The list of things women are told to avoid during pregnancy includes cat litter, alfalfa sprouts, deli meat, runny egg yolks, pet hamsters, sushi, herbal teas, gardening, brie cheese, aspirin, and a hint of pink. Contains colored meat, spicy. bathtub. Any of these are unlikely to harm your baby, so why take the risk?
However, few physicians in the United States educate pregnant women about the risk of contracting a ubiquitous virus called cytomegalovirus (CMV).The name may be confusing, but CMV is Main infection cause Birth defect rates in the United States far outstrip toxoplasmosis from cat litter and microbes from hamsters.Curiously, the majority of babies infected in utero are not affected, although estimates suggest 400 people born with CMV die each year. Thousands more suffer from hearing or vision loss, epilepsy, developmental delay, or microcephaly, an abnormally small head or brain. Exactly why the virus affects some infants so dramatically and others not is unknown. There is no cure, no vaccine.
Amanda Deveraux’s youngest child, Pippa, was born with brain-damaging CMV. Pippa is prone to seizures. She was unable to walk until she was two and a half years old and she was unable to speak at age seven. “She was stunned that no one had told her about her CMV,” says Deveraux, now program director for the National CMV Foundation. She raises her awareness of the virus. This non-profit organization was founded by parents of children with congenital CMV. “They all say, ‘Why didn’t you know about this?'” Deveraux told me.
One reason doctors are reluctant to spread the word is that the most obvious way to avoid the virus is to avoid infected infants. Symptoms from CMV are usually mild or absent in healthy adults and children. An infant who frequently catches her CMV in day care may continue to shed the virus in her bodily fluids for months or even years despite being perfectly healthy. “Every child in the 2-year-old classroom was shedding CMV,” Robert Pass, a former pediatrician and longtime CMV researcher at the University of Alabama, told me in 2021. (He died recently) , 81 years old. )
This creates a common scenario of congenital CMV. A nursery-aged infant carries her CMV home and infects mothers who are pregnant with younger siblings. One recent study found that congenital CMV is approximately the following condition: twice as common There are more second sons than first sons. Deveraux’s infant son was placed in day care while she was pregnant. “I was sharing food with him because he wouldn’t finish his breakfast,” she told me. She had no idea that his half-eaten muffin could harm her unborn daughter. In retrospect, she says, “I spend less time worrying about not eating deli meat, more focus, Hey, I’m leaving this toddler in daycare. at risk of CMV.“
CMV is a very tricky virus as there are very few absolutes. Mothers cannot categorically avoid infants. Most pregnant women infected with CMV do not pass it on to their babies. Most infected babies survive. Doctors warn their patients about the various risks during pregnancy (see list above), but in this case, thousands of parents are blinded to a very common virus each year. No one has a perfect answer on how to stop it.
Daycares have been known as CMV hotspots since at least the 1980s. alabama pass, and Other researchers in Virginia First, they began tracing congenital cases back to nursery schools. This virus is prevalent in nurseries for the same reason other viruses are prevalent in nurseries. Young children have no innate immunity and are less keen to avoid each other’s saliva, urine, runny nose, tears, etc. Have a CMV. One-third of mothers who have infected infants in day care have not contracted the virus within a year. And her first CMV infection during pregnancy is the highest risk scenario. These so-called primary infections are most likely to cause serious complications to the fetus. However, recent studies have found that viral reinfection and reactivation can also cause congenital CMV. (CMV, like chickenpox, caused by a related virus, remains in the body permanently after initial infection.)
Therefore, it is impossible to completely eliminate the risk of congenital CMV. However, some CMV experts advocate giving women a short list of actions to reduce their risk during the first nine months of pregnancy. Kiss the top of the head, not the mouth. Wash your hands frequently, especially after changing diapers. Clean surfaces that come in contact with saliva and urine.a study In Italy, they found that pregnant women who were taught these measures had a six-fold reduction in the risk of contracting CMV.a study In France, we found that the risk also decreased.
However, in the United States, patients are unlikely to hear this advice from their obstetricians. The American College of Obstetricians and Gynecologists does not recommend telling patients how to reduce their CMV risk. According to ACOG, the evidence that behavioral change leads to change is not strong enough from just a handful of studies, and organizations believe there are downsides to this approach. ACOG interim CEO Christopher Zahn said advice such as not kissing infants and toddlers could undermine “a mother’s ability to bond with her child,” and that these hygiene recommendations are not necessary. It said in a statement that it could “falsely reassure patients” about the risks of CMV. Atlantic.
