VIDEO: Addressing the threat of Anopheles stephensi
After being detected in Africa in 2012, the Anopheles stephensi mosquito has been spreading rapidly across the continent, threatening progress to end malaria. The U.S. President’s Malaria Initiative (PMI) is exploring new tools and approaches to mitigate its impact.
While many mosquitoes commonly found in Africa thrive in rural areas during the rainy season, Anopheles stephensi can survive through dry periods and in urban areas, which is changing where malaria occurs. So malaria prevention tools used in the past may not be as effective against this mosquito.
In Ethiopia, PMI VectorLink and the Ministry of Health’s malaria program are equipping communities with larvicide, an insecticide applied at mosquito breeding sites to kill the mosquito before it can infect people. PMI and partners are also giving residents the knowledge they need to protect themselves.
PMI will continue to work with countries to develop effective ways to detect, monitor, and control Anopheles stephensi to help end malaria.
In advance of the PMI VectorLink Project closeout in September 2023, we are pleased to present stories showcasing the work conducted under the project, which collaborated with country governments, local health systems, research institutions, and communities. See how collectively, PMI and its partners have strengthened local capacity, reached those previously unreached by vector control, helped to keep malaria services resilient, and innovated new tools and approaches to end malaria faster.
Cambodia has been making great strides toward malaria elimination, which it is aiming to achieve by 2025. As the country moves toward this goal, it has been implementing an electronic system known as the Malaria Information System (MIS). Led by Cambodia’s National Center for Parasitology, Entomology, and Malaria Control (CNM), this online data management system is essential for tracking country-wide data related to malaria cases but had been lacking a key component to give a more holistic picture of malaria transmission.
According to Pengby Ngor, lead of the CNM’s MIS Unit, “Entomological data had been a missing element within the current MIS, which was a constraint in driving us forward to achieve the malaria elimination goals by 2025. Current functionalities of the MIS cover case management, including screening, detection, and treatment for malaria plus the commodity management and insecticide treated net distribution; some data are even entered real-time.”
Pengby Ngor analyzing data on the Malaria Information System. Photo courtesy of Pengby Ngor, CNM.
Entomological data—for example, information linked to the types of mosquitoes transmitting malaria, their behavior, and testing their resistance to current insecticides—is critical for all countries, as it provides the evidence needed to inform vector control decision-making and to enable optimal interventions to be swiftly deployed. In Cambodia, where malaria cases have decreased significantly in recent years, groups of malaria cases often arise in “foci,” which are localized areas of transmission. Thus, entomological data is important in providing insight into the optimal selection and targeting of malaria control interventions that can stop malaria transmission.
With the support of the U.S. President’s Malaria Initiative (PMI) VectorLink Project, CNM began integrating this data into the MIS to complement the existing malaria case management information.
PMI VectorLink has been partnering with CNM since 2018, supporting CNM to conduct entomological surveillance in two provinces: Stung Treng and Mondulkiri. To assist CNM with this need, PMI VectorLink tapped into its existing entomological data for Cambodia, stored in the project’s own data management system, VectorLink Collect, which is a global system that houses robust vector control and entomological surveillance data across 25 countries, including Cambodia. VectorLink Collect was developed using the widely available District Health Information Software 2 (DHIS2) platform as its core.
The challenge for PMI VectorLink Cambodia was that CNM’s MIS platform is custom-built for Cambodia – meaning it isn’t built on DHIS2. Thus, to enable a seamless importation and transfer of VectorLink Collect’s entomology data into the MIS, the PMI VectorLink team had to design and develop data collection tools, user interfaces, and dashboards specifically to meet CNM’s MIS. Starting in July 2022, this six-month process included developing prototypes, testing, and integrating feedback for mosquito collection data and insecticide resistance data, which enabled creating a link between the entomology modules and malaria case data. When this work was completed, PMI VectorLink was able to transfer its existing Cambodia entomological data into CNM’s MIS to be accessed by CNM and used for routine purposes. This was the first time in the project’s six-year history that VectorLink Collect information has been used to help support a country to supplement its own proprietary information management system that is not based on DHIS2.
Log-in page for the CNM’s Malaria Information System.
