After a major global success in the fight against malaria, the positive trend stalled around 2015-apart from in Zanzibar in East Africa, where the disease is increasingly rare. In a new study published in BMC Medicine, researchers at Karolinska Institutet in Sweden explain why this was and show that new strategies are needed to eradicate the disease. One of the problems is a change in mosquito behaviour and selection in the parasites.
Professor Anders Björkman at the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, describes the millennium as a catastrophic with respect to the global spread of malaria. This outbreak triggered a worldwide initiative that resulted in new types of drugs and the widely distributed distribution of mosquito nets and domestic anti-mosquito sprays. The outcome was a halving of the global spread of the disease by 2015.
"But after that, the decline tailed off, except for Zanzibar, where the action taken for its 1.4 million citizens has led to an approximately 96% decline in the incidence of malaria. and can now explain why malaria has not been fully eliminated, "says Björkman, who has been running the malaria project for 18 years.
The study reveals that mosquitoes, which now bite outdoors instead of indoors, where netting prevents mosquitoes. They have also developed a kind of resistance to modern pesticides. Furthermore, there has been a process of selection in the pathogenic parasite, whereby the remaining form is more difficult to detect, but still spreads the disease as before. The researchers have been monitoring 100,000 or so residents of two districts in Zanzibar since 2002.
"Both the mosquitoes and the parasites have found ways to avoid control measures," says Professor Björkman. "We need to develop new strategies to overcome this if we are to achieve the goal of eliminating the disease from Zanzibar, an endeavor that can prove a model for the whole continent."
What surprised the researchers was the dramatic decline in child mortality in Zanzibar, where malaria control has resulted in more than 70 percent drop in the total child mortality rate. It was previously estimated that only 20 percent of child deaths in Africa were malaria-related; The researchers now think that the disease has a greater and more chronic effect on the child than suspected, thus lowering their disease to other early childhood.
"Malaria is still the greatest obstacle to a healthy childhood in Africa," says Professor Björkman. "If you ask African women today, their greatest concern is usually that malaria does not affect their pregnancy and their babies. to reach the goal of the ultimate elimination. "
Zanzibar was one of the first countries to put global initiatives against malaria to use and has since been in tireless in its work to control the disease. The researchers now hope that these lessons can revive anti-malaria strategies throughout Africa.
WHO: Malaria reductions stall after progress
Anders Bjorkman et al. From high to low malaria transmission in Zanzibar – challenges and opportunities to achieve elimination. BMC Medicine, online 22 January 2019, DOI: 10.1186 / s12916-018-1243-z
New study raises hopes of eradication of malaria (2019, January 22)
Retrieved 22 January 2019
This document is subject to copyright. Apart from any fair dealing for the private study or research, no
part may be reproduced without written permission. The content is provided for information purposes only.