In 1902, military doctor Ronald Ross obtained the Nobel Prize in Physiology and Medicine for demonstrating that the malaria parasite is transmitted through the bite of a mosquito.
The problem of the transmission of malaria was solved, and its discovery opened the way to seek methods of effective prevention and treatment against this devastating disease.
Nowadays, malaria is eradicated from developed countries, but more than half of the world’s population is still at risk of contracting this disease, which especially ravages Sub-Saharan Africa.
A fact that attracts attention, because we are talking about an infection that, as the World Health Organization (WHO) reminds us, can be prevented and treated.
In 2018, World Malaria Day has as its motto “Prepared to defeat malaria”, a message that reminds us that the global fight against this disease has stalled.
The WHO recalls that the pace of progress is not enough to achieve the objectives of the Global Malaria Strategy 2016-2030: reduce both cases and mortality caused by this disease by 40%.
The cause of malaria
The malaria is a disease caused by parasites of the genus Plasmodium . Some 175 species of these protists are known, but only five of them cause malaria in the human population. Of these, the most deadly are Plasmodium falciparum and P. vivax.
Most of the deaths caused by malaria in the world are due to P. falciparum , since this is the species that predominates in the African continent.
Transmission of malaria
How does the parasite get to infect a human? Like many other organisms, Plasmodium has two types of reproduction throughout its life cycle. Sexual reproduction occurs in Anopheles mosquito females , which are those that, through their sting, infect humans or other animals . In the latter, the asexual reproduction of the parasite takes place.
Of all the Anopheles mosquito species that exist, approximately 30 are malaria vectors. Transmission of the Plasmodiumparasite occurs with greater intensity in places or times in which it has more time to complete its cycle inside the mosquito. For this reason, in many regions there are peaks of malaria transmission that co-exist with rainy seasons.
Immunity, a key factor in the transmission
In areas with high transmission intensity, many adults are exposed to the parasite for years and eventually develop immunity. This never fully protects, but the risks of the infection degenerating into a more serious disease are reduced.
Therefore, in regions where Plasmodium is more abundant, such as the African continent, malaria hits children more intensely.