Influenza cases are surging in Maine, with 480 new cases reported last week, according to data released this week by the Maine Center for Disease Control and Prevention.

Case counts increased 42% in the most recent weekly report, from 338 in the week ending Dec. 28 to 480 last week, which includes data through Jan. 4.

Maine has recorded a total of 1,105 cases so far this flu season.

Meanwhile, wastewater data that indicates the prevalence of the COVID-19 virus is also showing “very high” levels in Maine, according to the U.S. CDC. The number of people hospitalized with COVID has remained low and flat for several months.

While influenza cases are rising, Maine likely has not reached its peak for the flu season, which extends from October to May. There were a total of 10,426 reported flu cases in the 2023-24 season — peaking at about 800-900 cases each week in February — which was considered a moderate season.

“Everything is trending upward over the last two weeks,” said Anna Krueger, an epidemiologist with the Maine CDC. “It’s always hard to predict when it’s going to peak, but we have at least several weeks of increased activity ahead.”

The U.S. CDC is also closely monitoring the bird flu, which has spread through domesticated poultry and cows and has so far caused fewer than 100 recorded human cases nationwide, none of which has been reported in Maine. Health authorities reported the first human death from the bird flu, in Louisiana, this week.

Dr. James Jarvis, director of clinical education for Northern Light Eastern Maine Medical Center in Bangor, said that, for seasonal influenza, “we are seeing a dramatic shift, from before the holidays to after the holidays, with more patients needing to be admitted to the hospital.”

Public health experts attribute the rise in part to increased time indoors during events and family gatherings over the holidays.

All counties in Maine except Lincoln County were considered to be under a “sustained increase” in flu cases, although most counties are still considered to have “low” influenza rates. York and Piscataquis counties have “moderate” influenza levels, the CDC said.

Flu hospitalizations, while representing a small percentage of people infected, increased from 33 in the last week of 2024 to 47 statewide for the week ending Jan. 4.

Among other New England states, flu levels in New Hampshire are considered “very high” and “high” in Massachusetts and Connecticut, “moderate” in Rhode Island and “minimal” in Vermont, according to the U.S. CDC.

“It’s not too late to get the flu shot if you haven’t already,” Krueger said.

While flu shot clinics typically happen in the fall, Krueger said there are ample supplies of the flu vaccine at doctor’s offices, pharmacies, hospitals and other health care settings.

Krueger said the vaccine is a “good match” for one of the two most actively circulating influenza A strains, H1N1. While it’s still possible to contract the flu even if you have been vaccinated, symptoms are much more likely to be milder and shorter for those who have gotten the shot.

Flu symptoms include fever, chills, cough, headaches, sore throat, runny nose, congestion, muscle aches and fatigue.

So far this flu season is tracking in a similar way to other influenza seasons, Jarvis said, with Maine about two weeks behind most of the rest of the country in seeing jumps in flu cases.

While COVID-19 cases are harder to track — case count data is no longer reliable because so many people test at home or do not get tested for COVID-19 — Jarvis said overall the wastewater data and anecdotal reports from the Northern Light Health system indicate that high levels of the coronavirus are circulating.

Krueger agreed, and said that “though indicators for severity, including hospitalization and deaths, remain relatively low, we are starting to see an increase in reported COVID-19 cases in Maine. Hospitalizations and death due to COVID-19 tend to lag behind case data, meaning we may start to see an increase in these indicators as well.”

COVID-19 hospitalizations in Maine have ranged from about 30-45 patients since May 2024.

Jarvis said they are also seeing an uptick in RSV cases. RSV is a respiratory virus with the most severe effects in infants and people age 60 and older.

“The data is suggesting we are going to see an upswing of all three of those viruses, flu, COVID-19 and RSV,” Jarvis said.

The U.S. CDC does not have a robust data tracking system for RSV compared to influenza and COVID-19.

The U.S. CDC estimates that nationwide each year, RSV infections result in 2.1 million outpatient visits for children under 5, about 50,000-80,000 pediatric hospitalizations and more than 100,000 hospitalizations for adults over 60.

The RSV vaccine is available for infants, those who are 32-36 weeks pregnant, people 75 or older and adults 60-74 who are at increased risk for RSV.

The updated COVID-19 vaccine is also available, and public health experts recommend people 6 months and older should get an annual COVID-19 shot. The shot can be given at the same appointment as the flu shot.

In addition to getting vaccinated, public health experts recommend frequent hand washing, staying home when sick, avoid touching your eyes, nose and mouth, avoiding close contact with people who are sick, and covering your mouth and nose when sneezing and coughing.