The article ‘5 questions about hearing loss in babies after a CMV infection’ was previously published. The article below discusses the CMV research within the LUMC.
CMV is a herpes virus that almost everyone comes into contact with during their lifetime. Like other herpes viruses, CMV remains dormant in the body. If a pregnant woman has a CMV flare-up or acquires a new infection, the virus can also infect the unborn child. In rare cases this can lead to serious complaints, of which hearing loss is the most common.
CMV is a rare condition. Of the 850 children with a CMV infection, 15% develop serious complaints. “Hearing loss is the most common, but we also see developmental delays, neurological problems and visual impairment,” says Ann Vossen. The severity of the complaints varies per child. “Some children are born deaf, others have hearing loss in 1 ear. And about 1 in 8 children with a CMV infection is born without symptoms, but in some cases can still develop complaints later.”
Diagnosis often missed
Thanks to a technique optimized by Vossen and her colleagues, the blood from the heel prick screening can be used to diagnose a CMV infection up to several years after birth. It is also possible to detect the virus in the urine up to 3 weeks after birth. “It is important to diagnose a CMV infection as early as possible to prevent further damage,” says Vossen. Unfortunately, not all healthcare providers are aware of this due to its rarity. “By improving information, I hope that in the future every child who has a negative result during the hearing screening will be immediately tested for CMV,” says Vossen.
Prevent deterioration of hearing
Unfortunately, there is no treatment yet that prevents hearing damage caused by CMV. However, babies born with complaints are treated with antiviral drugs. The idea is that this will not make their complaints worse. But there is still much debate about the effectiveness of this treatment. To clarify this, Vossen set up a study in which 2 groups were compared: one group of infants with CMV received antiviral medications for 6 weeks, and the other group was not treated. “We expect to publish the results soon, .” Vossen hopes that these results will adjust treatment guidelines so that more children with CMV can be treated.
Screen all babies?
CMV can therefore be detected early and possibly treated better in the future. Shouldn’t CMV be added to the heel prick screening? “Technically this is possible, but at the moment I am not in favor of this,” says Vossen. The vast majority of infected newborns never develop symptoms. If we screen all babies, more will be treated unnecessarily. This can also lead to unnecessary stress for the parents,” says Vossen. “If we have a 2 in the futuree develop a test that indicates the likelihood of long-term complaints, then I would welcome screening. But until then it is simply not effective.”
1 of Vossen’s 2 PhD students is working on such a test. “It would be fantastic if we ultimately had a kind of checklist for doctors with which they could estimate the risk of complaints per child,” says Vossen. The research into CMV also focuses on more basic questions. “We still don’t know exactly how the virus causes hearing loss. That is why we are investigating the effect of the virus on the development of the hearing organ in collaboration with the ENT department. We do this with cultured mini ears (organoids) in the lab.”
CMV out of the world
Ultimately, Vossen hopes that the research will ensure that the serious consequences of CMV are eradicated. “There are already a number of vaccines in the pipeline. That would of course be fantastic. Until then, I will continue to work for this rare patient group. For example, by organizing parents’ days. Then you will see what you are doing it all for.”
Most research into congenital CMV in the Netherlands is done at the LUMC. There is a lot of knowledge and experience with this rare condition. For this reason, Vossen single-handedly set up an expertise center about 7 years ago that is recognized by the Ministry of Health, Welfare and Sport. This center is broader than CMV alone and is committed to better care for patients with a congenital infection.