Outbreaks of publications about emerging infectious diseases: the case of SARS-CoV-2 and Zika virus

Ipekci, Aziz Mert; Buitrago-Garcia, Diana; Meili, Kaspar Walter; Krauer, Fabienne; Prajapati, Nirmala; Thapa, Shabnam; Wildisen, Lea; Araujo-Chaveron, Lucia; Baumann, Lukas; Shah, Sanam; Whiteley, Tessa; Solís-García, Gonzalo; Tsotra, Foteini; Zhelyazkov, Ivan; Imeri, Hira; Low, Nicola; Counotte, Michel Jacques

BACKGROUND: Outbreaks of infectious diseases generate outbreaks of scientific evidence. In 2016 epidemics of Zika virus emerged, and in 2020, a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic of coronavirus disease 2019 (COVID-19). We compared patterns of scientific publications for the two infections to analyse the evolution of the evidence. METHODS: We annotated publications on Zika virus and SARS-CoV-2 that we collected using living evidence databases according to study design. We used descriptive statistics to categorise and compare study designs over time. RESULTS: We found 2286 publications about Zika virus in 2016 and 21,990 about SARS-CoV-2 up to 24 May 2020, of which we analysed a random sample of 5294 (24%). For both infections, there were more epidemiological than laboratory science studies. Amongst epidemiological studies for both infections, case reports, case series and cross-sectional studies emerged first, cohort and case-control studies were published later. Trials were the last to emerge. The number of preprints was much higher for SARS-CoV-2 than for Zika virus. CONCLUSIONS: Similarities in the overall pattern of publications might be generalizable, whereas differences are compatible with differences in the characteristics of a disease. Understanding how evidence accumulates during disease outbreaks helps us understand which types of public health questions we can answer and when. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12874-021-01244-7.