All You Need to Know about Zika Virus

Jessica Lewis
August 17, 2017

Origins of the Zika Virus: Where did it come from?

Zika virus got its name after the Zika Forest[1] in Uganda. This virus was discovered in 1947. Many cases of people infected with Zika virus were discovered in 1952. The areas affected by this virus are the Pacific Islands, Southeast Asia and tropical forests of Africa.

The virus can circulate in humans, mosquitoes, and animals. In 2007, a case of Zika virus appeared in areas where this virus was unknown before: in the Federated States of Micronesia (Yap Island). Besides his area, Zika virus was reported in 2013 in French Polynesia.

Even on the Easter Island (an island belonging to Chile) have been reported outbreaks of Zika virus. In 2015, Brazil was confirming the existence of cases of people infected with Zika virus. That is why in 2016, the World Health Organization made a declaration about the dangers of this virus. This is how Zika virus became a Public Health Emergency of International Concern.[2]

Symptoms of Zika Virus Infection

It is interesting that a lot of people infected with this virus do not manifest any symptoms. When symptoms do appear, people are usually sick from two to seven days. The signs that you may be infected with Zika virus can include:

  • myalgia
  • lower back pain
  • itching
  • arthritis
  • rash
  • conjunctivitis (red eyes)
  • retro-orbital pain
  • fever
  • headache

These symptoms are similar to those of chikungunya virus and dengue. They all are viruses spread in the same areas. It is necessary to make a lab test to determine the right diagnosis.

If you visited areas suspected to be infected with Zika virus, it is recommended to visit your doctor and to explain the symptoms you have and to give detailed information about the places you visited.

A simple urine or blood test can reveal if you are or not infected with Zika virus.

At this moment, no medicine or vaccine is available to cure Zika virus.

What you can do, is to take care of you by treating the symptoms:

  • Take time to rest.
  • Make sure you drink a lot of water.
  • Take some paracetamol for fever and pain.
  • It is wise to avoid taking aspirin until you know for sure you are not infected with dengue because you might put yourself at risk of bleeding.
  • If you are taking other medicine for other health problems, consult your doctor before taking any other pills.

If you know for sure you have been infected with Zika, make sure you avoid mosquito bites the next weeks by wearing long sleeve clothes, frequently applying insect repellent and using special screens or mosquito nets:

  • During the first days of infection, Zika virus is present in the blood of the infected person and can be transmitted from that person to a mosquito.
  • The infected mosquito can then spread the virus to healthy people causing the occurrence of an epidemic.

When a person gets infected with Zika virus, usually doesn’t go to a hospital as the symptoms are not visible enough. Sometimes, people don’t even know that they were infected with this virus. It is very uncommon for people to die of Zika. What is dangerous though is to get infected while pregnant. The infection can cause severe birth problems. Microcephaly and other brain damages in infants are very common when the mother is infected with Zika. Guillain-Barre is a disorder that appears because of the infection with Zika virus.

The World Health Organization made recommendations to prevent the spreading of Zika virus: close surveillance of Zika virus in the affected countries, strict measures for people who are traveling and for pregnant women.

How is Zika Transmitted?

Responsible for the transmission of this virus is the infected female Aedes mosquito, known as Aedes aegypti. Other species of Aedes mosquito might be able to spread the virus as well. After the infected mosquito bites a healthy person, in three to twelve days this person can manifest the first symptoms.


People can be infected with Zika virus through mosquito bites, through unprotected sexual contact and can also be transmitted from mother to baby.

Advice for People Traveling in Zika Affected Areas

As we said before, no vaccine is available to cure or prevent Zika virus infection.

Aedes mosquitoes are the one responsible for the transmission of this virus, along with dengue, chikungunya, and yellow fever. These mosquitoes usually bite during the morning or in the afternoon, before dusk (they are different than mosquitoes that spread malaria, the second ones usually bite during the night).

If you decide to travel in one of the regions at risk, you should seek travel health advice before departing from a hospital or specialized clinic.

How to Prevent Infection by Mosquito Bites?

It is recommended to take mosquito bite avoidance measures if you travel in countries exposed to the infection with Zika virus. It is recommended to keep safe from mosquito bite during the day and night. As we said before, spray on your skin a good quality mosquito repellent (one that contains N-diethyl eta toluamide) and wear only long sleeve clothes.

