In many Kenyan homes, the signature whine of a mosquito hunting for human blood is a common feature, particularly in the evenings.
Apart from bothering, biting and leaving us with itchy spots, this tiny, long-legged insect is the world’s deadliest animal.
It is the main transmitter of malaria, which is caused by Plasmodium falciparum, a protozoan that infects the mosquito.
In 2019, at least 409,000 people died from malaria globally. They include around 30,000 Kenyans. Millions more fall sick each year.
Roughly half of the world’s population is at risk of this preventable disease.
While the global malaria burden has declined substantially as a result of the scale up of insecticide-treated bed nets (ITNs) and other interventions, malaria is a significant health challenge, particularly in sub-Saharan Africa.
Mosquitoes are also responsible for the spread of dengue fever.
For the last three decades, the global prevalence of dengue has risen by 3,000 percent, meaning its cases are 30 times more likely to occur in high risk areas.
Approximately 3 billion people or 40 percent of the world’s population live in areas with a risk of dengue. Dengue is a leading cause of sickness in such areas.
The insect also transmits lymphatic filariasis (LF), a parasitic disease.
LF is transmitted after a series of mosquito bites over a period of several months. The disease affects more than 120 million people in 72 countries and is a leading cause of permanent disability worldwide.
We can avoid getting mosquito borne diseases by preventing bites from infected mosquitoes.
Kenya, Mali, and Sri Lanka are taking part in clinical trials sponsored by the Centres for Disease Control (CDC) to produce repellents that will keep the insect away from us.
CDC is working with the University of Notre Dame, the Kenya Medical Research Institute, and other partners in the Advancing Evidence for the Global Implementation of Spatial Repellents (AEGIS) consortium.
AEGIS is a 5-year effort funded by Unitaid to determine the efficacy of a novel spatial repellent product in preventing mosquito-borne diseases such as malaria, dengue, and chikungunya.
Unitaid is a global health agency hosted by theWorld Health Organization that seeks to find affordable, innovative solutions to prevent, diagnose, and treat diseases such as HIV/AIDS, malaria, and tuberculosis in low-and middle-income countries.
CDC has been involved in global malaria control and elimination efforts since successfully eradicating malaria from the US in 1951 after a five year program that began on July 1, 1946.
The program succeeded due to a comprehensive data collection system that the Office of Malaria Control in War Areas (MCWA) used to formulate an epidemiologic plan of action in order to combat malaria and other future epidemics.
Building on its US success, the CDC has since switched its malaria focus from elimination to prevention, surveillance, and technical support for both domestic and international programs.
Working in 24 countries in sub-Saharan Africa and 3 in the Greater Mekong Subregion, the CDC co-implements the U.S. President’s Malaria Initiative, (PMIC) which is led by the U.S. Agency for International Development (USAID) .
Since 2001, concerted global health efforts have slashed malaria deaths by 50 percent and saved nearly 8 million lives.
However, the fight to eradicate malaria is faced with challenges like increasing insecticide resistance and emerging urban mosquito vectors like Anopheles stephensi and thus needs new methods.
Spatial repellents have proven to be an effective technique to prevent mosquito bites.
To discourage mosquitoes from biting us, spatial repellents release chemicals into the air that provoke the insects into moving away from the chemical stimulus.
This interferes with the mosquito’s ability to detect a human to feed on.
The trials will evaluate the efficacy and cost-effectiveness of a spatial repellent in reducing transmission and protecting against new infections of malaria in Kenya and Mali and dengue (Sri Lanka).
AEGIS will also conduct case studies among displaced populations in other areas.
Due to the ongoing COVID-19 pandemic, researchers were forced to spend 12 months incorporating necessary protections, including procuring personal protective equipment for the study team in Kenya.
Scientists also had to develop standard operating procedures to minimize the risk of COVID-19 infection while out in the field mingling with study participants.
Throughout this phase, the study team recruited participants and established the baseline of malaria infection in participants. Implementation of the spatial repellent intervention is set to begin at the beginning of September 2021.
CDC helped to ensure the study team was provided with the best technical guidance for safety while simultaneously administering research program protocols.
According to CDC, the first step of the Kenya trial, four months of baseline work, is now complete.
Apart from malaria, the mosquito is also responsible for the transmission of Lymphatic filariasis (LF).
Also known as elephantiasis, lymphatic filariasis is one of the world’s most stigmatizing and debilitating diseases.
Over 120 million people are infected with LF globally. Another 1.3 billion live in areas with documented risk of getting infected.
LF can be prevented with proper and efficient measures. In some African nations, the scale up of insecticide-treated nets (ITNs) has resulted in a corresponding decrease in LF incidence.
CDC is also involved in the fight to eradicate LF by issuing guidelines on mosquito control and other ways to reduce infection risk, such as mass drug administration (MDA) campaigns.
The MDAs provide preventive medication every year to vulnerable populations.
Among the areas where CDC and its partners are engaged in efforts to eliminate LF are Haiti, American Samoa, and other regions in the Americas.
