Dr. William Gill, head of neonatology at Tulane University Medical Center, has seen the effects respiratory syncytial virus (RSV) can have on babies, particularly those born prematurely. It is so common that most children contract it by the age of 2. This winter, RSV reached epidemic proportions in Louisiana, but vigilance and proper treatment can keep things under control, says Gill, who also is medical director of the neonatal intensive care unit (NICU) at Lakeside Hospital and co-medical director of the NICU at University Hospital.
Dr. William Gill is working on reducing RSV infection, especially in babies.
Q: What is RSV?
A: It's a very common virus and is especially dangerous for babies, particularly pre-term babies. It's common in the wintertime; it comes on in late fall, usually October, and finishes in February and March. It is a particularly a problem because we don't have an effective vaccine against this virus. In 1962-63 a vaccine was produced. We gave the vaccine to kids, and when the wintertime hit and the RSV peaked, the kids who got the vaccine got sicker than those who didn't. It really soured people on trying to do anything for prevention. We were very concerned (about that). With the premature babies that have to be put on ventilators, they were very susceptible. They get bronchiolitis; they start wheezing and having increased respiratory distress and increased secretions, which block their airways. Sometimes they have to ... be put back on the ventilator.
Q: What are the symptoms?
It starts off with a cold, lots of mucus, progressive cough and wheezing. Wheezing is a prolonged exhalation phase where they wheeze with the air coming out and have marked difficulty breathing. The bigger kids, full-term babies, have bigger airways; it's less likely they will have to go on a ventilator, but it sill causes a lot of respiratory difficulties.
Q: What ages or conditions make someone more susceptible?>
A: The largest number of kids who get RSV are pre-term babies, which is why we really need a vaccine. They are the most susceptible to severe infection.
Q: What can you do in the absence of a vaccine?
A: MedImmune developed a monoclonal antibody. They gave the respiratory syncytial virus to a laboratory animal and found on that mouse's immunoglobulin (used by the immune system to identify and neutralize viruses and other foreign objects), the place where that mouse developed immunity to the virus. With genetic engineering, they transposed that onto a human immunoglobulin. We can now give the premature babies the monoclonal antibody — palivizumab, commonly called Synagis — and it will get the baby's immunity in the blood up. Babies who get that injection and (additional) monthly injections through March will keep them from getting a severe enough case to go back in the hospital, or worse. It simply protects against the baby from getting the virus (by using its own immune system). It's expensive, about $1,000 an injection ... but less expensive than the baby going back into the hospital, which can cost about $30,000. At Tulane we give it to all preemies before they leave the hospital, then the parents have to bring them back every month for another shot. (Synagis only remains effective for 28 to 30 days.) We certainly want to emphasize to the parents of babies who are born premature and those who have complex congenital heart disease to get their monthly injection, because it's very effective and can keep them from getting the condition so badly that they have to go back on a ventilator — or possibly lose their lives.
Our hope is that a vaccine will become available in the future that will be able to affect all children. The other thing we're hoping for is a monoclonal antibody that lasts longer than a month.
Q: What are the long-term effects, if any?
A: You always worry whether the child will go on to have wheezing problems and bronchospasms and develop asthma.
Q: How dangerous is RSV, compared to influenza and other respiratory illnesses?
A: For premature babies and kids with congenital heart disease, it is as dangerous as influenza. Kids are the reservoir for the virus. By the time a child is 3, almost all of them have had exposure to RSV and are going to start building antibodies to it, and the disease will be less and less severe. It's still around, it just becomes less of a problem.
Q: The Centers for Disease Control reports RSV is an epidemic in Louisiana with three out of 10 babies tested found to be infected.
A: It is our leading viral (infection). The last report that I saw was that 29 percent of all the viral isolates (viruses found in specimens taken from patients) coming out of children is RSV. It reflects pretty much what is going on with our state.