Usually, Aedes aegypti mosquitoes live at altitudes of 2000 meters. If you know you are going to travel at these altitudes is safe to take the prevention measures against infection with Zika virus.

While you visit these areas, make sure the windows of the apartment where you are hosted have special mosquito screens and keep the air conditioner on if you plan to stay indoors during the day. It seems like a mosquito needs only a very small amount of water (the size of a bottle cap) to lay around 200 eggs. It is safe to avoid keeping any standing water in your room or apartment and keep all your dishes clean and wiped. Even if the water has dried out, the mosquito eggs can survive for months or a year inside of a vessel.

How to Prevent Infection by Sexual Transmission

Even if a small number of cases of sexual transmission of Zika virus has been discovered, it is still a possibility to get infected with Zika virus and you should be careful. In those cases, people were manifesting the Zika symptoms at the time they had the sexual contact. There is a case of a man who traveled in a Zika affected area who transmitted the virus without actually having himself the usual Zika symptoms. In most of the cases, men were those who infected their female partners. No cases of sexual transmission from female to their male partners were reported.

It seems like Zika virus can be present in semen, but they didn’t discover so far how long the virus persists. Even if the risk of being infected with Zika virus through sexual contact is low, a lot of cases are reported, and the number is growing.

When visiting an area affected by Zika virus is recommended the use of a condom during sexual intercourse (vaginal, oral or anal).

If the person who traveled in a Zika affected area manifest the symptoms is recommended to use condoms for the next six months. For a man who traveled in such an area, but doesn’t have any of the Zika symptoms, is safe to use the condom for the next eight weeks after the return.

What to do if Pregnant and Traveling in Areas Affected by Zika Virus?

If you are pregnant, and you are planning to travel in countries at risk, is essential to discuss your travel plans with your doctor to prevent the possibility of infection with Zika virus.

  • It is recommended that pregnant women should travel to areas with active Zika transmission until after the baby is born
  • when the travel to a zone affected by Zika virus cannot be avoided, the pregnant woman must be informed by the doctor of the risks of being infected with Zika virus
  • the pregnant traveler should be notified about the prevention measures against the mosquito bite
  • if a woman is pregnant, is recommended that the male partner to use condom during sexual intercourses; this way they reduce the risk of transmission of Zika virus during travel and for the duration of the pregnancy (use the condom even if you don’t manifest the Zika symptoms)

What to do if Planning to get Pregnant and Travelling in an Affected Area by Zika Virus?

Even if you are not pregnant yet, but you consider pregnancy, you should talk to your doctor if you plan to travel in a Zika affected country.

  • All women traveling in countries at risk should be informed by Zika virus infection in pregnancy; doctors say that it is better to avoid becoming pregnant while traveling in an area affected by Zika virus, and for up to 8 weeks after the return. After eight weeks, it is safe to become pregnant
  • The woman who plans to become pregnant should be informed about the prevention measures against the mosquito bite
  • If a woman planning to become pregnant develops symptoms compatible with Zika virus infection on her return home, she should see the doctor immediately. It is recommended that she avoids pregnancy for at least eight weeks after the recovery
  • When visiting a Zika affected area, the female travelers and their male partners should use contraceptive pills and a condom as well during sexual intercourse, to reduce the risk of Zika transmission. Take these precautions during travel and:
    • for eight weeks after the return from a Zika affected area if the partners do not have any symptoms compatible with Zika virus infection
    • for six months after the first Zika symptoms manifest[3]

Important information about Zika and Pregnancy

What doctors know about Zika and pregnancy:

  • Any pregnant woman exposed to Zika virus can get infected.
    • Through the bite of an infected mosquito, any pregnant women can get infected with Zika virus
    • Zika virus spreads through unprotected sexual contact by a man to his pregnant partner.
  • It is sure that a pregnant woman can pass Zika virus to the fetus.
    • Zika virus is transmitted from a pregnant woman to her baby during pregnancy or at delivery time.

