Africa more at risk of drug-resistant malaria than previously thought By Editor on October 22, 2015 1:51 am

Female Anopheles mosquito

PHOTO CREDIT:

google.com

A new research has shown that Africa is at higher
risk of drug-resistant malaria than previously
thought.
Essentially, the new research shows it is possible
for drug-resistant forms of the parasite –
currently confined to malaria-carrying
mosquitoes in Southeast Asia – to infect African
mosquitoes.
The new study, published in Nature
Communications, is the work of an international
team that includes scientists from the National
Institute of Allergy and Infectious Diseases
(NIAID) – part of the National Institutes of Health.
Nearly one million people die of malaria every
year, mostly babies, young children and pregnant
women, majority of whom are in Africa.
Estimates suggest a child dies of malaria every 30
seconds.
Malaria typically spreads in human populations
through the bite of female Anopheles mosquitoes
carrying Plasmodium parasites.
The main drug for treating malaria, artemisinin,
is becoming less and less effective in Southeast
Asia due to the spread of resistant strains of
Plasmodium falciparum – the deadliest of the
malaria parasites.
Experts are concerned that these drug-resistant
parasites will spread to Africa.
Currently, the drug-resistant parasites are spread
by Anopheles mosquitoes that are confined to
Southeast Asia, and before the new study,
scientists had little idea of the risk of it spreading
to Africa, where the major carrier of malaria is
the Anopheles coluzzii mosquito, previously
known as the Anopheles gambiae.
The researchers behind the new study decided to
assess the risk, to establish whether resistant
strains of P. falciparum can infect the African
mosquitoes.
For their study, they infected various mosquito
species from Southeast Asia and Africa with drug-
resistant parasites from Cambodia in a laboratory
setting.
Specifically, they produced gametocytes or germ
cells from samples that displayed artemisinin
resistance in patients and in lab cultures. Mature
gametocytes are responsible for the spread of the
parasite from infected people to mosquitoes.
They found that artemisinin-resistant P.
falciparum easily infected the Southeast-Asian
mosquito carriers A. dirus and A. minimus as
well as the African A. coluzzii.
They conclude: “The ability of artemisinin-
resistant parasites to infect such highly diverse
Anopheles species, combined with their higher
gametocyte prevalence in patients, may explain
the rapid expansion of these parasites in
Cambodia and neighboring countries, and further
compromise efforts to prevent their global
spread.”
The researchers also discovered that drug-
resistant parasites share a genetic feature that
enables them to evade the mosquitoes’ immune
system and may explain how they manage to
invade such a diverse range of species.