Malaria is a major problem, especially in Africa. It is one of the most common infectious diseases worldwide. It is still unclear which factors exactly cause malaria mosquitoes (Anopheles gambiae) to find people attractive, or less attractive. It is clear that there are many different factors involved. This research aims to find out to what extent beer consumption affects people’s attractiveness to malaria mosquitoes.
Material and method
Since alcohol consumption is increasing worldwide, this research can lead to important findings for a large group. Smell is an important one of the many factors that make people more attractive to malaria mosquitoes. For example, previous research has shown that pregnant women emit a scent that makes them more attractive to malaria mosquitoes. Previous research also showed that laboratory mosquitoes (Aedes aegypti) are more attracted to people who have consumed beer. By finding out which factors have the most influence, it is possible to provide adequate protection for the risk group. This has led to the following research question: Does drinking beer influence the attractiveness of people to malaria mosquitoes?
It is hypothesized that malaria mosquitoes show a stronger response to people who have consumed beer than to people who have not consumed beer, and find the first group more attractive. To test this, a group of men was asked to drink beer, after which the malaria mosquitoes were examined for activation by and orientation on the beer smell that these men release. The researchers expect to see that the malaria mosquitoes are more strongly activated by the beer scent and that a larger proportion of the mosquitoes will orient themselves to this scent when choosing between beer scent and outside air.
Research objects
The study included 43 healthy men aged 20 to 43 from Burkina Faso, who were on no medication. The group was split into two parts: 25 men were given beer to drink, the other 18 water.
Procedure
The attractiveness of the males to the malaria mosquitoes was tested using a y-olfactometer. The y-olfactometer consisted of a cage in which 50 malaria mosquitoes were released. The two arms of the y-olfactometer both ended up in a trap for the malaria mosquitoes. Air was drawn from two tents to the y-olfactometer, the tents were connected to the two traps. The test consisted of four parts in total, one of the tents always had the smell of outside air, the other tent had the scents successively:
- Smell of the men for consuming beer
- Smell of men 15 minutes after consuming beer
- Scent of the men for consuming water
- Fragrance of men 15 minutes after consuming water
The persons in the group ?? beer drinkers ?? were given a liter of Dolo, a local beer from Burkina Faso. The persons in the group ?? water drinkers ?? were given a liter of water from Bobo-Dioulasso to drink. So the mosquitoes each time had the choice between the smell of the outside air or that of the test subjects.
Analysis
It was determined what percentage of the 50 malaria mosquitoes that were released actually ended up in one of the two tents (activation) and in what proportion they preferred the outside air or the smell of the test subjects (orientation).
Results
A larger proportion of the malaria mosquitoes were activated by the smell of the beer drinkers. There was also more orientation towards the smell of the beer drinkers. In the booth ?? beer smell ?? more malaria mosquitoes were found from the y-olfactometer.
Discussion
Malaria mosquitoes show a stronger reaction to people who have drunk beer. From the results it can be concluded that drinking beer has a positive influence on the attractiveness of humans to malaria mosquitoes. So, as with laboratory mosquitoes, odor influences the reactivity of malaria mosquitoes. The breakdown of alcohol can cause a change in the smell of the breath. Since the drink used in this experiment is a very popular beer in West Africa, it is important to take this into account when dealing with malaria. Beer consumption can be an important factor in the spread of malaria in West Africa. Follow-up research will have to show whether it is the alcohol in Dolo that provides the increased attractiveness, another substance present in this beer, or a metabolite. If it turns out to be the alcohol or an alcohol metabolite, this can be used to investigate the influence of other alcoholic drinks on the reactivity of malaria mosquitoes. In short, the research shows that the smell of beer increases the attractiveness of people to malaria mosquitoes.