Lessons in contact tracing from Germany

Local public health

Covid-19 became a notifiable disease in Germany on 1 February 2020,5 earlier than in the UK.6 Disease notification requires clinicians by law to notify suspected cases to the public health authorities. Laboratories are similarly required to notify the authorities of tests for notifiable diseases. In Germany, disease notifications from clinicians and laboratories primarily go to local authorities, where most of the practical work in infection control takes place.

The first covid-19 outbreak occurred in Bavaria in late January, and it was rapidly controlled with testing, contact tracing, isolation, and quarantine. However, new outbreaks seeded from other sources began to spread,7 and the need to break the chain of transmission with nationwide measures (lockdown) became evident. At the same time local public health services were mobilised and revitalised. In April both federal and state governments agreed to provide additional investment to strengthen local public health authorities.8 Civil servants were redeployed to public health from elsewhere and extra staff employed to support local contact tracing. Germany built on existing infrastructure and experience from the outset, unlike England, where local public health departments were overlooked in favour of a centralised system run by outsourced companies.

Later, as population restrictions were being lifted, chancellor Angela Merkel and the prime ministers of the federal states agreed that local authorities should have five contact tracers for every 20 000 citizens.9 Inexperience of new staff members was overcome by embedding them in experienced organisational structures, helping to limit the difficulties reported in England.10

Local thresholds

Expanded capacity for contact tracing underpinned decisions on 6 May to reopen society in a stepwise fashion. States agreed that population infection control measures such as school closures or even “lockdowns” would be reactivated locally if infection rates reached a threshold of 35-50 cases per 100 000 inhabitants a week in a region.11 Overall, the flexibility of local infectious disease control with centralised coordination and support seems to be effective so far, and stands in contrast to the more centralised and privatised approach taken in the UK.

Like many other countries, Germany deployed technological solutions, including an anonymised and decentralised contact tracing app that was launched on 16 June. Concerns over privacy led to a reversal of previous plans to collect data more centrally and thus to a delay. Data protection rights are taken seriously in Germany, and data collected by the app is held only on individual phones, with no central database. Public health experts, however, have limited expectations: in a recent survey, 38% of responding public health departments had doubts about the added value of a contact tracing app or considered it potentially problematic.12

Although Germany’s lockdown was less intense and shorter than in some other European countries, including the UK, early implementation, in combination with widespread testing, contact tracing, and quarantine, have been successful in reducing the incidence of covid-19 and both covid-19 specific and excess deaths. So far, the epidemic has remained stable through stepwise relaxation of control measures, although recent outbreaks in several meat plants (one including more than 1000 cases) are obvious challenges to the system. Strong measures, including a regional lockdown, have been taken to control these outbreaks.

Timely data on suspected cases is now vital, along with rapid testing, fast turnaround times for results, and comprehensive contact tracing. National testing guidelines are adjusted regularly in response to developments.13 A second wave remains a risk, and the authorities continue to monitor the situation closely.14 With no vaccine, and no specific antiviral treatments, preventing transmission through public health measures is now more important than ever.15