Of course, the key to success with any data system is ensuring that the people using the system can get what they need when they need it, and then use this data to inform their actions. PMI VectorLink worked with CNM to train MIS staff, entomologists, and provincial-level staff on data collection tools used as the foundation for the MIS, and then introduced the entomological modules within the system.
“The support of PMI VectorLink in adding this entomology module was important and relevant,” said Mr. Ngor. “The entomology module has become a complementary tool to better inform and use data from that module for decision-making.”
Today, Cambodia has a more comprehensive national information system for tracking, treating, and preventing malaria. With data available at their fingertips, CNM is sure to continue its progress toward malaria elimination.
Evaline Nampima is a fierce advocate for her community. She is a district councilor, representing Muwayo town council, working as a bridge between her community and Bugiri District Council in Uganda. During the annual campaign to spray homes with a mosquito-killing insecticide to prevent malaria, Evaline became one of her town’s strongest supporters of the intervention.
Malaria is personal to Evaline. “I used to take my children almost weekly to the hospital. I would bring one home and another one would be down with malaria,” she shares. “As a leader, people used to come to my home nearly daily either asking for transport to the health center or money for treatment; I would help where I could, but it was overwhelming.”
This is why Evaline works so hard to ensure her community is protected from this disease. Evaline recalls that before homes were sprayed, “there used to be so many cases of malaria that when you’d go to the health center, it would be full.” Since the U.S. President’s Malaria Initiative (PMI) VectorLink Uganda Project’s spray campaign started in 2018, Evaline worked diligently as a campaign mobilizer in Bugiri district to educate her community on the benefits of indoor residual spraying for protection against malaria.
“During the campaign, I meet the spray team first before they go to the field to start their work,” shares Evaline. “I tell them how to approach a home and talk to the owners because home entry techniques and approach is very important in community acceptance of this malaria prevention method.” Evaline also participates in community dialogues—a participatory communication process where information is shared with groups of people to help solve problems such as increasing the number of households accepting spraying—when there is resistance to accepting the intervention.
Evaline during a radio talk show to talk about the benefits of having homes sprayed on NBS FM in Jinja. Photo Credit: Angom Dorcas Hope, Communication for Development Foundation Uganda.
Convincing community members to accept interventions that protect people from malaria is challenging. And that’s where Evaline comes in. With training from the Communication for Development Foundation Uganda (CDFU), she helped convince her community to accept having their homes sprayed.
PMI has worked with CDFU, a Ugandan nongovernmental organization that carries out social and behavior change, capacity strengthening, and community engagement programs, since 2015 to implement the necessary social and behavior change mobilization that supports spray campaigns. CDFU has trained Evaline and dozens of others as mobilizers to ensure Bugiri district was protected from malaria.
“Before the 2023 spray campaign began, we completed a five-day training where we were taken through communications skills, homeowner entry techniques, sexual violence prevention, and interpersonal communication,” explains Evaline. These skills help mobilizers communicate effectively with households and spray operators.
Interpersonal communication is particularly effective in encouraging community members to accept having their homes sprayed because it allows them an opportunity to express their concerns one-on-one. Some reasons people don’t want their homes sprayed include not liking the smell of the insecticide, thinking it leads to bed bug infestation, and that it can lead to infertility. “There are some issues in the community that people feel can’t be shared in public during community dialogues,” says Angom Dorcas Hope, project assistant for CDFU. Interpersonal communication enables community members to privately share their concerns.
Evaline’s community mobilization efforts have paid off. In Bugiri, spray operators have covered 92.6% of homes, protecting close to 80,000 people, including over 17,000 pregnant women and 110,000 children under five in 2023.
After the spray campaign finishes, Evaline talks to communities about the importance of sleeping under a mosquito bed net and getting rid of stagnant water around homes as malaria-carrying mosquitoes can breed there. When she gets a chance to talk with women’s groups, she encourages women to take their children to the health center if they have fevers and pregnant women to go early for antenatal care.
Evaline says, “if we continue to inform our community about spray benefits, but also embrace other preventive measures—seeking early testing and treatment and supporting health workers—we shall see a malaria-free Bugiri.”
