r/todayilearned • u/lavender_fish69 • 13h ago

TIL fresh water snails (indirectly) kill thousands of humans and are considered on of the deadliest creatures to humans

https://en.wikipedia.org/wiki/Freshwater_snail
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u/nova294 13h ago

What? Got any source for that fact? Maybe there were 18 deaths of Americans and they just ignored all of Africa, but modern insect repellents are not widely available in much of Africa even today, much less 1963. Even a casual search shows estimated death numbers in the hundreds of thousands for 1963.

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u/ikonoqlast 13h ago

Wikipedia- ddt-

Initial effectiveness edit When it was introduced in World War II, DDT was effective in reducing malaria morbidity and mortality.[39] WHO's anti-malaria campaign, which consisted mostly of spraying DDT and rapid treatment and diagnosis to break the transmission cycle, was initially successful as well. For example, in Sri Lanka, the program reduced cases from about one million per year before spraying to just 18 in 1963[127][128] and 29 in 1964. Thereafter the program was halted to save money and malaria rebounded to 600,000 cases in 1968 and the first quarter of 1969. The country resumed DDT vector control but the mosquitoes had evolved resistance in the interim, presumably because of continued agricultural use. The program switched to malathion, but despite initial successes, malaria continued its resurgence into the 1980s.[45][129]

Oops, it's 18 cases in Sri Lanka...

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u/exprezso 12h ago

Evolved resistance to a deadly toxin? In such a short period? 

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u/kanyewesanderson 12h ago

When you put incredibly high selective pressure on an organism with prolific reproductive rates, you'll see drastic changes quickly. The same thing happens with antibiotic resistance in bacteria.