The World Health Organisation on Monday cautioned against any relaxation of precautions or response actions after the slight decline in coronavirus disease cases across South Asia, including India, where daily cases are still rising in some states.

The upcoming festival season and the approaching winter could aggravate the situation if people let their guard down, a top WHO official in New Delhi warned amid a near-steady decline in India’s daily new Covid-19 cases for over four weeks.

“There should be no complacency in view of the declining numbers in recent weeks,” Poonam Khetrapal Singh, the WHO’s regional director for Southeast Asia, said in a statement.

“The pandemic continues unabated and the region still reports large numbers of Covid-19 cases. We need to continue to do our very best. Our response needs to be strengthened further to curtail the pandemic,” she said.

India’s seven-day average of daily new cases has declined steadily from around 97,000 in mid-September to 61,000 in mid-October. Over this period, the daily count has declined in most of the states but increased since Onam in Kerala and now in Bengal.

Bengal’s seven-day average has increased from 3,206 on September 18 to 3,747 on October 18, a steady rise that public health experts have attributed to greater mingling of people ahead of the coming festival weeks.

A Chennai-based scientist, who has been tracking Covid-19 across the states, said Bengal’s R value — a measure of how quickly the virus is spreading — has shown a marginal increase over the past four weeks from 1.01 to 1.03 to 1.05 to 1.07.

“Even a marginal increase like that, if sustained over many weeks, could result in large increases in the numbers of active cases,” said Sitabhra Sinha, the scientist from the Institute of Mathematical Sciences, Chennai.

Kerala, for instance, experienced a sharp rise in cases in the weeks after Onam, its seven-day average of daily cases climbing from around 2,000 in early September to more than 8,400 by mid-October. Kerala now has the third-largest number of active patients (over 87,000) after Maharashtra’s 247,000 and Karnataka’s 115,000.

The falling nationwide numbers look good for now but epidemiologists have cautioned that any relaxation in precautions such as the wearing of masks or physical distancing could quickly send the Covid-19 counts rising.

“We know from experience that health systems can get overwhelmed quickly,” an epidemiologist said.

India on Monday had over 772,055 Covid-19 patients under medical supervision. The country’s total count has crossed 7.5 million, with over 6.6 million patients having recovered and 114,610 having died.

Southeast Asia has registered a 6 to 8 per cent decline in Covid-19 cases, mainly thanks to a decrease in reported cases from India and Bangladesh. The region has reported over 8 million of the nearly 40 million Covid-19 cases worldwide.

The WHO, reaffirming messages already issued by health authorities in India, cautioned that the co-circulation of seasonal influenza and Covid-19 in winter might present challenges to the health facilities since both diseases feature similar symptoms.