5 minutes with Prof Mary-Ann Davies: Director of the Centre for Infectious Disease Epidemiology and Research

Prof Mary-Ann Davies has been extensively involved in epidemiologic analyses of COVID-19 in the Western Cape and leading the surveillance strategy in the province to guide our response. She has served on technical working groups for the Ministerial Advisory Committee and supported provincial planning for outbreak preparedness as well as vaccine rollout. We asked her a few questions.

Can you briefly describe your current role. 

I am a Public Health Medicine Specialist jointly appointed to the Western Cape Department of Health (DoH) and the University of Cape Town (UCT), where I am Director of the Centre for Infectious Disease Epidemiology and Research (CIDER). CIDER is a research group of about 40 staff which has been involved for nearly 20 years in epidemiologic research of priority infectious diseases such as HIV and tuberculosis (TB). I also convene the Masters in Public Health module on Infectious Disease Epidemiology. In the Department of Health, I am responsible for epidemiology and surveillance of the burden of disease in the province.

What has your role been during the pandemic response?

I have been extensively involved in epidemiologic analyses of COVID-19 in the Western Cape and leading the surveillance strategy in the province to guide our response. This has included providing regular updates to a range of stakeholders, assessing risk factors for poor outcomes in our setting, including whether the 501Y.v2 variant that emerged in the second-wave is associated with more severe disease. I have served on technical working groups for the Ministerial Advisory Committee and supported provincial planning for outbreak preparedness as well as vaccine rollout.

Briefly explain your findings on risk factors for COVID-19 mortality in low and middle-income countries, and other significant research you have been involved with. 

In April and May 2020, South Africa was one of the first low- and middle-income countries with a high HIV and tuberculosis burden to experience a substantial COVID-19 epidemic. There was concern that we might see extremely high COVID-19 mortality in people living with HIV, and so it was important to quantify the risk of COVID-19 death in these patients as soon as possible using the most robust data that we could. The Western Cape has developed a mature health information system over several years with sustained leadership and support through jointly appointed UCT/DoH staff. We were able to leverage this data system to be the first study to show that HIV and TB do increase risk of COVID-19 death, but only modestly, and the effect is much less than other risk factors like older age or diabetes. Studies in the US and Europe have subsequently found very similar increased risks of COVID-19 death in people with HIV. We have used the same data system to rapidly assess whether COVID-19 patients experienced more severe disease during the second wave compared to the first, as a proxy for assessing whether the 501Y.v2 variant could cause worse disease.

What were some of the biggest highlights during 2020?

It is difficult to talk about highlights in a year that has brought so much loss and hardship to so many people. In that context, I think the highlight for me has been the collaboration and innovation across traditional disciplinary and hierarchical boundaries, and commitment to grappling with complex questions in order to find the best ways to mitigate the devastating impact of COVID-19 on both individuals and the population.

What were the biggest challenges?

The pace of doing everything on COVID-19 timelines (from the start to the peak of the second wave in the Cape Town Metro was just 5 weeks during which the number of hospital admissions quadrupled and the number of daily deaths increased 10-fold). And hence the need to be very flexible and very adaptable, and change direction quickly if need be. 

What were the most valuable lessons?

Given how rapidly our understanding of COVID-19 has changed and continues to change, I think the most valuable lesson has been a renewed respect for uncertainty. In a world of many strongly held opinions about COVID-19, I particularly valued the commentary by George Davey-Smith and colleagues in the British Medical Journal which ends as follows: “When deciding whom to listen to in the covid-19 era, we should respect those who respect uncertainty, and listen in particular to those who acknowledge conflicting evidence on even their most strongly held views.”

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