4 ms·

Drug which makes human blood lethal to mosquitoes can reduce malaria: study

20 points by curtis 8y ago

bdamm 8y ago
The summary article is somewhat vague on the actual result. It seems to imply that villages were in or out of the control group en-masse but doesn't explicitly say so: > For the 18-week study researchers recruited 2,700 people, including 590 children, across eight villages with half in the treatment group receiving a dose of ivermectin every three weeks. > Regular visits from nurses were used to assess children for malaria symptoms and confirmed with a blood test and it found twice as many children in the treatment group had no malaria attacks. > In all there were an average of 2 malaria attacks per child in the treatment group compared to 2.49 in the control villages, without any additional harmful side effects.
- Someone 8y ago
  https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)32321-3/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... is a lot clearer: ”We invited villages (clusters) in Burkina Faso to participate in a single-blind (outcomes assessor), parallel-assignment, two-arm, cluster-randomised trial over the 2015 rainy season. Villages were assigned (1:1) by random draw to either the intervention group or the control group.” I find it interesting how that draw was done: ”Randomisation was done at a public event at the Health District offices in Diebougou, attended by members of the study team, community health workers from all eight villages, and the local health clinic nurses. In front of the attendees, the words “treatment” (ie, “intervention”) and “control” were written on four cards each, which were then sealed in identical opaque envelopes, mixed in a container, and randomly pulled from the container by each community health worker representing their village.” I guess that helped gain the trust of the participants. The text also shows how poor Burkina Faso is. Of the 590 children in the 18 week long experiment, they lost 6 because they died.
k_sze 8y ago
I haven’t gone to pull numbers from previous studies yet, but this somehow sounds more convoluted and at the same time less effective than using neutered mosquitoes to decimate the population. Do we know whether humans are the only feeding hosts of the mosquitoes? If not, don’t you need to feed the drug to every other species in the region that the mosquitoes feed on, in order for this method to be truly effective? Not dismissing the study, just raising some questions for further discussions.
- mehSoWhut 8y ago
  Well, this idea isn't an extinction level event for mosquitos, but then again, not everything needs to be conceived as such. Meanwhile, at least you don't get bit, and when you do, you don't catch as many diseases, and female mosquitos that bite humans are selected against, on some small level, albeit probably not enough to produce an evolutionary outcome unless literally all humans use the drug for centuries on end.
  - londons_explore 8y ago
    > female mosquitos that bite humans are selected against Their lifespan is only 6 weeks, and they might bite 20 people in a lifetime, so even if only 5% of humans had this treatment, I think it would have a rapid and major evolutionary response.
curtis 8y ago
One of the techniques used to eradicate malaria in the past was to spray the interior walls of houses with DDT. After feeding on human hosts who were infected with malaria, the mosquitoes would land on a nearby wall to digest the blood. If the wall was covered with DDT, then it would kill the mosquito before it had a chance to bite another person.[1] [1] https://www.newyorker.com/magazine/2001/07/02/the-mosquito-killer https://www.newyorker.com/magazine/2001/07/02/the-mosquito-k... (I think, the article is paywalled.)
mises 8y ago
Let's go back to DDT; it worked well. No link to cancer. It is widely speculated that banning DDT caused more deaths than Hitler. It wasn't perfect, but western moral imperialism and the corresponding pressure forced the third world to give up use of a lifesaving pesticide. Malaria killed more than DDT by far, and it was wrong to jump to conclusions.
- kkarakk 8y ago
  From[0] - The direct DDT exposure toxic effects in humans include developmental abnormalities [1], reproductive disease [2], neurological disease [3], and cancer [4]. The exposure DDT metabolite DDE (dichlorodiphenyldichloroehtane) also promotes abnormal human health effects such as childhood diabetes and obesity [5]. [0]:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124473/#B17 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124473/#B17 [1]:https://www.ncbi.nlm.nih.gov/pubmed/11463412 https://www.ncbi.nlm.nih.gov/pubmed/11463412 [2]:https://www.ncbi.nlm.nih.gov/pubmed/14645167 https://www.ncbi.nlm.nih.gov/pubmed/14645167 [3]:ATSDR. Agency for Toxic Substances and Diseases Registry (ATSDR)/US Public Health Service, Toxicological Profile for 4,4’-DDT, 4,4’-DDE, 4, 4’-DDD (Update) Atlanta, GA: ATSDR; 1994. [4]:https://www.ncbi.nlm.nih.gov/pubmed/10372419 https://www.ncbi.nlm.nih.gov/pubmed/10372419 [5]:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295349/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295349/

20 points by curtis 8y ago

The summary article is somewhat vague on the actual result. It seems to imply that villages were in or out of the control group en-masse but doesn't explicitly say so: > For the 18-week study researchers recruited 2,700 people, including 590 children, across eight villages with half in the treatment group receiving a dose of ivermectin every three weeks. > Regular visits from nurses were used to assess children for malaria symptoms and confirmed with a blood test and it found twice as many children in the treatment group had no malaria attacks. > In all there were an average of 2 malaria attacks per child in the treatment group compared to 2.49 in the control villages, without any additional harmful side effects.

