This year’s flu season has been virtually wiped out amid COVID-19 restrictions and safety precautions. While several hundred Hawaii residents typically die every year from the flu, there has only been one death this season, an adult over the age of 80 who died in October, according to the state Department of Health.

“The flu season in 2020 basically never came,” said Sarah Kemble, acting state epidemiologist.

Since the pandemic hit over a year ago, large numbers of residents have been working from home, businesses have closed and students have been engaged in more online learning. This, coupled with safety measures including wearing masks, social distancing and hand-washing, has largely stamped out the flu’s spread in Hawaii, as it has in many states.

Nationally, there were only about 600 flu-related deaths during the 2020-2021 flu season, according to data from the U.S. Centers for Disease Control and Prevention. By comparison, the flu has killed about 12,000 to 61,000 people a year since 2010.

While the flu has largely disappeared since the pandemic hit, the coronavirus still managed to spread throughout Hawaii, so far killing about 500 residents — a figure that surely would have been much higher if the state hadn’t enacted restrictions to limit gatherings and residents hadn’t widely adopted mask and distancing requirements.

“It does appear that COVID is more contagious than the flu,” said Kemble. “And that is part of the reason why, even with all of those precautions, it’s harder to stamp out, whereas the flu actually seems to be pretty responsive to those measures.”

In most cases people die of the flu after it progresses to pneumonia, which also kills COVID-19 patients.

Isles’ flu data inflated

In recent years Hawaii has recorded some of the highest influenza death rates in the country, but a recent review by state health officials found significant errors in their data.

From 2015 to 2019 Hawaii and Mississippi vied for the highest number of deaths per 100,000 people. In 2017 Hawaii recorded a high of 29.6 deaths per 100,000 people — 637 deaths total — a rate that was about double the national average, according to data provided to the CDC.

Hawaii’s high death rates from influenza made national headlines and baffled health officials. Last year the state Department of Health took a closer look at its numbers and realized that there were errors in how doctors were coding influenza deaths, said Kemble. For example, a nursing home patient may have died from aspiration pneumonia, which can happen when a senior starts to lose control over normal bodily functions, including eating. These deaths were often being erroneously recorded as influenza-related deaths.

State health officials have since recalculated past data on influenza mortality and found that Hawaii’s flu deaths are more on par with the national average.

Other viruses also disappear

The flu is not the only virus that the pandemic response has largely curtailed in Hawaii. State health officials have also noticed declines in certain viruses that cause common colds, such as non-COVID coronaviruses and the respiratory syncytial virus (RSV), which can make children with asthma very sick. By contrast, rhinovirus and enterovirus infections have persisted.

These trends are providing epidemiologists with a rare opportunity to gain insight into how common viruses spread.

“We are sort of learning which of the diseases that usually circulate are the most able to still transmit despite all of the precautions we are taking,” said Kemble. “It might be that these are diseases that are more easily transmitted (through surfaces).”

“It has been very interesting to me to see what remains when everyone is masking and distancing all the time.”

Overall, Hawaii has fared remarkably well throughout the pandemic when it comes to the overall health of its population. A year into the pandemic, there were about half a million “excess deaths” nationally. The excess death rate measures the number of deaths above what is expected and has been used to assess the overall toll the coronavirus has had on mortality. In Hawaii, however, there have been virtually no “excess deaths” despite the impact of COVID. The reduction in flu deaths, as well as other factors such as fewer traffic fatalities early in the pandemic, has helped keep the state’s overall number of deaths on par with previous years.