Zika Virus Testing. How Ordering Online Helps?

What is the Zika virus?

There were a lot of discussions about Zika virus and its testing. The Centers For Disease Control Prevention (CDC) is still researching the issue. However, there are no much details about Zika virus testing at the moment. And so - no much details about the difference in lab tests designed to detect it.

There is no answer on what are the chances of getting Zika even if you visited areas with the highest risk of exposure.

Zika is a part of the Flaviviridae family of viruses that also includes chikungunya, dengue, yellow fever, and West Nile.

Zika virus symptoms are mostly mild, but Zika is in the focus of media because of its effect on the fetus. The virus can cause microcephaly, a neurological disorder in babies when their heads are far smaller than normal. In some cases, developmental issues can cause death.

For this article, we reviewed a lot of available material from the Centers for Disease Control and Prevention (CDC), National Institutes of Health (NIH) and articles about Zika virus and Zika testing from healthcare professionals.

We made about 50 phone calls to clinics in one state with the highest risk of Zika in the US (according to CDC’s map ^[1]) to check how long does it take to make an appointment for patients with possible Zika. We checked if it’s a good idea to get testing for Zika virus done before the visit.

Additionally, we analyzed prices for Direct Access Testing (DAT) from 11 online lab stores via www.findlabtest.com. For your convenience, you can use this service as well to find and order lab test online. The knowledge of Zika and tests lead to better medical decisions. It also saves time and money.

This article covers the influence of the virus on different groups of people and the list of lab tests for Zika available now. Zika virus testing description allows to understand the process from lab test order to result receiving. So, you can get an additional knowledge and discuss your tests with a doctor.

Zika virus symptoms and risk groups

Symptoms of Zika can last up to a week. Some people ignore an infection since symptoms are mild or absent. Among symptoms of the Zika virus are:

• rash
• headache
• red eyes
• muscle pain
• joint pain
• fever

These symptoms are common for a high number of diseases. It makes it possible to confuse them with something more benign than Zika. That is another reason why it can be dangerous.

Despite this fact, most of the people do not have any reaction to Zika virus. In case if they had Zika and confirmed it, they can only treat symptoms, because there is no vaccine from Zika yet. The highest-risk group for Zika is pregnant women. This is the reason, why CDC’s diagnosis and testing guidance ^[2] for men, non-pregnant women and children are not that detailed and consistent with their guidance for pregnant women.

Men and non-pregnant women should have protected sex next six months ^[3] after possible Zika exposure or symptoms in case if they wish to have a child. If these groups of people wish to test for Zika, they need to know an approximate time of exposure, since it affects what tests should be performed to detect the virus.

During the pregnancy, Zika can cause birth defects to a fetus. The most complicated birth defect from Zika is microcephaly ^[4]. It means that the head of a fetus is smaller than normal.

According to Vital Signs report from the CDC, 1,300 pregnant women with possible Zika virus exposure were reported U.S. Zika Pregnancy Registry. Out of 1,000 of pregnancies from women with possible exposure of Zika that were completed by the end of 2016, 50 pregnancies had birth defects ^[5] caused by the virus.

About 15% of babies with Zika-related birth defects were born from women who confirmed infections in the first trimester of the pregnancy.

Earlier lab testing gives more time and possibilities for a pregnant woman to make mother’s decision if signs of Zika are found.

Nevertheless, preventive care for Zika is the best option until the anti-Zika vaccine is developed. To prevent yourself from getting or spreading Zika, please use insect repellents with one of following active substances: IR3535, oil of lemon eucalyptus, 2-undecanone, para-menthane-diol, DEET or picaridin.

It’s important to wear long pants and long-sleeved shirts and stay indoors in areas with high risk of getting Zika.

To prevent Zika spreading through sexual contact, use condoms for at least 8 weeks after symptoms started. In case of pregnancy, use them throughout the entire pregnancy.

Can you test for Zika? Zika virus testing process and providers

Unlike other tests that can be ordered at lab stores online, Zika testing cannot be performed without doctor’s decision and confirmation of its necessity.

Patients have not more than 12 weeks for testing (with antibody test) after possible exposure or symptoms onset.

Out of these 12 weeks, you can spend up to 3 weeks to get a doctor appointment (according to information we got through phone calls) and again for 3 more weeks for another appointment and test results.

According to recommendations for doctors, pregnant women with possible Zika exposure have high priority ^[6] for testing and other groups of people can face difficulty in getting their lab test done. Especially, if there have no symptoms related to Zika.

However, if you are planning to have a baby or simply wish to double-check if you have the virus, DAT may be the option for you.

To determine if you need Zika virus testing you need to consult your healthcare provider and answer the questions about recent travel or Zika related symptoms. Women also need to tell if they are pregnant or planning to become pregnant.

Men and non-pregnant women can visit primary-care provider (internist, family practice doctor, nurse practitioner) to get the consultation. In case if an appointment is not possible at the nearest time and symptoms occurred, patients may go to an urgent care facility or emergency room.

Pregnant women and those, who wish to become pregnant, should consult an obstetrical specialist ^[7] regarding their concerns.

A pediatric specialist can accept and treat babies born with Zika-related issues

If you have any concerns about possible Zika exposure, tell it to your doctor. Your provider will ask you about recent travel or Zika-related symptoms if you are planning to become a parent. All this information is needed to determine if you need testing for Zika virus.

The whole lab testing takes about 2-4 weeks ^[8]. It depends on laboratory’s workload, processing and reporting time. In summer, reporting time is the longest because of other diseases spread by mosquitoes.

Zika virus tests

Testing for Zika virus is quite complicated and requires three tests to be sure if the result is accurate and positive. With the guidance for each category of people, healthcare professional may order any number of tests, depending on test results, symptoms and person who gets tests for Zika. Nevertheless, there is a specific sequence in that all tests will be ordered for the best result.

