By Gary Evans, Medical Writer
With public health officials giving clinicians essentially a standing order to administer antivirals to high-risk patients with influenza due to a vaccine mismatch, infection preventionists are stepping up to play critical roles in response to a severe flu season.
IPs can help communicate and implement key recommendations1 by the CDC, including those advising administering antivirals to high-risk hospitalized patients that develop flu-like illness, says Linda Greene, RN, president of the Association for Professionals in Infection Control and Epidemiology (APIC).
“We are well aware that the flu is widespread and we know there is not a good match with the vaccine, so from the antiviral perspective, people in high-risk categories who have flu-like symptoms really need to seek medical help,” she says. “The antivirals are most effective within the first 48 hours. The people in the high-risk groups include the elderly, pregnant women, and others. I think most providers know this, but it is important that we reiterate these messages. As infection preventionists, it is part of our role that goes beyond our facility as a part of public health.”
In particular, IPs can spread the word that the old “48-hour rule” on administering antivirals should be strongly reconsidered due to new data and prevailing circumstances, says William Schaffner, MD, professor of preventive medicine at Vanderbilt University in Nashville.
“IPs should encourage treatment,” he says. “So many physicians learned the 48-hour rule — that antivirals works best if administered 48 hours from the onset of flu symptoms. There are now studies showing that there continues to be some benefit if the antiviral is administered beyond 48 hours, but that notion really hasn’t penetrated at every level.”
Indeed, the CDC cites a study of more than 29,000 hospitalized flu patients that found that, while antivirals delivered within 48 hours were most effective, there was a “survival benefit” to initiating patients after the first two days.2 In addition, another study3 reported clinical benefit when an antiviral was initiated 72 hours after flu onset among febrile children, the CDC reported.
“Frequently, adult patients in particular come in day four or day five, and so the doctors — knowing the 48-hour rule — choose not to treat for influenza because they think it is valueless,” Schaffner says. “But now there are data suggesting that even after four or five days it will have some benefit. Obviously, it is not as good as initiating treatment within the first 24 hours, but nonetheless there is still value to treating many of those patients. I agree with the CDC’s recommendation that if someone is hospitalized with influenza we ought to be strongly treating them with an antiviral while we are assessing for bacterial complications.”
An Ounce of Prevention
The CDC recommends administering antiviral treatment before flu is confirmed, if the clinical assessment warrants. “Empiric antiviral treatment should generally be initiated as soon as possible when there is known influenza activity in the community,” the CDC states.
Using this technique, a gerontologist colleague of Schaffner’s stopped an influenza outbreak in a long-term care facility.
“He had experienced the introduction of influenza in one of his nursing homes, and used prophylactic [antiviral] treatment in addition to treating actual cases,” Schaffner says. “He first gave it to one wing of the nursing home and then when it was evident that the flu had spread beyond that wing, he gave it to all patients in the nursing home. He thinks he aborted a much larger outbreak in that nursing home, and that is consistent with the CDC recommendations when you have a population that is confined to an institution like that.”
The flu shot is never universally effective, but it seems particularly appropriate this year for the CDC to repeat a standard admonition: “A history of current season influenza vaccination does not exclude a diagnosis of influenza in an ill child or adult.”
The H3N2 influenza A strain, which is causing the lion’s share of infections this season, is poorly matched with the H3N2 strain in the current vaccine. While some efficacy estimates out of Australia are in the 10% range, the CDC is projecting that, based on last year’s data, the vaccine could achieve efficacy of 32% in the U.S.
“The effective estimate comes from Australia and we had not yet had an interim efficacy estimate of the vaccine here in the U.S.,” Schaffner says. “I suspect the CDC will provide one at the end of January or in February. The [32% efficacy] is a hope, but we really don’t know what it is going to be yet.”
However, it is important to underscore that the common epidemiological measure of efficacy is flu prevention, meaning the benefits of minimizing the severity of an infection are not factored into the equation, Schaffner says.
“We measure efficacy by the complete prevention of the illness,” he emphasizes. “We do that for measles, polio, diphtheria, and all of the others. That is certainly a valid measure, but it undervalues the vaccine,” he says.
Even though people may get influenza after receiving a vaccination, “studies over the years have shown that they are less likely to have a severe case.” Schaffner notes that studies at the population level have shown that people who get sick after receiving the vaccine are less likely to have complications of pneumonia, be hospitalized, or die. “Complete prevention is one measure of efficacy,” he notes, “but we should also remember that there are other benefits to the vaccine.”
