Zika Virus

Zika virus disease is an infection caused by the Zika virus, which is primarily spread through the bite of an infected Aedes species mosquito. These mosquitoes are most active during the daytime. Zika virus was first identified in Africa but has since spread to many parts of the world, including tropical and subtropical regions.

Most people infected with Zika virus have mild illness or no symptoms at all. However, the infection is of particular concern during pregnancy because it can cause serious birth defects. There is no specific antiviral treatment for Zika virus infection. Care focuses on relieving symptoms, and prevention mainly involves avoiding mosquito bites and controlling mosquito populations.

Symptoms

Many people infected with Zika virus do not develop symptoms. When symptoms do occur, they usually begin within a few days to a week after being bitten by an infected mosquito and are generally mild.

Common symptoms include:

• Mild fever

• Skin rash

• Joint pain, especially in the hands and feet

• Red eyes, known as conjunctivitis

Other possible symptoms include:

• Muscle pain

• Headache

• Pain behind the eyes

• Fatigue

Symptoms usually last several days to a week. Severe illness and hospitalization due to Zika virus are uncommon.

Causes

Zika virus infection is caused by the Zika virus, which belongs to the flavivirus family. The virus is mainly transmitted to humans through the bite of infected Aedes mosquitoes.

Other ways the virus can spread include:

• From a pregnant person to the unborn baby

• Through sexual contact with an infected person

• Through blood transfusion, in rare cases

Once the virus enters the body, it multiplies and spreads through the bloodstream, triggering an immune response that leads to symptoms in some people.

Risk factors

Anyone who lives in or travels to areas where Zika virus is present can be infected.

Risk factors include:

• Living in or traveling to regions with active Zika virus transmission

• Exposure to mosquitoes that carry the virus

• Having unprotected sex with someone infected with Zika virus

• Pregnancy, due to the risk to the developing fetus

People who have previously been infected with Zika virus are likely to have immunity against future infections.

Complications

Most people recover fully from Zika virus infection without complications. However, serious complications can occur in certain situations.

Possible complications include:

• Birth defects when infection occurs during pregnancy, including microcephaly and other brain abnormalities

• Guillain-Barré syndrome, a rare condition in which the immune system attacks the nerves, causing muscle weakness and, in severe cases, paralysis

• Eye problems and developmental delays in infants born to infected mothers

The risk of complications highlights the importance of prevention, especially for pregnant individuals.

Prevention

There is currently no vaccine to prevent Zika virus infection. Prevention focuses on reducing exposure to mosquitoes and preventing other routes of transmission.

Preventive measures include:

• Using insect repellents approved for skin use

• Wearing long-sleeved shirts and long pants

• Keeping windows and doors closed or using screens

• Eliminating standing water where mosquitoes can breed

• Practicing safe sex, especially after travel to areas with Zika virus

• Avoiding travel to areas with active Zika outbreaks during pregnancy

Public health efforts to control mosquito populations play a key role in reducing the spread of Zika virus.