Article
Multidisciplinary Sciences
Cristina Yunta, Jocelyn M. F. Ooi, Folasade Oladepo, Sofia Grafanaki, Spiros. A. Pergantis, Dimitra Tsakireli, Hanafy M. Ismail, Mark J. I. Paine
Summary: Chlorfenapyr is an increasingly used pro-insecticide in combination with pyrethroids to control pyrethroid-resistant mosquito populations. Different P450s in mosquitoes were investigated for their ability to metabolize chlorfenapyr, providing valuable insights into its metabolism and highlighting the need for further investigation into effective vector control strategies.
SCIENTIFIC REPORTS
(2023)
Article
Parasitology
Cyntia-Muriel Y. Clegban, Soromane Camara, A. Alphonsine Koffi, Ludovic P. Ahoua Alou, Jean-Paul Kabran Kouame, A. Fernand Koffi, Philippe K. Kouassi, Nicolas Moiroux, Cedric Pennetier
Summary: Long-lasting insecticidal nets (LLINs) have been effective in reducing global malaria burden since 2000. In this study, two new brands of deltamethrin-impregnated nets were evaluated against wild pyrethroid-resistant mosquitoes, showing that they met WHO criteria and are suitable for further testing at the community level. With the increasing pyrethroid resistance, integrated vector management using a variety of control tools is needed for effective malaria control.
PARASITES & VECTORS
(2021)
Article
Infectious Diseases
Casimir Dossou Kpanou, Hermann W. Sagbohan, Fortune Dagnon, Germain G. Padonou, Razaki Osse, Albert Sourou Salako, Aboubakar Sidick, Wilfried Sewade, Andre Sominahouin, Patrick Condo, Saadani Hassani Ahmed, Daniel Impoinvil, Martin Akogbeto
Summary: The study revealed resistance to pyrethroids in Anopheles gambiae in Parakou, Kandi, and Malanville in Benin, posing a potential threat to malaria vector control.
Article
Biochemistry & Molecular Biology
Louisa A. Messenger, Lucy Mackenzie Impoinvil, Dieunel Derilus, Delenasaw Yewhalaw, Seth Irish, Audrey Lenhart
Summary: The study investigated the gene expression patterns of a multi-insecticide resistant population of Anopheles arabiensis from Oromia Region, Ethiopia, revealing resistance to malathion and permethrin but susceptibility to other insecticides. Transcriptomic analysis identified overexpression of specific genes in the resistant population, shedding light on the molecular basis of insecticide resistance in this malaria vector species.
INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
(2021)
Article
Infectious Diseases
Mgeni M. Tambwe, Sarah Moore, Lorenz Hofer, Ummi A. Kibondo, Adam Saddler
Summary: The study showed that transfluthrin-treated targeted insecticide can reduce mosquito-human contact, but the efficacy is weaker against pyrethroid-resistant mosquito strains, especially Anopheles arabiensis (Mbita and Kingani strains).
Article
Multidisciplinary Sciences
Maxwell G. Machani, Eric Ochomo, Fred Amimo, Wolfgang R. Mukabana, Andrew K. Githeko, Guiyun Yan, Yaw A. Afrane
Summary: Long-lasting insecticidal nets are effective in reducing malaria transmission, but it is important to understand the behavior of malaria vectors with insecticide resistance around human-occupied bed nets.
Article
Infectious Diseases
Desta Ejeta, Ansha Asme, Animut Asefa
Summary: In northwestern Ethiopia, ethnobotanical plant extracts showed promising insecticidal effects against the primary malaria vector, Anopheles arabiensis, with Azadirachta indica exhibiting the most significant results. These plant extracts have the potential for botanical mosquito insecticide development, but further research on wild mosquitoes is recommended.
Article
Multidisciplinary Sciences
Helena Marti-Soler, Mara Maquina, Mercy Opiyo, Celso Alafo, Ellie Sherrard-Smith, Arlindo Malheia, Nelson Cuamba, Charfudin Sacoor, Regina Rabinovich, Pedro Aide, Francisco Saute, Krijn Paaijmans
Summary: The study assessed the residual efficacy of SumiShield((TM)) 50WG, a third generation IRS product introduced in southern Mozambique, and found that it did not meet the current WHO threshold value for effective IRS in both young and old mosquitoes. Therefore, considering delayed mortality, residual efficacies ranged from 1.5 to >= 12.5 months, depending on mortality time post exposure, wall type, and mosquito age.
Review
Parasitology
Stephan Karl, Michelle Katusele, Timothy W. Freeman, Sarah J. Moore
Summary: Despite passing the World Health Organization's prequalification and pre-delivery inspections, substandard LLINs were distributed in Papua New Guinea for at least 6 years. This highlights major weaknesses in the current LLIN quality-assurance framework.
