Zika

Key points about the Zika virus

• Zika is a arboviral disease transmitted primarily by vectorsbut also sexual and maternal-fetal.
• The majority of infections are asymptomatic or benign.
• Infection during pregnancy can lead to serious congenital malformations.
• There is no specific antiviral treatment or vaccine.
• Prevention is based on vector and sexual protection.

What is Zika?

Zika is a viral infectious disease due to Zika virus, a flavivirus close to the viruses of dengue, yellow fever and chikungunyaThe transmission is primarily vector, by the bite of mosquitoes of the genus Aedes (Aedes aegypti et Aedes albopictus), active mainly during the day. Modes of transmission non-vector transmission are also described sexual, transmission mother-child Transmission can occur during pregnancy or childbirth, and more rarely through blood transfusion. After infection, transient viremia occurs, most often without clinical symptoms.

Zika around the world

The Zika virus is a mosquito-borne virus that was first identified in Uganda in 1947 in a rhesus macaque. Subsequently, evidence of infection and disease was reported in humans in other African countries in the 1950s. From the 1960s to the 1980s, sporadic infections were reported in humans in Africa and Asia. However, since 2007, large-scale Zika virus epidemics have been recorded in Africa, Latin America and the Caribbean, Southeast Asia, and the Pacific. Beginning in 2015, an outbreak of the disease in Brazil revealed for the first time the association between maternal and maternal infection. severe congenital malformationsand Zika virus infection and increased incidence of Guillain-Barré syndrome. Retrospective reviews in French Polynesia have yielded similar findings. Although the incidence decreased after the major epidemics, the virus continues to circulate. endemic or epidemic, with a risk of resurgence linked to the wide distribution of vector mosquitoes, the absence of a vaccine and surveillance that remains limited on a global scale.

Symptoms of the Zika virus

The infection is asymptomatic in 70 to 80% of casesWhen symptoms are present, they appear after an incubation period of 3 to 14 days and are most often mild: moderate fever, diffuse maculopapular rashNon-purulent conjunctivitis, arthralgia, myalgia, headaches, and asthenia. Neurological complications are possible, including Guillain-Barré syndrome and, more rarely, encephalitis or myelitis. The risk of birth defects following infection during pregnancy remains unknown. It is estimated that between 5 and 15% of infants born to mothers infected with the Zika virus during pregnancy show signs of complications related to the disease. In pregnant women, the infection can lead to severe fetal involvement even in the absence of maternal symptoms: microcephaly (small head size compared to normal), other congenital malformations of the infant, ocular abnormalities, hearing loss, but also loss of the fetus, stillbirth and premature birth.

Zika diagnosis

The diagnosis is based on the exposure context (stay or residence in an area where the virus is circulating, mosquito bites) and clinical manifestations. Confirmation is virological analysis by RT-PCR, which can be performed early in the blood, urine, or semen. Serology is difficult to interpret due to frequent cross-reactions with other flaviviruses. In pregnant women, a specific clinical, biological and ultrasound monitoring protocol is recommended.

Treatment for the Zika virus

There is no specific antiviral treatment against the Zika virus. Treatment is symptomaticTreatment relies on rest, hydration, and pain relievers (paracetamol). Non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin should be avoided as long as... Dengue fever has not been ruled out., due to the risk of bleeding.

Zika virus prevention

Currently there is no vaccine available against the Zika virus. Prevention relies on the mosquito control and personal protection (repellents, protective clothing, mosquito nets, air conditioning). Prevention of sexual transmission is essential, especially after a stay in a high-risk area. For pregnant women or those planning a pregnancy, risk assessment and travel recommendations are paramount.