With malaria cases rising, experts worry about impact of global warming

Malaria cases and deaths, which soared during the COVID-19 outbreak, have still not returned to pre-pandemic levels, according to a new report from the World Health Organization. Officials are also spooked about the effect a changing climate could have on the spread of the disease, adding urgency to their calls to ramp up existing interventions. “We don’t fully understand the dynamics of how climate change will affect malaria,” Peter Sands, the head of the Global Fund to Fight AIDS, Tuberculosis and Malaria, said at the launch of the World Health Organization’s World Malaria Report 2023 Thursday. “But we know it’s bad news.” The launch comes ahead of the first health day at this year’s United Nations climate conference, or COP 28, in Dubai. There was not much to celebrate in this year’s report, which documented 249 million malaria cases in 2022 — 16 million more than in 2019 and the highest total in those four years. WHO also reports 608,000 malaria deaths in 2022, which is down from the previous two years, but still higher than the 576,000 deaths recorded in 2019. The vast majority of those cases and deaths are in sub-Saharan Africa. “In view of the current trends, progress toward the targets of the current malaria strategy is off track and unfortunately by a wide margin,” Dr. Daniel Ngamije, director of WHO Global Malaria Programme, said during a press conference. The current global targets call for the number of malaria deaths to reach less than two among every 100,000 people who are at risk by 2030. At current rates, the number of deaths will reach nearly 13 people. While those increases justifiably raise alarm, Jane Carlton, director of the Johns Hopkins Malaria Research Institute, pointed out “that malaria burden worldwide has really been on the decline over the past several decades.” Three countries — Azerbaijan, Belize, and Tajikistan — were certified malaria-free by WHO in 2023. “But it is still a few countries where the malaria burden has increased and that’s very worrisome,” she told Devex. The trends come as more tools to treat and prevent malaria are available than ever before. That includes two vaccines, though neither has yet been rolled out widely. The RTS,S vaccine, which was approved by WHO in October 2022, has been trialed in Ghana, Kenya, and Malawi. More than 2 million children have been immunized, resulting in a dramatic reduction in severe malaria and a 13% drop in early childhood deaths, according to WHO. There is evidence that the new R21/Matrix-M vaccine, which WHO recommended in October, might be even more effective than RTS,S. That comes alongside the advancement of mosquito nets that combine two active ingredients in a bid to overcome emerging mosquito resistance to the insecticide commonly used in most nets. Experts are also enthusiastic about the impact of preventive chemotherapy, where health workers issue medicines to prevent infection at the height of malaria season. The problem is “there are delays in having these tools available for preventing malaria,” Ngamije said, not least because of massive funding gaps in the global response to the disease. Against a funding target of $7.8 billion in 2022, only $4.1 billion in global malaria funds were raised. “We have a little over half as much money as we need to deliver the strategy,” Sands said. “We need to make every dollar, euro, whatever, work as hard as possible.” Plans are in place to increase the distribution of RTS,S by the start of next year and R21/M vaccine soon after. Meanwhile, concerns over how climate change will affect the response loom. The report highlighted the situation in Pakistan, which saw its malaria cases rise by 2.1 million in 2022. Experts blamed floods that swept the country in 2022, displacing populations and leaving behind standing water, which was ideal for mosquitos to breed. It’s too early to say exactly how a changing climate will affect malaria distribution, though, Carlton told Devex. “In areas which are already dry and arid, if those get more dry and arid, that’s not going to increase the amount of malaria,” she said. If the moist, humid regions that mosquitoes prefer experience worsening conditions, though, “then the range of mosquitoes might change.” Ultimately, she said, “more research needs to be done in this area.” Funding and climate change were only two of the many factors that might impact malaria rates. Experts also pointed to conflict, which can make it difficult for patients to reach health services, and emerging resistance to existing malaria treatments. “We are at a crunch point,” Sands said. “We do have some great tools … but the context is becoming ever more challenging.”