Mosquito bites are common in tropical and subtropical countries. They bite more towards dusk and night. But we notice that these certain people seem to attract these mosquitoes more. But bite others less. What in a person attracts mosquitoes and which is the substance in the body or on the skin that repels them? Researchers from Johns Hopkins University have the answers from their new study.
Each one of us have been bitten by mosquitoes multiple times. The mosquito bites leave behind a wheal which itches. Mosquitoes are most active in the evening and night time. They are more outdoors and in gardens, woods, and forest areas. There are multiple creams and repellants available that can assist in prevention of these bites.
Often, we notice that mosquitoes swarm around and bite some people more than others. Whereas they do seem to go less near and around other people. What is the reason for it?
The Johns Hopkins University study
Johns Hopkins University researchers conducted a study to find out what in a person attracts or repels mosquitoes. They set up an ice rink-sized testing arena in Zambia for this study.
The research team asked six people to sleep in tents; one tent for one person. Each tent had a pipe that would pump out the aroma at night of each person. This pumped out aroma was thrown over a mosquito landing pad that the research team monitored.
They found that people who emitted more of carboxylic acids (due to skin microbes) attracted mosquitoes. But those whose aroma had more of eucalyptol were able to repel the pests.
What is eucalyptol?
Eucalyptol is the aromatic compound found in herbs and spices. Sage, rosemary, sweet basil, mugwort, cardamom have lots of it in them. Dr Conor McMeniman at the Institute said:
“Our study hints at the notion that high levels of eucalyptol in your body scent may make you less attractive to mosquitoes.”
“Interestingly all humans whose body scent we analysed in this study seemed to emit some eucalyptol. However, the person that was least attractive to mosquitoes had higher amounts of the chemical in their scent signature.”
“We think this person likely obtained this compound from plant-based foods in their diet (eucalyptol is abundant in many different herbs and spices including mugwort, sweet basil, rosemary, sage and cardamom); but it is also possible it could also have been from exogenous products as eucalyptol is also a common ingredient in toothpaste and mouthwash.”
The doctor continued:
“In the future we hope to expand our study to collect more detailed dietary information of participants and examine in finer detail the role that diet and the human skin microbiome play in influencing how we smell to mosquitoes; including other species of nuisance biting mosquitoes we all encounter in our backyards around the world.”
Eucalyptol acts like a deodorizer. It can mask the smell of carboxylic acid and thus lessen the mosquito bites.