What is Zika (virus): see the symptoms and how to prevent


What is Zika?

Zika, also called Zika fever , is a disease transmitted by the bite of the Aedes aegypti mosquito contaminated with the Zika virus.

Discovered in 1947 in the Zika forest in Uganda, the disease did not cause much concern since the infection is often asymptomatic, and when symptoms appear, they last only a few days, with no serious consequences.

However, the virus gained notoriety in Brazil when an epidemic of Zika fever affected the northeast of the country. It turned out that when pregnant women are contaminated by the disease, it is possible that there is contamination of the fetus, since the virus is able to cross the barrier formed by the placenta.

When the agent infects the baby, it can cause severe problems in fetal development, including the famous microcephaly.


Zika fever is caused by the Zika virus , an arbovirus, which means that it is transmitted by insects, specifically mosquitoes of the Aedes genus , such as Aedes aegypti , the same transmitter of dengue and chikungunya fever .

The virus is not particularly dangerous for humans already born.


The transmission of Zika fever occurs through the bite of mosquitoes Aedes aegypti and Aede s albopictus , which are vectors of the virus.

Only mosquito females need blood, so only they bite humans. If the female mosquito is infected and bites a person, it contaminates the area under the skin with the Zika Virus, which starts to multiply in the body.

In regions with many mosquitoes (even if not infected), it is easy for the disease to spread, as the virus is able to multiply in the body of a human enough that other mosquitoes that bite it become contaminated too, restarting the cycle.

Usually the Aedes have daytime habits, being more frequent in the early morning and late afternoon, so it is at these times that most infections occur.

It is possible that the Zika Virus is also transmitted by blood transfusions and sexual contact while the symptoms persist, which can last for approximately a week. When there are no symptoms, which is often, the disease can still be transmitted in this way and, likewise, the transmission lasts up to a week.

Groups and risk factors

At risk are those who live or travel to regions where the Aedes mosquito exists with the disease.

The website of the Center for Disease Control and Prevention (CDC) has a list of countries where the Zika virus can be found , and Brazil is among them.

It is recommended that pregnant women do not travel here. And if you live here in Brazil, the regions with the highest risk of contamination are in the northeast of the country, but all states have a record of Zika cases, so be safe from bites, no matter where you live.

It is especially necessary to take precautions during the summer. This season, especially in February, is when there are more mosquitoes.

Places where there is an accumulation of standing water can also be a risk factor as the mosquito needs water to reproduce.


The disease is often asymptomatic. Only 20% of patients have symptoms while the other 80% do not even realize they are infected, as symptoms, when they appear, are not usually strong. In general, they are as follows:


Zika fever gets its name because one of its most characteristic symptoms is a fever, a sign that the body is fighting the virus. However, Zika-related fever is low, rarely exceeding 37.5º C.

Red eyes

Another symptom known to be related to Zika fever is redness in the eyes. This redness, which accompanies swelling, does not have itching, burning or secretions, which differentiates it from a classic conjunctivitis .

Red spots

Red spots can appear on the skin of the patient infected by the Zika virus, in a similar way to those who are infected with dengue. Skin irritation is also common.

Other symptoms

In addition to these, some other symptoms may be present if the disease is symptomatic. Are they:

  • Chills;
  • Loss of appetite;
  • Sweat;
  • Joint and muscle pain;
  • Headache;
  • Vomiting;
  • Fatigue (tiredness).

Zika in pregnancy

Zika in pregnancy is one of the main medical concerns, because the virus, although less dangerous for people already born, manages to penetrate the placenta and infect the baby that is still developing.

Thus, the virus can cause problems in the child, who can be born with malformations that can accompany him throughout his life.

The risk is greater when the pregnant woman contracts the virus in early pregnancy. This is because in the first trimester of pregnancy the placenta allows the virus to pass through it more easily, while in more advanced stages of pregnancy it is more resistant and the chances of the virus getting through are less.

Among the malformations resulting from the Zika virus is microcephaly, which causes the fetus’ brain to have no space to grow and become small, causing several problems such as intellectual difficulties, developmental delays and motor problems.

How is the diagnosis made?

Some tests can be done to identify the Zika virus in the human body. The doctors best able to make the diagnosis are the infectologist and the general practitioner, and the ways to make it are:

Clinical diagnosis

Based on the symptoms and the region where the patient lives, the doctor can point out the possibility of Zika fever. However, the clinical diagnosis needs to be confirmed and tests can be ordered.

ELISA serological test

The serological test analyzes the blood serum , which is the liquid part of it without the red series (red blood cells and platelets). The test is done with a common blood collection and seeks to find out if the patient has the virus by looking for specific immunoglobulins for the Zika virus.

