ZIKA virus overview

Named after the Zika forest in Uganda, the Zika virus is all over the news at the moment.

The virus belongs to the Flavivirus genus which include diseases such as Dengue and Yellow fever. (other flavivirus diseases; japanese encephlitis, tick borne encephalitis, usutu virus and west nile virus). 

The Zika virus is trasmitted by the Aedes aegypti mosquito, which is endemic to South America and Africa and also responsible for the spread of Dengue and Chikungunya (fever and joint pains). 

The current outbreak is in Central and South America after starting in Brazil and French Polynesia.

Once bitten by the mosquito the incubation time is around 10 days.

Most people have little of no symptoms but it can cause a range of non-specific symptoms such as myalgias, headaches, fevers and arthritis.

The diagnosis is clinical and based on travel and exposure history. The viraemic period is short and patients will be positive for viral DNA tests 3-5 days after onset of symptoms. After that serology will be positive, look for the presence of Zika virus IgM. 

No vaccine available, although drug companies are under heavy pressure to develop one soon..

Treatment is primarily supportive care with antipyretics and painkillers if needed. Avoid use of NSAIDs or acetylsalicylic acid, because of fears of hemorrhagic syndrome or reyes syndrome. 

The disease has been brought to the attention of the news because of the possible link with Microcephaly in new borns. For this reason the brazilian government has advised against pregnancy until the disease is under control and better understood. Its also for this women who are pregnant or intending to be soon should avoid travel in the endemic areas. There is also many reported cases of Guillain-Barre syndrome (acute ascending symmetrical polyneuroathy).  

Useful  links: CDC, European centre for disease control

• Also spread by the Aedes albopictus mosquito. and some other Aedes mosquito species. 
• Genetically modified mosquitos are being explored as a potential way to combat the mosquito and disease. The possible environmental impact of this approach is being studied. 
• First isolated in 1945 from a Monkey
• Note that many of the non-specific symptoms are similar to Malaria, which is endemic to the same areas but carries a much higher mortality rate. 
• Urine will be positive for Viral RNA for ten days after symptoms onset.

Source: http://jeffreyhill.typepad.com/.a/6a00d8341d417153ef01b7c80f713d970b-800wi