Hi Everyone. Interesting paper published recently “Madumla, Edith P., et al. ““In starvation, a bone can also be meat”: a mixed methods evaluation of factors associated with discarding of long-lasting insecticidal nets in Bagamoyo, Tanzania.” Malaria Journal 21.1 (2022): 1-19.” on duration of use and methods of discarding old nets in Tanzania.  They mention that between the years 2000 and 2019 more than 1,8 billion LLIN’s were distributed. Insectidal duration typically around 3 years, but most nets discarded after about 2 years. Evidence from Tanzania suggests that decision to discard nets is mostly related to physical integrity of nets. Most common methods for getting rid of the nets is by burning or burial.

If you ever had doubts about the role of vector control in combatting malaria, think on these words taken from the highly-cited 2015 publication by Bahtt et al “In total, we estimated that malaria control interventions have averted 663 (542–753) million clinical cases since 2000, of which 68 (62-73)%, 22 (17-28)% and 10 (5-14)% were contributed by ITNs, ACTs, and IRS, respectively“. 68% of clinical cases averted between 2000 and 2015 can be attributed to the use of bednets, and then another 10% through Indoor Residual Spraying. That kind of sums it up. In fact, ever since it was discovered in 1898 that malaria was transmitted by Anopheles mosquitoes, malaria control has consistently and overwhelmingly relied on vector control. So do not let anyone tell you that entomologists are no longer relevant and important in control of vector-borne diseases, and that goes for arboviruses as well.

Here is the reference to the paper published by Bhatt et al in Nature in 2015 : Bhatt, Samir, D. J. Weiss, E. Cameron, D. Bisanzio, B. Mappin, U. Dalrymple, K. E. Battle et al. “The effect of malaria control on Plasmodium falciparum in Africa between 2000 and 2015.” Nature 526, no. 7572 (2015): 207-211.

Yet more confirmation that globally there is a need for capacity strengthening in national vector control agencies in the ability of countries to effectively respond to mosquito-borne diseases. Here is a hot-off-the-press publication regarding the WHO Eastern Mediterranean Region:

How far are we? National preparedness and response capacities for emerging infectious disease outbreaks in the WHO Eastern Mediterranean Region Lubna Al Ariqi ,1 Evans Buliva,1 Abrar Ahmad Chughtai ,2 Amal Barakat,1 Chiori Kodama ,1 Wasiq Khan,1 Muhammad Tayyab,1 Sherein El Nossery,1 Amir Aman,1 Tamer El-Maghraby, 1 Amgad Elkholy,1 Abdinasir Abubakar1

They say: ⇒ Ministries of Health in 22 countries of the WHO Eastern Mediterranean Region adopted the Strategic Framework for Prevention and Control of Emerging and Epidemic Prone Infectious Diseases in the Region for 2020–2024. To characterise the baseline national capacities pertaining to regional high-threat pathogens for monitoring implementation progress of this framework, an assessment was merited. ⇒ Countries in the Region reported varying levels of capacities, with relatively highest capacities in early detection and investigation of outbreaks and lowest capacities in prevention and preparedness. Countries experiencing humanitarian emergencies have reported relatively lower capacities across all areas. ⇒ The findings suggest that the 22 countries in the Region need to accelerate building their capacities to achieve the framework’s 2024 endorsed target goals.

You can access the article at https://gh.bmj.com/content/bmjgh/7/Suppl_4/e009826.full.pdf.

Thanks for your information, Dr. Leo and Wulan!

There is an interesting, easy-to-read article on the new Interceptor G2 New Generation bednet, which combines the usual synthetic pyrethroid with a new compound, Chlorfenapyr, which targets the insects mitochondrial energy centres. Trials in Africa have found very encouraging results for Interceptor G2, and it is hoped that WHO will officially endorse and recommend IG2 in 2023. Article written by Helen Jamet at Gates Foundation. Read the full story at https://www.gatesfoundation.org/ideas/articles/ig2-nets-malaria-eradication-financed-by-the-global-fund?utm_source=to&utm_medium=em&utm_campaign=wc&utm_term=lgc

Wow. Fascinating article that explains how mosquitoes prefer to rest on vertical surfaces, but are only able to “hang on” to such vertical surfaces if they are above a certain threshold of roughness, otherwise they cannot hold on. So if you can spray a “smoothener” onto the surface the mosquitoes cannot land. Read here:

Recla L, Rheault M, Golovin K. Complete Inhibition of Vertical Mosquito Landing through Topographical Surface Design. ACS Applied Materials & Interfaces. 2022 Aug 12.