A year ago, Angola was not yet able to conduct laboratory testing on mosquitoes responsible for transmitting malaria throughout the country. Julio Estobre, a molecular biology laboratory technician at the Instituto Nacional de Investigação em Saúde(National Health Research Institute – INIS), understood that data generated from laboratory testing is essential to informing national vector control decisions and sought to provide Angola with that capability. In response to INIS’s request for support, the U.S. President’s Malaria Initiative (PMI) VectorLink project provided trainings to the INIS staff to strengthen capacity to conduct laboratory tests that determine mosquito species and identify malaria parasites.
Julio Estobre, laboratory technician at INIS, working with solutions during the ELISA training session. Photo credit: Rossely Kuango, PMI VectorLink Angola laboratory technician.
“Conducting molecular analyses of mosquito samples in-country allows for more rapid determination of which species contribute to the transmission of malaria,” said Julio. The National Malaria Control Program (NMCP) can then use this information to make evidence-based decisions about which vector control interventions are most appropriate.
Julio became interested in working to end malaria thanks to his work at INIS. “At INIS, I was primarily working with Aedes mosquitoes and their role in dengue transmission. This work awakened my interest in other vector-borne diseases like malaria, which is primarily transmitted in Angola by Anopheles mosquitoes,” he shared.
The PMI VectorLink Angola team has been partnering with INIS and the NMCP since 2019 to collect and analyze samples obtained through routine entomological surveillance and insecticide resistance monitoring activities. As these activities progressed, PMI VectorLink Angola laboratory technician Dr. Rossely Kuango and the VectorLink Angola team worked diligently to procure necessary equipment and materials to start laboratory analyses. Once the necessary materials were on-hand, PMI VectorLink began organizing training to strengthen INIS’s skills.
In March 2022, the team hosted a CDC entomologist who supported INIS as they conducted the first molecular tests (by PCR) to identify species of mosquitoes collected by VectorLink Angola. Later in the year, PMI VectorLink successfully trained Julio and another technician from INIS and three NMCP staff on how to detect infective malaria parasites within mosquito samples, using CS ELISA tests. Each training day had two main parts: a session to review standard operating procedures for that day’s steps, and a hybrid Q&A session with PMI entomologists to troubleshoot, ask questions, and discuss technical concepts.
Julio, with NMCP technicians Luzala and Arlete, preparing solutions during the ELISA training session. Photo credit: Rossely Kuango, PMI VectorLink Angola laboratory technician.
Julio and the other trainees refined old skills and learned new ones, including “how to prepare Anopheles mosquitoes for molecular analysis through dissection and grinding. In addition, we learned a new way to extract the mosquito’s DNA and how to interpret PCR results, which together help us to identify which Anopheles species are present in the various areas in the country.”
Of the 150 field collected samples tested during the training, seven were positive for the malaria parasite, Plasmodium falciparum. The team has continued to consistently process samples at a rapid pace. These laboratory results will help inform future vector control efforts, and the capacity strengthening efforts will enable Angolans to continue to analyze malaria vector species in-country, allowing for vector control efforts to be tailored and adjusted as needed.
“My hope is that the entomological and molecular capacity increases,” shared Julio. “With the right data at our fingertips, we can help better understand malaria transmission in Angola.”
Rice fields are an ideal breeding site for mosquitoes, who lay their eggs in the irrigated water. This is bad news for many farmers in Madagascar, whose livelihoods depend on rice cultivation. Farmers, along with other people living around the rice fields, have an increasedrisk of infection by malaria-carrying mosquitoes because of the proximity to breeding sites.
To address this risk, Madagascar’s Ministry of Health, through the National Malaria Program (NMP), worked with the U.S. President’s Malaria Initiative (PMI) VectorLink Madagascar team to pilot larval source management (LSM) using drones as a complementary malaria vector control intervention in the districts of Ankazobe and Morombe.
LSM refers to the management of water bodies that are potential mosquito breeding sites by applying a biological or chemical larvicide. In Madagascar, this pilot initiative used the larvicide VectoBac® WG which contains a naturally occurring bacterium referred to asBti, which kills mosquito larvae present in waterbut does not harm humans, other insects, crops, or water supplies. A primary challenge of this malaria control intervention is to convince the community that the larvicide is safe and won’t impact their livelihood. Edmond Dadivahiny (seen in photo below) was tasked with just that.
