THE NATIONAL Test and Trace system is becoming less effective at contacting those who have been exposed to coronavirus in Bolton.

In the week from August 26 to September 2, just over half of the "close contacts" of people who tested positive were told to self-isolate.

For the system to work effectively, at least 80 per cent of those exposed must be reached.

The latest figures show 50.1 per cent of contacts identified by the national system were reached, down from the 63 per cent of contacts asked to self-isolate the week before.

Although the percentage of people reached has fallen, tracers are managing to reach more people overall.

This week, 421 people were identified as close contacts, up from 106 the week before.

The number of people who have tested positive, and had their case passed to the Track and Trace team, has also increased, up to 179 cases, from 36.

Since May 28, when the system was launched, 930 residents have been identified as people who have tested positive, with just over three quarters – 702 – reached to start the contact identification process.

From those, 2,027 close contacts have been identified, with NHS Test and Trace able to reach 1124 of them – 55.5 per cent – to ask them to self-isolate.

Considering the quarter of people who tested positive for covid-19 not reached to identify contacts, it's likely that fewer that two in five people who have been exposed to coronavirus have been contacted.