Three articles this week reminded me how unquestioned the belief that malaria is spread by insect vectors is. This belief is supported by confirmation bias. Every result that suggests a connection is highlighted. Any evidence that does not support the belief is explained away or ignored. This is no different than the approach of Ross or Grassi >120 years ago.
First, in the climate sceptic website wattsupwiththat there was an article entitled ‘European Trainee Doctors to Have Fake Malaria Climate Myths Added to Their Studies’. It challenges the climate change scare that higher global temperatures will increase malaria by increasing mosquito habitats, pointing out that malaria, then know as ague was well known in England during the cold Little Ice Age. I could point out, that while present, Anopheles mosquitos are rare in England and were likely rarer in colder times. The article blames an uptick in malaria cases in USA and Europe on travellers coming from countries where Malaria is present. I commented with a reference to usmalaria.com and only received negative responses such as ‘…but given the weight of historical evidence that controlling mosquitoes reduces Malaria transmission…’ from the author Eric Worrall who does not seem to understand that correlation does not prove causation. And this is a website, most of whose readers have open minds to examine Climate Change. But not mosquito transmission of malaria.
Second, in news-medical.net an article called ‘Surge in malaria cases linked to aircraft-transported mosquitoes’. The 145 cases described from nine countries, most in France, Belgium, and Germany, were classified as airport malaria, luggage malaria, or both, and quaintly called Odyssean Malaria. Half resided or worked near or at an international airport. Half of the cases were people born in Africa. There is no evidence presented that these people were bitten by a transported mosquito and it is unclear how often this happens. It only serves to prove that if physicians have reason to suspect malaria based on belief in ‘Odysseus the Mosquito’, they are likely to test for plasmodia. Otherwise, they wouldn’t, and you won’t find what you don’t seek.
Third, in Malaria World this week an article titled ‘Why does malaria transmission continue at high levels despite universal vector control? Quantifying persistent malaria transmission by Anopheles funestus in Western Province, Zambia’ by Ashton et al. (Maybe the two are not connected? ) The detailed study, which used good scientific methods, calculated that Children not sleeping under insecticide-treated nets (ITNs) experienced 13.6 bites per person per six-month season, while ITN users received 1.3 bites per person. They conclude that one infectious bite per person per six-month transmission season, must be sufficient to maintain high malaria transmission and burden.
Many believe because they have no reason to examine the issue, like me prior to 2022 prophylaxis decision. And others because their livelihood depends on it. To increase awareness I am making pdfs of my books available free of charge.
(Image from https://www.sciencejournalforkids.org/articles/should-you-worry-about-mosquitoes-on-planes/)