Edmond (middle), community health workers, a village leader, and the Vice President of FAMA conducting supervision of the social mobilization efforts in Tanandava Village during spraying. Photo credit: Mauricette Andriamananjara, LSM Manager for PMI VectorLink Madagascar
As a representative of the Federation of Water Users’ Associations of Lower Mangoky (Fédération des Associations des Usagers de l’Eau du Bas Mangoky – FAMA), Edmond was among those chosen to educate rice farmers about the pilot and the benefits of LSM, and why they should accept the intervention. “I explained that Bti is biological, and that there are no side effects on human health, farm animals, or plants,” he shares. “The best way to convince farmers is to tell them the good things about the intervention.”
FAMA ensures the management and maintenance of irrigation canals in rice fields among the water user associations in the area. Rice farmers in Lower Mangoky are organized into 23 different water user associations. Having members like Edmond supervise the spraying of the larvicide ensured that the farmers’ concerns were addressed by someone who understood their worries. FAMA representatives also supported advocacy at the district level and helped to train mobilizers.
The NMP and PMI VectorLink Madagascar, in coordination with the Ministry of Agriculture and Livestock and the Ministry of Environment and Sustainable Development, determined that drones would be the best way to spray the larvicide throughout the rice fields because they are able to fly over the fields without disturbing the crops. “The drone operator can also quickly complete the spraying,” says Edmond. This limits the disruption during the workday.
Edmond accompanied the drone pilots Fenohasina and Manjaka in his area to support the spraying. Photo credit: Mauricette Andriamananjara, LSM Manager for PMI VectorLink Madagascar
To prepare the community for the first round of this intervention, PMI VectorLink Madagascar and the NMP trained 35 technicians from the government and FAMA as supervisors who oversaw 178 community participants in Ankazobe and 154 in Morombe, who worked in roles such as mobilizers, and oversaw the implementation of the spraying.
“I was trained on the different strategies to fight malaria; the lifecycle of mosquitoes; how LSM works, especially the use of Bti and drones; when LSM should occur, and how Bti works in rice fields,” says Edmond. “I was also trained on how to communicate the benefits of this intervention, which included interpersonal, group, and mass communication.”
From February to July 2022, during the rainy season when malaria transmission is high, the NMP and PMI VectorLink Madagascar conducted the first round of LSM via drones in 17 fokontany (villages) in Morombe and Ankazobe. Drones sprayed Bti in irrigated rice fields twice per month to control vector populations. During this time, the communities’ understanding of the benefits also increased. “After the first spray, people saw that it was not deadly, and there were no effects on humans or animals,” shares Edmond. After spraying ended, “people were talking about how much malaria has decreased. It appears that this strategy is effective.”
A drone spraying in Morombe district. Photo credit: Mauricette Andriamananjara, LSM Manager for PMI VectorLink Madagascar
In Morombe, there has been a recorded decline in the number of mosquito larvae present in the rice fields. Before LSM began, the number of larvae per liter averaged 9.7 in Morombe. In September 2022, two months after the last spray of Bti for round one of LSM, the average larvae density was 5 per liter in Morombe. In Ankazobe, the results seem promising although contributing factors like the dryness of the rice fields make it difficult to attribute lower numbers of larvae exclusively to LSM.
For Edmond, this intervention has been a success for the rice farmers. Before LSM, mosquitoes made working in the rice fields challenging. “It was hard for them to finish their work,” he said. Using LSM as a complementary malaria control tool in rice farming communities can be an effective way to protect people while they go about their daily work.
Après quatre ans de collaboration avec l’Initiative Présidentielle des Etats Unis Contre le Paludisme (PMI) pour protéger les populations contre le paludisme dans trois districts sanitaires (Kampti, Kongoussi et Solenzo) au Burkina Faso, le Secrétariat Permanent pour l’Elimination du Paludisme (SP/Palu) avec l’appui d’une société d’extraction minière privée, a pris l’initiative en 2022 de lancer sa première campagne de pulvérisation intra domiciliaire (PID). Cette campagne à petite échelle est la première du genre menée par le gouvernement.
