The end of October marks the start of influenza season, bringing with it the predictable sniffles, sneezes, fever and aches that can extend well into the spring months.
But this year is different for two reasons. First is the Ebola epidemic in West Africa that spilled into the United States when a Liberian man traveled to Texas in September and infected two nurses who helped care for him.
The second is the late summer outbreak of enterovirus D68, a respiratory illness that has sickened more than 1,100 people in 46 states since August, the US Centers for Disease Control and Prevention said.
Most areas of the country are reporting a decline in EV-D68, but seven states including California say they are still seeing increases.
There is no vaccine against the EV-D68, which has been linked to paralysis and neurologic symptoms in a small number of child patients.
Nor is there any treatment on the market to cure or prevent Ebola, though experimental vaccines are being fast-tracked. The prospect of facing all three illnesses in a single season has led the CDC to start a public education campaign to help people understand the risks, and to remind people to get their annual flu vaccine.
"There may be some public concern or confusion between seasonal influenza and Ebola this season," a CDC spokeswoman said in an email to AFP, citing past experience with fears over the Middle East respiratory syndrome (MERS) and Severe acute respiratory syndrome (SARS).
"Flu-like symptoms in US residents this flu season will most likely be caused by seasonal influenza, not Ebola."
- Similar symptoms -
Flu and Ebola share some common symptoms, such as fever, headache, fatigue and aches and pains.
But there are big differences, too. Influenza causes cough, sore throat and runny nose, while Ebola does not.
Ebola leads to vomiting and diarrhea within three to six days, severe weakness and stomach pain, as well as unexplained bleeding and bruising.
To illustrate these differences, the CDC has issued a flyer titled "Flu or Ebola?" that offers a side-by-side comparison, available at www.cdc.gov/vhf/ebola/pdf/is-it-flu-or-ebola.pdf. The simple, bold print is accompanied by graphics, including one person sneezing on another to show how flu transmits by droplets spewed when sick people cough, sneeze or talk.
Ebola transmission is illustrated by a bright red blood drop and needle. "Ebola can only be spread by direct contact with blood or bodily fluids," the flyer says.
As part of increased screening measures, patients around the country are now asked to fill out a questionnaire asking if they have traveled to West Africa recently and if they have any Ebola symptoms.
"Everybody is screening now, in outpatient offices, in hospital emergency rooms, in ambulatory centers," said Debra Spicehandler, infectious disease expert at Northern Westchester Hospital in New York.
"The only problem is we are all spending a lot of time getting prepared for Ebola, so we may have lost our focus a bit on influenza and preparation for the influenza season," she told AFP.
The CDC recommends an annual flu shot for everyone over six months of age, preferably by the end of October.
Last year, 42 percent of adults and 59 percent of children received their flu shots. The CDC said it is too early to tell how many have received their vaccinations this year.
- By the numbers -
Every year, between five and 20 percent of Americans get the flu, as many as 200,000 are hospitalized and deaths have reached as high as 49,000 in recent decades, the CDC says. Worldwide, the flu infects anywhere from three to five million people per year and kills up to 500,000, according to the World Health Organization.
The current outbreak of Ebola in West Africa is the world's largest in history, killing more than 4,900 people and infecting more than 13,000 since the beginning of the year. Ebola is rare, but lethal about half the time. Of the nine patients treated for Ebola in US hospitals this year, however, just one has died.
The flu is common, but rarely lethal except among the young, the elderly and those with weakened immune systems. Only a doctor can tell if a patient should be tested for Ebola, based on travel history and potential exposure to infected patients.
"The important thing is not to panic. The most important thing to be concerned about is the flu, not Ebola," said Robert Glatter, an emergency physician at Lenox Hill Hospital in New York.
"The most important thing people can do is get a flu shot."