World Health Organisation (WHO)’s regional director (South-East Asia) Dr Poonam Khetrapal Singh says there is no difference in the protection medical masks and N95 respirators offer. She says scientific evidence shows both result in large reduction in the spread of Covid-19. In an interview to Sanchita Sharma, Singh also spoke about the need for the general population to wear fabric or medical masks in public places. Edited excerpts:
What is better? N95 respirator or surgical mask?
Randomised controlled trials do not show any difference between medical/surgical masks and N95 respirators in reducing the transmission of airborne infections. Some observational studies also show both medical masks and N95 result in large reductions in the transmission of coronavirus.
WHO recommends health care workers use N95 masks and other protection when conducting aerosol-generating procedures or in settings where these procedures are occurring. It is usually in health care settings, for example, when a health worker is intubating a patient.
What is the evidence regarding the protection provided by masks?
Masks are a part of a comprehensive package of measures to suppress transmission and save lives. The use of a mask alone is insufficient to provide an adequate level of protection.
What kind of mask should the general public wear?
The general public is advised to wear non-medical, fabric masks where there is a widespread transmission and limited capacity to implement control measures, such as case-finding and contact tracing. Wearing masks is important where physical distancing is not possible, such as on public transport, in shops or in other confined or crowded environments.
Following WHO research and development meeting in February, a research group was requested to conduct a study on masks. The study identified preferable types of fabrics, the number of layers, and the composition of a non-medical mask. It should include an inner layer of absorbent material such as cotton, a middle layer of non-woven material such as polypropylene, and an outer layer of a non-absorbent material such as polyester or polyester blend. The mask should allow you to breathe while talking and walking briskly.
With cases rising, what actions are needed to prevent a surge?
The transmissibility and severity of Covid-19 have not changed. …Severity also remains consistent. We know that the virus causes a range of illnesses, with a majority of people having experienced mild symptoms and 20% a more severe disease. As the transmission of Covid-19 is not typically homogenous within the country, a national risk assessment should be supported and implemented through sub-national or even community-level risk assessment. We need to aggressively implement core public health measures – detect and test, isolate and treat, and trace contacts, promote safe hygiene practices and respiratory etiquette, protect health workers, and increase health system capacity. This is a pandemic. It needs a whole-of-society approach. Our fight against Covid-19 is far from over. The world is still facing a big wave of the Covid-19 pandemic.
Do lockdowns work if infection rates are high?
Lockdowns have multiple objectives as public health measures for social distancing, to slow down the virus transmission, and to allow the healthcare systems enough time to strengthen infrastructure and capacities. The cornerstone of the response in any transmission scenario continues to be to find, isolate, test and care, and to trace and quarantine contacts.
Is more testing needed to diagnose and isolate?
Testing is an important component of surveillance and guides contract tracing, isolation, and treatment. It also shows where response efforts need to be directed to combat the disease. India has been calibrating its testing strategy as per the changing situation, taking into account scope, need, and capacity. With increased testing, the trajectory of positive cases will go up. But it will also help in better preparedness and response.
What is the role of antibody tests?
The PCR-based tests are better for telling whether you are infected or not and the serology, or the blood test, is better to detect whether you have been infected recently or in the past.
Tests to detect antibody responses to Covid-19 in the population will be critical to support the development of vaccines. Based on current data, WHO does not recommend the use of antibody-detecting rapid diagnostic tests for patient care.
