After major global successes in the battle against malaria, the positive trend stalled around 2015 -- apart from in Zanzibar in East Africa, where only a fraction of the disease remains. 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.
The years around 2000 professor Anders Björkman described as catastrophic with respect to the global spread of malaria. This triggered a world-wide initiative that was given a boost by new kinds of drug and the widespread distribution of impregnated 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," says Björkman, who is at the Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, who has been running the malaria project for 18 years. "Except for in Zanzibar, where the action taken for its 1.4 million citizens has led to approximately a 96 per cent decline in the incidence of malaria. We've optimized these measures with the Zanzibar Malaria Control Programme and can now explain why malaria has not yet been fully eliminated."
The study reveals altered behaviour in the malaria mosquitoes, which now bite outdoors instead of indoors. They have also developed a kind of resistance to modern pesticides. Furthermore, there has been a process of selection in the pathogenic parasite, where 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 Björkman. "We now need to develop new strategies to overcome this if we're to attain the goal of eliminating the disease from Zanzibar, an endeavour that can prove a model for the entire continent."
What surprised the researchers was the dramatic decline in child mortality in Zanzibar, where malaria control has caused more than a 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 the reason for this dramatic reduction is that the disease has a greater and more chronic effect on the general health of babies than suspected, thus lowering their resistance to other diseases throughout early childhood.
"Malaria is still the greatest obstacle to a healthy childhood in Africa," says Björkman. "If you ask African women today, their greatest concern is usually that malaria doesn't affect their pregnancy and their babies. The global community must continue the fight for improved strategies and control measures. If this happens, I think we'll be able to reach the goal of ultimate elimination."
Zanzibar was one of the first countries to put the global initiatives against malaria to use and has since been tireless in its work to control the disease. The researchers now hope that these lessons can revive anti-malaria strategies throughout Africa.
The study was mainly financed by the Erling-Persson Family Foundation and the Swedish Research Council.
Reference: "From high to low malaria transmission in Zanzibar - challenges and opportunities to achieve elimination". Anders Bjo?rkman, Deler Shakely, Abdullah Ali, Ulrika Morris, Humphrey Mkali, Abdul-Wahid Al-Mafazy, Khamis Haji, Juma Mcha, Rahila Omar, Jackie Cook, Kristina Elfving, Max Petzold, Michael Sachs, Berit Aydin-Schmidt, Chris Drakeley, Mwinyi Msellem and Andreas Martensson. BMC Medicine, online 22 January 2019, doi: 10.1186/s12916-018-1243-z.
Source: Karolinska Institutet
Product Locator: Spring and Early Mother's Day Gift Guide for Infection Prevention Personnel
March 27th 2024Whether it's a spring holiday, birthdays, or no reason at all, infection prevention personnel love to give and receive gifts that help at the end of a stressful day. Infection Control Today® offers some gift ideas for infection prevention personnel and their families.
Catching Up With Vangie Dennis, AORN 2022-2023 President at AORN 2024
March 26th 2024Infection Control Today (ICT) had the privilege of catching up with Vangie Dennis, MSN, RN, CNOR, CMLSO, at the Association of periOperative Registered Nurses' (AORN’s) International Surgical Conference & Expo 2024. As the former president of AORN and an esteemed figure in perioperative services, Vangie Dennis shared insights into her recent endeavors and the exciting new chapter she's embarked upon.
How To Optimize Your Time Management Strategies for the Busy Infection Preventionist
March 25th 2024Is your calendar resembling a chaotic masterpiece of overlapping tasks? Join the club of infection preventionists striving to balance responsibilities. Dive into proven strategies from a fellow infection preventionist to reclaim control of your time, streamline tasks, and boost productivity effectively. This is an IP Lifeline article.
CenTrak Unveils Revolutionary BLE Multi-Mode Platform for Health Care RTLS Solutions
March 22nd 2024CenTrak, the industry leader in real-time location technology, introduces the groundbreaking BLE Multi-Mode Platform, setting a new standard for Real-Time Location Systems (RTLS) in health care. Discover how this innovative solution enhances location data precision and streamlines operations for health care organizations.