Pregnancy, Obesity & Immunosuppression Among High-Risk Factors for Flu Complications in Updated Guidelines

Andrew Pavia, MD

Pregnant women, those who have recently given birth, and individuals who are extremely obese or have immunosuppression are among the people at high-risk for influenza complications, including death, updated guidelines from the Infectious Diseases Society of America (IDSA) state.

These people, among others in high-risk categories, should be tested and begin antiviral treatment promptly if they are sick enough to be hospitalized with flu symptoms, the guidelines advise.

“Initiation of antiviral treatment is recommended as soon as possible for persons with suspected or laboratory-confirmed influenza who are hospitalized, outpatients with progressive disease, and outpatients who are in a high-risk group for complications from influenza,” Timothy Uyeki, MD, MPH, MPP, co-chair of the guidelines committee, told MD Magazine®.

“Antiviral treatment should not be delayed while waiting for influenza testing results for hospitalized patients with suspected influenza,” stressed Uyeki, chief medical officer of the Influenza Division, National Center for Immunization and Respiratory Diseases at the US Centers for Disease Control and Prevention.

Very young children, adults aged 65 years and older, people with neurologic disorders, and chronic medical conditions—such as chronic pulmonary, cardiac, and metabolic disease, and those who are immunocompromised—continue to be at high risk for complications.

The updated guidelines also single out nursing home residents, American Indians, native Alaskans, and individuals with a body mass index (BMI) of 40 kg/m² or greater.

“Outbreaks in nursing homes can be deadly,” IDSA member Andrew Pavia, MD, FAAP, FIDSA, co-chair of the guidelines committee and chief of the Division of Pediatric Infectious Diseases at the University of Utah, told MD Mag®. “If you are in charge of health at a nursing home, become familiar with the testing and treatment recommendations.”

Overall elderly persons have the highest mortality rates attributable to influenza, the investigators wrote in Clinical Infectious Diseases.

“Influenza can cause complications that result in severe illness and death,” the investigators said. “Timely diagnosis may decrease unnecessary laboratory testing for other etiologies and use of antibiotics, improve the effectiveness of infection prevention and control measures, and increase appropriate use of antiviral medications.”

The guidelines are aimed at primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratory workers, infectious disease specialists, and those who manage patients with suspected or laboratory-confirmed influenza.

The latest IDSA directive both reinforces and updates guidance on influenza published in 2009.

Pavia said the update adds new risk groups, more guidance on who to test and how, an emphasis on using antivirals in high-risk and hospitalized patients, and a discussion of when to use—and when not to use—antibiotics.

“There is also a great deal more data to support the above recommendations,” he said.

In addition, with the advent of new influenza tests, the guidelines now emphasize molecular influenza tests for hospitalized patients with suspected influenza and rapid molecular assays for outpatients with suspected influenza, Uyeki said.

“Since the previous guidelines were issued, we experienced an influenza pandemic in 2009 with ongoing circulation of an influenza A(H1N1)pdm09 virus that emerged to cause the pandemic, as well as 8 more influenza seasons,” Uyeki said.

Clinicians should not use viral culture for initial or primary diagnosis because the results will not be available in time to inform clinical management. Medical personnel also should not use serologic testing to diagnose flu because results from a single serum specimen cannot be reliably interpreted, the investigators noted.

“We hope that clinicians will read and follow the IDSA Influenza Clinical Practice Guidelines, and that this will lead to improvement in clinical management of patients with influenza as well as better control of institutional influenza outbreaks,” Uyeki said.

As for advice to the public, Uyeki said that flu is an important health problem. The last influenza season was far more severe than typical and had a greater impact than even the 2009 H1N1 pandemic.

“Persons who are at high-risk for influenza complications who develop acute respiratory illness symptoms during influenza season should seek medical care promptly,” he said.

And while the IDSA guidelines do not address influenza vaccination because guidance from the CDC and elsewhere is available, the investigators stressed that the best way to prevent influenza is through annual flu shots.

Persons who are at high-risk for influenza complications and their family members who are aged 6 months and older should get vaccinated each year.

“Most importantly, everyone in the family or household should be vaccinated,” Pavia said. “If you have typical flu symptoms (fever, cough, sore throat, chills) during flu season, contact your provider early. Antivirals work best if they are started early.”

The study, titled, “Live Attenuated and Inactivated Influenza Vaccine Effectiveness,” was published in Clinical Infectious Diseases.