Effectiveness of contact tracing on COVID-19 examined

According to one study, one of the benefits of contact tracing is that it is the least intrusive of the non-pharmaceutical interventions.

Contact tracing mitigates the spread of COVID-19 but is found to be more effective against the original strains of the disease than the Delta variant. Extra effort needs to be made to properly conduct contact tracing for Delta, according to a study by the American Journal of Infection Control (AJIC). Author Marvin Du of the University of California writes that contact tracing can play a “significant role” in reducing COVID-19 cases and delaying the peak of cases. Symptom onset can be used to determine if someone should be quarantined, but COVID-19 test results can help quickly isolate asymptomatic and pre-symptomatic individuals.

“For the Delta variant, or other variants of much higher infectivity, contact tracing alone cannot significantly reduce the number of new daily cases, but is able to significantly delay peaks, thereby offering more time to explore and implement pharmaceutical interventions,” the study says. .

Du classifies contact tracing as non-pharmaceutical intervention (NPI) which is the least intrusive NPI compared to lockdowns, masking and social distancing. According to the Our World in Data website, 56.9% of the world’s population received at least 1 dose of the vaccine, but only 7.6% of people in low-income countries received 1 dose.

“When a vaccine is not available, NPIs can help ‘flatten the curve,’ saving valuable time to develop, manufacture and distribute the vaccine,” said the AJIC study states. “Even after a significant fraction, if not most, of the general population has been vaccinated, breakthrough infection by new virus variants among those vaccinated may still pose imminent threats, and NPIs may play an important role. to control the spread of infections. ”

The study indicates that if test results for the original COVID-19 virus can be supplemented so that infected people can be isolated on the eighth day of infection, it would significantly reduce the number of new cases. If infected individuals can be isolated within the sixth day of infection, it can almost produce what the study calls a “virus crush” or stop the spread effect. However, contact tracing alone should be used with other NPIs to achieve this result.

Also, the more people vaccinated and/or vaccinated, the better.

“To deal with outbreaks caused by SARS-CoV-2 variants, pre-existing immunity (obtained either through vaccination or previous infection) can play a vitally important role in reducing the number of new cases. daily,” the study said. “Therefore, vaccinating the general public not only helps combat the current epidemic, but also facilitates the management of future epidemics.”

Contact tracing should be used regardless of the level of infectiousness because, when done correctly, it usually leads to a drop in the number of new cases.

“This may include a more reasonable definition of ‘close contacts’, the use of digital equipment such as smart phones to find people who may have close contact with people known to be infected, the use of results testing to determine quarantine entry and exit, providing support for self-quarantine so she does not need to go to grocery stores and restaurants, maintaining daily contact with self-quarantine and providing support wherever and whenever needed,” the study says.

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