- Zika virus: Main suspicion of the cause of microcephaly
- How to know if the pregnant woman has Zika
- Other possible causes of microcephaly
- 1. Rubella Vaccine
- 2. Bovine diarrhea virus
- 3. Genetically modified mosquito
- 4. Water contaminated with larvicide
- Because the cause of microcephaly is not yet known
- How to tell if your baby has microcephaly
- How pregnant women can prevent microcephaly in their baby
Although it is not yet known exactly what is leading to the increase in microcephaly cases in northeastern Brazil and also in other countries, it is believed that this disease is related to the Zika virus, although there are also rumors that it may be related to vaccination against rubella, to the genetically modified mosquito created to fight Aedes and that the larvicide used in water reservoirs to decrease the mosquito's reproduction also have a relationship with this fetal malformation.
Zika virus: Main suspicion of the cause of microcephaly
The main suspicion is that Zika is causing microcephaly because viruses have already 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 have been born and have been diagnosed with microcephaly.
However, the relationship between Zika and microcephaly is not fully understood. The accepted hypothesis is that when the virus is 'protected' by the immune system it can cross the placental barrier, reaching the baby. This 'protection' can happen as follows:
When a woman catches Dengue, her defense cells attack and defeat the dengue virus, but when these cells meet the virus, which is very similar to the dengue virus, they only encompass this virus but cannot eliminate it from the body. With this protection, the virus can reach all regions of the body, which normally cannot be reached, and in this way it can cross the placenta and reach the baby, causing microcephaly.
How to know if the pregnant woman has Zika
The Zika virus is similar to dengue and is also caused by the Aedes Aegypti mosquito, however, its symptoms are milder.
The only way to know if anyone has Zika is through symptoms such as redness in the eyes (conjunctivitis), itchy red spots on the skin and fever, however the person may be sick and not have any 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 greatest chances of the baby having microcephaly occur in pregnant women who have already had dengue and who have had Zika at any stage of pregnancy. In addition, if the woman already 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 can be a cause of the microcephaly epidemic in babies, especially in northeastern Brazil, although there is still no scientific confirmation. However, there may also be other causes of microcephaly and that is why scientists in Brazil and the rest of the world are struggling to find out if:
- Is there any connection with rubella vaccination in women of childbearing age? Has the addition of pesticide in the water to stop the multiplication of the Zika transmitting mosquito affected the development of babies? The evolution of the Zika virus is related to the genetically modified mosquito that was loose to try to eradicate the Aedes Aegypti mosquito? Can the bovine diarrhea virus be one of the causes?
Better understand each of these suspicions:
1. Rubella Vaccine
According to rumors, vaccination against rubella 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 women who take this vaccine are not pregnant, and be careful to stay at at least, 1 month without getting pregnant after having 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 rubella cases in the northeast, the government carried out vaccination campaigns for women of childbearing age in early 2015, and apparently, cases of microcephaly may be related to this vaccination campaign. However, there is still no proof of this fact.
2. Bovine diarrhea virus
In July 2016, scientific research showed traces of the bovine diarrhea virus, with the acronym BVDV - previously present only in cattle, in the brains of 3 babies diagnosed with microcephaly in northeastern Brazil.
It is not yet known how pregnant women were infected with this virus, nor how it can affect children's brain development and, therefore, more research is being carried out on this subject.
Researchers discovered this virus in the babies' brains when looking for other types of viruses 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 fetuses of cows contaminated with the disease. Puppies that survive generally become hosts of the virus for life and although they do not show symptoms, they can contaminate all cattle and, therefore, their slaughter is important.
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 prevents its larvae from reaching adulthood.
However, when this mosquito comes into contact with antibiotics, which are currently present in the environment, they can undergo changes 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 Aedes Aegypti larvae 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 in cases of microcephaly.
However, there is still no scientific evidence that this larvicide can cause microcephaly, although its use has already been suspended by the Ministry of Health.
The manufacturer of the product states 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 not yet known
It cannot 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 test that is able to identify 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 in cases of microcephaly.
How to tell if your baby has microcephaly
The diagnosis of microcephaly can be made during pregnancy through the morphological ultrasound exam, but it can also be made after the baby is born, by measuring the size of the child's head. Other tests such as MRI and CT scan can be performed to indicate the degree of brain impairment and its possible consequences.
Microcephaly is a serious disease, where the baby's brain growth is restricted and has no cure, requiring rehabilitation through physical therapy and speech therapy in childhood and adolescence. See what life is like for the child with microcephaly.
How pregnant women can prevent microcephaly in their baby
To avoid microcephaly in the baby the pregnant woman can take measures such as:
- Use a condom if your sexual partner has Zika, until the end of the pregnancy because the virus also passes through intimate contact; Do not drink alcohol and use medications during pregnancy without the indication of the obstetrician; Avoid toxoplasmosis and infectious diseases such as 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 DEET repellent daily to avoid being bitten by Aedes Aegypt, which causes dengue, Zika and Chikungunya. The repellent should be applied every 6 hours throughout the body and clothing, and there is 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 clothes, long pants and socks.
