New study gives hope of eradicating malaria

After significant global successes in the fight against malaria, the positive trend has stopped around 2015, with the exception of Zanzibar in East Africa, where the disease is more and more rare. In a new study published in BMC Medicineresearchers at the Karolinska Institutet in Sweden explain why and have shown that new strategies are needed to eradicate the disease. One of the problems is a change in mosquito behavior and a selection of parasites.

Professor Anders Björkman of the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, describes the millennium years as catastrophic for the global spread of malaria. This epidemic triggered a global initiative that resulted in new types of drugs and large-scale distribution of insecticide-treated mosquito nets and household anti-mosquito sprays. The result has been a halving of the global spread of the disease by 2015.

"But after that, the decline has been mitigated, except in Zanzibar, where the measures taken in favor of its 1.4 million citizens have resulted in a decline of about 96% in the impact of the We have optimized these measures with the malaria control program in Zanzibar and can now explain why malaria has not yet been completely eliminated, "says Björkman, who has been leading the malaria project for 18 years.

The study reveals a change in behavior in malaria-carrying mosquitoes, which now bite outward rather than inward, where the net prevents mosquitoes. They have also developed a kind of resistance to modern pesticides. In addition, there has been a selection process of the pathogenic parasite, in which the remaining form is more difficult to detect, but continues to spread the disease as before. The researchers have followed approximately 100,000 residents from two districts of Zanzibar since 2002.

"Mosquitoes and parasites have found ways to avoid control measures," says Professor Björkman. "We must develop new strategies to overcome this problem if we want to achieve the goal of eliminating Zanzibar disease, a company that can prove to be a model for the entire continent."

What surprised the researchers is the dramatic drop in infant mortality in Zanzibar, where the fight against malaria has caused a fall of more than 70% in the total infant mortality rate. It had previously been estimated that only 20% of child deaths in Africa were related to malaria; The researchers now believe that this dramatic reduction is due to the fact that the disease has a greater and more chronic effect on the general health of babies than we have suspected, thus reducing their resistance to other diseases. during early childhood.

"Malaria remains the biggest obstacle to a healthy childhood in Africa," said Professor Björkman. "If you're asking African women today, their biggest concern is generally that malaria does not affect their pregnancy or their babies." The global community must continue to fight for better strategies and control measures achieve the ultimate goal of elimination ".

Zanzibar has been one of the first countries to use global malaria initiatives and has since struggled relentlessly against the disease. Researchers now hope that these lessons can boost anti-malaria strategies in Africa.

Provided by
Karolinska Institutet