Investigation of early epidemiological signals of COVID-19 in India using outbreak surveillance data

Background: The epidemic of novel coronavirus disease (COVID-19) started in Wuhan, China, in December 2019, has been progressed to a pandemic level with high morbidity and mortality affecting many countries globally. Due to varied clinical characteristics of the disease, diagnosis can be missed easily among the affected population. The epidemiological data and early signals of COVID-19 infection are crucial for the disease investigation. Aim: To assess the presence of early signals of COVID-19 in India before official reporting of cases in the country and to compare epidemiological characters using different surveillance sources in the study. Methods: This study uses Epiwatch outbreaks surveillance data from November 2019 to March 2020 was used to determine the trend of pneumonia of unknown causes in India in order to assess if the COVID-19 could have been detected before the first case was reported.The search was carried out using the search terms defined in the study to identify the early signals of COVID-19.The COVID-19 line list extracted from the crowdsourced database (https://www.covid19india.org/) was additionally used to determine the demographic characteristics of cases. A descriptive analysis was conducted. Results: A total of 379 reports was extracted from Epiwatch. In 2019, there were only six reports of pneumonia of unknown causes in India, and the majority of the reports were focused on swine flu or undetected influenza cases. In 2020, there were 312 news reports of unknown pneumonia and COVID-19. The early signals of COVID-19 in India were observed from 24th January 2020 as the trend of pneumonia news had moderately increased. The trend of pneumonia reporting was low before the first confirmed case was reported in India. The study findings also suggested that there was under-reporting of COVID-19 cases in India by the World Health Organization (WHO) and the Ministry of Health, India when compared to data reported by Epiwatch and the line list. Conclusion: The study findings suggested that there were early signals of COVID-19 in India around 24th January when there was a slight increase in the trend of pneumonia reports in the country. The number of COVID-19 cases in India is under-reported by the Ministry of Health and the WHO. The use of online media surveillance reports such as Epiwatch and the line list could provide real-time assessment and timely investigation of emerging diseases globally.