The CMV community disagrees with this. “I think they’re a little paternalistic,” says Gail Demler Harrison, a pediatric infectious disease doctor at Texas Children’s Hospital. His group of CMV experts international, including Demler Harrison, advocated a series of patient education. Consensus recommendations Deveraux, along with the CMV Foundation, positions this as a matter of choice. It shouldn’t be, “Someone else is saying, ‘I can’t handle this information, I can’t help you.'” I’m not going to tell you that,’ she told me. Without knowing about CMV, women cannot decide what risks they can tolerate and what hygiene changes are too burdensome. “To make or not to make is your choice,” she says. “It’s important to make that choice.”
Further data may be forthcoming about how well these behavioral changes work. Karen Fowler, an epidemiologist at the University of Alabama at Birmingham, enrolls hundreds of pregnant women at a hospital. clinical trials. Only 8% of the participants had heard of CMV before joining the study, she says. Patients receive a short informative session on CMV followed by 12 weeks of text message reminders. The point is, “We keep the message very simple.” That means less saliva sharing. Don’t eat leftovers, don’t share utensils, don’t clean the pacifier out of your mouth. This simple rule blocks the most likely infection vectors. Indeed, CMV is also excreted in urine, tears, and other bodily fluids, but mothers do not routinely ingest them.
CMV prevention receives a great deal of attention because treatment options are poor once fetuses are infected. The best antiviral drugs for CMV are not considered safe to use during pregnancy. Other antiviral drugs are safer but less potent. After an infected baby is born, antiviral therapy can help preserve hearing in people with other moderate to severe symptoms from CMV, but it cannot reverse brain damage. It’s also unclear how well antiviral drugs work for people with mild symptoms. When do the benefits outweigh the risks? “There’s a big gray area,” says Laura Gibson, a pediatric infectious disease doctor at the University of Massachusetts Chang School of Medicine. For these reasons, policies for testing all newborns vary from state to state, and even from hospital to hospital. Knowledge can be a power, but with a complex virus like CMV, knowledge of the infection does not always indicate the obvious best choice.
In an ideal world, all of this could be abolished by a CMV vaccine. However, despite much interest, such vaccines have proven difficult to obtain.Considered a CMV vaccine by the Institute of Medicine in the United States top priority Around the turn of the millennium, and then 24 vaccine candidates Being studied or being studied. However, all completed clinical trials have failed. “The immune system looks strong for the first month or year, but then it starts to wane,” says Demler-Harrison. Also, even vaccines that induce some immune response may not always induce an immune response strong enough to completely protect against CMV infection.
CMV is a very difficult virus to vaccinate due to the intricacies of our immune system. “It’s been evolving with humans for millions of years,” Gibson says. “It knows how to evade our immune system and stay alive.” Our immune system can’t eliminate viruses, but viruses occasionally emerge from cells, replicate, and move to another host. will try to find Therefore, a vaccine that fully protects against CMV would need to encourage our immune system to do what it cannot naturally do. It has to outperform our immune system. “I think as time goes on, fewer and fewer people think it might work,” says Gibson. However, a vaccine does not have to prevent all infections to be useful. Vaccination may reduce the risk of congenital CMV because the first infection poses the greatest risk to the fetus.
For CMV, who to vaccinate is also a difficult question to answer. Like rubella, all infants can be vaccinated, but rubella is most dangerous when it is passed from mother to fetus. This has the potential benefit of promoting broad immunity that suppresses circulation of CMV. But the virus doesn’t actually do much harm to young children, and their immunity may weaken by the time they reach childbearing age. Alternatively, teens can be vaccinated as they would for meningococcal disease, but teens are more likely to go unvaccinated and are still immune. Power can wear off quickly. What about all pregnant women? By the time a pregnant woman seeks medical attention, it may be too late to prevent CMV during early pregnancy, when the risk is highest. A better understanding of CMV immunity and spread may help scientists determine the best strategy. Gibson is conducting research into how the virus spreads and what kinds of immune responses correlate with shedding (funded by Moderna, which is testing a CMV vaccine candidate). ing).
Until a vaccine is developed, and even then, the only way to prevent CMV infection is by avoiding bodily fluids, a very old technique. it is incomplete. Its exact effect is difficult to quantify. One might think it is not worth it, given that he has a small absolute risk of CMV in a single pregnancy. After all, there are already many things to worry about when expecting a baby. One more thing? Or you might think there might be another one.