Monsieur Ardiouma Pagabelem, un ingénieur en génie sanitaire, est le point focal PID du SP/Palu anciennement connu sous le nom de Programme National de Lutte contre le Paludisme du Burkina Faso. Alors que l’utilisation de moustiquaires imprégnées d’insecticide est le principal outil de prévention du paludisme dans le pays, Monsieur Pagabelem collabore avec le projet PMI VectorLink depuis 2018 pour aider à mener une PID dans trois districts sanitaires les plus touchés par le paludisme où les moustiques ont une résistance élevée aux insecticides trouvés dans les moustiquaires.
Monsieur Pagabelem (chemise bleue) discutant avec des pulvérisateurs dans le village de Soungoulé. Crédit photo: SP/Palu, Burkina Faso
Les ressources gouvernementales sont limitées et ne sont pas suffisantes pour soutenir une campagne PID à l’échelle du district ; ainsi, lorsque l’insecticide restant étaient disponibles après la campagne PID 2021 de PMI VectorLink, Monsieur Pagabelem et ses collègues de SP/Palu ont cherché des opportunités pour maximiser les investissements déjà réalisés. À peu près à la même époque, le SP/Palu a été approché par la société minière Endeavour Mining, qui a proposé de financer une campagne PID dans la zone sanitaire de Dangouna, proche de ses opérations, et l’idée d’un programme pilote, le projet village sans paludisme, est née.
“Face à la difficulté de mobiliser les ressources financières de l’Etat, le projet village sans paludisme dans Dangouna fut une opportunité pour la mise en œuvre de la mini campagne PID,” dit Monsieur Pagabelem. Cela a également donné à l’équipe du SP/Palu, la chance de mettre en pratique les compétences qu’ils avaient développées lors de leur collaboration sur les campagnes PID mises en œuvre par PMI VectorLink.
Le SP/Palu a recruté des opérateurs de pulvérisation qui avaient auparavant travaillé sur des campagnes IRS mises en œuvre par PMI VectorLink. Monsieur Pagabelem et ses collègues ont formé ces opérateurs de pulvérisation à la mise en œuvre de la campagne pour, le projet village sans paludisme tout en travaillant avec les autorités sanitaires au niveau du district, de la région et au niveau locale pour s’assurer que ces travailleurs saisonniers reçoivent la supervision nécessaire.
Une réunion communautaire sur le site d’exploitation de Ble. Crédit photo: SP/Palu, Burkina Faso
L’exploitation d’or minière est une grande industrie au Burkina Faso, et des entreprises comme Endeavour Mining emploient des milliers de personnes dans les villages de leurs zones d’opération. Suite au succès du programme à Dangouna, la filiale d’Endeavour Mining, Houndé Gold Operation, a demandé à SP/Palu d’étendre le programme et de mener la PID à Lokiéhoun, où l’entreprise exerce également des activités.
En plus de fournir l’insecticide, PMI VectorLink Burkina Faso a fourni une assistance technique et a soutenu les activités de planification de SP/Palu avec le chef du parti, le Dr Adama Kone, surveillant les progrès de la campagne et guidant l’équipe en cas de besoin.
En août et octobre 2022, les pulvérisateurs ont pulvérisé plus de 4.700 habitations à Dangouna et Lokiéhoun, protégeant près de 15.500 personnes, dont plus de 400 femmes enceintes et 2.435 enfants de moins de cinq ans.
Opérateurs de pulvérisation arrivant sur le site d’exploitation de Blé. Crédit photo: SP/Palu, Burkina Faso
Alors que la PID protège les gens contre le paludisme, des questions concernant le financement demeurent. “La lutte anti vectorielle est capitale pour le Burkina Faso qui prévoit d’éliminer le paludisme d’ici 2030,” dit Monsieur Pagabelem. “Cependant la lutte anti vectorielle souffre d’une insuffisance de financement, notamment pour la mise en œuvre de la PID.” Des entreprises privées comme Endeavour Mining pourraient contribuer à la pérennité de ces interventions.
Grâce aux efforts de renforcement des capacités soutenus par PMI VectorLink, le Burkina Faso dispose d’un personnel qualifié au niveau national comme Monsieur Pagabelem qui a élargi ses compétences pour pouvoir mettre en œuvre la PID aux normes de l’OMS. Cependant, le pays a besoin de financement pour exécuter ces interventions. Travailler avec des entreprises privées pourrait combler le fossé et aider le pays à atteindre ses objectifs de lutte contre le paludisme.
