Pandemic SARS-CoV-2 laboratory preparedness in India: An opportunity beyond diagnostics

Sir,

I read the article on laboratory preparedness for SARS-CoV-2 testing in India published recently1, and want to put here a few points that may need attention of the authors.

The article is useful to guide the ongoing and any future pandemic response for early containment. However, some more information provided below may be of great help in better understanding of the COVID transmission. The abstract section indicated that quarantined individuals were tested twice at days 0 and 14. From both abstract and result sections, it seemed that the testing of suspected cases and contact was conducted once, but it was not clearly mentioned. If repeat testing of these cases were conducted, the results should be reported. It is presumed that an asymptomatic suspect with a travel history, but tested negative for COVID-19 once during the symptomatic phase, will not necessarily exclude COVID-19 infection. Hence, these reports will validate the need for such repeat testing even for symptomatic group. The symptoms might have been due to a non-COVID aetiology, and there could be a possibility of the viral shedding in the later dates, which might be a factor for transmission.

Among 1,369 individuals included for diagnostic evaluation based on the inclusion criteria, the details of travel history were not available in 106 individuals and of the rest 1,263 having the details of travel history, the details of 24 individuals were missing from the information provided (1,081 had documented foreign travel and 158 did not have pertinent overseas travel history, which accounts for a total of 1,239 individuals). As per the inclusion criteria, only close contacts of confirmed positive cases of COVID-19 infection were not supposed to have a history of overseas travel. The report also included 67 samples from 64 contacts leading to a little mismatch in the statistics.

Since the article was intending to focus on the preparedness and networking of laboratories skilled enough to undertake viral diagnostics in the country in a health emergency; the authors did not emphasize upon the transmissibility issues during the symptomatic and asymptomatic periods of COVID-19 infection. I feel that reporting of the above information will be useful to delineate the natural history of this newly emerging public health threat. This also carries relevance in a setting, where the incubation period can range from 0 to 24 days, and there is a possibility of missing cases, which is evident from the recent World Health Organization (WHO) report of revision of caseload in Wuhan as per the Chinese authorities' information to the WHO234. The information on the natural history and transmission of the virus will also be helpful, which is also a research priority to meet the coronavirus disease 2019 challenges5.