Second COVID-19 wave witnessed significantly higher mortality rate: ICMR study claims

Data collected under the NCRC were analysed to describe the differences in demographic and clinical features of COVID-19 patients recruited during these two successive waves.

File photo

New Delhi: The second COVID wave in India was slightly different than the first one, with higher mortality being reported in all age groups except those below 20 years, and more people developing acute shortness of breath and requiring supplemental oxygen and mechanical ventilation, a new study said on Saturday (July 3).

The study - Clinical profile of hospitalized COVID-19 patients in first and second wave of the pandemic: Insights from an Indian registry based observational study - was published in the Indian Journal of Medical Research and has been done by experts from the Indian Council of Medical Research (ICMR), All India Institute of Medical Sciences and National Centre for Disease Control (NCDC).

India witnessed a massive second surge of COVID-19 cases since March after a period of decline from September last year.

Data collected under the National Clinical Registry for COVID-19 (NCRC) were analysed to describe the differences in demographic and clinical features of COVID-19 patients recruited during these two successive waves, the study stated.

The NCRC, launched in September last year, is an ongoing multi-centre observational initiative, which provided the platform for the current investigation. Demographic, clinical, treatment and outcome data of hospitalized and confirmed COVID-19 patients were captured in an electronic data portal from 41 hospitals across India, it said.

Changes in symptoms:

Patients enrolled between September 1, 2020 and January 31, 2021 and February 1 to May 11, 2021 constituted the participants of the two successive waves respectively, it said.

As on May 11 this year, 18,961 individuals were recruited in the registry, 12,059 and 6,903 reflecting in-patients from the first and second waves respectively, it said.

The mean age of the patients was significantly lower in the second wave with higher proportion of patients in the younger age group intervals of less than 20 years, and 20-39 years, the study said.

It said approximately 70 per cent of the admitted patients were above 40 years in both the waves of the pandemic and the proportion of males were slightly lower in second wave as compared to the first.

The most common symptom was fever in both the waves, it said.

"In the second wave, a significantly higher proportion complained of shortness of breath, developed acute respiratory distress syndrome (ARDS), required supplemental oxygen and mechanical ventilation.

"Mortality also was significantly increased in the second wave in all age groups except in below 20 years," it said.

"The second wave of COVID-19 in India was slightly different in presentation than the first wave, with a younger demography, lesser comorbidities, and presentation with breathlessness in greater frequency," the study stated.

Incomplete data:

Noting that there were some limitations of the present investigation, it said the registry did not capture the initial phase of the first wave as data collection commenced from September 1, 2020.

There has been a considerable lag in obtaining a complete dataset due to time required for data verification and the unprecedented workload of the healthcare team involved in COVID-19 care. Hence, the outcome data were not available for many cases from the second wave, the study said.

Though the data was submitted from more than 40 hospitals across the country to the NCRC, data from some states like Maharashtra and Kerala were missing due to logistical reasons, thus constraining the national representation, it said.

Rapid and explosive spread of SARS-CoV-2 infection during the second wave of the pandemic in India resulting in huge caseload on the entire healthcare system of the country including the participating institutes, did not allow enrolling all in-patients in our registry.

(With inputs from news agencies)