The number of gut infections in the U.K. dropped during the early months of the COVID-19 pandemic, with outbreaks reduced by more than half. The change was likely driven by various factors, from better hygiene to changes in people's willingness to get medical attention.

Gastrointestinal (GI) infections are considered an important cause of mortality and morbidity globally, the researchers of a new study published in the BMJ Open noted. In England, it is estimated that there are more than 17 million cases of GI infections each year.

For their work, the researchers sought to find how the early months of the pandemic may have affected GI infections in the U.K., the British Medical Journal (The BMJ) said in a news release.

The researchers looked at data from seven U.K. Health Security Agency (UKHSA) surveillance systems collected from Jan. 1 to Aug. 2, 2020, and compared them to historical data. They divided the data into seven pandemic phases: pre-outbreak, early outbreak, pre-lockdown, early lockdown, late lockdown, lockdown easing and further easing. Data included organisms Shiga-toxin producing E.coli, norovirus, non-typhoidal Salmonella and Campylobacter among others.

They found that there was a whopping 52% decrease in GI outbreaks during the first six months of 2020 compared to the five-year average (2015-2019). Specifically, cases were still quite similar during the pre-outbreak phase but dropped by 22% during the early outbreak phase. This was much lower by 87% during the late lockdown phase and remained low during the rest of the COVID-19 response period.

They also found a 34% decrease in laboratory-confirmed cases. Even if the infections began to increase again starting from week 16, which was during the lockdown easing phase, the number was still much lower compared to the five-year average. These decreases were observed across all age groups and both sexes, the researchers noted.

According to the researchers, the trend could be explained by multiple factors. For one, there was a change in people's willingness to seek medical attention.

"Health seeking behavior changed substantially, with attendances decreasing prior to lockdown across all indicators," the researchers wrote.

Factors such as consultations, emergency care attendance calls to the 111 helpline regarding gastroenteritis and diarrhea/vomiting were lower than what was logged in 2019, the BMJ noted. Even if they eventually increased, they were still lower than the figures from 2019. Google searches related to such illnesses also dropped by weeks 11 and 13, while searches for "hand washing" and "disinfection" increased.

Still, it's likely that there was a "true decrease" because of the public health control measures that people adopted, the researchers said. Although transmission may vary depending on the pathogen, GI pathogens tend to be transmitted via contact with infected people, animals or contaminated surfaces, or by consuming contaminated food or drinks. In response to COVID-19, control measures included proper hand hygiene, social distancing and reducing social contact.

"This suggests that if some of these changes in behavior such as improved hand hygiene were maintained, then we could potentially see sustained reductions in the burden of GI illness," they wrote.

Overall, the researchers' work shows the marked effect of the pandemic on GI infections. That said, the researchers noted that they only looked at the first six months of the pandemic. Further analysis will have a look at the effect during further phases, such as during the relaxation of social distancing measures and the "usual winter outbreak period.