Immunoglobulins can be divided into Immunoglobulin M (IgM) and Immunoglobulin G (IgG). They are glycoproteins used in the body’s defense mechanism, having the function of antibodies. The immune system produces specific versions for the type of infectious agent the first time it encounters it.

IgM are produced during an infection (acute phase) and contain specific antibodies, serving as markers of the disease. On the other hand, IgGs serve as a kind of memory of the infection, so they act in the protection of the organism so that the body knows what to do if that same pathogen appears again.

The ELISA test uses materials that react with immunoglobulins to identify them in blood serum.

When the body has immunoglobulins G for the Zika Virus, but does not have the M, it means that the body has already had contact with the virus, but is cured and immune. However, when IgM is found in conjunction with IgG, the body is being affected by the virus and the diagnosis is made.

Exame RT-PCR

This test can identify the DNA of viruses transmitted by Aedes mosquitoes and is carried out with the patient’s blood collection. However, for the differentiation of Zika, dengue and chikungunya, specific tests for each one must be done.

Kit Nat

The Nat Kit is an examination kit capable of identifying and differentiating infections by the dengue, chikungunya and Zika virus.

The test identifies the agents’ DNA through a small blood sample and can differentiate them without the need for three different tests. The test is quick and, on average, takes 3 hours to produce results.

Is there a cure?

-Yeah . Usually Zika fever cures within a week, after the immune system has dealt with the contamination alone. The Zika virus is not able to do much damage to the human body and is eliminated by the immune system.

What is the treatment?

There is no specific treatment for curing Zika. Treatment is drug-based, aimed at relieving symptoms. As the disease usually cures on its own due to the immune system, the medications are intended to relieve symptoms when they are present.

In addition, rest and hydration are very important to ensure a quick and smooth recovery.


The use of acetylsalicylic acid or anti-inflammatory drugs is not recommended for the treatment of Zika fever, as these drugs increase the risk of hemorrhagic conditions caused by other infections close to Zika, such as dengue.

Medicines that can be used to treat symptoms such as fever and Zika fever pain are:

  • Paracetamol;
  • Sodium Dipyrone ;
  • Promethazine Hydrochloride ( Fenergan ).


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.


In most cases, a full recovery can be expected. Many people do not even know they have contracted the disease and can heal quickly. If you are not pregnant, there is probably no risk to your health if you get the virus.

However, if the diagnosis is confirmed, you should avoid being bitten by mosquitoes to prevent the disease from spreading further.


The prognosis for pregnant women is similar to that of the general population, which means that it tends to heal without major complications, however it is important to remember that there is a risk of problems for the fetus.

Pregnancy, in the case of infection, must be closely monitored by an obstetrician, who will identify possible fetal problems.


The complications of the Zika Virus are few. The disease does not always cause symptoms and is easy to fight, but there are risks in it. Are they:

Microcephaly for fetuses

The most serious complication of Zika virus infection occurs with the babies of women who are infected when pregnant. While the virus causes few problems for people born, babies who are not yet born can suffer severely from the infection, which is able to cross the placenta.

Inside, it can alter the child’s development, causing the skull bones (the softener) to close before the time, considerably reducing the space that exists for the growth of the brain and the child is born with microcephaly.

The condition causes intellectual, neurological problems, developmental delays and motor difficulties, in addition to dwarfism and other consequences of a reduced brain.

Guillain-Barré syndrome

There is evidence that Zika fever can rarely cause Guillain-Barré syndrome, an autoimmune disease that attacks the peripheral nervous system. This disease causes muscle weakness that develops suddenly.

In approximately 15% of cases, it can be life-threatening by weakening respiratory or cardiac muscles. In that case, mechanical breathing may be necessary.

Guillain-Barré Syndrome has no cure and it is possible that it returns from time to time, but the acute phase – when the muscles are weakened – resolves in a few months.

It is a rare disease, even considering all the risk factors, so it is hardly a major concern when contracting Zika fever.

Congenital Zika virus syndrome

Congenital Zika virus syndrome is any complication caused by the baby Zika virus during pregnancy, including microcephaly, but not just microcephaly.

There are cases of malformation of the head, convulsions , irritability, involuntary movements and other dysfunctions. It is also possible for the baby to be born with visual or hearing problems.

Spread the disease

In addition to the risks to your own health, if you are traveling and become infected, it may be that you take the virus home and mosquitoes in your area become infected through you, taking Zika fever to new regions.

How to prevent Zika?

The best way to prevent Zika is to avoid mosquito bites and proliferation. To do this, you can follow a few steps.

Do not leave standing water

Keeping standing water is a sure way to guarantee mosquitoes in your garden, as this is where they lay their eggs and reproduce. If there is no water, mosquitoes cannot be born and are eliminated.

