Pandemic’s fallout on malaria control appears limited so far

Pandemic’s fallout on malaria control appears limited so far

Pandemic’s fallout on malaria control appears limited so far

Back in March when COVID-19 hit, Pedro Alonso became alarmed about a different infectious disease. “I thought I would be witnessing the biggest malaria disaster in 20 years,” says Alonso, a malaria scientist at the World Health Organization (WHO). African countries went on lockdown to curtail COVID-19; worried about mass gatherings, they suspended campaigns to distribute mosquito-fighting bed nets. Fears abounded that with clinics overwhelmed by COVID-19, patients would be unable to get treatment for malaria, which kills an estimated 405,000 per year, mostly African children. In the worst case scenario, models projected, malaria deaths could more than double this year.

“It does not seem to be happening,” Alonso says. Lobbied hard by WHO’s Global Malaria Programme (GMP), which he heads, and its partners, countries resumed bed net campaigns. Rapid diagnostic tests and effective malaria drugs remain available. The situation could still go south as the COVID-19 epidemic accelerates, but for now, Alonso says, “We probably stopped the first big blow.”

In March, WHO recommended that countries halt mass vaccination campaigns for measles and other diseases, fearing they might spread COVID-19 (Science, 10 April, p. 116). Like other health agencies, the Africa Centres for Disease Control and Prevention advised people to stay home unless they were very, very sick, Alonso says. But a broad lockdown would be “a bullet straight to the heart of the malaria program,” he says. “For the past 40 years we have been saying that malaria can kill within hours. If a child has fever … go straight to the clinic.”

By 25 March, WHO had issued guidance telling countries they should proceed with malaria prevention and treatment—and could do so safely. “WHO was very effective in getting the message out,” says Thomas Churcher of Imperial College London (ICL), who published an alarming model about the effects of scaling back malaria interventions in Nature Medicine on 7 August.

The distribution of insecticide-treated bed nets was GMP’s first concern. Malaria deaths plunged from an estimated 839,000 in 2000 to 405,000 in 2018 largely thanks to the massive net rollout across Africa. But bed nets need to be replaced every 3 years, as the insecticide wears off and nets tear. Twenty-six African countries had scheduled mass distribution campaigns this year—but in March, many were wary of proceeding.

Benin was the most urgent priority. It had already completed the first phase of its campaign, distributing vouchers door to door that families could use to pick up their bed nets from a central point 1 month later. But the government had canceled the second phase. The concern was that people, worried about supplies, would rush to distribution centers to pick up their nets, says Marcy Erskine of the International Federation of the Red Cross and Red Crescent Societies. “Crowds can be very difficult to control,” she says, making physical distancing all but impossible.

“We all knew if Benin did not go ahead, there would be a massive domino effect” on other countries, Erskine says. So GMP and its partners—including the Global Fund to Fight AIDS, Tuberculosis and Malaria; the U.S. President’s Malaria Initiative; and the Alliance for Malaria Prevention (AMP)—started to lobby leaders in Benin and elsewhere, she says, armed with models. AMP advised countries on how to reduce COVID-19 risks—for instance, by distributing nets door to door instead of from a central point.

Benin agreed, distributing 8 million nets in April and setting an example for other governments, says Sussann Nasr of the Global Fund: “In the end, every country said yes.” Still, “We don’t want to get a false sense of security,” Nasr says. “We have to be sure that the 2021 countries do their campaigns, too,” says Hannah Slater, a modeler at PATH, a global health nonprofit in Seattle. The same holds for indoor spraying with insecticides and seasonal chemoprevention, in which children are given antimalaria drugs during the disease’s high season.

Even if preventive interventions continue, malaria deaths could soar if sick children don’t receive effective treatment—for instance, because frightened mothers keep them home. The ICL model projects that if access to treatment drops by 50% for 6 months, 129,000 additional malaria deaths would occur between May 2020 and May 2021.

Getting a fix on how many children are being treated is tough, Alonso says. But there are ominous hints. Antenatal visits are down in some places, and that’s where pregnant women, who are very vulnerable to severe malaria, receive chemoprevention and bed nets along with regular checkups. And routine immunizations for diseases such as measles have fallen off. “What I really worry about is a child who won’t be treated and deaths will go uncounted,” says Regina Rabinovich of the Harvard T.H. Chan School of Public Health—a problem even before the pandemic. Undercounting probably explains the “paradoxical” finding that reported malaria cases are down this year, Alonso says.

Churcher fears some countries may see COVID-19 peak during the high malaria season, leaving fragile health systems dealing with simultaneous epidemics. Even countries that go into strict lockdown must continue malaria services, he says: “It’s not a trade-off. You have to do both.”

Source: Science Mag