High Pediatric Influenza Hospitalization Rates Observed in Israel

Eli Somekh, MD

A new investigation from Israel compared the medical burdens of measles, influenza, and COVID-19 in the city of Bnei Brak and found that hospitalization rates and direct medical burdens of measles and the flue were significantly higher than those observed of COVID-19 in pediatric patients.

According to investigators led by Eli Somekh, MD, Mayanei Hayeshuah Medical Center, the city of Bnei Brak was considered to be one of the main epicenters of the COVID-19 virus in Israel, with one of the highest infection rates in the country.

Additionally, Bnei Brak had also been the epicenter of 2 other outbreaks, the first being a measles outbreak in 2018 and 2019 and the second being a seasonal flu outbreak during the winter of 2019-2020.

Investigators examined the medical burdens of each outbreak by comparing the number of hospitalizations and hospitalization rates, as well as the complications associated with each of these infections.

The Methods

Investigators conducted their study at Medical Hayeeshuah Medical Center, which is located in the city of Bnei Brak.

With children aged 0-19 years comprising nearly half of the total population of the city (200,000 people), investigators chose to focus on the pediatric population for their study.

Investigators reviewed the medical records of all children aged 0-17 years who were admitted to the medical center from April 1, 2018 until March 31, 2021, who were also discharged with a diagnosis of measles, flu, or COVID-19.

Eligibility criteria differed depending on the condition.

For measles, children admitted with a clinical picture of measles and laboratory confirmation by polymerase chain reaction (PCR) testing were eligible.

Similarly for flu, children admitted with respiratory symptoms and laboratory confirmed cases by PCR testing, and children with PCR confirmed SARS-CoV-2 infections were considered for the COVID-19 group.

Age, gender, vaccination status, hospitalization duration, laboratory test results, treatments, complication related to intensive care unit (ICU) admission, and more were recorded.

The Findings

A total of 247 children were hospitalized with the flu, followed by 65 COVID-19 admissions and 32 measles admissions.

Investigators observed that complications rates were higher following measles than after influenza and SARS-CoV-2 infections, with the hospitalization rate of measles-infected patients being 10%.

Regarding flu vaccination, only 1 child of the 177 who were hospitalized for the flu was vaccinated. Based on the available data, investigators assuming the infection rate during this period was 15%, with a resulting hospitalization rate of 1.2%.

Under more extreme assumptions, however, the hospitalization rate was 0.6%, with the assumption that 30% of the children in Bnei Brak were infected during the seasonal outbreak.

Finally, a more conservative assumption of hospitalization rate following COVID-19 was 0.25%.

Investigators noted that the differences in hospitalization rates among these 3 infections were all highly significant (P<0.0001 for all comparisons).

Despite some limitations in their study, such as uncertainty regarding the exact number of infected children in Bnei Brak, investigators were confident about their findings regarding flu and COVID-19.

“The differences between the burden of these infections were so prominent that even a conservative analysis taking into account an extreme case scenario, namely that 30% of children in Bnei Brak were infected with influenza and that only the children with confirmed and recorded positive SARS-CoV-2 PCR tests had a COVID-19 infection (without taking into account children who were unknowingly infected), also resulted in clear and significant differences in hospitalization rates between influenza and COVID-19,” the team wrote.

The study, “Comparison of the Medical Burden of COVID-19 with Seasonal Influenza and Measles Outbreaks,” was published online in Acta Pediatrica.