An alarming summary presented by the Punjab Primary and Secondary Healthcare Department to Chief Minister Sardar Usman Buzdar almost two weeks ago had revealed that "no workplace and residential area of any town is disease-free" in the provincial capital, and that total virus cases in the city are estimated at around 0.7 million, it emerged on Monday.

Advising the chief minister to immediately enforce a complete lockdown for "at least four weeks", the summary, a copy of which is available with Dawn.com, said a smart lockdown would not work since all areas of the city had been impacted by the disease, adding that asymptomatic cases became the "main source of infection and local transmission" in the metropolis.

"Any subsequent decision of lifting, relaxing or doing away with lockdown measures should be taken after reviewing the results of smart sampling conducted with regular intervals till the final tapering down of the virus," it had recommended.

The summary — signed by Primary and Secondary Healthcare Department Secretary Muhammad Usman and dated May 15 — listed the results of a "smart sampling project" to "detect and determine the spread of Covid-19 and to structure and guide [the department's] response towards its containment".

Under the exercise, randomised targeted sampling (RTS) and smart sampling (SS) were carried out; the former was to determine the prevalence of the disease in occupational sectors that remained functional during the lockdown, while the latter was to understand community spread.

After these exercises, the report said, it could be estimated that Lahore, which has a population of over 11 million, has around 670,800 coronavirus cases. But as of June 1, the entire Punjab province has officially reported just 26,240 infections and 497 fatalities.

Analysing the data from various hotspots including workplaces and residential areas, the summary noted "a worrisome picture of Covid-19 prevalence" in communities, with 5.18pc infection rate for RTS and 6.01pc for SS.

"This means that no workplace and residential area of any town is disease-free and, as such, Lahore exhibits an alarmingly similar transmission pattern."

Elaborating on the findings for the testing carried out in the provincial capital, the summary stated that six per cent of all those who were tested turned out positive for Covid-19, while some towns showed a positivity rate as high as 14.7pc.

"These cases being asymptomatic could not be reported to health facilities, but became the main source of infection and local transmission," the report said.

"The town wise breakdown shows a value of more than three per cent for all towns — except Wagha Town — and ranges between 2.11pc and 9.33pc."

The summary added that people over 50 years of age are the ones most affected by the respiratory illness, as is reflected in international literature and research.

It concluded that any decisions regarding lifting or enforcing lockdown measures can't and shouldn't be taken in isolation. "It should be necessarily articulated through larger consensus and based on evidence gathered through smart sampling and testing."

The sampling exercise was carried out with the technical assistance of a working group, consisting of a panel of experts, that was constituted on the directives of the provincial cabinet to provide an "international perspective and input to determine Covid-19 prevalence", according to the report.