Infectious diseases other than Covid-19 in 2020, a report from Lombardy Region

Background Non pharmaceutical interventions (NPIs) put in place to reduce the spread of Sars-Cov-2 had an impact also on other infections. Aim of this research is to describe the incidence of other infections and vaccination coverage rate (VCR) in Lombardy region from 2018 to 2020. Methods We analysed data coming from the regional surveillance system of notifiable infectious diseases and vaccination registry from 2018 to 2020. Results 13206 infectious diseases' cases were notified in 2020 compared to 36847 in 2019 and 42610 in 2018, this corresponding to, respectively, a 64.1% and 69% decrease. Some interesting data: measles; 24 cases in 2020, 542 in 2019 and 220 in 2018, with an incidence rate (IR) per 100.000 respectively of 0,2; 5,4 and 2,2; chicken pox; 2357 cases in 2020, 13478 in 2019 and 19463 in 2018 (IR 23,5; 134,3; 193,9) tubercolosis; 586 in 2020, 857 in 2019 and 945 in 2018 (IR 5,8; 8,6; 9,4) invasive bacterial diseases; 378 in 2020, 890 in 2019 and 882 in 2018 (IR 3,7;8,8;8,7) infectious diarrhea; 2080 in 2020, 3716 in 2019 and 4347 in 2018 (IR 20,7; 37,1; 43,3) legionellosis cases; 806 in 2020, 1051 in 2019 and 1096 in 2018 (IR 8; 10,5; 10,9) arbovirus infections (chikunguya, dengue, west nile, zika) were 118, in 2020, 126 in 2019 and 8 in 2018 (IC 1,2; 1,3; 0,1) In 2020 VCR at 24 months of age remained above 95% for hexavalent and measles-mumps-rubella vaccination while there was a decline for others vaccines. Conclusions During the COVID-19 outbreak in 2020 there was a decline in all notified infectious diseases compared to the previous years, likely due to massive NPIs adoption, as well as, possibly, to decreased access to care and preventive services that caused difficulties to the surveillance system to detect notifiable infectious diseases. VCRs were still high for most important vaccines while there was a decline for other vaccines as evidence of the impact of the pandemic on vaccination activities. Key messages NPIs had a deep impact on the reduction of airborne diseases. The decline for non-airborne infections is likely due to NPIs and limitations in the access to the healthcare system.