After four years working side-by-side with the U.S. President’s Malaria Initiative (PMI) to protect people against malaria in three health districts (Kampti, Kongoussi, and Solenzo) in Burkina Faso, the Permanent Secretariat for Malaria Elimination (SP/Palu) with the support of a private mining company took the lead in 2022 on a first of its kind, small-scale, government-led indoor residual spraying (IRS) campaign.
Mr. Ardiouma Pagabelem, a water and sanitation engineer, is the IRS focal point for Burkina Faso’s SP/Palu, formerly known as the National Malaria Control Program. While the use of insecticide-treated mosquito nets is the primary malaria control tool in the country, Mr. Pagabelem has been collaborating with the PMI VectorLink project since 2018 to help conduct IRS in three higher malaria burden health districts where mosquitoes have high resistance to insecticides found in mosquito nets.
Mr. Pagabelem (blue shirt) talking with spray operators in the village of Soungoulé. Photo credit: SP/Palu, Burkina Faso
Government resources are limited and aren’t sufficient to support a district wide IRS campaign; so, when leftover insecticide was available following PMI VectorLink’s 2021 IRS campaign, Mr. Pagabelem and his colleagues at SP/Palu looked for opportunities to maximize the investments already made. Around the same time, SP/Palu was approached by Endeavour Mining, which offered to finance an IRS campaign in the Dangouna health area, close to its operations, and the idea for a pilot program, the Malaria-Free Village project, was born.
“Faced with the difficulty of mobilizing the financial resources of the government, the Malaria-Free Village project in Dangouna was an opportunity to implement a small-scale IRS campaign,” said Mr. Pagabelem. It also gave SP/Palu the chance to put into practice the skills they had developed when collaborating on the PMI VectorLink-implemented IRS campaigns.
SP/Palu recruited spray operators who had previously worked on IRS campaigns implemented by PMI VectorLink. Mr. Pagabelem and his colleagues trained these spray operators to implement the campaign for the Malaria-Free Village Project while working with the regional, district, and local health officials to ensure that these seasonal workers received the necessary supervision.
A community meeting at Ble site. Photo credit: SP/Palu
Gold mining is a big industry in Burkina Faso, and companies like Endeavour Mining employ thousands of people in villages throughout their areas of operation. Following the success of the program in Dangouna, Endeavour Mining’s subsidiary, Houndé Gold Operation, requested that SP/Palu extend the program and conduct IRS in Lokiéhoun, where the company also has operations.
In addition to providing the insecticide, PMI VectorLink Burkina Faso provided technical assistance and supported SP/Palu’s planning activities, with Chief of Party Dr. Adama Kone monitoring the campaign’s progress and guiding the team when needed.
In August and October 2022, spray operators sprayed over 4,700 homes in Dangouna and Lokiéhoun, protecting close to 15,500 people, including more than 400 pregnant women and 2,435 children under five.
Spray operators arriving at Ble site. Photo credit: SP/Palu, Burkina Faso
While IRS protects people from malaria, questions around funding remain. “Vector control is crucial for Burkina Faso, which aims to eliminate malaria by 2030,” said Mr. Pagabelem. “However, vector control suffers from insufficient funding, particularly for the implementation of IRS.” Private companies like Endeavour Mining could contribute to the sustainability of these interventions.
Thanks to capacity strengthening efforts supported by PMI VectorLink, Burkina Faso has qualified personnel at the national level like Mr. Pagabelem who have expanded their skillsets to be able to implement IRS at WHO standards. However, the country needs the funding to execute these interventions. Working with private companies could bridge the gap and help the country meet its malaria goals.
Dr. Auwal Al-Hassan looking at the structure of an Anopheles stephensi mosquito through a microscope in Ethiopia. Photo credit: Dr. Lazarus Samdi, vector monitoring specialist for PMI VectorLink Nigeria.
Dr. Auwal Al-Hassan, a professor and entomologist at Abubakar Tafawa Balewa University in Nigeria, spends his days teaching and researching insects that transmit disease and how to control them. His latest area of research focuses on the invasive malaria-transmitting mosquito Anopheles stephensi. To better understand and address the threat that this mosquito could bring to Nigeria, Dr. Al-Hassan attended trainings supported by the U.S. President’s Malaria Initiative (PMI) VectorLink Project.