The first test is designed to detect the virus itself. It can be performed on blood and urine specimens and find viral RNA (genetic material) in them. Time for a blood test is less than a week after exposure or onset of symptoms. Test on the urine specimen can be done not later than 3 weeks after exposure. The full name of this test is Zika Virus RNA, Qualitative, Real-Time RT-PCR.

The second test is an antibody test and detects antibodies that patient’s body produces to fight the virus. It is called Zika Virus Antibody (IgM), MAC-ELISA test or serology test for antibodies. Unlike the RNA test, this test can be useful up to 3 months after the exposure. However, it can be false-positive because of another virus from the same group of viruses (dengue or chikungunya).

That is why the third test will be performed to rule out any virus, except Zika and to confirm the exposure in case if results of previous two tests are not enough. It is called plaque reduction neutralization test (PRNT). This is the most complicated test and can be performed only by a limited number of health department labs and the CDC itself.

All the tests for Zika are highly accurate, and RT-PCR test has 100% sensitivity and specificity when performed in the correct time ^[9] since test accuracy also depends on a number of virus RNA copies or antibodies in the specimen. Here is the information about lab tests that can be ordered by your healthcare provider:

Molecular Zika virus lab tests

Used to check if a person with symptoms has the infection. Usually, after visiting a region with Zika virus. Or transmitted by sexual contact with someone who visited those areas.

Zika Virus RNA, Qualitative, Real-Time RT-PCR

This Zika Virus test detects viral RNA in patient's blood. It is not likely to detect virus after seven days of symptoms onset. A patient needs to do the test less than a week after one of the symptoms appeared.

When to order: less than seven days after onset of symptoms. The list of Zika signs includes rash, red eyes, headache, muscle pain, fever, joint pain. After visiting area where Zika virus regularly found. After sexual contact with someone who traveled there.

Preparation: None

Price: $715 - $1,238

Additional notes: all following statements imply possible exposure. Pregnant women with symptoms must do an antibody test. For pregnant women without symptoms: use the test three times during pregnancy. Use for pregnant women with recent possible exposure and no Zika signs. Better to use serum/urine test in case if the fetus has Zika signs. In addition, the antibody test should be ordered.

Zika Virus RNA, Qualitative, Real-Time RT-PCR Panel, Serum/Urine

This type of Zika virus testing is like the previous one but also includes a urine sample. A urine specimen can be used to detect Zika during the first three weeks. The СDС said the urine sample is better. After a week after symptoms onset, it recommends to test both samples. This test is not currently available for online ordering. It should be requested by your doctor. To order this test, please visit your doctor first.

When to order: less than seven days after onset of symptoms (blood sample). 2 days - 2-3 weeks after onset of symptoms (urine sample)

Preparation: None

Price: $1,000 - $1,500

Additional notes:all following statements imply possible exposure. Preferred for pregnant women with a fetus with Zika. Antibody testing should be performed concurrently. Pregnant women with symptoms can use it along with antibody test. Women without symptoms should do this test three times during pregnancy. If the result is negative, an antibody test is a must. It's stated by the CDC and needs for diagnosis.

Antibody lab test for Zika virus

Zika Virus Antibody (IgM), MAC-ELISA

Detects antibodies produced by the immune system after exposure. Zika virus antibodies stay in patient's body up to 12 weeks. It let this test to detect them during a longer period. This test is the only option when molecular tests become useless.

An antibody test is commonly cheaper than molecular tests. This test is not available for online ordering at the moment. It should be requested by your doctor. To order this test, please visit your doctor first.

When to order: 4-5 days – 12 weeks after Zika illness start

Preparation: None

Price: ~$400

Additional notes:wrong test time leads to a false-negative result. Dengue or chikungunya viruses can cause a false-positive result. The CDC requires PRNT In case of positive result. PRNT is an additional bloodwork that confirms Zika antibodies presence.

Zika virus testing summary table

Taking in consideration the summary table, it will be a good idea to make a RT-PCR test on both samples and Zika antibody testing using online direct access testing online stores if it’s less than 2-3 weeks after possible exposure. In this case, you will pay out of pocket for all tests, but you will save your time on doctor visits. It’s very important, since RNA Zika virus testing can detect Zika within 3 weeks after exposure, and patients may wait about the same period for their doctor appointment (according to our phone calls).

In case if you wish to check if you ever have had Zika but missed it because of symptoms absence, order only antibody test. This test alone is cheaper than all the tests available online. It will show if you have or have no antibodies in your blood.

A negative result means that you were not exposed to any of Flaviviridae family of viruses, including Zika. But if the results will be non-negative, please visit your doctor as you may have recent exposure to Zika or other similar virus.

How long does zika stay in your body?

According to the CDC, women who have traveled to the place with a CDC Zika travel notice or red area where Zika is mostly spread should wait at least 8 weeks after travel or onset of symptoms before trying to conceive with their partner.

Men should wait and have protected sex during at least six months period. A waiting period for men is much longer than women’s waiting period because Zika stays in semen longer than in blood or urine.

Scientists think that it’s unlikely ^[13] that person can get sick with Zika once again in the future. After the immune system fights back the infection, it produces antibodies that prevent Zika exposure.

Testing for Zika virus main points

There is no Zika virus vaccine yet. As the disease itself may cause no acute health conditions, lab tests for Zika don’t seem to be useful for the majority of people. However, they are important for pregnant women, or men and women who wish to have a baby. It is because of Zika fever is dangerous for the fetus.

Doctors will not send every their patient to be tested without signs of Zika and possibility of exposure since testing for this particular virus is very complex.

Knowing in advance what questions are important for healthcare providers and how testing is performed, makes it easier to plan the entire testing process and getting the most accurate results.