Is lockdown an effective strategy to control infections like COVID-19? Might be! – shows this new study from Pune

By Dr. Jaimini Sarkar

A group of scientists from Pune did a recent study on the impact of local and national lockdowns on COVID-19. (Pic: Maharashtra Times)

Background

Do you remember the day when Prime Minister Narendra Modi declared the nationwide lockdown to tackle the spread of COVID-19 across the country in 2020? The move sparked a debate on whether it was the right step to control the infection or not? Was the timing of imposing and lifting the lockdown apt? Was there any science and evidence behind such an important move? Did nationwide lockdown achieve the desired results or area-specific lockdown was more successful? All of these questions have been a topic of research for a lot of researchers and scientists in the country.

One such group of scientists from Pune did a recent study on the association of regional and national lockdowns on COVID-19. The research study was published in the globally renowned Nature journal-Scientific Reports.

On 24th March 2020, Prime Minister Narendra Modi via television, called for a nationwide lockdown of 21 days to break the chain of infection. The move came at a time when there were 519 confirmed cases of Coronavirus in India and 10 deaths were reported across the country. The government stated that nations with the best medical facilities also struggled to contain the virus, and non-pharmaceutical interventions like social distancing/masking were the only options to mitigate the crisis.

Critics have argued that the government response to pandemic created a more challenging situation than the disease itself. It was argued that the proportionality of measures taken to tackle the pandemic – the national lockdown – was extremely severe, impacting the economy and creating hardships for the marginalized (migrant crisis, police brutality, poverty and hunger etc.), having very little effect on virus transmission. The timing and scope of the lockdown was also questioned.

This criticism did not come alone from the opposition, economists and industrialists but also the medical professionals. Experts advocated for local and area-specific lockdowns rather than a strict national lockdown strategy.

International media claimed this move by the Modi government as a hasty decision that was long on populist symbolism but short on foresight or compassion.

Social distancing/masking played a key role in mitigating the crisis. (Pic: Wikimedia Commons)

About the study

The objective behind this study was to examine important lessons for the management of pandemic in resource-limited settings like India.

The scientists studied the growth of confirmed COVID 19 patients:

  • before lockdown (1st February to 24th March 2020)
  • during lockdown (25th March to 31st May 2020)
  • after lockdown (Unlock 1 – 1st June to 13th July 2020)

After the unlock1, Pune imposed a regional lockdown from 14th July to 23rd July, and unlock 2 was from 24th July to 15th September 2020 during the first wave.

Data was captured and analyzed under Pune’s public health surveillance program from 1st February 2020 to 15th September 2020. Indicators like the weekly load of patients, infection rates, and epidemic curves were studied. The variables like sex, age, and population density were also considered during the analysis. The results were predicted using the compartmental model.

Findings of the study

Both national and regional lockdowns slowed the COVID19 infection rates in Pune urban. The study revealed that lockdowns flattened the COVID-19 pandemic curve with significant reductions in new patients and comparatively low infection rates during the nationwide and regional lockdown.

The study showed a delay in the peak of cases by almost 8 weeks in Pune city during the lockdown. The number of patients was lowered by 43% during the national lockdown and 22% during the local lockdown.

“Overall, in Pune city, the national lockdown reduced the spread of infection by 2-3X as compared to September 2020, the peak of the first wave. In localities which have high population density, the effect was much larger”, says Joy Merwin Monteiro, Indian Institute of Science Education and Research (IISER), Pune. He is one of the researchers of a six-member team that conducted this study.

He further tells that the shorter local lockdowns in Pune city in mid-July had a dramatic, though short-lived, impact on the growth of infections. “This goes on to say that there is much to be understood on the timing and duration of lockdowns and their impacts in real-life situations, and not in models”, adds Monteiro.

Number of daily COVID-19 patients across Pune Municipal Corporation ward offices. Subsequent unlock periods witnessed a sharp rise in patients peaked around the first week of September.

The greatest impact of the national lockdown was observed among Pune’s highly populated wards. These areas have shown a 2% weekly dip in new patients. The local lockdown in the city appeared to be the most effective in wards where more than 50% of the population resided in slum areas. One of the most significant findings of the study was that these slum areas have shown a 13% weekly decrease in new patients.

As per the study, the maximum increase in the number of patients was observed during later weeks of unlocking. This sudden jump occurred due to the resumption of normal routine activities leading to social contact.

The epidemic would have reached its peak in mid-July as against to actual peak in mid-September in the absence of national lockdown. The approximate delay of the growth of the patients was 8 weeks.

Conclusion

The study highlights that while national lockdown may be counterproductive from an economic standpoint, local/regional lockdowns can prove to be an effective public health measure to reduce the spread of infection. This study adds confidence that non-pharmaceutical interventions like targeted lockdowns can be instated to limit the transmission of infectious diseases in dense and resource-limited settings.

Dr. Jaimini Sarkar is PhD in Science from the University of Mumbai. For a decade she worked as a Faculty for M.Sc.-Biotechnology at the University of Mumbai. She is recipient of S. Ramaseshan Science Writing Fellowship at Current Science Association, Indian Academy of Sciences at Bengaluru. She writes for The Wire, Current Science, Science reporter, BMJ, Down-To-Earth, Srote etc.

The Analysis (TA) is a research and communication group working on the issues of environment, health, gender, law, and human rights. Feel free to share your submissions with us at contact@theanalysis.org.in

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s