Table 2.

Five clusters, their top 10 stemmed words from the TF‐IDF analysis on the subset, their topics and number of articles in the cluster

	Top 10 words based on TF‐IDF score	Topic	N
1	disord, social, diseas, studi, public, mental, patient, psychiatr, ptsd, health	Mental health	26
2	viral, may, caus, patient, diseas, immun, cell, vaccin, virus, infect	Viral diseases	38
3	cell, treatment, disord, studi, infect, diseas, zikv, may, children, patient	Diagnoses and treatments	57
4	breastfeed, hospit, patient, pneumonia, vaccin, infect, bronchiol, rsv, infant, children	Maternal care and paediatrics	33
5	virus, interact, dna, bind, express, activ, rna, gene, cell, protein	Genetics	105

Using a more extensive set of stopwords might have filtered ‘may’ and ‘caus’ out. ‘zikv’ is the often used abbreviation for Zika virus.