Corpus downloaded from PubMed 18th May: 13103 publications. There were 1861 keywords that occurred in three or more manuscripts. These divided into four main clusters.

This week’s rapport strengthens our observation from last couple of weeks that the clusters and topics seem to vary less, signifying that cluster may be more robust. This is true even if cluster 1 and 2 have changed places. Maybe this switch could imply that research and publication is switching more to how to managing the disease, than mainly be focused on the understanding of the phenomenon. In cluster 3 the term(s) (hydroxyl)chloroquine is  rising on the list. Last week there was a fifth cluster that we called “clinical issues”, but the terms included in this cluster have returned to the third cluster where they originated.


Cluster 1 could be called “disease epidemiology” and includes terms like pneumonia, epidemiology, outbreak, infection, infectious diseases, novel coronavirus pneumonia, treatment and transmission. This cluster contains 2 major topics: a) the main term “the disease” which in addition to the above mentioned terms, but also b) “inpatient care” which contains terms like ARDS, critical illness and airway management. In this cluster some smaller topics are also present.

Cluster 2 could be called «global virus pandemic» and includes terms (beta)coronavirus infection, viral pneumonia, pandemic/epidemic, public health, infection control and quarantine. This cluster contains 3 main topics a) “preventive epidemiology”, which in addition to the terms public health and quarantine contains terms like disease outbreak, travel and contact tracing, b) “care management” which includes terms like infection control, practice guidelines and health personnel and c) “vulnerability” that contains terms like mental health, psychological stress and health service accessibility.


Cluster 3 could be called “pathophysiology and origin” and includes terms like SARS, animals, zoonosis, antiviral agents, viral genome, phylogeny and chiroptera. This cluster contains to major topics: a) “viral biology” which in addition to terms like SARS, animals, viral genome and phylogeny includes terms like spike glycoprotein and peptidyl-dipeptidase a and b) “drug treatment” which in addition to the term antiviral agent, (hydroxyl)chloroquine and chiroptera contains terms like traditional Chinese medicine and lopinavir.

Cluster 4 could be named “clinical epidemiology” and contains terms like mortality, age, gender, clinical laboratory techniques and fever. Also in this cluster, there is only this major topic. Smaller topics include “population care”, “serology” and “pregnancy”.

Table of the most central keywords in each cluster

(Centrality measure used is weighted degree centrality)

Cluster 1 Cluster 2 Cluster 3 Cluster 4
pneumonia coronavirus infection sars female
epidemiology viral pneumonia animals male
outbreak pandemic antiviral agents adult
viruses betacoronavirus peptidyl-dipeptidase a middle aged
infection china zoonosis clinical laboratory techniques
infectious diseases disease outbreaks spike glycoprotein, coronavirus aged
mortality public health genome, viral young adult
treatment infection control hydroxychloroquine tomography, x-ray computed
critical illness travel viral vaccines children
respiratory infections quarantine chloroquine adolescent
transmission epidemic phylogeny lung
diagnosis global health antibodies, viral risk factor
prevention united states chiroptera retrospective studies
novel coronavirus pneumonia italy clinical trials as topic fever
ards health personnel middle east respiratory syndrome coronavirus aged, 80 and over
virology personal protective equipment ace2 infant
influenza practice guidelines as topic receptors, virus cough
guidelines time factors wuhan child, preschool
japan telemedicine cardiovascular diseases comorbidity
therapy mental health inflammation real-time polymerase chain reaction
acute respiratory distress syndrome contact tracing mers severity of illness index
telehealth world health organization angiotensin-converting enzyme inhibitors pregnancy
immunosuppression united kingdom immunization, passive surveys and questionnaires
lymphopenia infectious disease transmission, patient-to-professional lopinavir hospitalization
respiratory tract infections critical care hypertension prognosis


Cluster description in progress

To open the map directly in VOSviewer, please use these two files.


The maps are created with the following “thesaurus” to clean the data: