Chakravarty Aranyak, Panchagnula Mahesh V, Patankar Neelesh A
School of Nuclear Studies and Application, Jadavpur University, Kolkata, India.
Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India.
Front Physiol. 2023 Jan 19;14:1073165. doi: 10.3389/fphys.2023.1073165. eCollection 2023.
Respiratory viruses, such as SARS-CoV-2, preliminarily infect the nasopharyngeal mucosa. The mechanism of infection spread from the nasopharynx to the deep lung-which may cause a severe infection-is, however, still unclear. We propose a clinically plausible mechanism of infection spread to the deep lung through droplets, present in the nasopharynx, inhaled and transported into the lower respiratory tract. A coupled mathematical model of droplet, virus transport and virus infection kinetics is exercised to demonstrate clinically observed times to deep lung infection. The model predicts, in agreement with clinical observations, that severe infection can develop in the deep lung within 2.5-7 days of initial symptom onset. Results indicate that while fluid dynamics plays an important role in transporting the droplets, infection kinetics and immune responses determine infection growth and resolution. Immune responses, particularly antibodies and T-lymphocytes, are observed to be critically important for preventing infection severity. This reinforces the role of vaccination in preventing severe infection. Managing aerosolization of infected nasopharyngeal mucosa is additionally suggested as a strategy for minimizing infection spread and severity.
呼吸道病毒，如严重急性呼吸综合征冠状病毒2（SARS-CoV-2），最初感染鼻咽黏膜。然而，感染从鼻咽扩散到深部肺部（这可能导致严重感染）的机制仍不清楚。我们提出了一种临床上合理的感染扩散机制，即存在于鼻咽部的飞沫被吸入并输送到下呼吸道，从而扩散到深部肺部。运用了一个关于飞沫、病毒传播和病毒感染动力学的耦合数学模型来证明临床上观察到的深部肺部感染时间。该模型预测，与临床观察结果一致，在初始症状出现后的2.5至7天内，深部肺部可能会发展为严重感染。结果表明，虽然流体动力学在飞沫传输中起重要作用，但感染动力学和免疫反应决定了感染的发展和消退。观察到免疫反应，特别是抗体和T淋巴细胞，对于预防感染严重程度至关重要。这强化了疫苗接种在预防严重感染中的作用。此外，建议对受感染的鼻咽黏膜进行雾化处理，作为减少感染传播和严重程度的一种策略。
