Zika virus increases the risk of miscarriage that does not show any symptoms may be a common but unrecognized cause of miscarriages and stillbirths, raising concerns that the complications could be more common than currently thought, as per the report of the researchers.
Zika virus is a disease mainly spread by mosquitoes. For most people, it isn’t harmful but for women during pregnancy, it may pose a threat.
Fetal death in utero occurred in more than one-fourth of monkeys infected in the laboratory with Zika virus in early pregnancy, according to new research published in Nature Medicine. The finding raises the concern that Zika virus-associated pregnancy loss in humans may be more common than currently thought, according to the study authors.
Dawn Dudley, the lead author of the new study, expects the true rate of human miscarriage and stillbirth in Zika infected pregnancies is less than 26 percent, but still much higher than human studies show.
Unlike the mosquitoes that spread malaria, affected mosquitoes are most active during the day, especially during mid-morning, then late-afternoon to dusk.
Most people with Zika won’t show any symptoms. But if they do occur they will usually be mild and only last around two to seven days and that’s why the pregnant women affected won’t even know.
Present report by Researchers about miscarriages due to Zika virus:
Zika virus could pose a far greater threat to pregnancy than recent studies of miscarriage and stillbirth in human infections as per the report.
The study, published in Nature Medicine July 2, found 26 percent of nonhuman primates infected with Zika during early stages of pregnancy experienced miscarriage or stillbirth even though the animals showed few signs of infection.
Researchers at six National Primate Research Centers (NPRCs) combined results from individual studies to find that 26 percent of pregnancies in 50 monkeys infected with Zika virus during the first trimester of pregnancy ended in miscarriage or stillbirth, dwarfing the nearly 8 percent rate found earlier this year by a study of women infected with Zika early in pregnancy. Three more infant monkeys in the new study died soon after birth.
Previous Zika research only measured miscarriages and stillbirths in women who displayed signs or symptoms of the virus. A recent study of women who were known to be infected with Zika found that 5 percent did not carry to term or had stillbirths.
” For pregnant women who live in areas where Zika virus is prevalent, and who may experience spontaneous abortions, the possible link to Zika virus infection may be missed” as per the researchers.
Research recently published in the New England Journal of Medicine showed a 5.8 percent miscarriage rate and a 1.8 percent stillbirth rate in a cohort of pregnant women with symptomatic Zika virus infection.
Moreover, placental dysfunction, which is commonly presented in the form of increased placental calcification during ultrasound examinations may also affect the fetus development, the researchers said.
How the Zika virus spread initially?
The Zika virus is spread primarily through the bite of an infected mosquito, but also from the mother to the fetus during pregnancy, and through sexual contact. In 2014, a large outbreak of Zika virus infections in Brazil spread rapidly through South and Central America, the Caribbean and Mexico. Hundreds of thousands of cases were reported. The local transmission was detected in 2016 and 2017 in Texas, Florida, Puerto Rico and the U.S. Virgin Islands.
Zika virus is most often transmitted to humans via the bite of an infected Aedes aegypti mosquito. It also is transmitted sexually. Many people infected with Zika virus will not have symptoms; others may have a fever, rash, headache, joint pain, red eyes, and muscle pain. Zika virus can be passed from an infected pregnant woman to her fetus and cause a range of birth defects collectively known as congenital Zika syndrome.
Although the Zika virus was first discovered in 1947, Zika-related birth defects were not reported until 2015 during a large outbreak of Zika in the Americas. No licensed treatments or vaccines for Zika virus are currently available, but many are in various stages of development. For example, NIAID is leading an international Phase 2 trial of an experimental Zika vaccine.
What are the symptoms?
Symptoms of infection include rash, Conjunctivitis (red eyes), lower back pain, pain behind the eyes, itching all over the body, fever, headache, and joint and muscle pain. These symptoms tend to be mild and in many cases, the infection causes no symptoms at all.
However, thousands of pregnant women who became infected gave birth to children with severe neurological damage, abnormally small heads, eye and limb malformations and other disorders, collectively known as the Congenital Zika Syndrome.
Zika virus is widely known for causing children to be born with a brain abnormality called microencephaly and other malformations. Zika disease in human adults includes fever, rash, headache, joint and muscle pain, as well as red eyes, however, most are asymptomatic.
