus in wild A aegypti and by experimental transmission in rhesus monkeys.30-32 Following laboratory feeding of Aedes albopictus mosquitoes with Zika virus infected blood, the virus has been demonstrated in mosquito saliva. As other flaviviruses, Zika virus is mostly transmitted by Aedes aegypti mosquitoes.

In Africa, Zika virus is thought to have been largely maintained in a cycle involving transmission between non-human primates (such as monkeys and apes) and mosquitoes, with humans as occasional unintentional hosts. In areas outside Africa, however, humans have probably become the main host.

Zika virus related reference:

1, Marina Basarab specialty registrar. et al .Zika virus. BMJ 2016;352:i1049 doi: 10.1136/bmj.i1049
2, Pinto Júnior VL, et al. Zika virus: a review to clinicians, Acta Med Port 2015 Nov-Dec;28(6):760-765
3, Camila V Ventura, et al. Zika virus in Brazil and macular atrophy in a child with microcephaly. Published Online January 7, 2016
http://dx.doi.org/10.1016/ S0140-6736(16)00006-4