France has recorded a historic decrease in acute gastroenteritis that public health officials have linked to measures in place during the COVID-19 pandemic.

Following the first lockdown because of coronavirus very low levels were recorded from March 2020 in the 2019 and 2020 winter monitoring season that ran from mid-November to mid-April, according to data published by the public health agency Santé publique France.

The overall decline comes despite a significant peak at the end of December 2019 and start of January caused by an increase in food poisoning linked to the consumption of oysters.

From Dec. 11, 2019, to Jan. 22, 2020, 197 outbreaks suspected to be caused by eating raw shellfish were reported. These affected 1,121 people and 25 were hospitalized.

Co-infection between norovirus and other enteric viruses such as rotavirus, sapovirus, enterovirus and Aichi virus was identified in 10 of 26 cases. Because of confirmed norovirus contamination, 31 harvest sites were closed between late December and early January.

In March this year, Sante publique France reported 46 outbreaks linked to the consumption of oysters since mid-February with 164 people sick and two needing hospital treatment.

Impact of COVID-19 measures
Acute gastroenteritis in winter is dominated by norovirus and rotavirus. Norovirus affects people of all ages, while rotavirus predominantly impacts children under 5 years old. An increase is seen in winter in France and other EU countries.

Data comes from the emergency departments of the Organisation de la surveillance coordonnée des urgences (OSCOUR) network and the emergency general practitioners’ associations that provide house-calls called SOS Médecins.

There were 96,713 hospital visits for acute gastroenteritis with 44 percent involving children younger than age 5 and nearly 144,500 SOS Médecins consultations for acute gastroenteritis.

The proportion of emergency room visits for gastroenteritis fell sharply at the start of 2020 to historically low levels before stabilizing in April. The levels of decline had not been seen before in a decade of such surveillance.

The decrease is most likely related to the measures introduced during the COVID-19 pandemic such as lockdowns, physical distancing and strengthening of hand hygiene, according to officials.

Preventative measures for acute gastroenteritis include washing hands frequently for 30 seconds, rubbing fingernails and fingertips and thoroughly and regularly cleaning surfaces at high risk for transmitting viruses that can be resistant in the environment, according to Santé publique France.

The agency also advised keeping hydrated, especially for infants, to avoid serious illness complications.