Although it is not yet known exactly what is leading to the increase of cases of microcephaly in the Brazilian northeast and also in other countries, it is believed that this disease is related to the Zika virus, although there is also rumors that it may be related to vaccination against rubella, to the genetically modified mosquito created to combat Aedes and that the larvicide used in water reservoirs to decrease the reproduction of the mosquito are also related to this poor fetal formation.
Zika virus: Major suspected cause of microcephaly
The main suspect is that Zika is causing microcephaly because viruses have been found in the amniotic fluid that surrounds the baby during pregnancy and also in the cerebrospinal fluid present in the central nervous system of babies who were born and were diagnosed with microcephaly.
However, the relationship between Zika and microcephaly is not fully understood. The accepted hypothesis is that the virus being 'protected' by the immune system can cross the placental barrier, reaching the baby. This 'protection' can happen as follows:
When the woman gets Dengue, her defense cells attack and overcome the dengue virus, but these cells when they encounter the virus, which is very similar to dengue, only encompass this virus but can not eliminate it from the body. With this protection, the virus can reach all regions of the body, which normally can not be reached, and in that way it can cross the placenta and reach the baby, causing microcephaly.
Watch the video and learn what Microcephaly is and how it manifests itself:
How to know if the pregnant woman is with Zika
The Zika virus is similar to dengue fever and is also caused by the Aedes Aegypti mosquito, however, its symptoms are milder.
The only way to know if anyone is with Zika is through the symptoms such as redness in the eyes (conjunctivitis), red itchy skin on the skin and fever, though the person may be sick and have no symptoms.
There are no tests that can identify the virus in the blood because it remains active for only 1 week, and the only way to detect it is through an examination called RT-PCR, only in reference laboratories of the Ministry of Health, when requested in very special cases.
The highest chances of the baby having microcephaly occur in pregnant women who have ever had dengue fever and who had Zika at any stage of gestation. In addition, if the woman had Zika when she was not pregnant there is no possibility of the baby having microcephaly if she becomes pregnant after 1 month after the symptoms are controlled.
Other possible causes of microcephaly
Zika may be a cause of the epidemic of microcephaly in infants, especially in northeastern Brazil, although there is still no scientific confirmation. However, there may also be other causes of microcephaly and so scientists in Brazil and the rest of the world are struggling to find out if:
- Is there any link with rubella vaccination in women of childbearing age?
- Does the addition of pesticides in water to halt the multiplication of Zika's transmitting mosquito have affected the development of infants?
- The evolution of the Zika virus is related to the genetically modified mosquito that was released to try to eradicate the mosquito Aedes Aegypti ?
- Can bovine diarrhea virus be one of the causes?
Understand each of these suspicions better:
1. Rubella vaccine
According to rumors rubella vaccination may be related to the appearance of cases of microcephaly because the attenuated vaccine against rubella contains the virus of this inactive disease, being necessary that all the women who take this vaccine are not pregnant, and take care of being at less than 1 month without getting pregnant after taking this vaccine because it is already confirmed that the rubella virus can also cause serious brain changes such as microcephaly.
Although this vaccine is indicated for children, due to the increase in cases of rubella in the Northeast, the government carried out vaccination campaigns for women of childbearing age in early 2015, and it seems that microcephaly cases may be related to this vaccination campaign. However, there is still no evidence of this fact.
2. Bovine diarrhea virus
In July 2016 a scientific research showed traces of bovine diarrhea virus, with the abbreviation BVDV - previously present only in cattle, in the brains of 3 babies diagnosed with microcephaly in northeastern Brazil.
It is not yet known how the pregnant women were infected with this virus, nor how it can affect the brain development of children and therefore more research is being done on this subject.
Researchers have discovered this virus in babies' brains as they look for other types of virus in the nervous system of children diagnosed with microcephaly in recent months. However, it is still too early to confirm its relationship with microcephaly, although it is known that the BVDV virus can cause death and malformation in the fetuses of cows infected with the disease. Surviving pups usually become hosts of the virus throughout their lives and although they do not show symptoms, they can contaminate all livestock, and therefore it is important to slaughter them.
3. Genetically Modified Mosquito
The genetically modified mosquito, called Oxitec, was produced in the laboratory to reduce the amount of Aedes Aegypti mosquitoes in Brazil. This mosquito has a special feature that causes its larvae to not reach adulthood.
However, when this mosquito comes into contact with antibiotics, which are currently present in the environment, may undergo modifications in its genetic structure, which give rise to microcephaly.
4. Water contaminated with larvicide
The larvicide called Pyriproxyfen has been used to prevent the development of larvae of Aedes Aegypti in some regions of Brazil and therefore it is believed that the consumption of water contaminated with this larvicide is also related to the increase of cases of microcephaly. Understand how this pesticide can lead to microcephaly here.
However, there is still no scientific evidence that this larvicide can cause microcephaly, although it has already been suspended by the Ministry of Health.
The manufacturer of the product claims that its use is safe and has been approved by Anvisa since 2004, being used to control diseases in several countries.
Because the cause of microcephaly is still unknown
It can not yet be said that all cases of microcephaly are caused solely and exclusively by Zika because not all pregnant women and babies are subjected to the examination that is capable of identifying the virus. In addition, it is also not possible to know if it is actually the association of several factors that are linked to the increase of cases of microcephaly.
How To Know if Your Baby Has Microcephaly
The diagnosis of microcephaly can be made during pregnancy by ultrasound examination, but it can also be done after the birth of the baby by measuring the size of the child's head. Other examinations such as resonance and tomography can be performed to indicate the degree of cerebral impairment and its possible consequences.
Microcephaly is a serious disease, where there is restriction of the baby's brain growth and has no cure, and it is necessary to do rehabilitation through physical therapy and speech therapy in childhood and adolescence. See how the child's life with microcephaly is.
How the pregnant woman can prevent microcephaly in the baby
To prevent microcephaly in the baby the pregnant woman can take measures like:
- Use a condom if your sexual partner is with Zika until the end of pregnancy because the virus also goes through intimate contact;
- Do not drink alcohol and use medication during pregnancy without an obstetrician;
- Avoid toxoplasmosis and infectious diseases like herpes and rubella, taking the necessary vaccines and measures;
- Avoid contamination with mercury and other heavy metals.
In addition, it is also recommended that all pregnant women use a repellent with DEET daily not to be stung by Aedes Aegypt, which causes dengue, Zika and Chikungunya. The repellent should be passed on every 6 hours throughout the body and clothing, and no need to worry because it can be used during pregnancy because it is safe and does not harm the baby. Other measures that can prevent mosquito bites are to wear long-sleeved clothing, long pants and socks.
Learn what the myths and truths about zika virus are and ask questions.
