|LETTER TO EDITOR
|Year : 2021 | Volume
| Issue : 2 | Page : 131
Air droplet versus airborne transmission – Essential concepts for understanding COVID-19 infection control
Vinoth Kumar Kalidoss1, Satvinder Singh Bakshi2
1 Department of Community and Family Medicine, AIIMS, Mangalagiri, Guntur, Andhra Pradesh, India
2 Department of ENT and Head and Neck Surg, AIIMS, Mangalagiri, Guntur, Andhra Pradesh, India
|Date of Submission||06-Aug-2021|
|Date of Decision||04-Oct-2021|
|Date of Acceptance||07-Sep-2021|
|Date of Web Publication||30-Nov-2021|
Satvinder Singh Bakshi
Department of ENT and Head and Neck Surgery, AIIMS, Mangalagiri, Guntur - 522 503, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kalidoss VK, Bakshi SS. Air droplet versus airborne transmission – Essential concepts for understanding COVID-19 infection control. Dent Med Res 2021;9:131
|How to cite this URL:|
Kalidoss VK, Bakshi SS. Air droplet versus airborne transmission – Essential concepts for understanding COVID-19 infection control. Dent Med Res [serial online] 2021 [cited 2022 Jul 4];9:131. Available from: https://www.dmrjournal.org/text.asp?2021/9/2/131/331396
Air droplet transmission occurs through large infected droplets (>5 μm) during coughing, sneezing, talking, or singing by infected person to the person nearby (within 1 m). Infections such as Neisseria meningitidis, Streptococcus, and Respiratory syncytial virus transmit through air droplets. The transmission can occur either directly from person to person in close contact or indirectly through contaminated objects or surface (fomite transmission). In March 2020, the World Health Organization (WHO) suggested current coronavirus disease - 2019 (COVID-19) pandemic is primarily transmitted via respiratory droplets. In this context, they recommended preventive and control measures such as physical barriers, physical distancing, use of masks within droplet distance (within 1 m), respiratory etiquette, and wearing high-grade protection such as respirator, N95 or FFP2, or FFP3 masks during aerosol-generating procedures (AGPs).
Airborne infections are transmitted through droplet nuclei <5 μm in diameter and can remain in the air for a longer period of time and therefore can be transmitted to others over distances >1 m. Infections such as tuberculosis, measles, and chickenpox are transmitted through airborne route. Prevention and control measures for airborne transmission require measures to avoid inhalation of infectious aerosols, including natural ventilation, air filtration (HEPA-filter if room air is re-circulated), reducing crowding and time spent indoors, use of masks whenever indoors, attention to mask quality and fit, and higher-grade protection (N95 or FFP2 or FFP3) for health-care staff and frontline workers.
In the context of the current pandemic, WHO in July 2020 started evaluating the possibility of airborne transmission of SARS-CoV-2 in the absence of AGPs, particularly in indoor settings with poor ventilation. Greenhalgh et al. in their manuscript enumerated many possible explanations for airborne transmission of SARS-CoV-2. This discovery has two important implications: first, crowded and poorly ventilated places have high risk of transmission and second, we may need to use N95 or equivalent respirators even in the absence of AGP. The WHO Environment and Engineering Control Expert Advisory Panel for COVID-19 on the environment and engineering controls has given multiple recommendations regarding ventilation in various settings for control of the infection. These recommendations should be incorporated by governments worldwide in their fight against the coronavirus.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Ather B, Mirza TM, Edemekong PF. Airborne Precautions. StatPearls. Treasure Island (FL): StatPearls Publishing; 2021.
Greenhalgh T, Jimenez JL, Prather KA, Tufekci Z, Fisman D, Schooley R. Ten scientific reasons in support of airborne transmission of SARS-CoV-2. Lancet 2021;397:1603-5.