Egypt declared malaria-free after 100-year effort

I presume they used insecticides. Anyone know what they used?

I can't actually find any articles that actually describe it other than "vector control" and eliminating breeding sites, along with working with neighboring countries. I know some groups are using sterile male mosquitos to prevent breeding, as females can only mate once.

I don’t, but there are quite a few techniques aside from nasty insecticides:

Fish. Many species of fish think that mosquito larvae are delicious and will eat them. Some of these species will also thrive even in small bodies of water with little assistance.

Sterile insects. Male mosquitos don’t bite, and females only mate once, so releasing large numbers of sterile males will reduce the population.

Wolbachia. There are bacteria that live in mosquitoes, are quite effective at infecting the next generation, will not infect humans, and prevent malaria from living in the mosquito.

Bti. There’s a species of bacteria that produces a bunch of toxins that are very specific to mosquito larvae. I have no idea why it evolved to do this, but you can buy “mosquito dunks” and commercial preparations that will effectively kill mosquito larvae in water. They’re apparently entirely nontoxic to basically anything else. I expect that they’re too expensive for country-scale control, but they’re great for a backyard puddle.

You can kill mosquito pupae in water by spraying with an oil that makes a surface film for a few days. The pupae suffocate.

From what I know about malaria prevention, insecticides are mostly used in insecticide-treated bed nets.

There's a variety of insecticide classes:

pyrethroids (e.g., permethrin),organochlorines (e.g., DDT); carbamates (e.g., bendiocarb); and organophosphates (e.g., malathion)

Pyrethroids are most often in bed nets, insecticide impregnated clothing, etc. How and what to apply these chemicals to is the subject of a lot of ongoing research.

Beyond this, there's just things like finding and eliminating mosquito breeding sites.

Great overview. Add to the list the nuclear option of a “gene drive”, a genetic modification that spreads exponentially through a mosquito population.

I imagine it's more complicated than "spray insecticides everywhere" otherwise it'd be easy. Here's the WHO white paper on it:

https://www.who.int/publications/i/item/9789240031357

It's 40 pages long. To summarize, the three pillars are universal healthcare, identifying the areas where malaria is more/less prevalent/even eradicated, and surveilling eradicated/low transmission areas for new infection.

Insecticides are a part of the "universal healthcare" aspect because vector control is a part of actually preventing malaria. But you can kill mosquitoes with things other than insecticides and mosquitoes in different regions are sometimes immune, which is why it's important to identify specific regions to target for eradication as there's no "one-size fits all" strategy. The paper goes into more detail on page 18 on the various methods of using different insecticides or parasite killing methods. All the methods have to be utilized in concert.

Once a region has eradicated malaria, surveillance is what prevents it from coming back. But it's also necessary as the number of infections go down to spend more resources on trying to find the few that are left.

Interestingly, discrimination plays a role because the last people getting malaria are generally those of very low status that don't get healthcare. If you don't expand healthcare to every single person in a society, malaria will come back.

I'm probably oversimplifying the paper a lot as a non-expert, but it seems the best way to eradicate malaria isn't a magic technological bullet but effective administration and project management using the treatment methods we already have.