Introduction:
In December 2019, health authorities from Wuhan, Hubei province in China, local hospital were monitoring and reported group of pneumonia cases (Chinazzi et al., 2020; Haider et al., 2020). The specific pathogen triggering this viral pneumonia, on 7thJanuary 2020, was identified by Chinese Center for Disease Control and Prevention, and was named 2019-nCov, the new coronavirus, by the World Health Organization (Chen et al., 2020). Further investigations traced the origin of 2019-nCoV to a local Huanan seafood market. Since then 2019-nCoV was exported to many cities across the globe (Wu, Leung, & Leung, 2020) and ~12.6 million people have been infected due to 2019-nCoV resulting in more than 68000 deaths across the globe as on 7th April 2020, marking this as one of the biggest pandemics in this century. Since the detection of the first case in December 2019 in China, the 2019-nCoV has already reached in more than 200 countries/territories, with ~62% of infected cases are being in USA (26.3%), Spain (10.4%), Italy (10.2%), Germany (7.9%), and France (7.1%). There is no doubt that 2019-nCoV outbreak is posing the serous risk for human well-being and the world economy (Boldog et al., 2020; Hui et al., 2020).
India, the second most populous country in the world with total population of ~1.35 billion inhabitants, registered its first case on 30th of January 2020, as a 20-year-old female medical student, along with two other students, travelled from Wuhan to the south-western state, Kerala. Since then India has registered ~657 cases till 25th March, out of which ~62% were reported to be the imported cases traveling from various other affected countries. Eventually, India then suspended all international flights to curb the domestic spread due to 2019-nCoV on 25th March 2020. Right from the early days of the pandemic, body temperature screening to verify if the traveler has a fever, as an indication for the infection, as a major test was introduced at all international airports in India. However, it has been noticed that asymptomatic contact transmission of 2019-nCoV and passengers successfully passing the symptom-based screening have been tested positive for 2019-nCoV (Bwire & Paulo, 2020). If such passengers passing thermal screening test are later tested positive for 2019-nCoV, challenges this approach as body temperature screening could miss the passenger incubating the disease or concealing the fever by other means during the travel (Bwire & Paulo, 2020). Further to this India has also introduced an additional step of marking the passenger arriving from most affected countries and compelling self-isolation or home quarantine for the 14 days upon arriving in India.
The timing of 2019-nCoV outbreak and aftermath encompassing the lunar new year celebrations in China coincided with very large amount of human movement between China and rest of the world imposing major threat for rapid spread of infection (Haider et al., 2020). Owing to such risk it was important that countries take timely decisions to suspend the flights from affected areas, mainly from Chinese cities in this case. Amid the 2019-nCoV outbreak, WHO has observed that many countries are violating the International Health Regulations (IHR) defying the travel restriction against China during 2019-nCoV outbreak (Habibi et al., 2020). Further, many researchers in this direction have already made the assessments of risk of 2019-nCoV spread from China to the rest of the world including the effect of travel restriction on spread of 2019-nCoV (Anzai et al., 2020; Backer, Klinkenberg, & Wallinga, 2020; Boldog et al., 2020; Chinazzi et al., 2020; Gilbert et al., 2020; Nishiura et al., 2020; Pullano et al., 2020). Thus, while the outbound risk from China to many other countries/territories have been investigated in detail, the inbound risk of 2019-nCoV infection particularly to hugely populated India, however, is not investigated. Here, in a maiden attempt we estimate the risk of importation of 2019-nCoV due to international arrivals in India by screening available data from 19 international airports across the globe and developing the index for risk assessment.