Andy Adcock
Worst person on Birdforum
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Anti-Malarial resistance (1 Viewer)
- Thread starter Andy Adcock
- Start date
edenwatcher
Well-known member
Worth pointing out that this treatment rather than prophylaxis. Keep taking the tablets!
Rob
Rob
gandytron
Well-known member
Whilst artemisinin-resistance has been widespread in SE Asia for a while, it is concerning to see resistance in sub-Saharan Africa because:
a) the resistance appears to be novel (ie different from that found in SE Asia), and
b) locations in sub-Saharan Africa have a much higher rate of transmission (eg >350 infective bites per annum, or one per day) than is found in mainland SE Asia (eg <2 infective bites per annum).
a) the resistance appears to be novel (ie different from that found in SE Asia), and
b) locations in sub-Saharan Africa have a much higher rate of transmission (eg >350 infective bites per annum, or one per day) than is found in mainland SE Asia (eg <2 infective bites per annum).
Andy Adcock
Worst person on Birdforum
Isn't it the case that the treatement is just an increased dosage of the prophylaxis?
A
But doesn't necessarily mean that it will become ineffective in prevention even if ineffective in treatment.
Andy Adcock
Worst person on Birdforum
Not sure I follow the logic?
"This is an interesting and well conducted study and again emphasises the incredible ability of the malaria parasite to rapidly evolve to become resistant to antimalarial treatment,"
Anti Malarials are just antibiotics, resistance to them will be developed, it's just a matter of time and one of the reasons doctors don't like us to take them for greatly extended periods. The fact that the treatment of infection is being met with some resistance suggests that the same drugs as used in prevention are involved?
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gandytron
Well-known member
Whilst the mechanisms for the emergence of drug resistance are not completely understood, it should be noted that the bigger driver of resistance is not the parasite's exposure to people who are taking comprehensive prophylaxis, but rather exposure to people who are taking sub-standard antimalarials for treatment (eg counterfeit drugs that have trace elements of antimalarial medicines that offer the parasites non-fatal levels of exposure to them). Given that such fake medicines may be widely available at a population level they present a much greater opportunity for the selection of mutations that might offer a parasite resistance to antimalarials.
Furthermore the medicines used as prophylaxis (eg malarone, which is a combination of atovaquone and proguanil) are often different from those used for first line treatment (in the cases of treatment failure cited in the story, they all refer to treatment with artemether-lumefantrine, also known as Coartem). Indeed Coartem is not used as a prophylaxis (see https://www.pharma.us.novartis.com/sites/www.pharma.us.novartis.com/files/coartem.pdf).
ovenbird43
Well-known member
I'd be interested to know more too, but I can see how resistance might evolve to treatment, while the same drug could remain successful as a prophylactic (for now). The malarial parasite has a complex life history, it's possible that the same drug has different actions on the various life stages, taking it as a prophylactic would would only affect the sporozites injected by the mosquito, whereas the treatment would occur during the remaining life stages.