TRENDS IN PARASITOLOGY
(2021)
Article
Infectious Diseases
Bedjou P. N'Dri, Nadja C. Wipf, Jasmina Saric, Behi K. Fodjo, Giovanna Raso, Juerg Utzinger, Pie Mueller, Chouaibou S. Mouhamadou
Summary: This study investigated the species composition, insecticide susceptibility status, and resistance mechanisms of malaria vectors in southern Cote d'Ivoire. The results showed the presence of different mosquito species, including the first documented finding of Anopheles arabiensis in Cote d'Ivoire. Genetic testing revealed mutations in resistance-related genes. The findings suggest the use of non-pyrethroid insecticides for indoor residual spraying and the consideration of additional measures to control outdoor biting by Anopheles arabiensis.
Article
Public, Environmental & Occupational Health
Donald S. Shepard, John U. Odumah, Samson T. Awolola
Summary: PBO nets have been found to reduce symptomatic malaria cases by 33.4% in areas with moderate insecticide resistance, with an incremental cost-effectiveness ratio of $11 per disability-adjusted life year averted from a prevention perspective. From the health systems perspective, PBO nets were significantly cost-saving relative to conventional LLINs, with added economic benefits of $201 for every $1 in incremental costs.
AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE
(2021)
Article
Genetics & Heredity
Yvan Fotso-Toguem, Billy Tene-Fossog, Leon M. J. Mugenzi, Murielle J. Wondji, Flobert Njiokou, Hilary Ranson, Charles S. Wondji
Summary: The polymorphisms of CYP6M2 and CYP6P4 were analyzed to detect potential resistance markers in Anopheles coluzzii and Anopheles gambiae. The study found significant overexpression of CYP6M2 and CYP6P4 in resistant mosquitos, and a lower diversity in the upstream region of CYP6P4 potentially associated with resistance.
Article
Multidisciplinary Sciences
Mercy A. Opiyo, Halfan S. Ngowo, Salum A. Mapua, Monica Mpingwa, Nuru Nchimbi, Nancy S. Matowo, Silas Majambere, Fredros O. Okumu
Summary: The study showed that adding sub-lethal doses of PPF to larval habitats of pyrethroid-resistant malaria vectors led to significantly reduced mortality rates of emergent adult mosquitoes when exposed to pyrethroids, but no impact on carbamates or organochlorides. Additionally, mortality rates were reduced for adult mosquitoes exposed to Olyset(R) nets after aquatic exposure to PPF.
Article
Multidisciplinary Sciences
Kevin O. Owuor, Maxwell G. Machani, Wolfgang R. Mukabana, Stephen O. Munga, Guiyun Yan, Eric Ochomo, Yaw A. Afrane
Summary: The study found higher phenotypic, metabolic, and genotypic insecticide resistance in indoor resting populations of malaria vectors compared to their outdoor resting counterparts. The moderate resistance intensity in indoor resting mosquitoes is concerning and may impact the efficacy of existing pyrethroid-based vector control tools. The use of synergist (PBO) in LLINs could be a better alternative for regions with high insecticide resistance.
Article
Parasitology
Eliningaya J. Kweka, Lucille J. Lyaruu, Violet Temba, Shandala Msangi, Johnson O. Ouma, Wycliffe Karanja, Aneth M. Mahande, Yousif E. Himeidan
Summary: Despite high levels of pyrethroid resistance in malaria vectors, MiraNet, a pyrethroid-based net, demonstrated effective control against a wild population of An. arabiensis in northern Tanzania. The study showed that both unwashed and washed MiraNet and DuraNet achieved optimal knockdown and mortality rates against a susceptible strain of An. gambiae s.s. The killing effect of MiraNet on wild An. arabiensis was over 50%, indicating its efficacy in low to moderate resistant populations.
PARASITOLOGY RESEARCH
(2023)
Article
Infectious Diseases
Jacklin F. Mosha, Eliud Lukole, J. Derek Charlwood, Alexandra Wright, Mark Rowland, Olivia Bullock, Alphaxard Manjurano, William Kisinza, Franklin W. Mosha, Immo Kleinschmidt, Natacha Protopopoff
Article
Infectious Diseases
Manfred Accrombessi, Jackie Cook, Corine Ngufor, Arthur Sovi, Edouard Dangbenon, Boulais Yovogan, Hilaire Akpovi, Aurore Hounto, Charles Thickstun, Gil G. Padonou, Filemon Tokponnon, Louisa A. Messenger, Immo Kleinschmidt, Mark Rowland, Martin C. Akogbeto, Natacha Protopopoff
Summary: This study in Benin aims to assess the impact of two novel LLINs on malaria transmission. The three study arms will use different formulations of LLINs and monitor malaria incidence and mosquito populations over 24 months. The results will contribute to shaping future malaria control strategies in sub-Saharan Africa.
