Thread by @HendrixTN

📰🔊This is our analysis of the #COVID19 #testing strategy in #Tunisia🇹🇳, given the potential technical and contextual limitations, and future challenges.

medium.com/@OpenNiqash/co…

Happy to contribute to @OpenNiqash with @Jaber_Bel, @drziedbouslama & @droussamazekri!

https://twitter.com/OpenNiqash/status/1257258854359994369

Real-time RT-PCR (@WHO gold standard) is complex and requires technical equipment and skilled human resources. Deploying a military mobile lab for temporary missions in the south is a good step, but still, testing capacity remains limited: only 24,406 tests performed as of 02/05.

Antigen and antibody rapid tests provide a less costly and faster delivery of results compared to RT-PCR. However, before these tests can be used, it must be acknowledged that they serve different roles and thus need to be used in different scenarios.

There are variances in the ability of these tests to provide an accurate result. By using a rapid test with 90% sensitivity and 90% specificity rates, there will be 10 "false negatives" among 100 infected individuals, and 10 "false positives" within 100 uninfected individuals.

Unfortunately, there is no perfect test that is 100% sensitive and 100% specific. A strict application of case definitions and appropriate indications for each testing method is crucial to minimize testing errors.

Rapid #antigen test can be used in #HighRisk groups (exp. health workers). Due to low sensitivity, negative results must be coupled to RT-PCR.

Rapid #antibody test is used for #epidemiological investigations to help better understand the epidemic dynamics in a given population.

🇹🇳Tunisia's #testing strategy had been elaborated by a scientific committee mainly composed of medical doctors. With such an exclusively biomedical approach, contextual and #social factors that influence the behavior of individuals had not been taken into account.

Health policymakers must now demonstrate #trustworthiness and give a reason for people to further cooperate. Officials cannot force people to trust them; they have to earn it the right way. #Social science experts might help in designing more contextually relevant interventions.

Policymaking in uncertain #COVID19 times is difficult. Efforts towards good #quality testing with #equitable access for everyone who needs to be tested must be sustained. Lifting the current veil of ignorance is crucial to plan gradual #transition from lockdown arrangements.