“This mosquito has the potential to impede the progress already made in the fight against malaria due to its resistance to commonly used insecticides and its varying behavior compared to other mosquitoes we see here,” says Dr. Al-Hassan.
Anopheles stephensi was first detected in Biliri Local Government Area, Gombe State, Nigeria in 2020, by researchers at Gombe State University working in collaboration with the Nigeria Institute of Medical Research and the National Malaria Elimination Program (NMEP). It is widely recognized as an effective vector of malaria, particularly in urban and semi-urban areas, and its presence in Nigeria is a major concern for malaria control efforts in the country, which already accounts for over a quarter of the global malaria cases.
The PMI VectorLink Nigeria team is supporting the NMEP to strengthen its capacity to monitor the potential spread of this invasive mosquito species. In November 2022, the project successfully trained seven principal investigators and 14 entomology technicians selected from universities and research institutes across seven at-risk states in the country, including Dr. Al-Hassan, to strengthen their expertise in surveillance and identification of An. stephensi.
The training covered the preferred habitats of An. stephensi, which is key to detecting and understanding how to control its spread. “Adults prefer urban environments while larvae are commonly found to exploit several larval habitat types including human-made water containers such as plastic tanks, cisterns, discarded tires and plastic containers,” shared Dr. Al-Hassan.
PMI VectorLink Nigeria training principal investigators and entomology technicians on how to operate the Prokopac aspirator to collect adult Anopheles stephensi mosquitoes. Photo credit: Ifeanyi Okeke, monitoring, evaluation, and learning specialist, PMI VectorLink Nigeria.
PMI VectorLink Ethiopia Technical Manager Dr. Meshesha Balkew, who has been involved in An. stephensi surveillance and control efforts in Ethiopia, participated virtually in this training and shared best practices with the participants on identifying the breeding and resting sites of this species as well as how to identify adult An. stephensi mosquitoes.
Dr. Balkew shows Dr Al-Hassan and others the procedures for treating a water holding container with larvicide. Photo credit: Dr. Lazarus Samdi, vector monitoring specialist for PMI VectorLink Nigeria.
A few weeks later, Dr. Al-Hassan traveled to Ethiopia to learn more from Dr. Balkew and the PMI VectorLink Ethiopia team about their experience with An. stephensi. This training reinforced what he learned in Nigeria, but also delved into one of the main control strategies for An. stephensi: larval source management (LSM).
“For the control of [this mosquito], larval stages are targeted mostly. This is because the preferred habitats for the adults are difficult to locate and [they] seem to have resistance to multiple insecticide classes, posing potential challenges to its control,” shared Dr. Al-Hassan. Therefore, LSM—where a chemical, called a larvicide, is applied to water in containers in order to kill the mosquito in its immature stage—has the potential to help control An. stephensi and mitigate disease impacts.
With a well-trained team now in place, the next step is to intensify surveillance and identification of An. stephensi throughout the country. Ultimately, Nigeria’s NMEP will decide what approach it will use to combat An. stephensi, but data collected by researchers like Dr. Al-Hassan is key to informing that approach. As he says, “Data collected will help [the NMEP] use resources optimally, prioritizing key activities in order to achieve effective and sustainable control of An. stephensi in our environments.”
Xuxa Gara and Charmaine Matimba have always been committed to improving health outcomes in Zimbabwe but did not originally plan to work with malaria-transmitting mosquitoes. Thanks to the U.S. President’s Malaria Initiative (PMI) VectorLink project’s capacity strengthening efforts—including the opening of the Malaria Research and Reference Insectary at Africa University (AU), a state-of-the-art insectary and research space—these women have become some of Zimbabwe’s toughest malaria fighters: Xuxa as the insectary manager and Charmaine as the laboratory manager.
Xuxa works with her team to maintain an Anopheles arabiensis mosquito reference colony by managing optimal conditions for mosquito production in the insectary. “A drop in the ambient temperatures in the insectary can have a huge impact on productivity and eventually determine the number of mosquitoes that can be provided to our partners. This requires the insectary team to always be attentive and sensitive to the needs of the insectary,” Xuxa says.
