KAMPALA, Uganda — The warning sounded almost casual at first. As Uganda’s Parliament discussed a recent spike in severe malaria cases that claimed the lives of four students in Kampala, Health Minister Dr. Chris Baryomunsi introduced an unexpected factor into the conversation.
Many expected the discussion to focus on familiar concerns such as climate change, drug resistance or the emergence of a new malaria strain.
Instead, the minister pointed to something far less obvious: beer.
“If I sit down with you and you are drinking beer and I am taking juice, you will get more bites. This is science,” Dr. Baryomunsi told legislators.
The remark quickly drew attention, partly because it sounded surprising and partly because it touched on something many people have experienced without necessarily understanding: some people seem to attract mosquitoes far more than others.
Why can a group of people sit together outdoors while one person ends the evening covered in bites?
Why do mosquitoes appear to prefer certain individuals?
And what does that have to do with the deaths of four students in Uganda’s capital?
Behind the minister’s comments lies a growing body of scientific research that suggests mosquito attraction is far more complex than many people realise — and that human behaviour, biology and even what we drink may influence who becomes a mosquito’s next target.
The science behind being “attractive” to mosquitoes
Mosquitoes do not choose their victims randomly.
For decades, scientists studying malaria transmission have discovered that mosquitoes rely on a sophisticated combination of sensory cues to locate humans.
Carbon dioxide is among the most important.
“Mosquitoes get attracted to the carbon dioxide you exhale,” Dr. Baryomunsi explained.
Every person releases carbon dioxide when breathing, but not everyone emits the same amount. Larger individuals, pregnant women and physically active people often produce more carbon dioxide, making them easier for mosquitoes to detect from a distance.
Researchers describe carbon dioxide as the mosquito’s equivalent of a tracking signal.
Once detected, the insect begins searching for additional clues.
Those clues include body heat, skin chemicals and sweat.
“Secondly, when you have raised body temperature, that also attracts mosquitoes,” the minister added.
That observation is supported by numerous scientific studies showing mosquitoes are highly sensitive to temperature changes. Warm skin helps them identify living hosts and locate blood vessels near the skin’s surface.
But temperature alone does not explain everything.
The chemistry of human skin matters too.
Why alcohol may increase mosquito bites
The idea that alcohol attracts mosquitoes is not new.
Several international studies have found that people who consume alcohol, particularly beer, may experience more mosquito bites than those who do not.
Scientists believe alcohol affects the body in several ways that make a person more noticeable to mosquitoes.
One effect is increased body temperature.
Another is increased perspiration.
“If you sweat a lot, especially when you are pregnant or drinking, like what happens in bars, the sweat contains lactic acid and ammonia which attract mosquitoes,” Dr. Baryomunsi said.
Both lactic acid and ammonia are among the chemical compounds mosquitoes use to identify potential hosts.
Alcohol can also cause blood vessels near the skin’s surface to expand, creating additional heat signatures that mosquitoes can detect.
Researchers stress that alcohol does not magically summon mosquitoes.
Instead, it may amplify the biological signals mosquitoes already use when searching for a blood meal.
In practical terms, that can mean the person drinking at an outdoor gathering becomes easier for mosquitoes to find than someone nearby drinking water or juice.
Why pregnant women are particularly vulnerable
Among the groups most attractive to mosquitoes are pregnant women.
Public health experts have long recognised pregnancy as a significant risk factor in malaria transmission.
“There are factors that attract mosquitoes to some people more than others. For instance, pregnant women tend to attract mosquitoes,” Dr. Baryomunsi told Parliament.
The reasons are largely biological.
Pregnant women typically exhale more carbon dioxide than non-pregnant adults. They also tend to have slightly higher body temperatures and altered skin chemistry.
Together, these factors make them more detectable to mosquitoes.
The consequences extend beyond discomfort.
Malaria during pregnancy can lead to severe complications, including anaemia, miscarriage, premature birth and low birth weight.
That is why malaria prevention programmes across Africa frequently prioritise pregnant women for mosquito net distribution and preventive treatment.
The hidden vulnerability of city children
While the debate over alcohol and mosquito attraction captured headlines, the minister’s broader message focused on something more urgent: the deaths of four students from leading Kampala schools.
The Ministry of Health recently confirmed that two students from Makerere College School, one from Mengo Senior School and one from Gayaza High School died after developing severe malaria.
The cases sparked concern because Kampala is not traditionally regarded as one of Uganda’s highest malaria transmission zones.
Yet that apparent advantage may also create a hidden vulnerability.
Unlike children growing up in regions where malaria transmission occurs frequently, many children in Kampala develop limited natural immunity to the disease.
As a result, infections can become severe more quickly.
“In low-transmission areas such as Kampala, children who have not developed natural immunity can deteriorate rapidly after infection if treatment is delayed,” the minister warned.
This phenomenon is well documented across malaria-endemic countries.
Repeated exposure to malaria parasites can gradually build partial immunity, reducing the likelihood of severe illness. People living in areas with fewer infections often lack that protection.
The consequence is that a malaria infection that might be manageable elsewhere can become life-threatening if diagnosis and treatment are delayed.
Not a new malaria strain
The recent deaths have also triggered questions about whether Uganda may be confronting a more dangerous form of malaria.
Health officials say there is currently no evidence to support that fear.
According to the ministry, surveillance systems have detected no significant changes in Plasmodium falciparum, the parasite responsible for most severe malaria cases in Uganda.
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Instead, officials believe the deaths resulted from severe malaria infections in vulnerable individuals rather than the emergence of a new strain.
That distinction matters.
New strains often require different public health responses.
The ministry’s findings suggest the challenge remains one of prevention, early detection and timely treatment rather than a fundamental change in the disease itself.
A reminder that malaria remains deadly
Uganda continues to carry one of the world’s highest malaria burdens despite years of progress in prevention and treatment.
The disease remains among the country’s leading causes of illness and death, particularly among children and pregnant women.
Yet malaria’s familiarity can sometimes create complacency.
Public health experts warn that many people continue to underestimate symptoms, delay seeking treatment or fail to consistently use mosquito prevention measures.
The deaths in Kampala have served as a reminder that malaria remains capable of becoming deadly within days if severe infections are not treated quickly.
Whether someone attracts mosquitoes because of pregnancy, body temperature, sweat chemistry or even an evening beer, the underlying risk remains the same.
A mosquito bite may appear insignificant.
In a country where malaria remains endemic, it can still become a matter of life and death.
