21 Oct 2020
Increasing inequality: What malaria can teach us about COVID-19
We are launching a new limited series of columns exploring lessons learned from previous infectious disease pandemics, and how we can apply them to the COVID-19 response.
University of Melbourne Professor Stephen Rogerson, laboratory head at the Doherty Institute and Chief Investigator of the Australian Centre of Research Excellence in Malaria Elimination (ACREME), and Dr Julia Cutts, senior postdoctoral research at the Burnet Institute and Project Manager of ACREME.
Disadvantage breeds infection
Malaria is a disease of poverty that preys on the most vulnerable: Young children in sub-Saharan Africa, Indigenous communities in South America, mobile and migrant workers in Southeast Asia, pregnant women, and displaced persons. Increased risk of exposure to infection is compounded by socio-economic barriers to prompt diagnosis and quality treatment.
Similarly, COVID-19 seeps into society’s cracks: Compared to White Americans, Latinx and Black Americans are three times as likely to get COVID-19 and nearly twice as likely to die. In Melbourne, COVID-19 has disproportionately impacted the most disadvantaged areas of the city. Inadequate access to services, living conditions, and the prevalence of casual and insecure work without paid sick-leave have been blamed. Until we address underlying inequalities, infectious diseases will continue to take advantage of society’s fault-lines.
Community engagement is critical
Active community engagement and mobilization is essential for the ongoing success of programs designed to prevent the spread of malaria, such as bed-nets, community-driven vector control, and mass drug administration. No matter how evidence-based a preventive approach might be, if individuals do not see its merits - or if competing needs are prioritized - it will fail. For example, bed nets may be supplied to a community but then not used as intended because they perceived as too hot to sleep under, or unnecessary because the risk of mosquito bites is considered low. Adapt interventions to suit local needs and challenges is critical for the success of disease control programs.
Similarly, many countries have successfully limited COVID-19 transmission by deploying their own unique combinations of public health interventions to suit local requirements and capacity. In Victoria, we are witnessing calls for a more community-based response to COVID-19, with a proposal to shift COVID-19 contact tracing to local hubs.
Vaccines aren’t easy
As keen young PhD students, both authors were told: “We’ll have a malaria vaccine in five years”. Some years on, we have a single licensed malaria vaccine that provides only modest, short-lived protection - with lingering questions over its safety. Weekly, we hear news of COVID-19 vaccines on the horizon, often positive, sometimes not. Vaccine development is challenging and long term, detailed follow-up will be needed to demonstrate sustained protection and to exclude serious rare or delayed side effects.
Rapid diagnosis is a game changer
The malaria community has embraced point-of-care tests that can be in remote health facilities and by community health workers to diagnose malaria in minutes. A positive test means malaria treatment can be started on the spot; a negative result is a call to look carefully for other diagnoses, starting antibiotics in some cases, or reassuring the client or their parent in others.
For COVID-19, infection management, quarantine, and contact tracing would all be improved by a high quality point-of-care test. Such a test, ideally based on saliva rather than an uncomfortable nasal swab, would facilitate more frequent testing. Researchers at the Doherty Institute and others are developing and evaluating tests like this. If successful, they could be real “game changers” not just here in Australia but also in rural communities in low and middle income countries, who bear an increasingly disproportionate share of the burden of COVID-19.
The long road to eradication
Since the mid-20th century, the world has been striving to eradicate malaria. Over 100 countries, mostly richer countries like Australia and the USA, have eliminated malaria transmission within their borders, but many have been less fortunate. Sri Lanka went from over 2 million annual cases to just 17, but cases rebounded to over half a million once malaria control was relaxed. Similarly, after ceasing a successful control program, Indonesia saw malaria skyrocket from below 6,000 cases to 346,000. Tragically, when political commitment to malaria elimination falters, malaria cases rise rapidly.
Rapid resurgence of infections will be all too familiar to residents of Victoria as they check each day’s COVID case numbers and try to anticipate when life will start returning to normal. Malaria has taught us that as transmission declines, health promotion becomes even more important, as individuals will deprioritize malaria prevention activities as the immediate threat declines. As we see cases of COVID-19 decline, it is imperative that we remain committed to wearing masks, social distancing, and coming forward for testing.