Zika Virus & Symptoms

Zika Virus--Symptoms

Zika virus infection is a mild febrile viral illness transmitted by mosquitoes. Zika should only be considered in people who have recently travelled overseas.

About Zika virus

Zika virus is a flavivirus, closely related to dengue. Cases of Zika virus have previously been reported in Africa, southern Asia and the Pacific Islands. Beginning in 2014, Zika virus outbreaks have occurred throughout the tropical and sub-tropical areas of the western hemisphere, as far north as Mexico and Puerto Rico.

Because Zika, dengue and chikungunya viruses are transmitted by mosquitoes mostly active during daytime, it's important that all travelers visiting affected areas continue to take protective measures to prevent mosquito bites throughout the day.  

Zika virus infection is symptomatic in only about one out of every five cases. When symptomatic, Zika infection usually presents as an influenza-like syndrome, often mistaken for other arboviral infections like dengue or chikungunya.

Symptoms of Zika virus infection

• low-grade fever (between 37.8°C and 38.5°C)
• arthralgia, notably of small joints of hands and feet, with possible swollen joints
• myalgia
• headache, retro-ocular headaches
• conjunctivitis
• cutaneous maculopapular rash
• post-infection asthenia which seems to be frequent.

More rarely observed symptoms include digestive problems (abdominal pain, diarrhoea, constipation), mucous membrane ulcerations (aphthae), and pruritus.

Zika virus infection usually causes a mild disease (with the possible exception in pregnant women, as discussed below) and, other than notification, no particular action is required.  However, as Zika infection may cause a rash that could be confused with diseases such as measles or dengue, these serious diseases do need to be ruled out. Diagnosis of Zika will first and foremost be based on symptoms, travel history and exclusion of other diseases including measles, rubella and dengue.

The incubation period is typically 3–12 days. There is no specific therapy for Zika virus infection and acute symptoms typically resolve within 4-7 days. Use paracetamol for pain and fever if needed. Until dengue can be ruled out DO NOT take aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, given the risk of bleeding.

In French Polynesia, after a local Zika virus outbreak in 2013 and 2014, an increase in autoimmune and neurological diseases has been observed (73 cases, 42 of them being Guillain-Barré Syndrome, in a population of about 270,000). There is no proven link at this stage other than this temporal sequence. The simultaneous circulation of dengue serotype 1 and 3 viruses may also play a role.