World Mosquito Day 2017
On the occasion of World Mosquito Day (20 August), we bring you fascinating mosquito and malaria facts as presented in the Malaria Primer, published by Nature Reviews Disease Primers.
The 24-page malaria Primer, can be freely downloaded until 2 September 2017.
"Malaria is caused in humans by five species of single-celled eukaryotic Plasmodium parasites (mainly Plasmodium falciparum and Plasmodium vivax) that are transmitted by the bite of Anopheles spp. mosquitoes."
"The most deadly malaria parasite, Plasmodium falciparum, is only found in tropical areas…and is quite temperature-sensitive; a global temperature rise of 2-3° C might result in an additional 5% of the world population (that is, several hundred million people) being exposed to malaria."
Parasites enter into and replicate within the red blood cells. "In the human host, Plasmodium parasites invade red blood cells through a multi-step process. They replicate within the cell, which eventually “bursts” and release the parasites in the blood, where they can infect other cells."
“Human malaria parasites are transmitted exclusively by 40 species of the mosquito genus Anopheles. During Anopheles spp. mating, males transfer high levels of the steroid hormone 20-hydroxyecdysone to the females, and the presence of this hormone has been associated with favourable conditions for Plasmodium spp. development.”
"Malaria, along with tuberculosis and HIV infection, is a disease in which all components of the immune response… are involved yet provide only partial protection, which means that developing an effective vaccine will be a challenge. (The figure above shows the global pipeline for malaria vaccines)."
There are a multitude of molecules in the global pipeline for antimalarial drugs that target only the asexual blood stages. This "reflects the fact that many of these compounds are at an early stage of development, and further assessment of their Target Candidate Profile is still ongoing."
"Artemisinin (also known as qinghaosu in China) is extracted from the leaves of the Artemisia annua plant…Owing to the ability of artemisinin to rapidly reduce parasitaemia and fever, the effect that artemisinin and its derivatives have had on the management of malaria cannot be overstated; since their introduction in the 1970s … millions of lives have been saved."
"The most comprehensive antimalarial portfolio has been developed by the not-for-profit product development partnership Medicines for Malaria Venture (MMV) in collaboration with its partners in both academia and the pharmaceutical industry, with support from donors."
"Pregnant women are more susceptible to Plasmodium spp. infection, particularly in their first pregnancy… Placental malaria might be asymptomatic or clinically mild, but it also leads to an increased risk of death for both the fetus and the mother. It predisposes to miscarriage, stillbirth, preterm delivery and babies with low birth weight."
"The socioeconomic burden of malaria is enormous…In many endemic areas, each individual experiences multiple episodes of malaria per year, with each episode causing a loss of school time for children and work time for their parents and guardians."
Cover Image & Slide 4 - iStock.com/pernsanitfoto; Slides 1, 2, 3, 5, 6 - Nature Reviews Disease Primers; Slide 7 - Liu Tianwei; Slides 8, 9 & 10 - Elizabeth Poll/MMV