How could Zika virus increase the risk of miscarriage?
A study found that, following the Zika virus infection of the mother, the fetus died in 13 of 50 animals studied (26 percent). This was significantly higher than the 4 percent to 11 percent rates of miscarriage and stillbirth among uninfected animals housed in the primate centers.
The timing of infection was found to be an important predictor of fetal loss. Exposure during the first trimester of pregnancy was more likely to result in fetal death, a finding that parallels human reports. Another finding from the study was placental dysfunction, which commonly presented in the form of increased placental calcification during ultrasound examinations.
Still more women may have Zika-affected miscarriages before they even know they are pregnant. Others avoid follow-up care for even later-term miscarriages for cultural or other personal reasons.
“You could never account for those women having a miscarriage due to Zika virus infection,” Dawn Dudley, lead author of the new study, said “Women get enrolled in the studies because they have Zika symptoms, but we know that up to half of the people who have Zika don’t show any symptoms at all. So, the pregnancy studies are probably missing half of the people who have Zika.”
Researchers say that in early pregnancy in mice with complete immune systems, Zika virus can cross the placenta – intended to protect the developing fetus – and appears to lead to a high percentage of miscarriages and to babies born with thin brain tissue and inflammation in brain cells.
The placenta is the key organ to a healthy pregnancy. It is typically organized into discrete layers of tissue. Under a microscope, the researchers found that the layers of tissue in the placentas of the mice infected with Zika virus were no longer organized well and might be how the virus could penetrate the fetus.
By administering Zika virus directly into the reproductive tract of pregnant mice that have an intact immune system, the researchers found that the Zika virus appears to create disorganization in the cellular layers of the placenta that keep toxins, bacteria, and viruses from crossing. This disorganization could be how the virus penetrates the placenta to infect the fetus. The researchers also discovered a mechanism by which Zika may be keeping antiviral proteins in the body from doing their job of protecting cells from the virus.
Few vital things about the Zika Virus you must be aware of:
# The Virus is mostly transmitted through mosquitoes
In most cases, Zika is a mosquito-borne virus. The female Aedes aegypti mosquito and sometimes the Aedes albopictus mosquito bites are responsible for the spread of this infection. These mosquitoes transmit yellow fever and dengue as well. However, if a mosquito bites a person carrying this virus, it is likely to pass on the virus to 15 other people throughout its lifespan.
# The virus shows very mild symptoms
The Zika virus shows very mild symptoms like rashes, fever, joint aches and Conjunctivitis. These symptoms are common with many other health conditions. It looks like it is not a big deal and is nothing to worry about. And to make things worse, 80% people do not even realize that they are infected with Zika. It looks like a harmless infection.
# The virus stays in your blood for a week
Just like the dengue virus, Zika stays in your blood for a period of seven days. The virus is likely to pose certain health risks to pregnant women if it sticks around for too long. But once the virus goes away, the risk posed by this virus reduce. Nevertheless, it might stick around in bodily fluids like in the semen, urine or saliva.
# It can also be transmitted sexually
Zika can be transmitted sexually as well. Researchers recently confirmed that Zika can stick around in the semen for as long as 62 days after the symptoms start to appear. However, there is not much evidence to support the fact that the disease may spread through vaginal excretions. A study conducted in France also suggests that the virus may spread through oral sex.
# Pregnant women should avoid areas of Zika outbreak
Pregnant women need to be protected from this virus the most. They are expected to avoid traveling to places where the virus is prevalent. it could increase the risk of miscarriage. This also goes for women who are trying to conceive.
# Some preventative methods for this virus
To reduce your risk of infection you should avoid being bitten. Using insect repellent that contains DEET, wearing loose nothing that covers your arms and legs, and sleeping under a mosquito net in areas where malaria is also a risk.
# Pregnant women avoid few places for travel
Belize, Bolivia, Costa Rica, Cuba, Ecuador, Nicaragua, Peru and Puerto Rico are all labeled as being high-risk areas. Before traveling you should seek travel health advice from your Doctor or a travel clinic, ideally four to six weeks before you go. After all, prevention is better than cure!