In years past, if a person living in sub-Saharan Africa began to experience a fever and chills, they might reasonably assume they had malaria. While it’s true that plenty of other diseases, like dengue, share those early symptoms, malaria is by far the most common: In 2018, there were an estimated 228 million cases of malaria worldwide, with 93 percent of those cases occurring in Africa.
But that was before 2020, when the world was introduced to a new threat: Covid-19. Across Africa, confirmed Covid-19 cases surpassed one million earlier this month, though some experts say the true count may be anywhere from five million to 14 million. Like malaria, Covid-19 tends to begin with a fever, difficulty breathing, fatigue and headache. In a perfect world, diagnostic tests for both illnesses would be available to anyone experiencing symptoms. But in rural communities in particular, testing capacity is less than optimal. That’s a problem because the reality is that distinguishing the two diseases is not that easy.
“Differentiating the various causes of fever—malaria, bacterial, or viral infections—is very difficult,” Julie Gutman, a medical officer with the Centers for Disease Control’s malaria branch, writes in an email. “And now with Covid-19—which has many symptoms that overlap with other diseases—in the mix it becomes even more difficult to determine who should be treated for malaria.”
As many parts of the continent enter malaria season, health workers are bracing themselves for a surge of infections that they don’t currently have the resources to handle. As Covid-19 continues to wreak havoc across the globe, its presence is threatening to derail the management strategies that have proven to be so effective for treating malaria. A new modeling study published in Nature found that malaria-related deaths in sub-Saharan Africa could more than double in 2020 from 2019 if prevention is interrupted by Covid-19.
Peter Olumese, a medical officer with WHO’s global malaria program, acknowledges that Covid-19 is a dangerous disease that can lead to high mortality, particularly in underserved areas. But in Africa, where malaria is endemic, “the secondary mortality from misdiagnosing or not diagnosing and treating malaria might actually be higher than the mortality from Covid,” he says.
Malaria deaths in Africa have plunged in the last several years for three main reasons: The first is the increased availability of rapid diagnostic tests, which helped curb the tendency of clinicians to treat patients for malaria based on symptoms alone. The second is the wider availability of artemisinin-based combination therapy, or ACTs, generally known as the most reliable antimalarial treatments available today. And the third and most effective measure has been prevention, primarily through the distribution of treated bed nets and insecticide spraying. These strategies have yielded impressive results: In 2000, the World Health Organization reported an estimated 839,000 malaria deaths. In 2018, the number dropped to 405,000.
But disruptions to the global supply chain are already taking their toll on malaria management. Shipping slowdowns caused by factory and border closures has curtailed deliveries of personal protective equipment, malaria drugs, tests and other essential supplies.
Restrictions on travel and crowds, along with a lack of personal protective equipment, have reduced the ability of health workers to distribute treated bed nets. On top of that, several companies that produce malaria rapid diagnostic tests have announced their intention to pivot to Covid-19 tests, which retail for higher. A shortage of malaria rapid diagnostic tests poses a number of potential risks, says Olumese: If patients are presumptively diagnosed with malaria, they’ll be prescribed medications they may not need, which contributes both to the problem of drug resistance, and also depletes the already limited supply of drugs.
Even though drug companies are producing more Covid-19 tests, it doesn’t mean they’re widely available, especially in rural areas. The entire nation of the Gambia, for example, has only two labs equipped to process Covid-19 tests, meaning that those who do manage to secure a test will often have to wait several days to get the results, says Alfred Amambua-Ngwa, an assistant professor at the London School of Hygiene and Tropical Medicine who co-authored a paper on the risks associated with pausing the fight against malaria.
Compounding the problem is that many people don’t even want to get tested for Covid-19. “A good number of the uneducated community thinks that Covid is a conspiracy,” Amambua-Ngwa says.
In many countries, getting diagnosed with Covid-19 carries a stigma, since it requires isolating from family and friends. In the Gambia, anyone who wants to can buy malaria drugs over the counter; as a result, many people are simply choosing to assume they have malaria in order to avoid the ordeal that comes with a Covid-19 diagnosis. “If you turn out positive, then you have to go through the Covid quarantine system that requires you to stay away from your family,” he says. “People don't want that.”
Furthermore, Covid-19 outbreaks among medical staff—due to the scarcity of personal protective equipment—has led to widespread avoidance of hospitals.
The perils of self-diagnosing go both ways. Unlike treating Covid-19, where the messaging has largely been to stay home and self-isolate, malaria is not a disease to sit on. Though it’s treatable, it does need to be dealt with quickly, says Olumese. “The biggest challenge with malaria is that it can kill rapidly,” he says. “Life can be lost within three days within four days of symptoms if you don't get treatment as quickly as possible.”
Though children are especially susceptible to malaria, adults are not immune. Amambua-Ngwa says he knows of at least one adult who died from severe malaria after staying at home for fear of a Covid-19 diagnosis.
Without testing, it’s virtually impossible for a person to distinguish which disease they have—and that’s assuming they only have one. In the Gambia, Amambua-Ngwa’s colleagues in the field have told him that a huge percentage of cases testing positive for malaria are also testing positive for Covid-19—and that’s before malaria season, which spans the wet months from around June to October, even reaches its full power. In fact, the risk of co-infections is shaping up to be one of Africa’s major challenges. While no one knows yet what effect one will have on the other, it’s unlikely to be positive.
In a paper published in The American Journal of Tropical Medicine and Hygiene, Gutman and her colleagues explore some of the potential effects of co-infection. Malaria has several known interactions with other diseases: Combining with Epstein-Barr virus, for instance, can lead to Burkitt’s lymphoma; those with HIV tend to experience malaria more severely. Among the many possibilities is that malaria can increase Covid-19-related complications and potentially shift the age pattern of comorbidities to younger people, the paper says. If this happens, then the burden of Covid-19 may be substantially worse than predicted. Another risk, of course, is that because of their similar symptoms, one or the other disease may be overlooked, leading to more fatalities.
Once researchers have a better understanding of how the diseases interact, they will ideally develop a means to treat patients diagnosed with both Covid-19 and malaria simultaneously, as they have with plenty of other diseases, like tuberculosis and HIV. But in the near term, doctors agree that keeping personal protective equipment, rapid testing kits and medication flowing to the continent is absolutely critical. “We must ensure, whatever it takes, that those essential services, including malaria services, are not disrupted,” says Olumese. Otherwise, the mortality from non-Covid illnesses will far outnumber the mortality from Covid-19, he says.
With no end to the pandemic in sight, officials need to prepare not for a sprint, but a marathon. “We have been able to keep our foot on the pedal up until now,” says Olumese. “And we should not in any way remove it. Otherwise we'll be in trouble.”