What doctors don’t know about Zika and pregnancy

  • When pregnant woman is exposed
    • They don’t know how high the risk for her to get Zika virus is.
  • When a pregnant woman is infected
    • They don’t know how this virus will affect the mother and the infant.
    • They don’t know how high the risk is that Zika virus to pass to the fetus.
    • They don’t know if the baby infected during pregnancy will develop birth defects.
    • They don’t know when during the evolution of the pregnancy this infection might damage the baby’s brain.
    • They don’t know whether the infant will be born with birth defects.
    • They don’t know if sexual transmission of Zika virus can develop birth defects in infants different than mosquito-borne transmission.

Brazil has experienced a series of outbreaks of Zika virus since 2015. Recently, Brazilian government reported a large number of children born with microcephaly.

After this alarming number of cases of babies born with microcephaly, scientists across the world began studying the Zika virus during pregnancy and the severe effects on children. Many studies concluded that there is enough evidence that shows that Zika virus infection in pregnant women is causing microcephaly and other serious fetal brain damages in infants and has been associated with different other problems, including hearing loss, eye defects, and low immune system.

Other causes of microcephaly

Microcephaly can occur because of:

  • Accurate and unusual changes in the genes of the baby
  • Unexpected infections in the mother’s body
  • Handling or being exposed to different toxins during pregnancy

Recent articles have suggested that a pesticide called pyriproxyfen can cause microcephaly in infants. This pesticide has been approved by the World Health Organization. Pyriproxyfen has been used a lot in Brazil and other countries without health consequences in humans.

Besides microcephaly, other health issues have been detected among infants infected with Zika virus before birth, such as reduced hearing, eye defects, and impaired growth. Although Zika virus is a cause of microcephaly and other severe fetal brain defects in infants, there is more to study about the effects that this virus has on pregnant women and their babies.

Based on the cases known so far, doctors believe that Zika virus infection in a woman who is not pregnant will not grow the risk for microcephaly in future pregnancies after the blood of the woman is cleared of the Zika virus. From what scientists observed so far, it seems like after a person has been infected with Zika virus, this person is likely to be protected if another Zika infection occurs.[4][5][6]

It is shocking, but Zika virus can even paralyze adults.

Doctors say up to 80% of people infected with Zika virus don’t have any usual symptoms, while up to 20% of them manifest only a few symptoms, mostly mild ones like a rash, fever, and pain in the body.

However, this virus has also been associated with an autoimmune disorder called Guillain-Barre. This disorder can cause temporary paralysis. In some cases, Zika virus caused meningoencephalitis.

Nine countries announced the increasing number of Guillain-Barre cases in people infected with Zika virus. In Brazil, things are worse, because at every 100.000 people two individuals are affected by Guillain-Barre disorder. When the country experienced the Zika outbreak, they registered even 7 cases per 100.000 people.

It is important to learn all the necessary prevention measures when it comes to Zika virus because Guillain-Barre and meningoencephalitis are very severe brain complications.

The Impact of Zika Virus on the US

In the continental US, there have been no cases of infection with Zika virus. Doctors are worried that the virus might be already entered the country, and people are not aware of it.


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That is why it is so important to pay attention to all unusual symptoms you might have that are similar to those of Zika virus.[7]

Is it safe to travel to Rio (Brazil)?

Brazil reported so far up to 1.000 cases of microcephaly. So, we can understand if you are wondering if you should or not attend the 2016 Summer Olympics and Paralympics in Rio de Janeiro. There will be 15.000 athletes from 200 countries, and the city will be occupied by more than 800,000 international visitors. Some of the athletes have talked about their worries, and a member of the US women’s soccer team said that she plans to have a family, and she doesn’t like to take any risks.

Probably the safest place you can be during the games is in front of your TV at home. But, if you do want to go there, make sure you take all the prevention measures against Zika virus infection.

What does the Government do to Prevent the Transmission of Zika Virus in the US?

It seems like Houston have a very sophisticated system that controls the population of mosquito. New York City, for example, controls a type of mosquito that spreads West Nile virus, but it has no prevention measures against the kind that spreads Zika virus. The city doesn’t have populations of Aedes aegypti mosquitoes, but it does have Aedes albopictus, which can also be responsible for spreading the disease. The city is investing 21 million dollars to control the population of mosquitoes and to research the cases of American travelers infected with Zika. North Carolina is in a delicate position because they eliminated in the last years the mosquito control programs and now, with the new risks of being infected with Zika virus, the officials have to start all over again.

The best thing you can do is to stay informed and to take all the necessary prevention measures against infection with Zika virus.[8]