Contrary to popular opinion, a child does not have to face a debilitating marathon bout of the flu, or suffer a chronic medical condition, in order to face increased risk of death. Out of the 830 children that died of influenza infection between 2004 and 2012, a recent study found the flu killed more than a third of the kids within the first three days of developing symptoms and before they were ever hospitalized.

Influenza gained heightened national attention mere weeks ago when the government shutdown rendered federal agencies unable to track the virus’ path and infection rates. Though the government has resumed its duties, new data puts the virus back in the spotlight, as its lethality may have previously been understated. Publishing in the journal Pediatrics, researchers from the Centers for Disease Control and Prevention (CDC) found kids with and without medical conditions faced similar risk of death when confronted with the virus.

"Healthy kids are at risk, too. I think that's something that a lot of people don't recognize," lead author Dr. Karen Wong, a CDC medical epidemiologist, told LiveScience. "People can get very sick very quickly, even if they don't have an underlying medical condition."

Fifty-seven percent of the study’s 830 flu deaths involved children with chronic medical conditions. But what surprised researchers was that children without chronic conditions were twice as likely to die before reaching a hospital, or within three days of symptom onset. The problem with otherwise healthy children is that their parents tend to underestimate the virus’ power, while parents of children with conditions are already more aware of the health risks, so they feel compelled to act sooner, according to Dr. Marcelo Laufer, a pediatric infectious diseases specialist at Miami Children's Hospital.

"First, parents don't realize that flu can be fatal,” he told HealthDay. Second, the ones with kids who have chronic conditions "know the system better, so they come earlier than healthy patients."

Wong, for her part, stressed the importance of pregnant women receiving a flu shot for the sake of the developing baby, as doctors advise against vaccination until a child is at least 6 months old. Of the 511 who died and were eligible for immunization, only 16 percent received the vaccine. Wong conceded the reason for such high rates of healthy deaths is still a mystery, but urged children who develop symptoms to seek antiviral treatment.

“That's another thing they can talk to their health care provider about," she added.

Among the diseases that elevate a child’s risk for serious flu complications are asthma, lung disease, heart disease, and cancer. More than 200,000 people a year are hospitalized for respiratory and heart-related illnesses as a result of influenza virus infections, according to the CDC.

"Parents should realize that influenza is much more than sniffles," Laufer said. "A kid with influenza is a kid who is very sick, is a kid who is lethargic, has decreased appetite, is not drinking as much and not urinating as much in addition to other flu symptoms.”

Source: Wong K, Jain S, Blanton L. Influenza-Associated Pediatric Deaths in the United States, 2004–2012. Pediatrics. 2013.