An important corollary to this is that partial efficacy reduces circulating flu virus and reduces transmission to others.
“You become less likely to transmit it to others, and that is something of value to most people,” he says. “Nobody wants to be a spreader of the virus.”
Particularly not H3N2, which often causes more hospitalizations and deaths when it prevails as the predominant strain in a flu season, the CDC notes.
A Vaccine Not Given...
“The vaccine is certainly not 100% effective, but a vaccine not given is 100% ineffective,” Greene says. “You really have to realize that even with minimal efficacy, vaccines often can lessen the severity of disease. Some people don’t understand that, saying, ‘Why should I even get vaccinated — it is going to be a poor match.’ Nonetheless, vaccination is still recommended because that percentage of protection is still important.”
Even if those vaccinated come down with flu symptoms and need antivirals, the partial efficacy of the vaccine may help prevent one of the gravest flu complications — pneumonia, Greene says.
“People can get primary influenza pneumonia, or secondary bacterial pneumonia,” she says. “In the elderly, particularly people with heart disease and lung disease, pneumonia can lead to death. I think this year we really have to be on our guard.”
As of Dec. 27, 2017, influenza A was the primary cause of flu infections and H3N2 had caused about 80% of all influenza in the U.S.
Overall, 21 states reported high levels of flu activity. Among the infected are healthcare workers, who historically have shown a propensity to report for work ill.
“When flu is widespread, healthcare providers will come to work ill — this idea of presenteeism,” Greene says.
“In our own organization, we are sending messages that reiterate the fact that if you are a young, healthy adult you may have minimal symptoms, but you can still transmit the disease to vulnerable patients — and that can be devastating,” she says. Therefore it is important for healthcare providers to stay home when ill.
Greene says healthcare providers often ask, “‘Who is going to take care of patients if I’m not there?’ But there has to be a very robust message from the infection preventionists on this. It is so important that especially febrile workers not show up for work. It is important that they really think about that and refrain from exposing the fragile patients that we take care of.”
Greene cites a recent study in the APIC journal, which found that 41.4% of 1,914 healthcare workers with influenza-like illness (ILI) still showed up for work for a median of three days.4
The findings underscore the need for sick leave policies, with ILI defined in the study as fever, cough, and sore throat.
“The CDC recommends that people not work until they have been afebrile for at least 24 hours,” says lead author, Sophia Chiu, MD, MPH, of the National Institute for Occupational Safety and Health.
“Some of the most common reasons [sick workers] gave is that they could still perform their job duties, and they didn’t feel badly enough to miss work,” Chiu says.
To protect workers on the job and the patients they are caring for, it is imperative that infection preventionists keep sick workers home. But there are other factors to keep in mind.
“Obviously, good handwashing goes across all these things,” Greene says. “We talk about it every year, but this year flu is widespread. We want to identify those patients who come into our organization as quickly as possible and get them in appropriate precautions — usually droplet isolation, wearing a mask, and what have you,” Greene adds.
“Also, we encourage people who are on the antivirals — usually they are prescribed for about five days if they are prescribed in the outpatient settings — to take them for the entire time,” Greene says. “People start feeling better, and they don’t complete the course.”
APIC has also created a visitor handout that urges the public to not come to the hospital if they have symptoms that include fever, cough, runny or congested nose, body aches, chills, nausea, and diarrhea. (Available at: http://bit.ly/2CRkQ0O.)
“It’s important to do the things we talk about all the time — good hand hygiene, covering coughs, staying home if sick, and certainly educating not only our patients, but the public,” Greene says.
- CDC. Seasonal Influenza A(H3N2) Activity and Antiviral Treatment of Patients with Influenza. Health Alert Network. Dec. 27, 2017. Available at: http://bit.ly/2E9AstE.
- Muthuri SG, Venkatesan S, Myles PR, et al. Effectiveness of neuraminidase inhibitors in reducing mortality in patients admitted to hospital with influenza A H1N1pdm09 virus infection: a meta-analysis of individual participant data. Lancet Respir Med 2014;2(5):395-404.
- Fry AM, Goswami D, Nahar K, et al. Efficacy of oseltamivir treatment started within 5 days of symptom onset to reduce influenza illness duration and virus shedding in an urban setting in Bangladesh: a randomised placebo-controlled trial. Lancet Infect Dis 2014;4(2):109-118.
- Chiu S, Black CL, Greby SM, et al. Working with influenza-like illness: Presenteeism among US health care personnel during the 2014-2015 influenza season. Am J Infect Control 2017;45(11):1254-1258.
