Flu cases fall further, but chickenpox is quickly rising, health officials say

Dutch health officials report a decline in flu cases, even as chickenpox infections among children rise sharply. Data from general practitioners, compiled by the Dutch Institute for Health Services Research (Nivel), show that last week 21 per 100,000 residents visited a doctor with flu-like symptoms. This is a significant drop from the previous week, when the number was 40 per 100,000.

Researchers had warned of a potential early flu epidemic, but current figures suggest that a widespread outbreak is unlikely. Nivel defines an epidemic as exceeding 46 doctor visits per 100,000 residents for at least two consecutive weeks, combined with laboratory confirmation of circulating flu viruses.

Last week, doctors collected 45 samples from patients with flu symptoms. Nine tested positive for influenza, four of which were the H3N2 variant, sometimes called the “super flu” in the United Kingdom.

According to Dutch authorities, current flu vaccines appear effective against H3N2, which has been circulating in the Netherlands for months. H3N2 generally causes more severe symptoms than a common cold.

Nine cases of respiratory syncytial virus (RSV) were also detected. RSV usually causes mild cold-like symptoms in adults but can lead to serious respiratory infections in infants. The number of detections this season is lower than in previous years at this time, possibly due to the introduction of RSV immunization for newborns.

Last winter, many planned surgeries and treatments for children were postponed because pediatric intensive care units were full of patients with RSV-related respiratory issues. This year, RSV spread appears delayed, with few children currently requiring ICU care. An RIVM spokesperson described the early results as “hopeful” but cautioned against drawing conclusions from initial data.

Flu cases decreased among children aged 0 to 14 and adults over 65, while adults between 15 and 44 showed a slight increase in flu-like symptoms. The last flu epidemic in the Netherlands began in mid-January and lasted nine weeks.

Meanwhile, chickenpox is increasing among children. Nivel’s data show a noticeable rise, particularly in children aged 5 to 14. Last week, about 25 children per 100,000 were diagnosed with chickenpox, up from just over 10 per 100,000 the previous week. General practitioners usually see such numbers mainly during the summer months.

Chickenpox is caused by a virus that can remain dormant in the body and may reactivate later in life as shingles. Authorities report no unusual increase in shingles cases among adults. A spokesperson for RIVM could not explain the surge in chickenpox cases to ANP, and Nivel was unavailable for comment due to the holiday period.