According to the WHO, contact tracing - along with robust testing, isolation, and care of cases is a key strategy for interrupting chains of transmission of SARS-CoV-2 and reducing mortality associated with COVID-19. Contact tracing, however, has a number of challenges. These include incomplete identification of contacts, inefficiencies in paper-based reporting systems, complex data management requirements, and delays in the identification of contacts and testing of contacts. In many settings, contact tracing has proven to be too resource-intensive to implement at scale, especially with higher levels of community transmission, highlighting the need for more efficient contact tracing approaches. Digital tools afford the possibility of strengthening contact tracing for COVID-19, in a more efficient way. However, there is limited evidence of the effectiveness and impact of these tools in the COVID-19 response, including contact tracing.

This study proposes to compare the cascade of care between two strategies for COVID-19 contact tracing of SARS-CoV-2 infected index patients in Cameroon. In one strategy (intervention), the health facilities and health district testing units will implement contact tracing using a digital tool developed to support the tracing and testing of contacts (addition of a digital contact tracing module to the main platform for COVID-19 testing in Cameroon (Mamal Pro app)). This strategy will be compared to the standard contact tracing process (control), based on the current routine approach (use of the Mamal Pro application without the digital contact tracing module).

The study's general objective is to assess the effectiveness, feasibility, acceptability, and cost associated with the addition of a Mamal Pro digital contact tracing module to the Mamal Pro app in improving COVID-19 contact tracing and testing in Littoral, Cameroon.

Specific objectives are:

1. Primary objective: To determine the effectiveness of the use of a Mamal Pro digital contact tracing module added to the Mamal Pro app in improving COVID-19 contact tracing and testing compared to the SOC as measured by:

   • The number and proportion of reported contacts who received SARS-CoV-2 testing.
   • The number and proportion of contacts who are successfully reached by phone by MOH district contact tracing unit.
   • The number and proportion of contacts testing positive for SARS-CoV-2 infection.
   • The time from SARS-CoV-2 infected index patient identification of contacts to communication with the contact by the district contact tracing unit.

2. Secondary objectives:

   • To assess the feasibility and acceptability of the use of the Mamal Pro digital contact tracing module through structured interviews with MOH facility staff, district unit contract tracing teams, and individuals undergoing SARS-CoV-2 testing.
   • To estimate the total cost of using the Mamal Pro contact tracing module for tracing SARS-CoV2 positive case contacts and cost per contact traced using the module.

Inclusion Criteria:

• All contacts listed by individuals registered in the Mamal Pro app for testing, who test positive for SARS-CoV-2 in the selected health district testing units and health facilities in Cameroon.

Exclusion Criteria:

• None