Coronavirus outbreak: A report published in the ICMR's Indian Journal of Medical Research (IJMR) has used a mathematical model based on the primary understanding of the coronavirus-induced COVID-19 to understand what intervention strategies would work more effectively in containing the spread of the virus. The study was published by the ICMR on Monday in the journal's special edition on coronavirus.
The study, which was completed on February 27, aimed to find out if the screening of passengers and travel restrictions could contain or delay the outbreak in a country, and in case of countries where in-country transmission had started, the study aimed to understand how quarantine would impact the spread of the disease.
What were the key findings of the study?
The study found that for a substantial delay in the outbreak, there was a need to screen all symptomatics and identify at least 75% asymptomatic individuals with infections. Moreover, if the identification of asymptomatic individuals having infections was increased to 90%, then it could delay the average time for the outbreak by 20 days. However, the study deemed this level of screening to be infeasible. It further stated that no matter how effectively the measures to contain symptomatic individuals are undertaken, it would be negated by the asymptomatic individuals who would escape the screening process and aid in the transmission of the disease.
On the other hand, if the government undertakes quarantining measures and, in an optimistic scenario, quarantines 50% of the symptomatic cases within three days of development of symptoms, it could reduce the cumulative incidence by 62%, having a flattening effect on the curve of the outbreak.
The research, thus, makes a case for more emphasis on the intervention strategy involving post-travel tracking rather than undertaking screening at the border, itself, according to the IE report. However, the report adds, the study took into account the factor that an outburst of cases would make confirmations tests impossible and thus proposed that the intervention strategy should include surveillance of symptomatic individuals along with the quarantine measures.
Limitations of the study
The paper only used the data for airport arrivals and that too from certain areas in China, while now cases of coronavirus in India have been imported from places like Italy, Middle East and the UK also. The paper also states that for the purpose of the study, the authors only created scenarios of metropolitan cities with highest population density, while ignoring the rural population around these cities and their chances of migrating to the cities or the connectivity.