Someone 8y ago
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)32321-3/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... is a lot clearer: ”We invited villages (clusters) in Burkina Faso to participate in a single-blind (outcomes assessor), parallel-assignment, two-arm, cluster-randomised trial over the 2015 rainy season. Villages were assigned (1:1) by random draw to either the intervention group or the control group.” I find it interesting how that draw was done: ”Randomisation was done at a public event at the Health District offices in Diebougou, attended by members of the study team, community health workers from all eight villages, and the local health clinic nurses. In front of the attendees, the words “treatment” (ie, “intervention”) and “control” were written on four cards each, which were then sealed in identical opaque envelopes, mixed in a container, and randomly pulled from the container by each community health worker representing their village.” I guess that helped gain the trust of the participants. The text also shows how poor Burkina Faso is. Of the 590 children in the 18 week long experiment, they lost 6 because they died.

k_sze 8y ago

I haven’t gone to pull numbers from previous studies yet, but this somehow sounds more convoluted and at the same time less effective than using neutered mosquitoes to decimate the population. Do we know whether humans are the only feeding hosts of the mosquitoes? If not, don’t you need to feed the drug to every other species in the region that the mosquitoes feed on, in order for this method to be truly effective? Not dismissing the study, just raising some questions for further discussions.

mehSoWhut 8y ago
Well, this idea isn't an extinction level event for mosquitos, but then again, not everything needs to be conceived as such. Meanwhile, at least you don't get bit, and when you do, you don't catch as many diseases, and female mosquitos that bite humans are selected against, on some small level, albeit probably not enough to produce an evolutionary outcome unless literally all humans use the drug for centuries on end.
- londons_explore 8y ago
  > female mosquitos that bite humans are selected against Their lifespan is only 6 weeks, and they might bite 20 people in a lifetime, so even if only 5% of humans had this treatment, I think it would have a rapid and major evolutionary response.

curtis 8y ago

One of the techniques used to eradicate malaria in the past was to spray the interior walls of houses with DDT. After feeding on human hosts who were infected with malaria, the mosquitoes would land on a nearby wall to digest the blood. If the wall was covered with DDT, then it would kill the mosquito before it had a chance to bite another person.[1] [1] https://www.newyorker.com/magazine/2001/07/02/the-mosquito-killer https://www.newyorker.com/magazine/2001/07/02/the-mosquito-k... (I think, the article is paywalled.)

mises 8y ago

Let's go back to DDT; it worked well. No link to cancer. It is widely speculated that banning DDT caused more deaths than Hitler. It wasn't perfect, but western moral imperialism and the corresponding pressure forced the third world to give up use of a lifesaving pesticide. Malaria killed more than DDT by far, and it was wrong to jump to conclusions.

kkarakk 8y ago
From[0] - The direct DDT exposure toxic effects in humans include developmental abnormalities [1], reproductive disease [2], neurological disease [3], and cancer [4]. The exposure DDT metabolite DDE (dichlorodiphenyldichloroehtane) also promotes abnormal human health effects such as childhood diabetes and obesity [5]. [0]:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124473/#B17 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124473/#B17 [1]:https://www.ncbi.nlm.nih.gov/pubmed/11463412 https://www.ncbi.nlm.nih.gov/pubmed/11463412 [2]:https://www.ncbi.nlm.nih.gov/pubmed/14645167 https://www.ncbi.nlm.nih.gov/pubmed/14645167 [3]:ATSDR. Agency for Toxic Substances and Diseases Registry (ATSDR)/US Public Health Service, Toxicological Profile for 4,4’-DDT, 4,4’-DDE, 4, 4’-DDD (Update) Atlanta, GA: ATSDR; 1994. [4]:https://www.ncbi.nlm.nih.gov/pubmed/10372419 https://www.ncbi.nlm.nih.gov/pubmed/10372419 [5]:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295349/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295349/