Related Experiment Video
Updated: Aug 7, 2025

Nasal Brushing Sampling and Processing Using Digital High Speed Ciliary Videomicroscopy – Adaptation for the COVID-19 Pandemic
Published on: November 7, 2020
Clinico-demographic profile of COVID-19 positive patients - first wave versus second wave - an experience in
Abhijit Kumar Prasad1, Annie Bakorlin Khyriem2, Wihiwot Valarie Lyngdoh2
1Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Raipur, India.
Introduction:
India witnessed two distinct COVID-19 waves. We evaluated the clinico-demographic profile of patients infected during first wave (FW) and second wave (SW) in a hospital in north-east India.
Methodology:
Patients who tested positive for severe acute respiratory syndrome-coronavirus-2 specific gene by reverse transcriptase polymerase chain reaction across FW and SW were diagnosed as COVID-19 positive. The clinico-demographic data of these positive patients were retrieved from the specimen-referral-form. Vital parameters including respiratory rate, SpO2, data on COVID-19-associated mucormycosis (CAM), COVID-19-associated acute respiratory distress syndrome (CARDS) were obtained from hospital records for in-patients. Patients were categorized based on disease severity. The data obtained in both waves were analyzed comparatively.
Results:
Out of a total of 119,016 samples tested, 10,164 (8.5%) were SARS-CoV-2 positive (2907 during FW, 7257 during SW). Male predominance was seen across both waves (FW: 68.4%; SW:58.4%), with more children infected during SW. Patients with travel history (24%) and contact with laboratory confirmed cases (61%) were significantly higher during SW relative to FW (10.9% and 42.1% respectively). Healthcare worker infection was higher in SW (5.3%). Symptoms like vomiting [14.8%], diarrhea [10.5%], anosmia [10.4%] and aguesia [9.4%] were more in SW. More patients developed CARDS in SW (6.7%) compared to FW (3.4%) with 85% and 70% patients expiring across FW and SW respectively. No case of CAM is documented in our study.
Conclusions:
This was probably the most comprehensive study from north-east India. Industrial oxygen cylinder usage may have been the source of CAM in the rest of the country.
Related Concept Videos
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health...
Pareto Chart
The Pareto chart is named after the Italian economist Vilfredo Pareto, who described the Pareto...
Bias in Epidemiological Studies
COPD: Pathogenesis and Clinical Features
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...
Pulmonary Tuberculosis II
Here is a detailed explanation of its pathophysiology:
Transmission: The process begins when a person inhales droplet nuclei containing M. tuberculosis. These are typically released into the air when an individual with pulmonary or...
Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...

