In this post, we present the current focus of the COVID-19 literature, based on publications registered in PubMed as published during December 2020. During this month, there were 7 148 publications, and 907 keywords occurred in five or more manuscripts. We used a higher resolution this month, 1.5, and then the keywords divided into 10 clusters. To create the map, we used the LinLog method.

In the table below, we have listed the 15 most central keywords in each cluster. The topic in each cluster seems to be:

  • Cluster 1: Vaccines.
  • Cluster 2: Health care delivery
  • Cluster 3: Mental health issues
  • Cluster 4: Treatment
  • Cluster 5: Public health
  • Cluster 6: Testing
  • Cluster 7: Risk factors and mortality
  • Cluster 8: Children and socioeconomic factors
  • Cluster 9: Pregnancy
  • Cluster 10: Demographic

To open the map directly in VOSviewer, please use the Keyword co-occurrence MAP and NET files from January 6th, available through the Open Science Foundation (OSF) repository: https://osf.io/54gqw/

Cluster 1 Occurrences
antiviral agents 62
inflammation 84
animals 49
sars 66
hydroxychloroquine 58
covid-19 vaccines 42
vaccine 85
angiotensin-converting enzyme 2 39
spike glycoprotein, coronavirus 33
chloroquine 26
ace2 61
cytokines 31
antibodies, monoclonal 18
lopinavir 11
ritonavir 12
Cluster 2 Occurrences
united states 77
telemedicine 157
infection control 60
personal protective equipment 66
delivery of health care 49
united kingdom 25
health services accessibility 31
masks 34
singapore 14
emergency service, hospital 25
healthcare workers 40
mass screening 20
neoplasms 20
kidney failure, chronic 12
tertiary care centers 16
Cluster 3 Occurrences
surveys and questionnaires 113
cross-sectional studies 107
mental health 184
anxiety 137
depression 122
health personnel 78
stress, psychological 47
health knowledge, attitudes, practice 32
mental disorders 29
exercise 34
students 30
stress 53
quality of life 28
social media 38
social isolation 24
Cluster 4 Occurrences
treatment outcome 47
coronavirus infection 72
critical care 62
intensive care units 47
prospective studies 35
viral pneumonia 41
respiration, artificial 25
cohort studies 25
pneumonia 60
respiratory distress syndrome 25
case-control studies 18
critical illness 19
respiratory insufficiency 20
randomized controlled trials as topic 18
betacoronavirus 17
Cluster 5 Occurrences
china 123
public health 166
quarantine 86
physical distancing 64
italy 69
communicable disease control 68
disease outbreaks 63
epidemiology 81
lockdown 74
infectious diseases 83
incidence 37
contact tracing 41
health policy 56
spain 27
france 31
Cluster 6 Occurrences
covid-19 testing 78
time factors 41
tomography, x-ray computed 40
lung 42
antibodies, viral 32
rna, viral 29
asymptomatic infections 25
covid-19 nucleic acid testing 25
sensitivity and specificity 29
viral load 17
symptom assessment 9
reverse transcriptase polymerase chain reaction 13
algorithms 14
real time polymerase chain reaction 32
nasopharynx 12
Cluster 7 Occurrences
retrospective studies 130
risk factor 139
hospitalization 77
comorbidity 76
severity of illness index 59
mortality 112
prognosis 66
hospital mortality 30
biomarkers 44
hypertension 36
risk assessment 27
logistic models 15
diabetes mellitus 33
follow-up 19
obesity 38
Cluster 8 Occurrences
young adult 165
adolescent 160
children 140
child, preschool 53
infant 65
age factors 34
brazil 43
sex factors 20
socioeconomic factors 21
schools 22
hospitals 23
ethnic groups 11
health status disparities 13
parents 16
disease transmission, infectious 12
Cluster 9 Occurrences
pregnancy 51
infection 38
pregnancy complications, infectious 10
pregnant women 12
mothers 6
alcohol drinking 6
cesarean section 6
new york 5
breastfeeding 6
vertical transmission 9
disability 6
antibody response 5
neutralizing antibodies 5
Cluster 10 Occurrences
female 544
male 531
middle aged 381
adult 392
aged 293
aged, 80 and over 137