Chongqing- The number of new COVID-19 infections in Chongqing has recently reached its peak, with three aspects of decline, including daily infection growth rate, the proportion of cases in society, and adequate reproduction number (Rt), according to the press conference on November 24. 

Chongqing, one of the major economic centers in Southwest China, has been plagued with the complicated situation of the COVID-19 pandemic in November. 

The city reported 258 locally transmitted confirmed cases and 6,242 local asymptomatic infections for November 24, said the Chongqing Health Commission on November 25.

The analysis of some epidemiological data and positive nucleic acid results revealed some characteristics and differences between this virus Omicron BA.5.2 strains with previous ones, said Qiu Jingfu, director of the School of Public Health and Management at Chongqing Medical University.

For example, the people who get the Omicron BA.5.2 strains hold high viral loads and are very contagious initially. Another point features the mode of transmission that the virus transmits by aerosols, which are more likely to spread in humid, confined, and crowded spaces, thus leading to a large number of people being infected with great rapidity. 

In response to the virus' spread features and current situation, the Chongqing government took measures of coordinated prevention and control in the central urban area from November 12. "For more than ten days now, the strategy has achieved some progress, with the three indicators falling," said Qiu. 

First, the daily growth rate of infected cases has gradually decreased. Based on the preliminary screening positive numbers analysis, the daily growth rate dropped from 23% on November 12 to 12% on November 23. 

Meanwhile, the proportion of infected cases in society has fallen daily, from 62.65% on November 12 to 7.2% on November 23. 

Another essential indicator, the effective reproduction number (Rt), witnessed a steady decline, defined as the average number of secondary infectious cases produced by a primary infectious case. 

After the coordinated prevention and control, the Rt in the central urban area went down from an average of 1.82 people on November 11 to 1.14 people on November 22. If Rt continues to drop to less than 1, the virus will stop spreading.

"Preliminary results indicated that the measures adopted are correct and effective," said Qiu. "All people need to work together to achieve the final victory, and it is very important to limit the movement."