I’ve been thinking about the current influenza season which is upon us and whether all of the Covid prevention measures will lower the number of cases. Additionally I tried to find information on the effect of those measures on overall infectious disease rates. There isn’t a lot of data out there but here’s what I found.
This article published in the New England Journal of Medicine, Journal Watch looked at infections in children. The researchers looked at data from a large pediatric practice in Massachusetts specifically the incidence of acute otitis media, bronchiolitis, common cold, croup, gastroenteritis, influenza, nonstreptococcal pharyngitis, pneumonia, sinusitis, skin and soft tissue infections, streptococcal pharyngitis, and urinary tract infections. They compared cases in 2019 vs. 2020 and found that diagnosis rates per 100,000 patients were significantly lower after social distancing. Interestingly, reported cases of influenza, croup, and bronchiolitis almost disappeared ! You can read the summary article here: https://www.jwatch.org/na52378/2020/09/03/impact-covid-19-social-distancing-other-infections
In early May shortly after the shutdowns, there was an article in Nature magazine that noted a dramatic drop in late Spring influenza disease. Seasonal flu cases in the northern hemisphere usually peak in February and tail off by the end of May. Lab confirmed cases of influenza dropped dramatically in April worldwide. “The data comes from tests of more than 150,000 samples from national influenza laboratories in 71 countries that report data to FluNet, a global surveillance system.” This finding was also confirmed when looking at New York state data. The conclusion was that “measures such as movement restrictions, social distancing and increased personal hygiene likely had an effect on decreasing influenza and other respiratory virus transmission”. Co-author, infectious-disease researcher Pak-leung Ho at the University of Hong Kong also noted drops in chicken pox, measles and rubella. Interestingly sexually transmitted diseases ALSO showed a drop off in new cases! I’ll have to look at birth rates next !! The article in its entirety is here: https://www.nature.com/articles/d41586-020-01538-8
But not all of the news is good in regards to Covid distancing. An article in The Lancet discusses the disruption of routine Tuberculosis services. They looked at mathematical models of TB transmission in three high incidence countries: India, Kenya and Ukraine. They “estimated that a 3-month suspension of TB services, followed by 10 months to restore to normal, would cause, over the next 5 years, an additional 1⋅19 million TB cases and 361,000 TB deaths in India; 24,700 (16,100–44,700) TB cases and 12,500 deaths in Kenya, and 4,350 cases and 1,340 deaths in Ukraine. The primary cause was predicted to be the undetected TB cases during lockdown. An abstract of the study is found here: https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(20)30347-3/fulltext
There appear to be definite changes in some very important infectious disease transmission rates during Covid distancing. Time will tell if overall awareness of preventive measures such as hand washing, covering coughs and isolating when feeling ill will be long lasting beyond the Covid pandemic. I think it is likely that the days of going to school and work when not fully well may be over. If that’s the case, some of the decreases in infectious disease rates may be long lasting after we’ve gotten Covid under control through vaccines, therapeutics and herd immunity. Could there actually be something positive from all of this?
