Tackling the flu and RSV

September 18, 2017

Every pediatrician has experience with influenza and respiratory syncytial virus (RSV), but there are still many cases in which these illnesses are misdiagnosed or mismanaged.

Every pediatrician has experience with influenza and respiratory syncytial virus (RSV), but there are still many cases in which these illnesses are misdiagnosed or mismanaged.

Octavio Ramilo, MD, professor of pediatrics at The Ohio State University and chief of Infectious Diseases at Nationwide Children’s Hospital, Columbus, Ohio, led a session titled “Influenza and RSV: Best practices for those in the trenches” at the American Academy of Pediatrics (AAP) 2017 National Conference and Exhibition on Sunday, September 17, which detailed the best practices for the prevention, diagnosis, and treatment of influenza and RSV, as well as new advances in vaccine development for RSV.

Influenza

Influenza is characterized by a sudden onset of symptoms with a typical incubation period of 2 to 3 days, but up to 7 days. The infectious period varies by age, and children shed the virus longer than adults-for 2 to 3 days before and from 7 to 10 days after the onset of symptoms.

In infants, symptoms can present like sepsis or apnea, and for children aged younger than 5 years, symptoms can include fever and upper respiratory problems with pneumonia resulting in 10% to 50% of cases. In children aged older than 5 years, there is usually a sudden onset of fever, headache, and cough. Immunocompromised individuals may have a fever but lack systemic symptoms.

Although pediatricians may think they are experts at diagnosing flu, Ramilo reports that flu is often misdiagnosed as pneumonia, asthma, and more, and standard tests could not identify influenza A in more than 30% of cases tested. Rapid viral flu tests are 50% to 70% sensitive and 90% to 95% specific, whereas the sensitivity and specificity of polymerase chain reaction (PCR) assays are 90% to 95%.

Accurate and timely diagnosis can reduce the use of unnecessary antibiotics, reduce other diagnostic tests and procedures, and improve patient satisfaction, Ramilo says. It can also help improve mortality rates for influenza, which are 12% for children aged younger than 6 months; 8% for children aged 6 to 11 months; 20% for children aged 1 to 2 years; 23% for children aged 2 to 4 years; 17% for children aged 5 to 10 years; and 20% for preteenagers and adolescents aged 11 to 17 years.

In addition, contrary to popular belief, influenza does not kill just the elderly, the very young, and those with high-risk conditions. In fact, 33% of deaths from influenza occur in children with high-risk conditions and 20% occur in children with underlying conditions, but 47% of flu deaths occur in otherwise healthy children, Ramilo says.

Pediatricians should stress the importance of the flu vaccine, which, although not perfect, is very effective at both reducing incidence of the flu and the duration and severity of illness. Overall vaccine efficacy is around 65%, Ramilo reports.

In terms of treatment of children who do get the flu, antivirals are very effective and have shown efficacy in children with acute influenza, particularly when initiated early.

Ramilo says he hopes pediatricians will take note of the importance of flu vaccination. “Sometimes we focus on the fact that the uncomplicated flu is very inconvenient and we forget about the huge impact of the flu in hospitalizations and death,” he says. “We have a huge opportunity to reduce hospitalizations and complications. We need to optimize use of the vaccine as a first choice but also keep in mind antivirals have a unique role.”

Ramilo says researchers now are looking into ways to strengthen the body’s immune reaction to the flu vaccine. “We are understanding better the body’s response to vaccines,” he says. “Maybe there are ways to find the right adjuvant so the vaccine produces a more potent response.”

RSV

Respiratory syncytial virus is the most common cause of death in children around the world after malaria, and pediatricians know it is a major challenge for their patient population, Ramilo says.

There is a new effort to develop vaccines against the virus, and new medications to treat it are being tested. A passive vaccine administered to pregnant mothers to provide protection to newborns is also being investigated, Ramilo says.

“There’s a huge effort to develop new vaccines,” he says. “This is really exciting because for years pediatricians have been arguing that we need new therapies.”

The primary method of treating RSV is to treat the symptoms by offering intravenous fluids, managing secretions, supplementing oxygen, and using bronchodilators. Inflammatory responses are mediated through the use of corticosteroids and antileukotrienes, and antivirals such as ribavirin also may be used to attack the virus.

More antivirals are in development as well, Ramilo says. Presatovir reduces viral load and clinical illness in healthy adults infected with RSV, and lumicitabine rapidly reduces RSV viral load and clinical disease severity in healthy adults, according to Ramilo’s presentation.

Prevention, however, is key, as the virus is transmitted through large particles and drops and can survive for up to 6 hours on hard surfaces. More than half of medical personnel become infected when RSV is prevalent in the community, Ramilo adds, and nosocomial infections remain a serious problem.

Education is a big issue, too, as many families aren’t aware of RSV or the damage it can cause. “It’s clear we need to do greater education and outreach,” Ramilo says, adding that pediatricians should stress the use of isolation when there is an illness in the family, as well as keeping young children away from other individuals who are sick.

“We see all the time educated parents who never heard of RSV, and not everyone knows it’s such a major issue in babies,” he says.