BMC INFECTIOUS DISEASES
(2021)
Article
Parasitology
Jackline L. Martin, Franklin W. Mosha, Eliud Lukole, Mark Rowland, Jim Todd, Jacques D. Charlwood, Jacklin F. Mosha, Natacha Protopopoff
Summary: The study evaluated the personal protection provided by PBO-Py LLIN (Olyset Plus) compared to standard LLIN (Olyset net) against pyrethroid-resistant Anopheles mosquitoes in North-West Tanzania after 20 months of use. The results showed that PBO-Py LLINs offered improved protection, demonstrating higher bioassay mortality and absence of resistant mosquitoes collected from inside the nets, regardless of their physical integrity.
PARASITES & VECTORS
(2021)
Article
Medicine, General & Internal
Jacklin F. Mosha, Manisha A. Kulkarni, Louisa A. Messenger, Mark Rowland, Nancy Matowo, Catherine Pitt, Eliud Lukole, Monica Taljaard, Charles Thickstun, Alphaxard Manjurano, Franklin W. Mosha, Immo Kleinschmidt, Natacha Protopopoff
Summary: This study compares three promising dual active ingredient LLINs to evaluate their effectiveness in combating insecticide-resistant malaria vectors. The findings will be actively disseminated through various channels to enhance malaria prevention and control efforts.
Article
Multidisciplinary Sciences
Boulais Yovogan, Arthur Sovi, Gil G. Padonou, Constantin J. Adoha, Bruno Akinro, Said Chitou, Manfred Accrombessi, Edouard Dangbenon, Hilaire Akpovi, Louisa A. Messenger, Razaki Osse, Aurore Ogouyemi Hounto, Jackie Cook, Immo Kleinschmidt, Corine Ngufor, Mark Rowland, Natacha Protopopoff, Martin C. Akogbeto
Summary: This study conducted in southern Benin aimed to assess the characteristics of vector populations and malaria transmission. The main malaria vectors, An. coluzzii and An. gambiae s.s., were found to be highly resistant to pyrethroids, despite the high usage of standard LLINs in the study area. The results indicate intense malaria transmission and the presence of multiple resistance mechanisms, making it suitable for the trial evaluating the impact of novel dual-AI LLINs on insecticide-resistant vectors.
Article
Multidisciplinary Sciences
Nancy S. Matowo, Jackline Martin, Manisha A. Kulkarni, Jacklin F. Mosha, Eliud Lukole, Gladness Isaya, Boniface Shirima, Robert Kaaya, Catherine Moyes, Penelope A. Hancock, Mark Rowland, Alphaxard Manjurano, Franklin W. Mosha, Natacha Protopopoff, Louisa A. Messenger
Summary: Anopheles funestus is the predominant vector in malaria transmission in Northwest Tanzania, with Anopheles gambiae playing a lesser role which is influenced by seasonal rainfall. Both vectors show similar resistance to alpha-cypermethrin and permethrin, highlighting the need for new vector control strategies to combat persistent malaria transmission in the region.
SCIENTIFIC REPORTS
(2021)
Article
Entomology
Salum Azizi, Janneke Snetselaar, Alexandra Wright, Johnson Matowo, Boniface Shirima, Robert Kaaya, Rashid Athumani, Filemoni Tenu, Natacha Protopopoff, Matthew Kirby
Summary: Malaria control has traditionally relied on insecticides like treated bed nets or residual spraying in households, but the scaling up of such interventions has led to insecticide resistance in mosquitoes. There is an urgent need for new insecticides effective against these resistant mosquitoes. This study describes the challenges faced in establishing and maintaining a resistant mosquito strain in the laboratory, reflecting characteristics of wild-resistant mosquito populations in East Africa.
Article
Multidisciplinary Sciences
Johnson Matowo, David Weetman, Patricia Pignatelli, Alexandra Wright, Jacques D. Charlwood, Robert Kaaya, Boniface Shirima, Oliva Moshi, Eliud Lukole, Jacklin Mosha, Alphaxard Manjurano, Franklin Mosha, Mark Rowland, Natacha Protopopoff
Summary: In Africa, the efficacy of long lasting insecticidal nets (LLINs) in reducing malaria transmission is being reduced by pyrethroid resistance in the major vectors. A study found that pre-exposure to piperonyl butoxide (PBO) followed by permethrin exposure partially restored susceptibility in mosquitoes. The study also identified multiple over expressed P450 genes in pyrethroid-resistant mosquitoes.