The mosquitoes are provided to the National Malaria Control Program (NMCP) and partners to test the quality of malaria vector control interventions—indoor residual spraying (IRS) and insecticide-treated nets (ITNs)—and inform their decision-making on the most appropriate malaria control method. The construction of the insectary means they can use lab reared mosquitoes that are known to be susceptible to the insecticides used for vector control interventions and do not need to rely on wild-caught mosquitoes.
VectorLink Zimbabwe has provided Xuxa with training and mentoring on insectary management so she can effectively run the insectary. “It was always my ambition to work in health and as a scientist,” says Xuxa. “It’s interesting being able to generate so much informative data from just a single mosquito caught in the field.”
Insectary Manager Xuxa Gara washing the ELISA plate during Plasmodium falciparum circumsporozoite (CSP) detection in mosquitoes. Photo credit: Wesley Kuture, design and content development assistant at AU.
Xuxa and her team are responsible for raising mosquitoes while Charmaine leads efforts in the laboratory. The analyses conducted by Charmaine and her team include mosquito species identification, insecticide resistance testing, and determining the malaria parasite infection rate. The information gathered from these analyses helps answer some key questions such as where are the gaps in protection, which mosquitoes are transmitting the parasite, why some insecticides no longer work, and where are people being bitten?
For Charmaine, what inspires her most is the zeal to answer these questions. “I had little knowledge of malaria when I first started working at AU on the Zimbabwe Entomology Support in Malaria Programme (ZENTO) Project, also funded by PMI. The interest grew as I was doing the work and I saw that there were so many questions to be answered. I believe that some of the answers will come out from the work I am doing here at the AU molecular laboratory through analyzing the mosquitoes that are collected in malaria endemic areas in Zimbabwe,” she shares. THE PMI ZENTO Project conducts continuous entomological surveillance in Nyanga and Mutasa districts as well as Mutare City, all in Manicaland Province. VectorLink Zimbabwe currently conducts much of the mosquito surveillance in Zimbabwe, which PMI ZENTO is set to take over with the closing of the PMI VectorLink Project.
Malaria Research Laboratory Manager Charmaine Matimba preparing a PCR mastermix for An. gambiae s.l. mosquito species identification. Photo Credit: Wesley Kuture, design and content development assistant at AU.
PMI Zimbabwe, through VectorLink Zimbabwe and the U.S. Centers for Disease Control and Prevention, works with the AU laboratory to strengthen capacity and provides technical and management support and oversight to entomological activities in the country. Efforts included procurement of new laboratory equipment and supplies, on-site training, and regular mentoring by the VectorLink Zimbabwe team. In 2022, VectorLink Zimbabwe Technical Manager Dr. Hieronymo Masendu led a training on insecticide resistance testing using CDC and WHO techniques, which enabled AU staff to complete the procedure on their own, with guidance. Shortly after, Charmaine attended a regional entomology training hosted by the global PMI VectorLink Project in Dakar, Senegal.
“The trainings enhanced my knowledge in field work and surveillance that is done in order to answer specific questions and generate data that is meaningful and useful in vector control implementation,” says Charmaine.
“I now have the capacity to test an insecticide to measure its effectiveness in combating the malaria vector,” adds Xuxa, a skill that many AU staff did not previously have.
Charmaine Matimba receiving a certificate of achievement from PMI VectorLink Technical Director Dr. Matthew Kirby in Dakar, Senegal. Photo credit: Stephen Kantum, senior research officer at Navrongo Health Research Center in Ghana.
Bolstering the skills of scientists like Xuxa and Charmaine is critical to increasing Zimbabwe’s capacity to implement vital testing to ensure the NMCP is using the most effective vector control interventions to combat malaria. Through the establishment of the insectary, and the support of projects like PMI VectorLink and PMI ZENTO, AU is establishing excellence in malaria research in Zimbabwe, enabling the growth of malaria fighters like Xuxa and Charmaine.
Research and monitoring are so important to understanding mosquitoes and figuring out how to prevent them from spreading malaria. “Working in research allows me to be the first to identify something new and be able to tell the whole world a story about it,” says Xuxa. “My hope is that mosquitoes will one day not be referred to as a vector of malaria but rather a mere nuisance insect.”