What is Zika Virus?
The Zika virus is a type of RNA virus from the Flavivirus family and genus. It has two main types: Asian and African. For most people, getting infected with the Zika virus results in a mild illness that goes away on its own. These days, if someone gets infected with the Zika virus, it is required to be reported.
What Causes Zika Virus?
The Zika virus, which mainly causes diseases passed on by insects, is often spread through the bites of female Aedes aegypti and Aedes albopictus mosquitoes. However, it can also be transmitted through contact between people, such as through sexual contact, blood transfusion, organ transplants, and from a mother to her unborn child.
The Zika virus is related to several other insect-borne viruses known to cause diseases in humans. These include the Japanese encephalitis virus, tick-borne encephalitis virus, West Nile virus, dengue virus, and the yellow fever virus.
Risk Factors and Frequency for Zika Virus
The Zika virus was first discovered in Uganda in 1947, when scientists were studying another disease, yellow fever. The first known infection of a human was recorded in Nigeria in 1954. From then on, scientists found the virus to be widely spread throughout Africa and Asia. Up until 2014, Zika had not been spotted in the Americas.
There are no records of significant Zika outbreaks before 2007. However, in 2007, one such outbreak happened in Central Africa’s coastal region; this was after people started mistaking it for the dengue or chikungunya epidemics. Another outbreak occurred in Micronesia (in the western Pacific Ocean) in the same year. Outbreaks became more common in French Polynesia in 2013 and 2014, and they continued into 2015 to 2016, on other Pacific islands like New Caledonia, Easter Island, the Cook Islands, Samoa, and American Samoa.
The virus was reported in Brazil in late 2014 and early 2015, and it quickly spread to South and Central America. The first known case of Zika in the continental United States was reported in the week of July 24, 2016. Out of the Zika cases identified as of April 19, 2017, 223 cases were traced back to local mosquito bites and primarily occurred in Florida, while 76 cases were traced back to other methods of transmission. The breakdown of these 76 cases are as follows:
- 46 were transmitted sexually,
- 28 were congenital (passed from a mother to her baby during pregnancy), and
- two were transmitted through other unspecified means.
Signs and Symptoms of Zika Virus
Zika virus infection can be a possibility when a person has traveled recently to places where Zika virus transmission is suspected. This also includes those who have a sexual partner who has traveled to these areas. It’s not certain how long the virus can stay active in bodily fluids after getting infected. Yet, researchers have found Zika virus in semen for up to 90 days after the symptoms started. They have also detected its genetic material in blood up to 58 days and in semen for as long as 188 days.
Interestingly, a majority of patients infected with Zika virus (60 to 80%) show no symptoms or mild ones. Symptoms, when they appear, usually start two to 14 days after a mosquito carrying the virus bites a person. The common signs are:
- Rash (seen in more than 90% infections)
- Conjunctivitis or red eyes (55 to 82%)
- Fever (65 to 80%)
- Headache (45 to 80%)
- Joint pain (65 to 70%)
- Muscle pain (48 to 65%)
- Eye pain (39 to 48%)
Less common symptoms include swelling, vomiting, and stomach pain. Diagnosing Zika can be challenging in areas where diseases like dengue fever and chikungunya are prevalent as they share many similar symptoms. However, rash and red eyes are more commonly seen in Zika virus infections than with dengue or chikungunya.
During a Zika virus outbreak in French Polynesia, there was a rise in cases of Guillain-Barre syndrome, which is a sudden muscle weakness caused by nerve damage. It’s suspected that Zika virus infection is a likely trigger for this syndrome. Cases of acute myelitis, an inflammation of the spinal cord, and meningoencephalitis, an inflammation of the brain and its surrounding membranes, have been reported after Zika virus infection too. Therefore, a full neurological exam is suggested when Zika virus is suspected.
Zika virus during pregnancy can cause various birth defects, including an abnormally small head and brain issues. So, women in their childbearing age living in areas with a probable Zika virus threat should keep their doctors informed about their pregnancy status and future pregnancy plans.
Testing for Zika Virus
Testing for the Zika virus depends on several factors, including the person’s likelihood of exposure to the virus, their symptoms, and whether they’re pregnant. Many times, regular lab tests don’t show any significant changes, although there may occasionally be minor changes, such as a slight decrease in white blood cells, blood platelets, and an increase in liver enzymes.
The U.S. Centers for Disease Control and Prevention (CDC) has made the following recommendations regarding Zika testing as of April 25, 2017:
- People who have been exposed to Zika (by living in or visiting an area with Zika, or having unprotected sex with someone who has) and displaying symptoms of infection should be tested.
- Women who are pregnant and have been exposed to the virus should also be tested.
- If an ultrasound shows potential signs of Zika infection in a fetus, the pregnant woman should be tested.
- For women exposed to the Zika virus, Zika testing should be included as a standard part of prenatal care, at the first prenatal visit and during the second trimester.
Which specific test to use to identify a Zika infection depends on how long the person has been displaying symptoms (less than or more than 14 days) and whether they’re pregnant. The detection of the Zika virus involves a PCR test and an antibody test.
Treatment Options for Zika Virus
Most people who have the Zika virus don’t show any symptoms or only have mild symptoms. The treatment involves getting plenty of rest, staying hydrated, and using pain relievers and fever reducers. If there’s a chance that the person’s symptoms could be due to dengue fever, they should avoid aspirin and other types of non-steroidal anti-inflammatory drugs because these could potentially increase the risk of bleeding and a condition called Reye syndrome. To reduce the risk of spreading the Zika virus in the local area, it’s important to protect infected individuals from mosquito bites.
What else can Zika Virus be?
Dengue, Chikungunya virus, Malaria, and Yellow Fever are all serious diseases that can greatly impact your health. Here’s a simple explanation of each:
- Dengue: This is an illness caused by a virus and is usually spread through mosquito bites. Symptoms often include high fever, severe headaches, and muscle and joint pain.
- Chikungunya virus: Also a virus spread by mosquitoes, it can cause intense joint pain, fever, and might lead to serious complications.
- Malaria: This serious disease is also transmitted via mosquito bites. The main symptoms usually include fever, chills, and flu-like illness.
- Yellow Fever: Transmitted through mosquito bites, it can cause fever, aches, and nausea and can be critical in severe cases.
It’s essential to take necessary precautions to avoid these diseases, especially if you live in or are traveling to high-risk areas.
What to expect with Zika Virus
Most people who get infected with the Zika virus experience mild symptoms and get better on their own. However, in some cases, the virus can lead to serious nerve diseases like Guillain-Barre syndrome. There’s also a significant worry that if a pregnant woman becomes infected with the Zika virus, it could cause brain and eye abnormalities in the baby.
Preventing Zika Virus
The best way to prevent infection is by taking preventative measures. These measures include using bug repellants, dressing appropriately in long-sleeved shirts and pants, and eradicating mosquito breeding grounds, such as stagnant water in tires or birdbaths. It’s also beneficial to prevent mosquitos from entering homes by using screens. If one has recently visited an area known for Zika virus, it is recommended to avoid mosquito bites for several weeks to avoid spreading the virus locally.
