Strict closures in New Zealand last year appear to have helped a recent outbreak in children of respiratory syncytial virus, or RSV, a highly contagious flu-like illness whose symptoms include a runny nose, cough, sneezing, and fever.
Children in New Zealand were mostly stuck indoors amid last fall’s lockdowns, which run from March through May in the southern hemisphere. After the country reopened last winter, health officials said few of them contracted seasonal viruses and infections, likely because they had been underexposed to germs.
In a typical year, New Zealand experiences a peak in cases of respiratory infections from June to September. But in 2020, the country experienced “the total absence of an annual winter flu epidemic”, with a 99.9% reduction in influenza cases and 98% reduction in RSV, according to a study published in Nature in February.
This year, however, the same children have been more vulnerable than usual to these same ailments.
Since the start of winter five weeks ago, during which there have been no restrictions on coronavirus, children’s services in New Zealand have seen dozens of patients, many of them infants, battling the disease. sometimes fatal, while some elementary schools have reported having as many as half of their students absent due to respiratory illnesses.
The country reported 969 RSV cases in five weeks, compared to an average of 1,743 cases over the entire 29-week winter season in the five years leading up to the pandemic, according to the New Zealand Institute of Science and Technology. environmental research.
The recent increase has yet to plateau, said Dr Sue Huang, a virologist at the Institute of Environmental Science and Research and lead author of the Nature study.
“The exponential increase is very strong,” she said in a statement. “The absence of RSV last winter means there is a young cohort of children from last year, plus a new cohort this year, who have not been exposed to the seasonal virus. “
Doctors around the world have warned of the risk of “immune debt,” when a drop in the number of viral and bacterial infections during blockages is followed by an increase in disease once restrictions are lifted.
In an article published in May in the journal Infectious disease now, a team of French medical researchers suggested that less exposure to microbial agents could create a lack of “immune stimulation” for susceptible people, especially in children. “The longer these periods of ‘low viral or bacterial exposure’, the greater the likelihood of future outbreaks,” they wrote.
New Zealand closed its borders at the start of the pandemic, unveiling strict lockdown measures that were lifted last April and May and have allowed the country to virtually eliminate transmission of coronaviruses. No community case has been reported for more than four months.
In other developments around the world:
Spain faces yet another blow to its summer tourist season after Germany classified the entire country as a “risk area”. From Sunday, travelers entering Germany from anywhere in Spain, including its Balearic and Canary Islands archipelagos, will need to provide a negative coronavirus test or proof of vaccination or recovery to avoid quarantine. The Italian government also warned on Saturday that it was considering greater restrictions on travelers from Spain and Portugal. Both countries are grappling with an increase in coronavirus cases fueled by the highly contagious Delta variant, especially among unvaccinated young people.