Article
Entomology
Mark T. Fowler, Rosemary S. Lees, Josias Fagbohoun, Nancy S. Matowo, Corine Ngufor, Natacha Protopopoff, Angus Spiers
Summary: This study demonstrates the use of a convolutional neural network to automate the classification of mosquito ovaries' fertility status, improving assessment speed, accuracy, and consistency. The method is useful for evaluating the efficacy of insecticides like Pyriproxyfen and can be applied practically to measure effectiveness and durability.
Article
Entomology
Natalie Lissenden, Jennifer S. Armistead, Katherine Gleave, Seth R. Irish, Jackline L. Martin, Louisa A. Messenger, Sarah J. Moore, Corine Ngufor, Natacha Protopopoff, Richard Oxborough, Angus Spiers, Rosemary S. Lees
Summary: Mosquitoes are becoming increasingly resistant to pyrethroid insecticides, leading to the development of new insecticide-treated nets. However, there is a lack of standardized methods to measure the efficacy of these nets against mosquitoes in the long term.
Article
Infectious Diseases
Jackline L. Martin, Louisa A. Messenger, Franklin W. Mosha, Eliud Lukole, Jacklin F. Mosha, Manisha Kulkarni, Thomas S. Churcher, Ellie Sherrard-Smith, Alphaxard Manjurano, Natacha Protopopoff, Mark Rowland
Summary: This study aims to assess the insecticide and textile durability of three classes of dual-active ingredient (A.I.) LLINs using techniques derived from established WHO LLIN testing methods, and provide reference for preferred product characteristics of each class of LLIN.
Article
Entomology
Rosemary S. Lees, Jennifer S. Armistead, Salum Azizi, Edi Constant, Christen Fornadel, John E. Gimnig, Janet Hemingway, Daniel Impoinvil, Seth R. Irish, William Kisinza, Natalie Lissenden, Henry D. Mawejje, Louisa A. Messenger, Sarah Moore, Corine Ngufor, Richard Oxborough, Natacha Protopopoff, Hilary Ranson, Graham Small, Joseph Wagman, David Weetman, Sarah Zohdy, Angus Spiers
Summary: To test the effectiveness and durability of new bed nets, it is necessary to study and test insecticide-resistant mosquitoes. A group of experts collaborated to develop a protocol for standardized monitoring and accurate characterization of resistant mosquitoes, providing valuable guidance for malaria control programs and stakeholders.
Article
Public, Environmental & Occupational Health
Manfred Accrombessi, Martin C. Akogbeto, Edouard Dangbenon, Hilaire Akpovi, Arthur Sovi, Boulais Yovogan, Constantin Adoha, Landry Assongba, Aurore Ogouyemi-Hounto, Germain Gil Padonou, Charles Thickstun, Mark Rowland, Corine Ngufor, Natacha Protopopoff, Jackie Cook
Summary: Despite the extensive use of long-lasting insecticidal nets (LLINs), indoor residual spraying, and malaria case management in Benin, malaria still poses a significant burden in this country. This study focused on a rural area of Benin with high net coverage and pyrethroid-resistant mosquito vectors to determine the malaria burden and its associated risk factors. The results showed a high prevalence of malaria infection despite the high usage of nets. Factors such as high household density, low socioeconomic status, young age (<15 years), poor net conditions, and low net usage were significantly associated with malaria infection. Therefore, the development of new classes of LLINs effective against resistant vectors is crucial in reducing malaria transmission in this area.
AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE
(2022)
Article
Entomology
Alina Soto, Mark Rowland, Louisa A. Messenger, Mathew Kirby, Franklin W. Mosha, Alphaxard Manjurano, Natacha Protopopoff
Summary: This study compared two techniques for measuring the sterilization effect of insecticidal bed nets on malaria mosquitoes. The results showed that both egg-laying observation and ovarian dissection had similar sensitivity for identifying mosquitoes exposed to insecticides. However, for identifying non-exposed mosquitoes, ovarian dissection had higher specificity. Therefore, ovarian dissection is a more sensitive and accurate method for evaluating sterility in malaria mosquitoes.
Article
Medicine, General & Internal
Jacklin F. Mosha, Manisha A. Kulkarni, Eliud Lukole, Nancy S. Matowo, Catherine Pitt, Louisa A. Messenger, Elizabeth Mallya, Mohamed Jumanne, Tatu Aziz, Robert Kaaya, Boniface A. Shirima, Gladness Isaya, Monica Taljaard, Jacklin Martin, Ramadhan Hashim, Charles Thickstun, Alphaxard Manjurano, Immo Kleinschmidt, Franklin W. Mosha, Mark Rowland, Natacha Protopopoff
Summary: This study evaluated new classes of LLINs with different active ingredients against resistant malaria vectors, showing that chlorfenapyr LLINs provided better protection against malaria in areas with insecticide-resistant mosquitoes and had good cost-effectiveness.