
Averting resurgence
In malaria-endemic spots like 1940s China, fluctuating case tallies are a regular occurrence. Because mosquitoes are notoriously adept at spreading diseases, imported cases can bring malaria to areas where local transmission may be low, firing up a new chain of infections.
To prevent carrying the disease across borders, travelers can use antimalarial treatments as a prophylactic—taking medicine in advance to preempt infection. But for endemic areas, these drugs are rarely seen as a long-term solution. After all, overuse can spur resistance. P. falciparum, for example, has grown resistant to drugs like chloroquine and sulfadoxine, rendering them ineffective.
Given these concerns, health experts consider mass drug administration only as an emergency response in small, high-risk spots or a supplementary intervention in larger settings where strong surveillance measures are well-established. When the wrong combination of strategies is applied, however, countries on the verge of elimination may see infections flare back up in sudden bursts.
Road towards zero
For China, its last stretch towards elimination required a different approach—shifting the focus from interventions that tackle morbidities to strategies that nip potential infection sources at the bud.
Through its National Malaria Elimination Program, the country initiated the 1-3-7 norm in 2012 to diagnose, confirm and contain malaria.
“The norm includes strict timelines over the course of seven days to stop malaria in its tracks and prevent onward transmission of the disease,” Zhou explained.
On the first day, healthcare providers report cases through a web-based information system. Any individual with feverish conditions is checked for malaria, such as through a rapid diagnosis test or microscopic examination of clinical samples.
Within three days, cases are confirmed through gold standard diagnostic methods that detect DNA sequences signaling the presence of Plasmodium parasites. Armed with these genetic technologies, health authorities carry out accurate diagnosis and classify cases as local or imported.
By Day 7, local leaders then take appropriate steps to minimize the risk of the disease spreading in the area surrounding the case. For example, this could entail indoor insecticide spraying as well as screening the rest of the community for possible infections.