Keep the garbage tightly closed

This ensures that water does not enter and accumulate in the trash, preventing standing water from getting trapped inside, allowing more viruses to be released into nature.

Put sand in pots of plant pots

The sand is used in the plant pots to absorb the water left over from irrigation. Thus, the liquid does not accumulate and remains in the pot, waiting for the mosquito.

Sleep with hammocks (mosquito net)

There are hammocks to put on the bed keeping insects away while you are sleeping. The Aedes is usually most active during dawn and dusk, but it is possible that pokes at night also.

Protection screens

It is possible to install screens on the windows to prevent mosquitoes from entering your home, protecting those inside.

Use your clothes to protect yourself

The use of long sleeves and pants reduces the area of ​​exposed skin that the mosquito can bite, decreasing the chances of the virus contracting.

Use repellents

Repellents prevent mosquitoes from approaching to bite you. This reduces the chances of you being infected as most Zika virus infections occur from mosquito bites.

Read more: Repellent for pregnant women, (icaridine, DEET), brands, which is the best?

Use condom

Although the mosquito is the main means of contamination, unprotected sex is also capable of transmitting Zika fever. For this reason, it is important to use a condom during sexual intercourse, especially in regions at risk or in outbreaks of the disease, as this can prevent you from contracting the disease.

Notify the city hall about breeding grounds

If you find a possible breeding ground for mosquitoes – such as standing water tires, open-air pots – on land that is not yours, you can let the city know. The complaint can be made both on the land of neighbors who do nothing in relation to mosquitoes, and on vacant land, whose owner does not appear.

In this case, the city hall of your city will be responsible for notifying the owner of the place or, in the case of the land belonging to the city hall, responsible for cleaning the place.

Differences between Zika, dengue chikungunya

Although similar and transmitted by the same Aedes vectors, the three diseases are different from each other.

Zika fever is a disease with less intensity compared to others and the symptoms, although very similar among the other 2, appear mildly in most cases. Some of the differences are as follows:

General symptoms

Zika fever rarely has symptoms. Only 20% of patients with the disease show signs of it and, in most cases, the fever is not even noticed.


Fever in dengue and chikungunya is usually high, while it is low or absent in Zika.


In addition, one of the main differences is in transmissibility , that is, the ability of the disease to spread.

A study by Fiocruz in 2016 indicated that the Zika virus is poorly transmitted. Only 20% of mosquitoes that bite someone who has the disease can pass it on to someone else.

Dengue, on the other hand, has a transmission rate of up to 40% and chikungunya reaches 70%.

Spontaneous hemorrhages

Dengue is known to cause bleeding, especially the second time it is contracted, when it becomes hemorrhagic dengue . Chikungunya can also cause bleeding in this way, although they are milder than those of dengue. Zika fever, on the other hand, does not present hemorrhages.

Neurological problems

Neurological problems caused by Zika virus are more common than in the cases of dengue and chikungunya, but in none of the cases are they frequent.

Common questions

Is it possible to catch Zika by the kiss?

No , the Zika virus does not pass through the kiss. The virus exists in saliva, but it is not able to infect someone through kissing, so you can kiss without worry.

Is there a vaccine for Zika fever?

There is no vaccine against Zika fever released to the public. However, there are tests. In August of this year a vaccine against the virus proved to be a success when tested in mice.

Rodents are the first step in testing for a vaccine, but their bodies are extremely different from humans, so it is still in the study phase.

Can mothers infected with the Zika virus breastfeed their babies?

-Yeah . The World Health Organization recommends that the feeding of the newborn baby be exclusively through breastfeeding, even in cases where there is an infection with the Zika virus. Traces of the virus can be found in the infected mother’s breast milk, but this is not a way in which the disease can be transmitted.

How long does Zika infection last?

The Zika virus can be found in the blood during the first seven days of infection, which is long enough for the symptoms, if present, to disappear. In the urine, the virus appears for up to 10 days, and in the semen the virus can be found up to two months after the onset of the infection.

Is there another way to get the disease?

At first, the only ways of contagion of the Zika virus are the bite of the infected mosquito, the sexual transmission and the transfusion of infected blood, already described in the text.

Who was infected with the Zika virus once can get the disease again?

It is known that there is immunity after contagion since the body starts to have antibodies to deal with the Zika virus, but studies are being carried out to find out if contracting the disease makes a person immune for life.

The doubt about the permanence of this immunity comes from the fact that we do not know if there are other serotypes of the virus, which could lead to a new infection, in the same way that it is possible to catch flu several times in life.

Zika fever is a disease that spreads through Aedes aegypti , the same mosquito that transmits dengue, and although asymptomatic most of the time, it can have serious consequences when it infects pregnant women, so it is important to be careful and prevent the mosquito from spreading. reproduce so that we can eliminate these diseases.

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