Aðalsteinn Dalmann Gylfason¹
Agnar Bjarnason^1,2
Kristján Orri Helgason³
Kristján Godsk Rögnvaldsson¹
Brynja Ármannsdóttir³
Ingibjörg J. Guðmundsdóttir^1,4
Magnús Gottfreðsson^1,2,5

¹Faculty of Medicine, School of Health Sciences, University of Iceland, ²Department of infectious diseases, Landspitali University Hospital, ³Department of clinical microbiology, Landspitali University Hospital, ⁴Department of cardiology, Landspitali University Hospital, ⁵Department of science, Landspitali University Hospital.

Correspondence: Magnús Gottfreðsson, magnusgo@landspitali.is

Key words: Non-pharmaceutical interventions, covid-19, influenza, myocardial infarction, pneumonia, blood stream infections, sexually transmitted diseases.

 

INTRODUCTION: Nonpharmaceutical interventions to contain the spread of COVID-19 infections in Iceland in 2020 were successful, but the effects of these measures on incidence and diagnosis of other diseases is unknown. The aim of this study was to evaluate the impact of the COVID-19 pandemic on the diagnosis of myocardial infarction (MI) and selected infections with different transmission routes.

MATERIALS AND METHODS: Health records of individuals 18 years or older who were admitted to Landspitali University Hospital (LUH) in 2016-2020 with pneumonia or MI were extracted from the hospital registry. We acquired data from the clinical laboratories regarding diagnostic testing for Chlamydia trachomatis, influenza, HIV and blood cultures positive for Enterobacterales species. Standardized incidence ratio (SIR) for 2020 was calculated with 95% confidence intervals (95%CI) and compared to 2016-2019.

RESULTS: Discharge diagnoses due to pneumonia decreased by 31% in 2020, excluding COVID-19 pneumonia (SIR 0.69 (95%CI 0.64-0.75)). Discharge diagnoses of MI decreased by 18% (SIR 0.82 (95%CI 0.75-0.90)), and emergency cardiac catheterizations due to acute coronary syndrome by 23% (SIR 0.77 (95%CI 0.71-0.83)), while there was a 15% increase in blood stream infections for Enterobacterales species (SIR 1.15 (95%CI 1.04-1.28)). Testing for Chlamydia trachomatis decreased by 14.8% and positive tests decreased by 16.3%. Tests for HIV were reduced by 10.9%, while samples positive for influenza decreased by 23.6% despite doubling of tests being performed.

CONCLUSION: The number of pneumonia cases of other causes than COVID-19 requiring admission dropped by a quarter in 2020. MI, chlamydia and influenza diagnoses decreased notably. These results likely reflect a true decrease, probably due to altered behaviour during the pandemic.

Fig 1.

Table I.

95% CI, 95% confidence intervals. SIR, standardized incidence ratio.

Disease	Observed 2020	Expected 2020	SIR	CI (95%)
Pneumonia - Admissions	622	898	0,69	0,64-0,75
Myocardial infarction - Admissions	443	539	0,82	0,75-0,90
Emergency percutaneous coronary interventions	665	866	0,77	0,71-0,83
Enterobacterales blood stream infections	335	291	1,15	1,04-1,28

 

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