Ordinarily, Biosafety level (BSL)-3 labs are enough to handle respiratory viruses. SARS and MERS were handled with these labs. But for coronavirus, the labs being used are BSL-4 labs. This could possibly be due to extra precautions or fear of it being much more deadly than SARS.

BSL-4 suit laboratories are designed to study high-consequence pathogens for which infection prophylaxes or treatment options do not exist. The key features of such laboratories include customized airtight doors, dedicated supply and exhaust airflow systems, a negative-pressure environment, and use of positive-pressure (“space”) suits.

Firm training and adherence to strict safety protocols and standard operating procedures minimize the risks for specialists working with highly pathogenic agents. Researchers switch to BSL-4 suit laboratories when working with a high-consequence pathogen.

Entering and exiting the BSL-4 suit laboratories are complex and time-consuming in comparison with BSL-2 and BSL-3 laboratories.

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA